US20220023588A1 - Catheter system - Google Patents

Abstract

An injection adaptor hub for a medical catheter.

Description

CLAIM OF PRIORITY
• This application is a continuation-in-part of U.S. application Ser. No. 13/776,685, filed on Feb. 25, 2013, which is incorporated by reference in its entirety.
TECHNICAL FIELD OF THE INVENTION
• This invention relates generally to medical catheters and catheter introducer needles.
BACKGROUND OF THE INVENTION
• The use of radiofrequency (RF) generators and electrodes to be applied to tissue for pain relief or functional modification is well known. For example, the RFG-3B RF lesion generator of Radionics, Inc., Burlington, Mass. and its associated electrodes enable electrode placement of the electrode near target tissue and heating of the target tissue by RF power dissipation of the RF signal output in the target tissue. For example, the G4 generator of Cosman Medical, Inc., Burlington, Mass. and its associated electrodes such as the Cosman CSK, and cannula such as the Cosman CC and RFK cannula, enable electrode placement of the electrode near target tissue and heating of the target tissue by RF power dissipation of the RF signal output in the target tissue. Temperature monitoring of the target tissue by a temperature sensor in the electrode can control the process. Heat lesions with target tissue temperatures of 60 to 95 degrees Celsius are common. Tissue dies by heating above about 45 degrees Celsius, so this process produces the RF heat lesion. RF generator output is also applied using a pulsed RF method, whereby RF output is applied to tissue intermittently such that tissue is exposed to high electrical fields and average tissue temperature are lower, for example 42 degrees Celsius or less.
• RF generators and electrodes are used to treat pain, cancer, heart defects, high blood pressure, uterine fibroids, sleep apnea, and other diseases. Examples are the equipment and applications of Cosman Medical, Inc., Burlington, Mass. such as the G4 radiofrequency generator, the CSK electrode, CC cannula, RFK cannula, and DGP-PM ground pad. Related information is given in the paper by Cosman ER and Cosman BJ, “Methods of Making Nervous System Lesions”, in Wilkins R H, Rengachary S (eds.); Neurosurgery, New York, McGraw Hill, Vol. 3, 2490-2498; and is hereby incorporated by reference in its entirety. Related information is given in the book chapter by Cosman ER Sr and Cosman ER Jr. entitled “Radiofrequency Lesions.”, in Andres M. Lozano, Philip L. Gildenberg, and Ronald R. Tasker, eds., Textbook of Stereotactic and Functional Neurosurgery (2nd Edition), 2009, and is hereby incorporated by reference in its entirety. A paper by Luigi Solbiati et al. entitled “Hepatic Metastases: Percutaneous Radiofrequency Ablation with Cool-Tip Electrodes,” Radiology 1997, vol. 205, no. 2, pp. 367-373 describes various techniques and considerations relating to tissue ablation with RF electrodes which are internally-cooled by circulating fluid, and is incorporated herein by reference. A paper by Rosenthal et al entitled “Percutaneous Radiofrequency Treatment of Osteoid Osteoma,” Seminars in Musculoskeletal Radiology, Vol. 1, No. 2, 1997 reports the treatment of a primary benign bone tumor using a percutaneously placed radiofrequency electrode, and is incorporated herein by reference.
• Radiofrequency cannula include a hollow metal shaft, a hub at the proximal end, an injection port, electrical insulation covering the proximal end of the metal shaft, and a length of shaft at the distal end that is not covered by electrical insulation and is referred to as the active tip. An RF cannula can include a removable stylet that includes a cap at its proximal end that engages with the cannula hub, and a solid rod that can occlude the inner lumen of the hollow shafts. The stylet can be positioned with in the inner lumen of the cannula's hollow metal shaft when the cannula is used to penetrate tissue. The stylet can be removed from the cannula's inner lumen, and fluid injected into the hub is conducted to and outflows from a hole in the cannula's distal end. The hub typically includes a luer injection port. An RF electrode can be placed in the cannula's inner lumen, and the electrode can be connected to an RF generator, so that electrical signals from the generator, including nerve stimulation and RF signals, are conducted to the cannula and thus to tissue in contact with the cannula's active tip. The RF electrode can include a temperature sensor and can be position within the cannula to monitoring a temperature within the cannula's active tip. In one embodiment, an RF cannula has a flat, sharp bevel at the distal end of the cannula shaft; the bevel is characteristic of spinal needles used for nerve block procedures. Examples of a sharp RF cannula include the CC cannula and RFK cannula, both manufactured by Cosman Medical, Inc. of Burlington, Mass. In another embodiment, an RF cannula's shaft includes a closed distal end and a hole on the side for outflow of injected fluids. Examples of blunt-tip RF cannula include the blunt tip RFK cannula. The shaft of an RF cannula can be straight, such as in the example of the CC cannula. The shaft of an RF cannula can be curved at its distal end, such as in the example of the RFK cannula. The curvature of the cannula can be 15 degrees or more. The curvature of the cannula can be configured to facilitate the manipulation of the cannula when it is placed within tissue. RF cannula are available insizes 23, 22, 21, 20, 18, and 16 gauge. Examples of RF electrodes configured to be used with RF cannulae include the Cosman CSK electrode, Cosman TCD electrode, and Cosman TCN electrode. Such RF electrodes typically include a temperature sensor at their distal end to monitor the temperature of the active tip and tissue in contact with the active tip of the cannula. Such RF electrodes are thinner than RF cannula and RF electrode configured to be used without a cannula, for example 28 gauge. The length of such RF electrodes are match to the length of the RF cannulae with which they are intended to be used so that the temperature sensor include in the electrode's distal tip fall within the active tip of the cannula when the electrode is placed inside the cannula. The Cosman CSK and TCD electrodes have a shaft that is stainless steel. The Cosman TCN electrode has a shaft that is Nitinol. One limitation of such RF cannula and electrode systems, such as the Cosman CSK electrode and Cosman CC cannula, is that fluid injection into the cannula cannot be achieved when the electrode is positioned within the cannula. One limitation of such RF electrodes configured to be used with RF cannula is that they are not catheters. One limitation of such RF electrodes configured to be used with RF cannula is that they are not configured for placement in the epidural space. One limitation of such RF cannulae is that they are not flexible enough to be guided through the epidural space. One limitation of such RF cannulae with sharp bevels is that they have sharp cutting edges that can damage a catheter that is introduced into a living body though such a cannula. One limitation of such RF cannulae with sharp bevels is that they can damage the dura and other sensitive structures if placed in the epidural space. One limitation of such RF cannulae in the prior art is that their bevels are not configured both to reduce the likelihood of damage to the dura and to reduce damage a catheter when a catheter is introduced into the epidural space through an RF cannula. One limitation of such RF cannulae with sharp bevels is that they are not configured for the introduction of medical catheters, such as epidural catheters and catheter-type electrodes, into the human body. One limitation of blunt-tip RF cannulae is that they are not configured to introduce a catheter into the human body through their inner lumen. Related information is given in Cosman Medical brochure “Four Electrode RF Generator”, brochure number 11682 rev A, copyright 2010, Cosman Medical, Inc., and is hereby incorporated by reference herein in its entirety.
• In one embodiment, U.S. Pat. No. 7,862,563 by ER Cosman Sr and ER Cosman Jr presents a unitized injection electrode with an electrically-insulated shaft, an exposed metallic tip, a temperature sensor within the exposed metallic tip, cables that connect to the electrode via a single, flexible leader connector that splits into two parts of which the first is terminated by a connector configured to carry high-frequency and stimulation signals and temperature-measurement signals, and the second is terminated by an injection port through which fluid can be injected into the shaft and out the distal end of the electrode. One limitation of the prior art in U.S. Pat. No. 7,862,563 is that it does not show a unitized injection electrode for which the metallic tip and insulated shaft are constructed using a spring coil and a central stiffening wire. One limitation of the prior art in U.S. Pat. No. 7,862,563 is that it does not show the application of a unitized injection electrode in the epidural space.
• Radiofrequency injection electrodes have a shaft including metal tubing with sharp distal end for insertion into tissue, for example to reach a spinal target. Example of RF injection electrodes include the CU electrode, the CR electrode, and the CP electrode models, manufactured for Cosman Medical, Inc. in Burlington, Mass. Related information is given in Cosman Medical brochure “Four Electrode RF Generator”, brochure number 11682 rev A, copyright 2010, Cosman Medical, Inc., and is hereby incorporated by reference herein in its entirety. The CU, CR, and CP models have shaft length lengths 6 cm (2.4 inches), 10 cm (3.9 inches), or 15 cm (5.9 inches). The shaft of an RF injection electrode in the prior art are configured to penetrate the skin surface, muscle, and other solid bodily tissues to enable percutaneous placement of the active tip at nerves outside and around the bony spinal column. The shaft of an RF injection electrodes in the prior art is electrically insulated except for uninsulated distal length, termed the active tip, has an electrical connection to a signal generator for delivery of stimulation or RF signal outputs to the target tissue via the active tip. Each RF injection electrode has a flexible injection tube and a port to allow injection of contrast, anaesthetic, or saline solution fluid to the target tissue. The CU electrode incorporates a temperature sensor positioned within the exposed, conductive tip portion. The CR and CP electrodes do not incorporate a temperature sensor. The CP electrode can be used to effect a stimulation-guided nerve block, whereby an electrical stimulation signal is applied to the CP electrode via its electrical connector, stimulation signals are applied to nerve tissue nearby the conductive tip of the CP electrode, and anesthetic fluid is injected through the CP shaft once desired stimulation response is achieved by positioning of the exposed tip. The CR electrode can be used to effect a stimulation-guided RF therapy without temperature control, whereby an electrical stimulation signal is applied to the CR electrode via its electrical connector, the stimulation signal is applied to nerve tissue nearby the conductive tip of the CR electrode in order to position the exposed tip of the electrode near target nerves, RF generator output is applied to the CR electrode via the same electrical connector, RF output is applied to tissue nearby the exposed tip of the electrode without temperature monitoring. The CR electrode can also be used to effect non-stimulation-guided RF therapy, whereby stimulation guidance is not utilized. The CU electrode can be used to effect a stimulation-guided RF therapy with temperature monitoring and control, whereby an electrical stimulation signal is applied to tissue via the CU electrode to position its exposed tip near target nerves, and RF output is applied to tissue near the exposed tip to effect medical treatment. The CU electrode can also be used to effect non-stimulation-guided RF therapy, whereby stimulation guidance is not utilized. One limitation of the prior art in RF injection electrodes is that they are not configured to be guided into and through the epidural space. One limitation of the prior art in RF injection electrodes is that their tips are sharp. One limitation of the prior art in RF injection electrodes is that their shaft does not include a spring coil. One limitation of the prior art in RF injection electrodes is that they are not introduced into the human body via an introducer needle. One limitation of the prior art in RF injection electrodes is that they are not configured to introduce a catheter into the human body.
• In the prior art, the TEW electrode system, manufactured by Cosman Medical, Inc. of Burlington, Mass., includes an electrode with a spring-coil tip that has a temperature sensor at its distal closed end. Related information is given in Cosman Medical brochure “Four Electrode RF Generator”, brochure number 11682 rev A, copyright 2010, Cosman Medical, Inc., and is hereby incorporated by reference herein in its entirety. The TEW electrode is introduced into the human body by means of a fully-electrically-insulated metal cannula. The TEW cannula does not have an active tip. The TEW cannula includes a sharp, flat bevel, and a removable stylet. The TEW electrode is designed for RF treatment of the trigeminal facial nerve via the foremen ovale of the human skull. The TEW electrode is not electrically insulated. The shaft of the TEW electrode is a metallic tube to the distal end of which is attached a spring coil. The coil tip of the TEW electrode is configured to emerge from the end of the cannula and into the body without diverging substantially from its predetermined curve. The TEW electrode's spring coil is no longer than 0.33 inches. The TEW electrode's spring coil emerges from the distal end of the cannula by no more than 0.33 inches. One limitation of the TEW electrode is that it is not configured to be threaded though the epidural space. One limitation of the TEW electrode is that it is not configured to be threaded through 12 inches to 34 inches of the epidural space. One limitation of the TEW electrode is that it is not long enough to apply RF therapy to multiple spinal nerves via a single skin puncture and the epidural space. One limitation of the TEW electrode is that it does not have an integral injection port. One limitation of the TEW electrode is that it is that it not configured to allow for outflow of fluids from its spring coil tip. One limitation of the TEW cannula is that it is configured for the introduction of a catheter into the human body. One limitation of the TEW cannula is that it does not have an active tip. One limitation of the TEW cannula is that when an electrode is placed within its inner lumen, electrical signals applied to the cannula by the electrode are not transmitted to tissue in contact with any substantial part of the cannula. One limitation of the TEW cannula is that it does not have an tip characteristic of an epidural needle. One limitation of the TEW cannula is that it is not configured for placement in the epidural space and to perform RF therapy in the epidural space.
• In the prior art, the Flextrode RF electrode system, manufactured by Cosman Medical, Inc. of Burlington, Mass., includes an electrode and an introducer cannula. Related information is given in Cosman Medical brochure “Four Electrode RF Generator”, brochure number 11682 rev A, copyright 2010, Cosman Medical, Inc., and is hereby incorporated by reference herein in its entirety. The flextrode electrode's shaft is approximately 15 cm (5.9 inches) in length and is constructed from a metal tube whose distal end has a spiral cut over the distal 1.25 inches. A temperature sensor is located at the distal, closed end of the shaft. The electrode is introduced into the human body via the introducer cannula which includes a sharped distal end with a flat bevel, and whose shaft is electrically insulated over substantially all of its length, except for at most 1-2 mm at the distal end. When the electrode is introduced through the cannula, 11 mm of the electrode extends beyond the cannulas distal end into the tissue. The Flextrode electrode is not electrically insulated. RF energy is applied to the tissue by the length of the Flextrode electrode that extends beyond the cannula's distal tip and the uninsulated distal tip of the cannula. The Flextrode is configured to penetrate tissue, such as the fibrous tissue of the intervertebral disc, where it emerges from the distal end of the cannula. The Flextrode's stiffness is configured so that its tip can move through the curved tip of the introducer cannula but remain substantially straight as it penetrates tissue. One limitation of the Flextrode electrode is that it is not configured for placement in the epidural space. One limitation of the Flextrode electrode is that it is configured for injection of fluids into the human body. One limitation of the Flextrode cannula is that its bevel is not configured for the introduction of catheters into the human body. One limitation of the Flextrode cannula is that its bevel is not configured for the introduction of catheters whose external surface is soft material, such a plastic, into the human body. One limitation of the Flextrode cannula is that its bevel is not an epidural bevel, such as a tuohy bevel, RX bevel, Wavepoint bevel, Cath Glide bevel, or the bevel shown in Higuchi. One limitation of the Flextrode cannula is that sharp surfaces of its bevel can damage a soft catheter passing through it.
• The Radionics DiscTrode RF electrode system includes an electrode and an introducer cannula. Related information is given in an article by PM Finch entitled “The Use of Radiofrequency Heat Lesions in the Treatment of Lumbar Discogenic Pain”, Pain Practice, Volume 2, Number 3, 2002, pages 235-240, which is here incorporated by reference herein in its entirety. The disctrode electrode's shaft is approximately 9 inches in length and is constructed from a metal tube whose distal end has thin cuts over the distal 2.5 inches. A temperature sensor is located at the distal, closed end of the shaft. The electrode is induced into the human body via the introducer cannula which has a sharped, flat bevel at its distal end, and whose shaft is substantially electrically insulated, except for 1-2 mm at the distal tip bevel. When the electrode is introduced through the cannula, 5 cm (2 inches) of the electrode extends beyond the cannula's distal end into the tissue. The disctrode electrode is not electrically insulated. RF energy is applied to the tissue by the length of the disctrode electrode that extends beyond the cannula's distal tip and the uninsulated distal tip of the cannula. The disctrode is configured to penetrate tissue, such as the fibrous tissue of the intervertebral disc, where it emerges from the distal end of the cannula. The disctrode's stiffness is configured so that its tip can move through the curved tip of the introducer cannula but remain substantially straight as it penetrates tissue. One limitation of the DiscTrode electrode is that it is not configured for placement in the epidural space. One limitation of the DiscTrode electrode is that it is configured for injection of fluids into the human body. One limitation of the DiscTrode cannula is that its bevel is not configured for the introduction of catheters into the human body. One limitation of the DiscTrode cannula is that its bevel is not configured for the introduction of catheters whose external surface is soft material, such a plastic, into the human body. One limitation of the DiscTrode cannula is that its bevel is not an epidural bevel, such as a tuohy bevel, RX bevel, Wavepoint bevel, Cath Glide bevel, or the bevel shown in Higuchi. One limitation of the DiscTrode cannula is that sharp surfaces of its bevel can damage a soft catheter passing through it.
• The Oratec Spinecath system includes a catheter and an introducer cannula. Related information is given in an article by PM Finch entitled “The Use of Radiofrequency Heat Lesions in the Treatment of Lumbar Discogenic Pain”, Pain Practice, Volume 2, Number 3, 2002, pages 235-240, which is here incorporated by reference herein in its entirety. The catheter's shaft consists of a resistive coil that is entirely covered by electrical insulation. RF energy applied to the coil heats the internal resistive coil and tissue is heated by thermal conduction. RF current is not applied to the tissue. A temperature sensor is located in the spinecath catheter. The electrode is induced into the human body via the introducer cannula which has a sharped, flat bevel at its distal end. The spinecath emerges from the distal end of the cannula by approximately 5 cm (2 inches). One limitation of the spinecath catheter is that it is not configured for placement in the epidural space. One limitation of the spinecath catheter is that it is not configured for injection of fluids into the human body. One limitation of the spinecath catheter is that it is not a radiofrequency electrode with an active tip. One limitation of the spinecath catheter is that it does not apply RF signals to tissue that are in contact with it. One limitation of the spinecath cannula is that it is not configured to function as an RF cannula. One limitation of the spinecath cannula is that it does not have an epidural bevel, such as a tuohy bevel, RX bevel, Wavepoint bevel, Cath Glide bevel, or the bevel shown in Higuchi. One limitation of the spinecath cannula is that it is not configured for introduction of epidural catheters. One limitation of the spinecath cannula is that it is not electrically insulated.
• The use of catheters in the epidural space to treat pain is well known. A flexible catheter is introduced into the epidural space through an epidural needle inserted percutaneously through the sacral hiatus, through an intervertebral foramina, or through vertebral interspaces. An epidural needle includes a hollow metal shaft with inner lumen, an hub including a port such as a luer port, a distal bevel configured for placement in the epidural space, and a removable stylet rod configured for placement in the epidural space. The bevel of an epidural needle typically has rounded surfaces and edges configured to reduce the likelihood of damage to sensitive structures around the epidural space, to reduce the likelihood of penetration of the dura, and to reduce the likelihood of damage to a catheter that is introduced through the epidural needle's hollow shaft. Examples of epidural introducer needles include the touhy needle, the RX needle disclosed in U.S. Pat. No. 5,810,788 authored by Racz, and the Cath Glide needle manufactured by Spectra Medical Devices, Inc. of Wilmington, Mass. An injection adaptor is a separate device that can be attached to the proximal end of the catheter to provide for the injection of fluids into the proximal end of the catheter that outflow into patient anatomy through the distal end of the catheter. Examples of injection adaptors for epidural catheters include the tuohy-borst adaptor and the catheter connection hub disclosed in U.S. Pat. No. 8,038,667 authored by Racz and Bullard. Injection adaptors in the prior art have two openings, one distal opening into which the catheter is clamped with a fluid seal, and one proximal opening through which fluid can be injected and a stylet can be advanced into the inner lumen of the catheter; the proximal opening is typically a luer injection port, and the stylet wire must be removed in order that injections are made into the hub and thus the catheter. Techniques such as lysis of adhesions, chemical neurolysis of nerve roots, and other medial methods are well known. Related information is in “Epidural Lysis of Adhesions and Percutaneous Neuroplasty” by Gabor B. Racz, Miles R. Day, James E. Heavner, Jeffrey P. Smith, Jared Scott, Carl E. Noe, Laslo Nagy and Hana finer (2012), in the book “Pain Management—Current Issues and Opinions”, Dr. Gabor Racz (Ed.), ISBN: 978-953-307-813-7, InTech, and is hereby incorporated by reference in its entirety. Examples of epidural catheters include the Tun-L-XL catheter manufactured by EpiMed International, Farmers Branch, TX. The Tun-L-XL catheter comprises a stainless steel spring coil whose distal end is welded into a ball, and which is covered by a plastic tube over its entire length except for the distal end. The coil wire is closely coiled except for a region of the exposed, distal coil where the cool loops are loosely wound to provide for preferential outflow of injected fluids. The coil can have a metal safety strap welded at the proximal and distal end of the coil. A stylet comprising a metal wire and a plastic hub attached to the proximal end of the wire is inserted into the proximal end of the catheter to stiffen it. The stylet is removed, an injection adaptor is attached to the proximal end of the catheter, and fluids can be injected. Nerve stimulation signals can be delivered through the exposed metallic tip of the catheter by connecting the proximal end of the stylet to the output of a nerve stimulator, perhaps by means of an alligator clip, while the stylet is positioned inside the catheter. One limitation of the prior art in epidural catheters is that an electrode with a temperature monitoring is not used as a stylet. One limitation of the prior art in epidural catheters is that the stylet does not have an integrated connection cable to an electrical generator. One limitation of the prior art in epidural catheters is that the stylet does not have an integrated connection cable to an RF generator that includes both a wire for conducting an RF signals and a wire for conducting temperature signals. One limitation of the prior art in epidural catheters is that prior catheters do not provided for temperature-controlled RF lesioning. One limitation of the prior art in epidural catheters is prior catheter systems are not a unitized injection electrode. One limitation of the prior art in epidural catheters is prior catheter systems are not a unitized injection electrode whose shaft includes a spring coil. One limitation of the prior art in introducer needles for catheters is that the needles are not electrically insulated along their shafts. One limitation of the prior art in introducer needles for medical catheters is that the needles do not both provide a tip configured for introduction of a catheter, and provide an insulated shaft that defines an active tip for the targeted delivery of electrical signals, such as nerve stimulation signals and RF signals. One limitation of the prior art in introducer needles for catheters is that the needles' most distal bevel surface is not curved when viewed from the side of the bevel. One limitation of the prior art in injection adaptors for epidural catheters is that fluid cannot be injected into the injection adaptor when the stylet is inserted into the injection adaptor. One limitation of the prior art in injection adaptors for epidural catheters is that the injection adaptors do not include two fluid seals. One limitation of the prior art in injection adaptors for epidural catheters is that the adaptors do not include a first fluid seal for connection to a catheter and a second fluid seal to prevent outflow from the stylet port. One limitation of the prior art in injection adaptors for epidural catheters is that the adaptors do not contain three ports, one for the catheter, one for the stylet, and one for injection of fluids. One limitation in stylets for epidural catheters is that the stylet does not provide a port for injection into the catheter into which the stylet is placed.
• U.S. Pat. No. 6,551,289 by A Higuchi and H Hyugaji presents an outer needle of an anesthetic needle assembly to be injected into an epidural area comprising a distal end formed with an annular cutting edge, wherein the distal end is gently curved, and the annular cutting edge has a forward half portion in the form of bifurcated convex surfaces over a plane including outer major and minor axes of said annular cutting edge, said annular cutting edge having an outer frontal corner part with a cutting angle that is larger than a crossing angle between said major axis and a longitudinal line of an outer surface of said outer needle in a plane including said major axis and perpendicular to said minor axis. One limitation of the needle in Higuchi is that it has a gentle curve at its distal end. One limitation of the needle in Higuchi is that the shaft is not substantially straight at the bevel.
• NeuroCath epidural catheters and the Wavepoint epidural needles are sold by Neurotherm, Inc. of Wilmington, Mass. Related information is given in Neurotherm brochure “Epidural Product Line”, brochure number SS 129 Rev. 0, copyright 2011, Neurotherm, Inc., and is hereby incorporated by reference herein in its entirety. One limitation of the Wavepoint epidural needles is that they are not electrically insulated.
• U.S. Pat. No. 2,716,983 by E F Windishchman et al presents a needle for the medical arts that includes a bevel at the needle's distal end wherein the bevel's distal surface is flat, the bevel's middle surface is flat, and the bevel's proximal surface can be either flat with a fillet between the middle and proximal surfaces, or curved.
• U.S. Pat. No. 6,246,912 by M E Sluijter, W J Rittman, and ER Cosman presents inFIG. 9 a catheter electrode with one or more electrical contacts, where the catheter electrode is placed in the epidural space and applies high frequency signals via its electrical contacts. The electrical contact are tubular rings bonded to the substrate catheter and connected to wires internal to the catheter. The catheter may have reinforced metal spirals in its construction. One limitation of the art presented in U.S. Pat. No. 6,246,912 is that the catheter electrode does not provide for the injection of fluids. One limitation of the art presented in U.S. Pat. No. 6,246,912 is that the catheter electrode does not apply high frequency signals to the tissue by the same spring coil that is part of its shaft construction.
• U.S. Pat. No. 8,075,556 by A Betts presents a specific construction of a device configured for placement in the spinal canal and delivery of RF energy. Betts describes a catheter delivery device to transmit radiofrequency energy to a spinal canal, comprising: a needle having an open proximal end and an open distal end, and a lumen that extends from the open proximal end to the open distal end; a catheter having a blunt, metallic tip on a distal end of the catheter that transmits a radio frequency energy to the treatment site, wherein the catheter is telescopically disposed within the needle lumen to allow the tip to be maneuverably positioned within the spinal canal; a catheter hub coupled to a proximal end of the catheter a metallic wire element telescopically disposed within a lumen of the catheter; and an adapter hub coupled to a proximal end of the wire element, wherein the adapter hub is cooperatively engageable to the catheter hub to form a single shaft, wherein a proximal end of the adapter hub is configured couple to a radio frequency generating device, and wherein the adapter hub and the catheter hub are sized and dimensioned relative to one another such that engagement of the adapter hub to the catheter hub allows a distal end of the wire element to touch a seating surface of the tip such that the wire element delivers a radio frequency energy from the radio frequency generating device to the tip. One limitation of the prior art in Betts is that the catheter has an adaptor hub. One limitation of the system described in Betts is that a standard epidural catheter is not used. One limitation of the system described in Betts is that construction of the catheter using a metal coil is not described. One limitation of the system described in Betts is that a safety strap within the catheter shaft is not described. One limitation of the absence of a metallic safety strap is that the impedance of the catheter shaft can distort and/or diminish electrical signals conducted along the shaft. One limitation of the system described in Betts is that RF is not delivered without seating of the RF wire in the inner surface of the distal end of the catheter. One limitation of the system described in Betts is that the system does not provide for temperature monitoring. One limitation of the system described in Betts is that the system does not provide for temperature-monitored RF therapy delivered through the catheter. One limitation of the system described in Betts is that the RF wire does include a temperature sensor. One limitation of the system described in Betts is that it is not a unitized injection electrode. One limitation of the system described in Betts is that the RF wire is separate from the catheter. One limitation of the system described in Betts is that injection through the catheter cannot be effected while the RF wire is in place within the catheter. One limitation of the system described in Betts is that it does not provide for simultaneous injection of fluids and delivery of electrical signals. One limitation of the prior art in Betts is that the needle is not covered by electrical insulation to define an active tip. Another limitation of the prior art in Betts is that the needle is not connected to an electrical energy source, such as a stimulator, or an RF generator. Another limitation of the prior art in Betts is that the introducer needle for a medical catheter electrode is not used as a path for return currents from the medical catheter electrode. One limitation of the prior art in Betts is that fluid cannot be injected through the catheter hub and into the catheter when the metallic wire element is telescopically disposed within a lumen of the catheter. One limitation of the catheter hub described in Betts is that it does not provide for simultaneous injection of fluids and delivery of electrical signals. One limitation of the catheter hub is does not describe more than one fluid clamp.
• US patent application 2004/0210290 by Omar-Pasha describes a catheter electrode for pulsed RF treatment of nerves in the epidural space. One limitation of the prior art in Omar-Pasha is that it does not describe the use of a coil to construct the catheter electrode. Another limitation of the prior art in Omar-Pasha is it does not describe an RF electrode system in which an RF electrode stylet is inserted into a standard epidural catheter. One limitation of the prior art in Omar-Pasha is that the catheter electrode does not have a stylet port, nor a stylet port with a clamp. One limitation of the prior art in Omar-Pasha is that the catheter electrode does not have a separable injection adaptor.
• The Pulsetrode electrode manufactured by BioAmpere Research SRL, Verona, Italy is a flexible electrode comprising a plastic shaft, three ring electrodes near its distal end, a hub, an injection port connected to a tube that is connected directly to the hub, a generator wire that connects directly to the hub, a moveable stylet is inserted into the injection port and travels along the shaft of the electrode. The Pulsetrode is configured for placement in the epidural space and delivery of radiofrequency fields to anatomy. Related information is given in Bioampere Research brochure “Pulsetrode” and is hereby incorporated by reference herein in its entirety. One limitation of the Pulsetrode is that it does not describe the use of a coil to construct the catheter electrode. One limitation of the Pulsetrode is that an active electrode tip of the catheter is constructed from the same coil that is included in the catheter shaft. Another limitation of the Pulsetrode is that it is not an RF electrode system in which an RF electrode stylet is inserted into a standard epidural catheter. Another limitation of the Pulsetrode is that the distal end of the electrode is electrically insulated. Another limitation of the Pulsetrode is that the active tip is not the sole active tip. One limitation of the Pulsetrode electrode is that the stylet must be removed from the electrode in order that injection take place. Another limitation of the pulsetrode electrode is that the stylet port is not capable of producing a fluid-tight seal around the stylet. Another limitation of the pulsetrode electrode is that the injection port is not separate from the stylet port. Another limitation of the pulsetrode electrode is that the injection port is not separable from the catheter.
• Needles, catheters, and catheter guidewires are used in medicine for a variety of applications, including without limitation injecting of anesthetics, neurolytic agents, injection of medicine, and injection of radiographic contrast. Needles and catheters are used in medicine to inject and insert substances and devices in a variety of targets in the human body including muscles, nerves, organs, blood vessels, bone, connective tissue, body cavities, bodily spaces, bodily potential spaces, the urinary tract, reproductive tracts, and peri-neural spaces and potential spaces such as the epidural space.
• The Cool-Tip Electrode of Radionics, Inc. and Valley Lab, Inc. is a 16-gauge (or 1.6 millimeter diameter) electrode with partially-insulated shaft and water-cooling channel inside its rigid, straight cannula shaft. The Cool-Tip electrode has an uninsulated active tip. The brochure from Radionics, document number 921-91-001 Rev. B, is hereby incorporated by reference in its entirety. The Cool-Tip Electrode is used for making large RF heat ablations of cancerous tumors, primarily in soft-tissue organs and bone. It has a closed trocar point that includes a metal plug that is welded to the metal tubing that is part of the electrode shaft. The distal end of the metal plug is sharpened to form a three sided, axially symmetric trocar. The distal end is a closed and sealed metal structure. The sharpened portion of the distal tip does not include the metal tubing itself, but rather the sharpened end of the metal plug that is welded to the metal tubing. The Cool-Tip electrode has the limitation that it does not provide a hollow tube for injection of fluids. The Cool-Tip electrode has the limitation that it is straight.
• The present invention seeks to overcome the limitations and disadvantages of the prior art.
SUMMARY OF THE INVENTION
• In one aspect, the present invention relates to a medical catheter system that includes an introducer needle, an injection adaptor hub, and a flexible catheter. In certain embodiments, the introducer needle includes electrical insulation that covers at least a portion of the needle's shaft. In certain embodiments, the catheter system includes an epidural needle, an injection adaptor hub, and an epidural catheter. In certain embodiments, the catheter can provide for the delivery of electrical signals, such as radiofrequency and nerve stimulation signals, to the living body. In certain embodiments, the epidural needle includes electrical insulation that covers at least a portion of the needle's shaft.
• In one aspect, the present invention relates to a medical catheter system that includes an introducer needle and a flexible catheter that includes an injection port and that is configured for the injection of fluids into the living body. In certain embodiments, the introducer needle can include electrical insulation that covers at least a portion of the needle's shaft.
• In one aspect, the present invention relates to methods for use of medical catheter systems. In certain embodiments, the present invention relates to methods of pain relief. In certain embodiments, the present invention relates to methods of epidural anesthesia. In one aspect, the present invention relates to the use of an electrode catheter to energize the introducer through which the electrode catheter is introduced into a living body.
• In one aspect, the present invention relates to a medical electrode system that includes an introducer needle, an injection adaptor hub, a flexible catheter configured to delivery an electrical signal to a living body, an electrode configured to delivery an electrical signal to the catheter, and an electrical signal generator. In certain embodiments, the electrode includes a temperature measurement device and the electrical signal generator includes a temperature control circuit. In certain embodiments, the electrical signal includes an RF signal. In certain embodiments, the electrical signal includes a nerve stimulation signal. In certain embodiments, the injection adaptor hub is integral to the catheter. In certain embodiments, the electrode is integral to the catheter. In certain embodiments, the catheter is a unitized injection electrode catheter. In certain embodiments, the introducer needle can include electrical insulation that covers at least a portion of the needle's shaft.
• In one aspect, the present invention relates to method for the use of medical, electrode catheter systems. In certain embodiments, the present invention relates to methods of electric field therapy. In certain embodiments, the present invention relates to electric field therapy applied to nerves in the epidural space. In certain embodiments, the present invention relates to methods of radiofrequency pain therapy. In certain embodiments, the present invention relates to methods of radiofrequency lesioning. In certain embodiments, the present invention relates to methods of cancer therapy.
• In one aspect, the present invention relates to a system and method for an electrode system having a flexible shaft. In one aspect, the present invention relates to flexible radiofrequency electrode configured for placement in the epidural space. In one aspect, the present invention relates to a flexible electrode that provides for stimulation-guidance and the injection of fluids into the epidural space. In one aspect, the present invention relates to a flexible electrode that provides for nerve-stimulation-guidance of the catheter placement.
• In one aspect, the present invention relates to the construction of catheter-style medical electrodes. In one aspect, the present invention relates to the use of a coil in the construction of a flexible electrode. In one aspect, the present invention relates to the use of a coil in the construction of a flexible, temperature-sensing, radiofrequency electrode. In one aspect, the present invention relates to a flexible injection electrode system that provides for injection of fluids and whose shaft includes a metal coil that is covered over at least a part of its length by electrical insulation, that is uncovered over at least a part of its length for the application of electrical signals to tissue.
• In one aspect, the present invention relates to a catheter electrode system that is “unitized” wherein a flexible catheter electrode includes an injection port, a generator connection, and a temperature sensor. In one aspect, the present invention relates to a one-piece, flexible electrode wherein the electrode's shaft is constructed using a spring coil whose proximal end is covered by an electrically-insulated sheath, and whose distal end is closed by a weld that incorporates the spring coil, an RF wire, a thermocouple wire, and an internal structuring wire, such as a safety strap or movable stylet. In one aspect, the present invention relates to a one-piece, flexible electrode wherein the electrode's shaft is constructed using a spring coil whose proximal end is covered by an electrically-insulated sheath, and whose distal end includes an opening and a weld that incorporates the spring coil, an RF wire, a thermocouple wires, and an internal structuring wire, such as a safety strap or moveable stylet.
• In one aspect, the present invention relates to a catheter electrode system that includes a catheter with metallic active tip and a temperature-sensing electrode configured to be positioned within an inner lumen of the catheter and to energize the catheter's active tip; One advantage of this aspect is that the electrode can both deliver electrical signals to a catheter tip, monitor the temperature at the catheter tip, and provide variable stiffening of the catheter shaft and tip.
• In one aspect, the present invention relates to an injection adaptor hub for a medical catheter.
• In one aspect, the present invention relates to an injection adaptor hub that includes a first clamp configured to create a watertight seal between the injection adaptor hub and a catheter, a second clamp configured to create a watertight seal between the injection adaptor hub and the catheter's stylet, and an injection port configured to conduct fluid into the catheter. In certain embodiments, the first clamp and the second clamp are tuohy-borst style clamps.
• In one aspect, the present invention relates to an injection adaptor hub that includes a first clamp configured to create a watertight seal between the injection adaptor hub and a catheter, a second clamp configured to create a watertight seal between the injection adaptor hub and an electrode, and an injection port configured to conduct fluid into the catheter, wherein the electrode is configured to deliver electrical signals through a portion of the catheter to a living body. In certain embodiments, the electrode can be a temperature-sensing RF electrode. In certain embodiments, the first clamp and the second clamp are tuohy-borst style clamps.
• In one aspect, the present invention relates to an injection adaptor hub and an injection stylet, wherein the injection adaptor hub includes a first clamp configured to create a watertight seal between the injection adaptor hub and a catheter, a second clamp configured to create a watertight seal between the injection adaptor hub and the catheter's stylet, and wherein the injection stylet includes an injection port configured to conduct fluid into the catheter and an elongated shaft configured to reside in an inner lumen of the catheter. In certain embodiments, the first clamp and the second clamp are tuohy-borst style clamps.
• In one aspect, the present invention relates to an injection adaptor hub and an injection electrode, wherein the injection adaptor hub includes a first clamp configured to create a watertight seal between the injection adaptor hub and a catheter, a second clamp configured to create a watertight seal between the injection adaptor hub and the injection electrode, and wherein the injection stylet includes an injection port configured to conduct fluid into the catheter, an elongated shaft configured to reside in an inner lumen of the catheter, and a conductive element configured to deliver electrical signals through a portion of the catheter to a living body. In certain embodiments, the injection electrode can be a temperature-sensing RF electrode.
• In one aspect, the present invention relates to a method of injection through a medical catheter by means of an injection hub while the catheter's stylet is positioned within an inner lumen of the catheter. In one aspect, the present invention relates to a method of injection through a medical catheter by means of an injection hub while an electrode is positioned within an inner lumen of the catheter.
• In one aspect, the present invention relates to a needle that is configured both for the introduction of a catheter into a living body, and the delivery of electrical signals through a part of the needle's shaft.
• In one aspect, the present invention relates to a medical needle bevel that is configured for placement in the epidural space of the human body. In one aspect, the present invention relates to a needle bevel that is configured for the introduction of a flexible catheter into the living body. In one aspect, the present invention relates to a needle bevel that is configured for the introduction of an epidural catheter into the living body. In one aspect, the present invention relates to a needle bevel that is configured both to penetrate solid tissue and to minimize damage to a flexible catheter passing through the bevel. In one aspect, the present invention relates to a needle bevel that includes at least two surfaces, wherein the most distal surface is a curved surface. In one aspect, the present invention relates to a needle bevel that includes at least two surfaces, wherein the most distal surface is a curved surface, the heel of the bevel is smoothed to reduce cutting edges, and the inner edges of the bevel are smoothed to reduce cutting edges. In one aspect, the present invention relates to a needle system that includes a cannula and a stylet, wherein the cannula's bevel includes at least two surfaces, wherein the most distal surface is a curved surface, and wherein the stylet engages with the cannula such that the combined bevel is substantially a flat, angled bevel.
• In one aspect, the present invention relates to a needle that includes a hollow shaft, a bevel that is configured for the introduction of a flexible catheter into the living body, and electrical insulation covering a part of the needle's shaft. In one aspect, the present invention relates to a needle that includes a tubular metal shaft, a bevel that is configured for the introduction of a flexible catheter into the living body, and electrical insulation covering a part of the needle's shaft. In one aspect, the present invention relates to a needle that includes a tubular metal shaft, a bevel that is configured for the introduction of a flexible catheter into the living body, and electrical insulation covering the proximal end of the needle's shaft. In one aspect, the present invention relates to a needle that includes a tubular metal shaft, a bevel that is configured for the introduction of a flexible catheter into the living body, and electrical insulation covering to the proximal end of the needle's shaft and fixedly attached to the needle's shaft. In one aspect, the present invention relates to a needle that includes a tubular metal shaft, a bevel that includes a rounded proximal heel and a rounded inner edge, and electrical insulation covering the proximal end of the needle's shaft and fixedly attached to the needle's shaft.
• In one aspect, the present invention relates to a needle that includes a hollow shaft, an epidural bevel, and electrical insulation covering a part of needle's shaft. In one aspect, the present invention relates to a needle that includes a hollow shaft, an epidural bevel, and electrical insulation covering the proximal end of the needle's shaft, leaving the distal end of the needle's shaft electrically-uninsulated. In one aspect, the present invention relates to a needle system for the medical arts that includes a needle and a stylet, wherein the needle includes a hollow shaft, an epidural bevel, and electrical insulation covering a part of the needle shaft, and wherein the stylet is an elongated structure that can be positioned in the inner lumen of the needle.
• In one aspect, the present invention relates to an RF cannula that includes an epidural bevel. In one aspect, the present invention relates to an RF cannula that includes a bevel that is configured for percutaneous placement in the epidural space and for introduction of an epidural catheter into the epidural space. In one aspect, the present invention relates to an RF cannula that is configured to penetrate solid tissue and to minimize the likelihood of damage of a catheter passing through the cannula's inner lumen. In one aspect, the present invention relates to an RF cannula wherein the edges of the cannula's bevel heel is rounded to reduce sharp edges and wherein the inner edge of the cannula's bevel are rounded to reduce sharp edges. In one aspect, the present invention relates to an RF cannula that is configured for epidural anesthesia.
• In one aspect, the present invention relates to a needle that is configured for both epidural anesthesia and radiofrequency lesioning.
• In one aspect, the present invention relates to an RF cannula that includes a bevel configured for placement in the epidural space. In one aspect, the present invention relates to an RF cannula that includes a bevel configured for placement in the epidural space, and a physically-separate RF electrode configured to electrify the RF cannula. In one aspect, the present invention relates to an RF electrode that includes a bevel configured for placement in the epidural space.
• In one aspect, the present invention relates to a method of introducing an RF cannula into the living body and energizing the RF cannula using an electrode catheter. In one aspect, the present invention relates to a method of introducing an RF cannula into the living body, energizing the RF cannula using an electrode catheter, and advancing the electrode catheter beyond the RF cannula into the living body and energizing the electrode catheter. In one aspect, the present invention relates to a method of introducing an RF cannula into the epidural space and energizing the RF cannula using an electrode catheter.
• In one aspect, the present invention relates to a method of introducing an RF cannula into the epidural space and energizing the RF cannula using an RF electrode. In one aspect, the present invention relates to a method of introducing an RF cannula into the epidural space via the sacral hiatus and energizing the RF cannula using an RF electrode. In one aspect, the present invention relates to a method of introducing an RF electrode into the epidural space and performing an RF pain management procedure.
• In one aspect, the present invention relates to a needle that includes a bevel configured for introducing a catheter, a hollow shaft that is covered by electrical insulation to define a conductive active tip configured to deliver electrical signals to tissue, and a connection configured to conduct an electrical signal to the active tip. In one aspect, the present invention relates to an RF cannula that includes an epidural bevel configured for introducing an epidural catheter, a shaft that is partially insulated to define an active tip configured to conduct electrical signals to tissue in contact with the tip, and a wire configured to conduct an RF signal to the active tip. In one aspect, the present invention relates to an RF cannula that includes an epidural bevel configured for introducing an epidural catheter, a shaft that is partially insulated to define both an active tip configured to conduct electrical signals to tissue in contact with the active tip, and an conductive connection point configured to conduct electrical signal to the active tip.
• In one aspect, the present invention relates to a method wherein an RF cannula is connected to the reference jack of an RF generator, an electrode catheter is connected to the RF output of the RF generator, the needle is placed in the living body, the electrode catheter is inserted into the living body through the needle, and RF current flows from the active tip of the needle to the active tip of the electrode catheter.
DESCRIPTION OF THE DRAWINGS
• FIG. 1A is a schematic diagram showing a catheter system including an injection catheter electrode, an epidural RF cannula, an electrical generator, and a ground pad, wherein the cannula is placed in the epidural space of living body, the catheter is advanced beyond the cannula into the epidural space, and the catheter is energized by the generator in a monopolar manner, where a ground pad carries return currents from the catheter through the living body.
• FIG. 1B is a schematic diagram showing a catheter system including an injection catheter electrode, an epidural RF cannula, an electrical generator, and a ground pad, wherein the cannula is placed in the epidural space of a living body, the conductive active tip of the catheter is positioned such that it conducts electrical signals the cannula, and the catheter and cannula are both energized by the generator in a monopolar manner, where a ground pad carries return currents from the catheter and cannula through the living body.
• FIG. 1C is a schematic diagram showing a catheter system including two injection catheter electrodes, two epidural RF cannulae, and an electrical generator, wherein the cannulae are placed in the epidural space of a living body, each catheter is introduced into the epidural space through one of the cannulae, and the generator energizes the catheters in a bipolar manner.
• FIG. 1D is a schematic diagram showing a catheter system including an injection catheter electrode, an epidural RF cannula including a generator connection, an electrical generator, wherein the cannula is placed in the epidural space of living body, the catheter is advanced beyond the cannula into the epidural space, and the catheter and cannula are energized by the generator such that the catheter and cannula carry return currents from each other through the living body.
• FIG. 2A is a schematic diagram showing in an external view a unitized injection electrode with a flexible active tip, a flexible shaft, an injection port, and a generator connector.
• FIG. 2B is a schematic diagram showing in an external view a unitized injection electrode with a flexible active tip, a flexible shaft depicted in a straight position, an injection port, and a generator connector.
• FIG. 2C is a schematic diagram showing in a sectional view a unitized injection electrode where a coil is used in the construction of the shaft and active tip, and where the electrode has a an integrated stylet, temperature sensor, injection port, and a generator connector.
• FIG. 2D is a schematic diagram showing in a sectional view a unitized injection electrode where a coil is used in the construction of the shaft and active tip, and where the electrode has a an integrated stylet, temperature sensor, injection port, and a generator connector.
• FIG. 2E is a schematic diagram showing in a sectional view a unitized injection electrode where a coil is used in the construction of the shaft and active tip, and where the electrode has a an integrated safety strap, temperature sensor, injection port, and a generator connector.
• FIG. 3 is a schematic diagram showing a unitized injection electrode with a flexible active tip, closed distal end with diameter larger than the outer diameter of the proximal part of the active tip, a flexible shaft, an injection port, and a generator connector in an external view.
• FIG. 4A is a schematic diagram showing connector in an external view a unitized injection electrode with a flexible active tip, a flexible shaft depicted in a straight position, an injection port, a generator connector, and a moveable stylet.
• FIG. 4B is a schematic diagram showing in a sectional view a moveable stylet positioned inside a unitized injection electrode where a coil is used in the construction of the shaft and active tip, where the electrode has a temperature sensor, injection port, and a generator connector.
• FIG. 5A is a schematic diagram showing connector in an external view a unitized injection electrode system with a flexible active tip, a flexible shaft depicted in a straight position, an injection port, a generator connector, and a moveable stylet, where the injection port and generator connector are each connected separately by means of a dedicated tube to the proximal end of the electrode.
• FIG. 5B is a schematic diagram showing in a sectional view a moveable stylet positioned inside a unitized injection electrode where a coil is used in the construction of the shaft and active tip, where the electrode has a temperature sensor, injection port, and a generator connector, and where the injection port and generator connector are each connected separately by means of a dedicated tube to the proximal end of the electrode.
• FIG. 6A is a schematic diagram showing connector in an external view a unitized injection electrode system with a flexible active tip, a flexible shaft, an injection port, a generator connector, and a moveable stylet, where the injection port is integrated into the hub at the proximal end of the electrode.
• FIG. 6B is a schematic diagram showing in a sectional view a moveable stylet positioned inside a unitized injection electrode where a coil is used in the construction of the shaft and active tip, where the electrode has a temperature sensor, injection port, and a generator connector, and where the injection port is integrated into the hub at the proximal end of the electrode.
• FIG. 7 is a schematic diagram showing connector in an external view a unitized injection electrode system with a flexible active tip, a flexible shaft, an injection port, a generator connector, and a moveable stylet, where the injection port and generator connector are both integrated into the hub at the proximal end of the electrode.
• FIG. 8A is a schematic diagram showing in an external view an electrode system comprising a flexible catheter, injection hub, and stylet electrode.
• FIG. 8B is a schematic diagram showing in a sectional view an electrode system comprising a flexible catheter, injection hub, and stylet electrode.
• FIG. 9A is a schematic diagram showing in an external view an electrode system comprising a flexible catheter and stylet electrode.
• FIG. 9B is a schematic diagram showing in a sectional view an electrode system comprising a flexible catheter and stylet electrode.
• FIG. 10A is a schematic diagram showing an injection catheter system in an external view, wherein the injection catheter system includes a catheter, an injection adaptor hub, a stylet, and a stylet electrode, and wherein the injection adaptor hub includes a fluid clamp for the catheter, a fluid clamp for the electrode and stylet, and an injection port.
• FIG. 10B is a schematic diagram showing an assembled injection catheter system in an external view, wherein the injection catheter system includes a catheter, an injection adaptor hub, a stylet, and a stylet electrode, and wherein the injection adaptor hub includes a fluid clamp for the catheter, a fluid clamp for the stylet or stylet electrode, and an injection port.
• FIG. 10C is a schematic diagram showing the construction of an injection adaptor hub for a catheter that includes a fluid clamp for a catheter, a fluid clamp for a stylet, and an injection port.
• FIG. 10D is a schematic diagram showing an injection catheter system in an cross-sectional view, wherein the injection catheter system includes a catheter, an injection adaptor hub, and a stylet electrode including a flexible cable, and wherein the injection adaptor hub includes a fluid clamp for the catheter, a fluid clamp for the stylet electrode, and an injection port.
• FIG. 10E is a schematic diagram showing an injection catheter system in an cross-sectional view, wherein the injection catheter system includes a catheter, an injection adaptor hub, and a stylet electrode including a handle configured to connect to an electrical generator, and wherein the injection adaptor hub includes a fluid clamp for the catheter, a fluid clamp for the stylet electrode, and an injection port.
• FIG. 11A is a schematic diagram showing an injection catheter system in an external view, wherein the injection catheter system includes a catheter, an injection adaptor hub, and an injection stylet, and wherein the injection adaptor hub includes a fluid clamp for the catheter and a fluid clamp for the injection stylet.
• FIG. 11B is a schematic diagram showing an assembled injection catheter system in an external view, wherein the injection catheter system includes a catheter, an injection adaptor hub, and an injection stylet, and wherein the injection adaptor hub includes a fluid clamp for the catheter and a fluid clamp for the injection stylet.
• FIG. 11C is a schematic diagram showing the construction of an injection adaptor hub for a catheter that includes a fluid clamp for a catheter and a fluid clamp for a stylet.
• FIG. 11D is a schematic diagram showing an assembled injection catheter system in a cross-sectional view, wherein the injection catheter system includes a catheter, an injection adaptor hub, and an injection stylet, and wherein the injection adaptor hub includes a fluid clamp for the catheter and a fluid clamp for the injection stylet.
• FIG. 11E is a schematic diagram showing an assembled injection catheter system in a cross-sectional view, wherein the injection catheter system includes a catheter, an injection adaptor hub, and an injection stylet electrode, and wherein the injection adaptor hub includes a fluid clamp for the catheter and a fluid clamp for the injection stylet electrode.
• FIG. 11F is a schematic diagram showing an assembled injection catheter system in a cross-sectional view, wherein the injection catheter system includes a catheter, an injection adaptor hub, and an injection stylet, and wherein the injection adaptor hub includes a fluid clamp for the catheter and a fluid clamp for the injection stylet.
• FIG. 12A is a schematic diagram showing a cannula system configured for the introduction of a catheter into the living body.
• FIG. 12B is a schematic diagram showing an assembled cannula system configured for the introduction of a catheter into the living body.
• FIG. 12C is a schematic diagram showing an assembled cannula system configured for the introduction of a catheter into the living body.
• FIG. 12D is a schematic diagram showing an assembled cannula system configured for the introduction of a catheter into the living body, wherein the shaft of the cannula includes a bend.
• FIG. 12E is a schematic diagram showing an assembled cannula system configured for the introduction of a catheter into the living body, wherein the shaft of the cannula has a bend and the stylet is configured to protrude from the distal end of the cannula.
• FIG. 12F is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12G is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12H is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12I is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12J is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12K is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12L is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12M is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12N is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12O is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12P is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12Q is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12R is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12S is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12T is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12U is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12V is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12W is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12X is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 12Y is a schematic diagram showing a needle bevel and a stylet bevel configured for the introduction of a catheter into a living body.
• FIG. 13 is a schematic diagram showing a cannula system configured for the introduction of a catheter into the living body, wherein the cannula has a depth stop and a conductive region configured for attachment to an electrical generator.
• FIG. 14 is a schematic diagram showing a cannula system configured for the introduction of a catheter into the living body, wherein the cannula has a connection cable configured for attachment to an electrical generator.
• Like reference symbols in the various drawings indicate like elements.
• A reference to a figure by its numeric index alone is a reference to all figures having that numeric index as their prefix; for example, “FIG. 4” refers toFIG. 4A andFIG. 4B collectively.
DETAILED DESCRIPTION
• Referring toFIGS. 1A, 1B, 1C, and 1D,FIG. 1 present several embodiments of a medical catheter system, in accordance with the present invention, wherein the medical catheter system includes aninjection catheter system160, anintroducer needle170, and anelectrical power supply180, wherein thecatheter system160 andintroducer needle170 are configured for placement in the human body.Catheter system160 includes aconnection140 topower supply180, aninjection port150, ahub120, ashaft110 with a distal end and a proximal end, and atip100. Thehub120 can be at the proximal end of thecatheter shaft110. Thetip100 can be at the distal end of theshaft110. Theneedle170 can include ahub171 at its proximal end, ashaft172,electrical insulation173 covering theshaft172, and an electrically-conductivedistal tip174. In certain embodiments, theneedle hub171 includes an injection port, such as a female luer port. Thetip100 can include a temperature sensor. Thecatheter160 can include multiple temperature sensors, in certain embodiments. The needle can penetrate the livingbody190. Theneedle170 can include ashaft172 that is constructed from a metal tube. The bevel at thedistal end174 of the needle'sshaft172 can be an epidural needle bevel, such as a touhy bevel. In certain embodiments, the needle has features both of an RF cannula and an epidural needle. Thecatheter tip100 andshaft110 can pass through an inner lumen of theneedle170 into the livingbody190, such as the human body. The living body can includes abrain191, aspinal cord192, andperipheral nerves193. In certain embodiments, the needle'sdistal tip174 can be percutaneously positioned in the epidural space of the livingbody190, thecatheter shaft110 can be introduced into the epidural space of the livingbody190, and thetip100 of thecatheter160 can be positioned nearby anerve193 in the epidural space. In one example,electrode160 enters the epidural space via a median or paramedian approach. In one example,electrode160 enters the epidural space via the sacral hiatus. In one example,electrode160 enters the epidural space via an intervertebral foramina of the spinal column. In one example, theactive tip100 of theelectrode160 is positioned near a dorsal spinal nerve root. In one example, theactive tip100 of theelectrode160 is positioned near a dorsal root ganglion (DRG). In one example, theactive tip100 of theelectrode160 is positioned near a spinal nerve. Thecatheter160 can be an electrode catheter. Theshaft110 can include electrically insulation surrounding an electrical conductor, and theactive tip100 can be electrically conductive, so that electrical signals delivered toconnector140 is conducted throughgenerator cable133,tube131,hub120,shaft110,active tip100, and totissue190 in contact with theactive tip100, but not to tissue in contact with theshaft110 of thecatheter160. Asyringe159 can be connected toport150 and fluid injected intoport150 is conducted throughtubing131,hub120,shaft110, and out from holes that can be positioned along theshaft110, thetip100, or the distal end of thetip100. In certain embodiments,port150 is a luer port, such as a female luer port. Thegenerator180 can include afirst output pole186 and asecond output pole185. Thegenerator180 can produce an electrical potential betweenoutput pole185 andoutput pole186. In certain embodiments,generator180 can produce a radiofrequency signal. In certain embodiments,generator180 can produce a pulsed radiofrequency signal. In certain embodiments,generator180 can produce a nerve stimulation signal. In certain embodiments, thegenerator180 can produce a PENS signal. In certain embodiments, thegenerator180 can produce a TENS signal. In certain embodiments, thegenerator180 can produce a muscle stimulation signal. In certain embodiments, thegenerator180 can be a medical RF generator. In certain embodiments,generator180 can produce a continuous radiofrequency signal. In certain embodiments,generator180 can produce a pulsed radiofrequency signal. In certain embodiments, thegenerator180 can be a direct current generator. In certain embodiments, thegenerator180 can produce a neuromodulation signal. In certain embodiments,generator180 can produce a high frequency electrical signal. In certain embodiments,generator180 can include additional output poles and can impose an electrical potential on each pole and can impose a high-impedance pathway between any pair of output poles. In certain embodiments, thegenerator180 can include temperature-measurement circuitry. In certain embodiments, thegenerator180 can control its output level in response to a temperature signal measured by thecatheter160. In certain embodiments, thegenerator180 can control the temperature measured attip100 by amplitude modulation of an RF signal output. Thegenerator180 can produce a voltage, current, or power output level. In certain embodiments, the catheter system can be used to apply pulsed radiofrequency fields to nerves in the epidural space, such as a dorsal nerve root or a doral root ganglion, of the livingbody190, for example, for the treatment of neuropathic pain. In certain embodiments, the system can be used to produce heat lesions in the living body, for example, heat lesions of nerve roots in the epidural space for the purpose of controlling pain in a patient suffering from terminal cancer. One advantage of the method of RF heat lesioning of nerve roots is that it provides for the treatment of cancer pain without greater control of targetry than does injection of fluid neurolytic agents. In certain embodiments, theactive tip100 of the electrode can be at the distal end of thecatheter160. In certain embodiments, theactive tip100 of theelectrode160 can have electrical insulation distal to theactive tip100 along theshaft110. In certain embodiments, theelectrode100 can have multiple active tips that can be connect togenerator180 output potentials via a switching system. In certain embodiments, theneedle170 can be energized by a standard RF electrode, such as one with a shaft constructed from a stainless steel hypotube and including a thermocouple temperature sensor. In certain embodiments, theneedle170 can include a curve in itsshaft172. In certain embodiments, theneedle170 can have a bend at theactive tip174 of thecannula170. In certain embodiments, theneedle170 can have a bend in itsshaft172 such that when thecatheter160 is positioned inside thecannula170, at thedistal end100 of thecatheter160 is aligned with the distal end of thecannula shaft174, theactive tip100 of thecatheter160 is positioned at the location of a bend in theshaft172 of thecannula170. One advantage of a curve in theshaft172 is that when theactive tip100 is positioned within theshaft172 near the location of the curve, the active100 is more likely to make contact with the inner lumen of theshaft172 and thereby more reliably conduct electrical signals from theactive tip100 to theshaft172. In certain embodiments,needle170 can be tissue-piercing. In some embodiments, theelectrode shaft110 includes a feature that provides for enhanced visualization of theshaft110 using ultrasound imaging. In some embodiments, theactive tip100 includes a feature that provides for enhanced visualization of thetip100 using ultrasound imaging.
• Referring now toFIG. 1A andFIG. 1B, several embodiments of a medical catheter system are presented.Cable181 includesconnector182,connector182 is attached tocatheter connector140, andcable181 conducts the signal output fromgenerator jack186 to thecatheter160.Cable183 is attached toground pad184,ground pad184 is placed on the surface ofbody190, andcable183 conducts electrical signals fromgenerator jack185 to theground pad184. In one example,pole185 can be the reference jack ofgenerator180. Theshaft110 ofcatheter160 passes through the inner lumen ofneedle170.Element111 is the portion ofcatheter shaft110 that is proximal to theneedle170. Whengenerator180 produces and electrical output, current passes between the electrodeactive tip100 and thereference ground pad184; this configuration can be referred to as a “monopolar” configuration.
• Referring toFIG. 1A specifically, the catheter is advanced into the living body such that the entirely of theactive tip100 extends beyond the distal end of theneedle170. In this configuration, the needle is electrically insulated from electrical signals applied to thecatheter160 by means of the electrical insulation covering theshaft110. In this configuration, electrical signals from thegenerator180 are applied to the tissue through theactive tip100 of the catheter, and not through theneedle170.
• Referring toFIG. 1B specifically, thecatheter160 is positioned within theneedle170 such that theactive tip100 of thecatheter160 contacts a portion of the conductive inner lumen of theneedle170. In this configuration, electrical signals applied to thecatheter160 are applied to tissue in contact with the conductiveactive tip174 of theneedle170. In one example, thecatheter160 is positioned such that thetip100 is within thetip174 of the needle; one advantage of this positioning is that it provides for temperature-controlled RF lesioning of tissue in contact with theactive tip174 of the needle. In another example, a part of theactive tip100 of theelectrode160 can protrude from the distal end of theneedle170; one advantage of this configuration is that the protruding portion oftip100 and thetip174 form a combined, enlarged active tip.
• In certain embodiments, a monopolar method of electric field therapy includes the steps of (1m) inserting into a living body190 acannula170 that includes a tip bevel configured to prevent damage to acatheter160 passing through thetip bevel opening174, (2m) inserting anelectrode catheter160 through theneedle170, (3m) applying areference electrode184, such as a ground pad or an indifferent electrode, to the livingbody190, and (4m) applying an electric signal between theactive tip100 of theelectrode160 and thereference electrode184. In certain embodiments, the electric signal in the said monopolar method of electric field therapy can include a radiofrequency signal. In certain embodiments, the electric signal in the said monopolar method of electric field therapy can include a nerve stimulation signal. In certain embodiments, the electric signal in the In certain embodiments, the said monopolar method of electric field therapy can include the step of (5m) positioning theactive tip100 of thecatheter160 within theneedle170 such that the electrical signal is applied to the livingbody190 through theactive tip174 of theneedle170. In certain embodiments, the said monopolar method of electric field therapy can include the step of (6m) positioning theactive tip100 of thecatheter160 beyond theneedle170 such that the electrical signal is applied to the livingbody190 through theactive tip100 of theelectrode160. In certain embodiments, the said monopolar method can include the step (6m) of injecting a fluid agent, such as a radiographic contrast agent, an anesthetic fluid, a fluid configured for lysis of epidural adhesion, a neurolytic agent, or an alcohol into the living body via thecatheter160 or theneedle170. In certain embodiments, the said monopolar method includes steps (1m), (2m), (3m), (4m), (5m), and (6m) of the said monopolar method. In certain embodiments, the said monopolar method can include the step of introducing theneedle170 andcatheter160 into the epidural space of the livingbody190. In certain embodiments, step (4m) includes adjustment of the electric signal to control a temperature measured bycatheter160. In certain embodiments, the electric signal in step (4m), such as a nerve stimulation signal, can be used strictly for the purpose of positioningactive tip100 oractive tip174, rather than for a therapeutic purpose per se. One advantage of the said monopolar method of electric field therapy is that electrical field therapy can be applied to nerve adjacent to theactive tip174 of thecannula170 and to a nerve at another location at which theactive tip100 of thecatheter100 can be positioned.
• Referring toFIG. 1C, the catheter system includes asecond needle70 andinjection electrode catheter60. In certain embodiments, theneedle70 can have an embodiment that can be taken by theneedle170. In certain embodiments, thecatheter60 can have an embodiment that can be taken bycatheter160.Catheter system60 includes aconnection40 to thepower supply180, aninjection port50, ahub20, ashaft10 with a distal end and a proximal end, and atip1. Thehub20 can be at the proximal end of thecatheter shaft10. Thetip1 can be at the distal end of theshaft10. Theneedle70 can include ahub71 at its proximal end, ashaft72, electrical insulation73 covering theshaft72, and an electrically-conductivedistal tip74. Thetip1 can include a temperature sensor. The needle can penetrate the livingbody190. Theneedle70 can include ashaft72 that is constructed from a metal tube. The bevel at thedistal end74 of the needle'sshaft72 can be an epidural needle bevel, such as a touhy bevel. Thecatheter tip1 andshaft10 can pass through an inner lumen of theneedle70 into the living body90, such as the human body. Asyringe159 can be attached toport50 and thereby fluid an be injection through thecatheter60 into the living body.Output pole185 can be connected tocatheter connector50 by means of cable83 and cable connector84 and thereby the electrical potential ofjack185 is applied toactive tip1 ofcatheter60. When an electrical output, such a nerve stimulation output or radiofrequency output is applied betweenjacks185 and186, electrical current flows through the living body betweenactive tip100 ofcatheter160 andactive tip1 ofcatheter60; this configuration can be referred to as a “bipolar” configuration. One advantage of a bipolar configuration that includes two catheter electrodes is that electric field therapy can be applied without the use of a reference a ground pad or indifferent electrode. One advantage of the bipolar configuration that includes two catheter electrodes is that the electric field can be focused between theactive tips1 and100 of thecatheter electrodes60 and160. In some configurations, one or both of theelectrodes60 and160 can be positioned within the electrode'srespective needle70 or170, and theactive tip74 or174 can be energized by thegenerator180.
• In certain embodiments, a bipolar method of electric field therapy includes the steps of (1b) inserting into a living body190 afirst cannula170 that includes a tip bevel configured to prevent damage to acatheter160 passing through thetip bevel opening174, (2b) inserting afirst electrode catheter160 through thefirst needle170, (3b) inserting into a living body190 asecond cannula70 that includes a tip bevel configured to prevent damage to acatheter60 passing through thetip bevel opening74, (4b) inserting asecond electrode catheter60 through thefirst needle70, (5b) applying an electric signal between thefirst catheter160 and thesecond catheter60. In certain embodiments, the electric signal in the said bipolar method of electric field therapy can include a radiofrequency signal. In certain embodiments, the electric signal in the said bipolar method of electric field therapy can include a nerve stimulation signal. In certain embodiments, the said bipolar method of electric field therapy can include the step of (6b) positioning theactive tip100 of thecatheter160 within theneedle170 such that the electrical signal is applied to the livingbody190 through theactive tip174 of theneedle170. In certain embodiments, the said bipolar method of electric field therapy can include the step of (7b) positioning theactive tip1 of thecatheter60 within theneedle70 such that the electrical signal is applied to the livingbody190 through theactive tip74 of theneedle70. In certain embodiments, the said bipolar method of electric field therapy can include the step of (8b) positioning theactive tip100 of thecatheter160 beyond theneedle170 such that the electrical signal is applied to the livingbody190 through theactive tip100 of theelectrode160. In certain embodiments, the said bipolar method of electric field therapy can include the step of (9b) positioning theactive tip1 of thecatheter60 beyond theneedle70 such that the electrical signal is applied to the livingbody190 through theactive tip1 of theelectrode60. In certain embodiments, the said bipolar method can include the step (10b) of injecting a fluid agent, such as a radiographic contrast agent, an anesthetic fluid, a fluid configured for lysis of epidural adhesion, a neurolytic agent, or an alcohol via thecatheter160 or theneedle170. In certain embodiments, the said bipolar method can include the step (11b) of injecting a fluid agent, such as a radiographic contrast agent, an anesthetic fluid, a fluid configured for lysis of epidural adhesion, a neurolytic agent, or an alcohol via thecatheter60 or theneedle70. In certain embodiments, the said bipolar method includes steps (1b), (2b), (3b), (4b), (5b), (6b), (7b), (8b), (9b), (10b), and (11b). In certain embodiments, the said bipolar method can include the step of introducing theneedle170 andcatheter160 into the epidural space of the livingbody190. In certain embodiments, the said bipolar method can include the step of introducing theneedle70 andcatheter60 into the epidural space of the livingbody190. In certain embodiments, the said bipolar method can include the step of introducing theneedles70 and170 andcatheters60 and160 into the epidural space of the livingbody190. In certain embodiments, step (5b) includes adjustment of the electric signal to control a temperature measured by eithercatheter160 orcatheter60. In certain embodiments, a method of electric field therapy can include steps from both the said monopolar method of electric field therapy and the said bipolar method of electric field therapy. In certain embodiments, the electric signal in step (5b), such as a nerve stimulation signal, can be used strictly for the purpose of positioningactive tip100,active tip174,active tip1, oractive tip74, rather than for a therapeutic purpose per se.
• Referring toFIG. 1D, the catheter system omits a ground pad and includes aconnection175 between theoutput pole185 of thegenerator180 to thecannula170. In certain embodiments, theconnection175 is an alligator clip attached to an element of theneedle170, such as a uninsulated portion of the shaft outside the livingbody190, that is in electrical communication with theactive tip174 of thecannula170. In certain embodiments, theconnection175 is a cable connected to theconductive shaft172 of theneedle170. In certain embodiments, theconnection175 is included in thehub171 of thecannula170. Theactive tip100 of theelectrode160 is advance beyond the distal end of theneedle170 such that thetip100 is not in direct contact with theneedle170. The electrical insulation onshaft110 of thecatheter160 prevents direct flow of electrical current between theneedle170 and thecatheter160. In this configuration, an electrical signal applied betweenjacks186 and185 generates electrical current between theactive tip100 ofcatheter160 and theactive tip174 ofneedle170. In certain embodiments, theneedle170 can be one of the embodiments presented inFIG. 13 andFIG. 14. One advantage of the system presented inFIG. 1D is that electric field therapy, such as pulsed RF field therapy, can be applied by means of acatheter electrode160 without with use of a ground pad. One advantage of the system presented inFIG. 1D is that electric field therapy, such as pulsed RF field therapy, can be applied to structures adjacent to theactive tip174 of theneedle170 and structures adjacent to theactive tip100 of thecatheter160 at the same time.
• In certain embodiments, an electrode-needle method of electric field therapy includes the steps of (1e) inserting into a living body190 acannula170 that includes a tip bevel configured to prevent damage to acatheter160 passing through thetip bevel opening174, (2e) inserting anelectrode catheter160 through theneedle170 such that theactive tip100 of theelectrode160 is not in contact with theneedle170, and (3e) applying an electric signal between theelectrode160 andneedle170. In certain embodiments of step (3e) electric current flows between theactive tip100 of thecatheter160 and theactive tip174 of theneedle170. In certain embodiments, the electric signal in the said electrode-needle method of electric field therapy can include a radiofrequency signal. In certain embodiments, the electric signal in the said electrode-needled method of electric field therapy can include a nerve stimulation signal. In certain embodiments, the said electrode-needle method of electric field therapy can include the step (4e) of injecting a fluid agent, such as a radiographic contrast agent, an anesthetic fluid, a fluid configured for lysis of epidural adhesion, a neurolytic agent, or an alcohol into the living body via thecatheter160 or theneedle170. In certain embodiments, the said electrode-needle method includes steps (1e), (2e), (3e), and (4e) of the said electrode-needle method. In certain embodiments, the said electrode-needle method can include the step of introducing theneedle170 andcatheter160 into the epidural space of the livingbody190. In certain embodiments, step (3m) includes adjustment of the electric signal to control a temperature measured bycatheter160. In certain embodiments, the electric signal in step (3e), such as a nerve stimulation signal, can be used strictly for the purpose of positioningactive tip100 oractive tip174, rather than for a therapeutic purpose per se. In certain embodiments, embodiments of catheter systems presented inFIG. 1 can be energized in mixed monopolar-bipolar configurations wherein multiple catheters and ground pads are simultaneously energized.
• Referring toFIG. 1 generally, in certain embodiments,catheter160 can have a different construction from that presented inFIG. 1. In certain embodiments,catheter system160 can be a flexible injection electrode. In certain embodiments,catheter system160 can include a catheter that is energized by a physically-separate electrode, for example, by placing the electrode into an inner lumen of the catheter. In certain embodiments,catheter system160 can include acatheter shaft110 that is separable from theinjection hub120. In certain embodiments, thecatheter shaft110 can include a metal coil spring. In certain embodiments, thetip100 can be an uninsulated metallic coil, such as a round-wire spring coil, a flat-wire spring coil, a spiral cut metal tube, a laser-cut metal tube. In certain embodiments, thetip100 can be stainless steel. In certain embodiments, theshaft110 andtip100 can include the same coil. In certain embodiments, the outer surface ofshaft110 can be electrically conductive and in electrically communication with theactive tip100. In certain embodiments,catheter system160 can be one of the embodiments presented inFIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11. In certain embodiments,needle170 can be an epidural needle, for example a needle with a tuohy bevel. In certain embodiments, theneedle170 can be a spinal needle. In certain embodiments,needle170 can be one of the embodiments presented inFIGS. 12, 13, and 14. In certain embodiments, theneedle170 has a removable stylet that is used to make the needle substantially solid during insertion, and removed to allow for passage of fluids and devices into the body through the inner lumen of theneedle170. In certain embodiments,needle170 can omitelectrical insulation173. In certain embodiments,hub120 can be an injection adaptor hub for a catheter. In certain embodiments, thecatheter160 can be a non-electrode catheter.
• In certain embodiments, the systems and methods presented inFIG. 1 can provide for stimulation-guided epidural anesthesia and temperature-monitored radiofrequency treatment, including pulsed radiofrequency treatment, of nerves. In certain embodiments, the systems and methods presented inFIG. 1 can provide for the application of high frequency electric fields to nerve by means of placing an electrode via the epidural space. In certain embodiments, the systems and methods presented inFIG. 1 can provide for the application of high-frequency electric fields to nerve by means of placing an electrode within the neural foramina. In certain embodiments, the systems and methods presented inFIG. 1 can provide for cost-effective manufacturing of a catheter electrode configured for placement in the epidural space. In certain embodiments, the systems and methods presented inFIG. 1 can provide for cost-effective manufacturing of a temperature-monitoring catheter electrode configured for placement in the epidural space. In certain embodiments, the systems and methods presented inFIG. 1 can provide for the construction of a catheter electrode capable of delivery of nerve stimulation signals, delivery of radiofrequency signals, and fluid injection for medical procedures, such as pain management. In certain embodiments of the system and methods presented inFIG. 1, the nerve stimulation signals produced bygenerator180 can be used to position theelectrode160 for the purpose of an epidural anesthesia procedure, such as lysis of adhesions, chemical epidural neurolysis, epidural injection of alcohol, and epidural injection of phenol. In certain embodiments of the system and methods presented inFIG. 1, theelectrode160 can provide for the injection of fluids, such as radiocontrast agents, anesthetics, neurolytics agents, alcohol, phenol, saline, hyaluronidase, local anesthetic, corticosteroids, hypertonic saline. In certain embodiments of the system and methods presented inFIG. 1, theelectrode tip100 andshaft110 can be visible in x-ray images, such as fluoroscopy; one advantage of these embodiments is that radiographic imaging can be used to position theelectrode160 in thehuman body190. In certain embodiments, the systems and methods presented inFIG. 1 can be used to relieve pain. In certain embodiments, the systems and methods presented inFIG. 1 can be used to relieve pain by means of applying pulsed RF electric fields to a dorsal root ganglion. In certain embodiments, the systems and methods presented inFIG. 1 can be used to relieve pain by means of applying pulsed RF therapy at a spinal nerve. In certain embodiments, the systems and methods presented inFIG. 1 can be used to relieve pain due to cancer. In certain embodiments, the systems and methods presented inFIG. 1 can be used to relieve pain due to cancer by means of radiofrequency heat lesioning of a dorsal nerve root; one advantage of heat lesioning of a nerve roots is improved control of the neurolytic zone relative to injection of neurolytic fluids, such as alcohol. One advantage of the application of radiofrequency signals, such as pulsed RF, using an epidurally placed electrode is that nerve structures at multiple levels of the spine can be targeted by moving the epidural electrode through the epidural space.
• In certain embodiments,needle170 can introducecatheter160 through the skin of the human body. In certain embodiments,needle170 can introducecatheter160 through a natural opening in the human body, such as the urethra. In certain embodiments,needle170 can introducecatheter160 into a blood vessel of the human body. In certain embodiments,needle170 can introducecatheter160 into the epidural space of the human body. In certain embodiments,needle170 can introducecatheter160 into the subdural spaces of the human body. In certain embodiments, the entirety of theneedle shaft172 can be electrically insulated; one advantage of a fully insulatedcannula170 is that electrical signals cannot be inadvertently applied to the tissue on contact with thecannula170 when the catheter'sactive tip100 is in contact with thecannula170.
• Referring toFIG. 2, meaningFIGS. 2A, 2B, 2C, 2D, and 2E, in accordance with several aspects of the present invention, a unitized injection electrode is presented that comprises anactive tip200, an electricallyinsulated shaft210, ahub220,cables230,electrical signal connector240, andinjection port250. The electrode can be constructed so that itsactive tip200,insulated shaft210,hub220,cables230,signal connector240, andinjection port250 are inseparably connected. The distal end of the electrode is the end of theactive tip200, and the proximal end of the electrode is end of thecables230. Electrode structures that are more distal are closer to thedistal tip205. Electrode structures that are more proximal are closer to thegenerator connector240 and/or to theinjection port250.
• Theactive tip200 is constructed fromcoil201 and closeddistal end205. The closeddistal end205 can be a weld, which can be formed by laser, electrical discharge, or other methods known to one skilled in the art. The closed205 distal end can be formed with conductive glue. The closeddistal end205 can be created using solder. The close distal end can be formed using glue. The closeddistal end205 can be configured to be electrically conductive. The closeddistal end205 can be configured to be electrically connected to thecoil201. Thetip200 can be configured to deliver electrical signals, such as stimulation and RF signals, to tissue, such as nerves. Thetip200 can be configured to allow for the outflow of fluid. Thetip200 can be configured to allow for preferential outflow of fluid from one or more parts of the tip. In the embodiment presented inFIG. 2, thetip200 has aproximal region202 which is closely-coiled wire. Thetip200 has amiddle region203 in which the coils are separated to allow for fluid outflow. For example, theoutflow region203 can have a ratio between wire diameter and inter-wire spacing of 1:1. Thetip200 has adistal region204 which is closely-coiled wire. It is understood one or more of thetip regions202,203, and204 can be omitted in other embodiments of the electrode.
• The closeddistal end205 can have the same outer diameter as the outer diameter of the rest of theactive tip200. The closeddistal end205 can be full radiused. The closeddistal end205 can be hemispherical. The closeddistal end205 can be flat. The closeddistal end205 can have a smaller diameter than the outer diameter of the rest of theactive tip200. The closeddistal end205 can have a larger diameter than the outer diameter of the rest of theactive tip200. In another embodiment of the present invention, thedistal end205 can be open; an advantage of this embodiment is that fluid can exit the electrode from the distal end.
• Theinsulated shaft210 is constructed ofelectrical insulation211 that surrounds thecoil201 within it. Thecoil201 within the shaft can be closely coiled wire like that of theproximal tip region202. In one embodiment, thecoil201 can extend through the entire length of theshaft210. In one embodiment, thecoil201 can extend only part of the length of theinsulated shaft210 and connect to another structure that has different flexibility, such as a tube or a spiral-cut tube. In one embodiment, thecoil201 can extend though theshaft210 and thehub220. In one embodiment, thecoil201 can extend though theshaft210, thehub220, and thecables230.
• Thetip200 andshaft210 can be flexible. Thetip200 andshaft210 can be configured for placement within the epidural space in the human body. Thecoil201 can be a stainless steel spring coil. In one example, thecoil201 can be a spring coil used in the construction of epidural catheters, as is familiar to one skilled in the art of epidural anesthesia. Thecoil201 can be constructed of wound round wire. Thecoil201 can be constructed of wound flat wire. Thecoil201 can be laser-cut tubing. Thecoil201 can be laser-cut stainless-steel hypodermic tubing. Theelectrical insulation211 can be constructed from one or more pieces and/or applications of medical grade plastic tubing, fluoropolymers, fluoroelastomers, silicone, polyester, polyolefin, polyimide, and other materials that are familiar to one skilled in the art of RF electrodes and epidural catheters. Theelectrical insulation211 can be constructed from materials configured to produce shaft stiffness appropriate for epidural placement in the human body. Theelectrical insulation211 can be a single a tube of fluoropolymer material, such as PTFE, FEP, ETFE, PET. Theelectrical insulation211 can be heat shrink tubing that is shrunk over thecoil201. Theelectrical insulation211 can be applied by coating the wire of thecoil201 before that wire is wound into thecoil201. Theelectrical insulation211 can be PTFE heat shrink tubing that is shrunk over thecoil201. Theelectrical insulation211 can be FEP heat shrink tubing that is shrunk over thecoil201. Theelectrical insulation211 can be ETFE heat shrink tubing that is shrunk over thecoil201. Theelectrical insulation211 can be PET heat shrink tubing that is shrunk over thecoil201. Theelectrical insulation211 can consist of two layers of plastic material that surround thespring coil201, as is familiar to one skilled in the art of epidural anesthesia catheters. Theelectrical insulation211 can be produced by applying a layer of a first material to the coil, for example by spraying or painting, and then applying a second material, such as a tube, over the first material. Thecoil201 can be wound wire of 0.004 inch diameter. Thecoil201 can be wound wire of 0.005 inch diameter. Thecoil201 can be wound wire of 0.006 inch diameter. Thecoil201 can be wound wire of 0.007 inch diameter. Thecoil201 can be wound wire of less than 0.004 inch diameter. Thecoil201 can be wound wire of greater than 0.007 inch diameter. The outer diameter of thecoil201 can be in the range 21 gauge to 18 gauge. The outer diameter of thecoil201 can be smaller than 21 gauge. The outer diameter of thecoil201 can be larger than 18 gauge. The outer diameter of thecoil201 can be 20 gauge. The outer diameter of thecoil201 can be 19 gauge. Theelectrical insulation211 can have wall thickness in the range 0.003 inches to 0.008 inches. Theelectrical insulation211 can have wall thickness less than 0.003 inches. Theelectrical insulation211 can have wall thickness greater than 0.008 inches. Theelectrical insulation211 can have wall thickness 0.005 inches. The outflow section of thecoil203 can have spaces between adjacent coil loops that is substantially equal to the thickness of the wire from which the coil is wound. The outflow section of thecoil203 can have spaces between adjacent coil loops that is in the range 0.003 inches to 0.008 inches. The outflow section of thecoil203 can have spaces between adjacent coil loops that is less than 0.003 inches. The outflow section of thecoil203 can have spaces between adjacent coil loops that is greater than 0.008 inches. The outflow section of thecoil203 can have spaces between adjacent coil loops that is 0.005 inches. The outflow section of thecoil203 can have spaces between adjacent coil loops that is 0.006 inches. The length of the outflow section of the coil can be in the range 0.100 to 0.140 inches. The length of the outflow section of the coil can be less than 0.100. The length of the outflow section of the coil can be greater than 0.140 inches. The length of the outflow section of the coil can be 0.120 inches.
• In another embodiment of the electrode, more than one segment of insulation can be applied along the length of the electrode shaft, withbare coil201 between each segment; an advantage of this embodiment is that RF energy can be applied to multiple separated tissue regions without applying RF energy directly to intervening regions. In another embodiment, a segment of insulation can coverclosed end205 and thedistal end204 of thetip200. In another embodiment of the electrode, the insulation can be configured such that at one or more segments of the shaft, there is a gap in the insulation on one side of the shaft that exposes theunderlying coil201, and insulation covers the other opposite side of the coil; an advantage of this embodiment is that RF energy can be applied to tissue in contact with only one side of the electrode.
• Thetip200 can have length between 2 mm and 60 mm. Thetip200 can be longer than 60 mm. The length of theactive tip200 can be 5 mm. The length of theactive tip200 can be 10 mm. The length of theactive tip200 can be 15 mm. The length of theactive tip200 can be 20 mm. The length of theactive tip200 can be 25 mm. The length of theactive tip200 can be 30 mm. Theactive tip200 can have length configured to the application of RF signals to nerves for pain management. Theactive tip200 can have length configured for epidural placement and injection of epidural anesthetics.
• The length of theshaft210 can be between 12 inches and 33 inches. The length of theshaft210 can be configured for epidural anesthesia procedures, as if familiar one skilled in the art. The length of theshaft210 can be longer than 33 inches. The length of theshaft210 can be shorter than 12 inches. The length of theshaft210 can be 16 inches. The length of theshaft210 can be configured to reach the L2 vertebral level percutaneously and epidurally via the sacral hiatus.
• Thehub220 can have a diameter larger than theinsulated shaft210. Thehub220 can be configured to facilitate rotation of theelectrode shaft210 andtip200. Thehub220 can be omitted and thecables230 can connect directly to theshaft210. Thehub220 can have similar outer dimension and aspect as tuohy-borst adaptors that are typically attached to the end of epidural catheters, as is familiar one skilled in the art. Thehub220 can have outer diameter in the range 0.250 inches to 0.500 inches. Thehub220 can have outer diameter less than 0.250 inches. Thehub220 can have outer diameter greater than 0.500 inches.
• Thecable230 can be flexible. Thecable230 can be rigid. Thecable230 can have both rigid and flexible element. Thecable230 can have a hollow inner lumen capable of carrying injected fluids into theelectrode shaft210 andtip200. Thecable230 can contain a tube capable of carrying wires for connection to the jacks on an RF generator. In one embodiment, thecables230 can be construction from flexible tubes, glue, and wires for connection to the generator. In one embodiment, thecables230 can be construction from flexible tubes, glue, a Y-splitter structure, and wires for connection to the generator. In one embodiment, thecable230 can be constructed like the cable of the Cosman CU electrode, sold by Cosman Medical, Inc. In other embodiments, the cable can be constructed using the systems and methods presented in U.S. Pat. No. 7,862,563 by ER Cosman Sr and ER Cosman Jr. In the embodiment shown inFIG. 2, thecable230 has asingle root231 that connects to thehub220, abranch232 that connects to and carries fluid frominjection port250, and abranch233 that connects to and carries wires from theconnector240.
• Theelectrical signal connector240 can be configured to carry signals from an RF generator to theactive tip200 of the electrode, as is familiar to one skilled in the art. In one embodiment, theconnector240 can be configured to connect to a nerve stimulation device Theconnector240 can be configured to carry sensory nerve stimulation signals, motor nerve stimulation signals, thermal RF signals, pulsed RF signals, signals with carrier frequency in the radiofrequency range, signals withcarrier frequency 500 kHz, signals with one component in the radiofrequency range, signals with one component in the range 250-1000 kHz. Theconnector240 can be configured to carry temperature measurement signal(s) from the electrode to an RF generator or another temperature measurement device, as if familiar to one skilled in the art. In the embodiment presented inFIG. 2, thegenerator plug240 comprises twopins242 and243, of which one can both connect to one output pole of an RF generator and to one pole of the RF generator's temperature sensing circuit, and of which the other can connect to the second pole of the RF generator's temperature sensing circuit. For example, pin242 can connect to one lead from a thermocouple or thermistor sensor in theactive tip200 of the electrode, and pin243 can connect to the other lead from the said thermocouple or thermistor sensor in theactive tip200 of the electrode. Theconnector240 can be configured to carry other signals, such as additional temperature measurement signals, as is familiar to one skilled in the art. In one embodiment, theconnector240 can have more than two pins. In one embodiment, theconnector240 can have three pins. In one embodiment, theconnector240 can have at least three pins, of which one carries therapeutic and/or diagnostic signals from a generator to the electrode, and the other two connect to a thermocouple contained in the electrode.
• Theinjection port250 can be configured to carry injected fluids into and through thecables230, thehub220, theshaft210, and out thetip200. Theinjection port250 can be configured to aspirate fluids from theelectrode tip200, for example to confirm proper placement of theelectrode tip200, as is familiar one skilled in the art of epidural anesthesia. The injection port can be a female luer injection port. Theport250 can have a luer lock. Theport250 can have a cap. Thecable232 connecting the luer injection port can have an external clamp to prevent outflow of fluids.
• One advantage of the embodiments of a one-piece electrode catheter presented inFIG. 2 is ease of manufacturing.
• FIG. 2A presents one embodiment of the present invention in which theshaft210 andtip200 are positioned in one example of a flexed position.
• FIG. 2B presents the electrode shown inFIG. 2A, where itsflexible tip200 andflexible shaft210 are in substantially straight position.
• FIG. 2C,FIG. 2D, andFIG. 2E present three embodiments of the internal construction of the electrode fromFIGS. 2A and 2B, shown in cross-sectional views. Referring now toFIG. 2C,FIG. 2D, andFIG. 2E, thecoil201 is shown in a cross-sectional view wherein round-wire winds appear substantially elliptical. In another embodiment ofcoil201, the cross-section of thecoil201 does not appear as an ellipse, for example if flat wire is used to construct thecoil201, the cross section has a substantially rectangular. In one example, thecoil201 is a stainless steel spring coil, which is familiar to one skilled in the art of epidural catheters. The closeddistal end205 of thetip200 is shown in cross-section. Theinsulation211 is shown in a cross-sectional view wherein its tubular structure appears on both sides of thecoil201. In one example, theinsulation211 is a flexible plastic tube, familiar to one skilled in the art of epidural catheters. In one example, theinsulation211 is constructed from a flexible plastic tube within which is another coating, as is familiar to one skilled in the art of epidural catheters. Thehub220 is shown in cross-section wherein its tubular structure appears on both sides of theinsulation211 and thetubing234. In one example, thehub220 is a rigid structure composed of a plastic tube and glue that prevents fluid leakage out from thecoil201,insulation211, andinjection tube234. Theinjection tube234 is shown in a cross-sectional view wherein its tubular structure appears on opposite sides of the central lumen of theinjection branch232 and theroot231 of thecable230. Theinjection tube234 connects theinjection port250 and thehub220. Theinjection tube234 provides a channel through which fluids injected into theinjection port250 can flow into theshaft210, into thetip200, and then out from spaces between the coil loops of thetip200, preferentially through the larger gaps between coil loops in theoutflow section203 of thetip200. Theinjection port250 is shown in a cross-sectional view wherein it appears on opposite sides of the opening at the end of theinjection port branch232 of thecable230. Theport250 can be a female luer connector. Theconnector branch233 of thecable230 is shown in cross-sectional view so that its walls appear on opposite sides of the internal space through whichwires236 and237 travel from thegenerator connector240 into theroot231 of thecable230. Theconnector240 is shown in a cross-sectional view wherein pins242 and243 and mounted within thebody241, which appears in three parts around and between thepins242 and243. It is understood that thewires236 and237 can each be constructed from multiple pieces of wire, rod, tubing, solder joints, crimps, hooks, and other elements familiar to one skilled in the art of medial device manufacturing.
• Thewall235 of theinjection tube234 limits fluid flow into theconnector branch233 of thecable230. It is understood that thiswall portion235 can, in another embodiment, be constructed of a different material from that of thetube234; for example, from a glue plug. Thewires236 and237 travel through thewall235. It is understood that other embodiments of the construction of thecables230 can be used to provide both connection to a generator and a pathway for injection of fluids. For example, the cable constructions presented in U.S. Pat. No. 7,862,563 by ER Cosman Sr and ER Cosman Jr can be used. For example, thecable230 can be constructed like the cable of the Cosman CU electrode, sold by Cosman Medical, Inc.
• Thewire236 can be configured to carry electrical signal output from an RF generator and/or a stimulation waveform generator. Thewire236 can be composed of a conductive material, such as copper. Thewire236 can be coated with an electrical insulator. Thewire236 can be bare. Thewire236 can be configured to connect viapin242 to both the electrical signal output of a generator, such as an RF generator, and to the first terminal of a temperature-monitoring circuit, which can be integrated into the same generator or which can be housed in a separate unit. Thewire237 can be configured to connect viapin243 to the second terminal of the said temperature monitoring circuit. Thewire237 can be an electrically-insulated constantan wire. In another embodiment,pin242 connects to the electrical signal output of a generator,wire236 carries signals from the output of said generator,pin243 has isolated prongs each of which connects to a isolated terminal of a temperature-monitoring circuit, andwire237 is an bifilar thermocouple wire, such as a copper-constantan bifilar.
• Referring now specifically toFIG. 2C, the unitized injection electrode includes acentral wire260 within the inner lumen of thecoil201. Thecentral wire260 can be configured to stiffen theshaft210 and thetip200 of the electrode. Thecentral wire260 can improve torque transmission from the proximal end of theshaft210 to the distal end of theshaft210. Thecentral wire260 can be configured to provide sufficient stiffness for epidural placement of the electrode, and limited stiffness to prevent puncture of sensitive structures around the epidural space, as is familiar to one skilled in the art of epidural catheters. Thecentral wire260 can be a stainless steel rod. Thecentral wire260 can be copper. Thecentral wire260 can be a tapered metal rod. Thecentral wire260 can be a rod with a substantially circular cross section. Thecentral wire260 can be a hollow tube. Thecentral wire260 can be a plastic rod. Thecentral wire260 can be a rod with a substantially rectangular cross section. Thecentral wire260 can be electrically conductive. Thecentral wire260 can be electrically insulative. Therod260 can be a bare metal structure. Therod260 can be covered by an electrically-insulative coating. Thecentral wire260 can have an outer dimension in the range 0.001″ to 0.016″. Thecentral wire260 can have an outer diameter 0.010″. The central wire can have an outer diameter 0.011″. Thecentral wire260 can have an outer diameter 0.012″. The central wire can have an outer diameter 0.013″. Thecentral wire260 can have an outer diameter 0.014″. The central wire can have an outer diameter greater than 0.016″. Thecentral wire260 can have an outer diameter configured to fit within thecoil201 and to allow injected fluid to flow from one end of the coil to the other. Thecentral wire260 can be configured to conduct electrical signals, such as high frequency signals, RF output, and nerve stimulation signals, from a generator to thetip200 of the electrode. Thecentral wire260 can be configured to reduce the impedance of electrical potentials, such as high frequency electrical waveforms, radiofrequency potentials, and nerve stimulation waveforms, between thegenerator connector240 and the uninsulatedmetallic electrode tip200. The dimensions of thecentral wire260 can be configured to provide a flow path of desired area for injected fluids along the electrode shaft.
• Thecentral wire260 can be attached at the distal end of thecoil201 and at the proximal end of thecoil201; one advantage of this embodiment of the invention is that thecentral wire260 prevents extension of thecoil201 if itsdistal end204 or theclosed end205 is caught in some anatomy, such as between two vertebra. Thecentral wire260 can carry electrical signals from the generator to thetip200 of thecoil201; one advantage of this of this embodiment of the invention is that it reduces the electrical impedance between the generator and theactive tip200 of the electrode. Thecentral wire260 can be configured to maintain a bent configuration. Thecentral wire260 can be configured to maintain a bent configuration when bent by the user, such as a physician. An advantage ofcentral wire260 holding a bend is that a bend can be imposed in the electrode shaft. An advantage of a bent electrode shaft is that the bend can maneuvering of the electrode in the human body, such as in the epidural space.
• Thecentral wire260 is connected atjunction263 to both the proximal end of thecoil201 and to thewire236. Thejunction263 can be electrically conductive. Thejunction263 can create an electrically connection between thewire263 and thecoil201. Thejunction263 can create an electrical connection between thewire263 and thecentral rod260. Thejunction263 can be configured to transmit electrical signals from thewire263 to thecoil201, either by direct electrical connection of thewire263 to thecoil201, by electrical connection between thewire263 androd260 and then electrical connection between therod260 and thecoil201 atjunction261, or both. In one example, thejunction263 is a solder joint. In another example, thejunction263 includes both a weld and a solder joint. In another example, thejunction263 includes glue. In another example, thejunction263 includes a mechanical lock. In another example thejunction263 is a weld, such as a laser weld. In one example, thejunction263 is a solder joint that incorporates thecoil201, thewire236, and thecentral wire260. In another example, thejunction263 is a solder joint between thewire236 and thecentral wire260, and thecentral wire260 is configured so that it mechanically locks with thecoil201; for instance, thecentral wire260 can be folded over on itself so that it hooks around the proximal end of thecoil201. In another example, the junction can be a laser weld between thecentral wire260 and thecoil201, and a solder joint between thewire236 and thecoil201. It is understood that thejunction263 can take other forms as is familiar to one skilled in the art of medical device manufacturing. In another embodiment, thecentral wire260 can be anchored to another element of thehub220.
• Thecentral wire260 is connected to the closeddistal end205 of thetip200 atjunction261. Thejunction261 can be electrically conductive. Thejunction261 can be electrically insulative. Thejunction261 can be configured so that therod260 and the closeddistal end205 connected electrically. In one example, thejunction261 is part of the weld that formed the closeddistal end205. It is understood that thejunction263 can take other forms as is familiar to one skilled in the art of medical device manufacturing, including without limitation, gluing, welding, soldering, crimping, hooking, mechanical locking.
• Thewire237 is connected to the closeddistal end205 of thetip200 atjunction262. Thejunction262 can be electrically conductive. Thejunction262 can be electrically insulative. Thejunction262 can be configured so that therod260 and the closeddistal end205 connected electrically. In one example, thejunction262 is part of the weld that formed the closeddistal end205. It is understood that thejunction263 can take other forms as is familiar to one skilled in the art of medical device manufacturing, including without limitation, gluing, welding, soldering, crimping, hooking, mechanical locking. In one embodiment thewire237 is an insulated constantan wire, thecoil201 is stainless steel, and thejunction262 is electrically conductive such that it forms a thermocouple junction. In one embodiment thewire237 is an insulated metal wire, thecoil201 is composed of a dissimilar metal, and thejunction262 is electrically conductive such that it forms a thermocouple junction. In one embodiment, the closeddistal end205 is a weld that incorporates both thewire237 and thecoil201. In one embodiment, the closeddistal end205 is a solder joint that incorporates both thewire237 and thecoil201. In one embodiment, thewire237 is a thermocouple bifilar, such as a copper-constantan bifilar, as is familiar to one skilled in the art of thermocouples, and the junction includes an element that forms the thermocouple junction between the two wires of the bifilar237, for example by means of a weld, and an element that mechanically attaches the distal end of thebifilar wire237 to the closed end of thecoil205.
• It is understood in different embodiments that thewire237 can take any one of a number of paths along theshaft210, for example, entirely within the coil inner lumen, between thecoil201 andinsulation210, or passing into the inner lumen and out into the space between theinsulation211 and thecoil201 by passing between adjacent loops of thecoil201 any number of times.
• In one example, the closed end of the coil is a weld that connects thewire237, therod260, and thecoil201. In one example, the closed end of the coil is a solder joint that connects thewire237, therod260, and thecoil201.
• In one example, thewire236, thecentral wire260 and thecoil201 itself carry electrical output of an electrosurgical generator, such as radiofrequency and/or stimulation waveforms, to thetip200 of the electrode. In one example,wires236 and237 connect to opposite poles of a temperature sensor, such as a thermocouple junction, at thetip200 of the electrode, and conduct signals from said temperature sensor to a temperature monitoring system.
• In another embodiment, thetemperature connection243, thewire237, and thejunction262 can be omitted. In this embodiment, electrical signals are conducted through the electrode without temperature monitoring. An advantage of this embodiment is that it is easier to build. An advantage of this embodiment is that the electrode provides for stimulation-guided placement in the epidural space. An advantage of this embodiment is that it can be used for non-temperature-monitored application of RF therapy, such as thermal RF lesioning and pulsed RF treatment.
• In one embodiment of the present invention, an example of which is shown inFIG. 2C, the unitized electrode is configured for placement in the epidural space, temperature monitoring of the electrode's active tip, and delivery of radiofrequency signals via the electrode's active tip; wherein the electrode consists of a metallic coil with a proximal and distal end, an electrically insulative sheath that covers the proximal length of the coil and leaves the distal end of the coil exposed, a temperature sensor in exposed distal end of the coil, a port that allows for injection of fluids into the inner lumen of the coil, and a connector to an electrosurgical generator. In a more specific embodiment, the unitized electrode includes a central wire that mechanically connects the distal end of the coil to proximal hub structures. In a more specific embodiment, the said spring coil is stainless steel. In a more specific embodiment, a thermocouple junction is formed at the distal tip of the electrode by welding a constantan wire to the coil and to the central metallic wire.
• Referring now toFIG. 2D, the unitized injection electrode includes acentral wire270. In this embodiment,junction273 connects thecentral wire270 and thewire236, andjunction271 connects thecentral wire270 to the closeddistal end205 of theactive tip200.Junction272 is the connection of thewire237 to the closeddistal end205 of theactive tip200. In one embodiment, high frequency electrical signals are carried to theactive tip200 of the electrode viawire236 androd270. In one embodiment, the junction betweenwires237 and270 at the closeddistal end205 form a thermocouple junction. In one embodiment, thewire236 is a bifilar wire that carries signals from a temperature sensor atjunction272. Thejunction273 andwire236 can be configured to anchor therod270 to the generator connector; an advantage of this configuration is that thewire270 prevents thetip200 from separating from the electrode. Thejunction273 can include elements familiar to one skilled in the art of medical device construction, including soldering, welding, crimping, clamping, gluing, hooking, and twisting. In one example, therod270 is cover by electrically insulation along its length, so that signals carried bywire236 are not conveyed to the closeddistal end205 by thecoil201. In another example, therod270 is uninsulated so that electrical signals are carried to theactive tip200 via thecoil201 if the coil touches thecentral wire270. Thecentral wire270 can be a metal rod. Thecentral wire270 can be a flat wire with rectangular cross section. Thecentral wire270 can have outer diameter at a value in the range 0.001 to 0.018 inches. Thecentral wire270 can have outer diameter 0.011 inches. Thecentral wire270 can have a rectangular cross section with cross section substantially similar to 0.003 inches by 0.009 inches. Thecentral wire270 can be dimension and geometry configured to provide desired separation force between thetip200 and thehub220. Thecentral wire270 can be dimension and geometry configured to provide desired separation force between the distal end of thecoil201 and the proximal end of thecoil201. Thecentral wire270 can be configured to produce a desired flexibility for theshaft210 andtip200. Thecentral wire270 can be configured to maintain a bent configuration. Thecentral wire270 can be configured to maintain a bent configuration when bent by the user, such as a physician. An advantage ofcentral wire270 holding a bend is that a bend can be imposed in the electrode shaft. An advantage of a bent electrode shaft is that the bend can maneuvering of the electrode in the human body, such as in the epidural space. Thecentral wire270 can be configured so that the electrode is suitable for placement in the epidural space.
• Referring now toFIG. 2E, the unitized injection electrode includes asafety strap280. Thesafety strap280 is connected to the distal end of thecoil201 atjunction281 and to the proximal end of thecoil201 atjunction283. Thewire236 is connected to thecoil201 atjunction283. Thewire237 is connected to the distal end of thecoil201 atjunction282. Thewire236 and thecoil201 itself can carry RF output and/or stimulation output to theactive tip200 of the electrode from a medical electrosurgical generator to whichconnector240 is attached. In one embodiment, the junction between thespring coil201 and thewire237 at the closeddistal end205 of thecoil201 forms a temperature sensor, such as a thermocouple, and thewires236 and237 carry signals from said temperature sensor to theconnector240. In another embodiment, thewire237 is a bifilar wire, such as a copper-constantan thermocouple wire, andjunction272 is a temperature-sensing junction, such as a thermocouple weld, that is mechanically anchored to thetip200. Thesafety strap280 can be a metal rod. Thesafety strap280 can be a flat wire with rectangular cross section. Thesafety strap280 can have outer diameter at a value in the range 0.001 to 0.018 inches. Thesafety strap280 can have outer diameter 0.010 inches. Thesafety strap280 can have a rectangular cross section with cross section substantially similar to 0.003 inches by 0.009 inches. Thesafety strap280 can be dimension and geometry configured to provide desired separation force between thetip200 and thehub220. Thesafety strap280 can be dimension and geometry configured to provide desired separation force between the distal end of thecoil201 and the proximal end of thecoil201. Thesafety strap280 can be configured to produce a desired flexibility for theshaft210 andtip200. Thesafety strap280 can be configured to maintain a bent configuration. Thesafety strap280 can be configured to maintain a bent configuration when bent by the user, such as a physician. An advantage ofsafety strap280 holding a bend is that a bend can be imposed in the electrode shaft. An advantage of a bent electrode shaft is that the bend can maneuvering of the electrode in the human body, such as in the epidural space. Thesafety strap280 can be configured so that the electrode is suitable for placement in the epidural space.
• FIG. 3 presents a unitized injection electrode for which the closeddistal end305 has a larger outer diameter than the outer diameter of the rest of theactive tip300, in accordance with several aspects of the present invention. In one embodiment, the electrode inFIG. 3 is analogous to the electrode presented inFIG. 2. The electrode comprises a flexibleactive tip300, an electrically-insulatedflexible shaft310, ahub320,cables330,electrical signal connector340, andinjection port350. The electrode can be constructed so that itsactive tip300,insulated shaft310,hub320,cables330,signal connector340, andinjection port350 are inseparably connected. The distal end of the electrode is the end of theactive tip300, and the proximal end of the electrode is end of thecables230. As in the electrode presented inFIG. 2A, in one embodiment, thetip300 andshaft310 include acoil301, andelectrical insulation311 covers the coil in theshaft region310 and is absent in thetip region300, to form the metallicactive tip300 of the electrode. The tip includes anoutflow region303 that can be configured to preferentially emit fluids injected into theport350. Theactive tip300 can be configured to be energized by a generator attached toconnector340. Temperature can be measured at theactive tip300 by a temperature measurement circuit attached to theconnector340. The length of the electrode'sshaft310 can be configured for epidural placement. The length of the electrode's activemetallic tip300 can be in the range 2-30 mm or more, and it can be configured by performing RF and pulsed RF therapy.
• FIGS. 4A and 4B each present a unitized injection electrode withmovable stylet460, in accordance with several aspects of the present invention. The electrode withstylet460 can be configured for placement in the epidural space. Referring to bothFIG. 4A andFIG. 4B, thestylet460 comprises ahub461 andshaft462. The electrode, within which thestylet460 can move, comprises anactive tip400, an electricallyinsulated shaft410, ahub420,cables430,electrical signal connector440, andinjection port450. The electrode can be constructed so that itsactive tip400,insulated shaft410,hub420,cables430,signal connector440, andinjection port450 are inseparably connected. InFIGS. 4A and 4B, thestylet460 is shown positioned within the unitized injection electrode. Thetip400 can be constructed from ametallic coil401, such as stainless steel spring coil, and have regions oftight coiling402 and404, and regions oflooser coiling403 to allow for preferential outflow of fluids injection intoport450, and a closeddistal end405 that is, in one embodiment, blunt and atraumatic. Thecoil401 can extend into theshaft region410, where it is covered byelectrical insulation411. Theactive tip400 can be configured to be energized by a generator attached toconnector440. Temperature can be measured at theactive tip400 by a temperature measurement circuit attached to theconnector440. Thestylet hub461 can be configured to be grasped by human fingers. Thestylet hub461 can be omitted. Theelectrode hub420 can be omitted. The length of the electrode'sshaft410 can be configured for epidural placement. The length of the electrode'sshaft410 can be in the range 12 to 33 inches. The length of the electrode's activemetallic tip400 can be in the range 2-30 mm or more, and it can be configured by performing RF and pulsed RF therapy. The diameter of theelectrode shaft410 andtip400 can be in the range 21 gauge to 18 gauge.Electrode shaft410 andtip400 can be substantially equal to 19 gauge.Electrode shaft410 andtip400 can be substantially equal to 20 gauge.Electrode shaft410 andtip400 can configured for epidural placement.
• The distal end of the electrode is the end of theactive tip400, and the proximal end of the electrode is end of thecables430. Electrode structures that are more distal are closer to thedistal tip405. Electrode structures that are more proximal are closer to thegenerator connector440 and/or to theinjection port450. The distal end of thestylet460 is thedistal tip463. The proximal end of thestylet460 is thehandle461.
• When inserted, thestylet460 can enter theport450, travel throughbranch432 and431 of thecables430, thehub420,shaft410, and all, part, or none of thetip400. In one embodiment, not shown, thecable branches431 and432 can present a straight path through which the stylet moves. In one embodiment, thecable branches431 and432 can be rigid in whole or in part to facilitate movement of thestylet shaft462 within them. In one embodiment thecable branch433 that is associated with thegenerator connector440 is flexible. In another embodiment thecable branch433 that is associated with thegenerator connector440 is rigid.
• Theshaft410 andtip400 can both be flexible when thestylet460 is inserted and when thestylet460 is not inserted. The stylet can be physically separable460 from the electrode. An advantage of the embodiment where thestylet460 can be fully withdrawn and removed from the electrode is that when the stylet is fully removed from the electrode, fluids can be injected intoport450 and delivered to anatomy nearby theelectrode tip400. Thestylet460 can be physically inseparable from the electrode, for example, by providing a mechanical element that prevents removal of the stylet from the electrode. The electrode andstylet460 can be configured to enable the user to move thestylet460 within the inner lumen of the electrode; an advantage of a unitized injection electrode with amoveable stylet460, is that thestylet460 can be moved to adjust the flexibility of theelectrode tip400 andshaft410. The electrode andstylet460 can be configured for placement in the epidural space of the human body. The electrode can be configured to provide for radiofrequency treatment and injection of fluids, such as radiocontrast agents, anesthetics, neurolytics agents, alcohol, phenol, saline, hyaluronidase, local anesthetic, corticosteroids, hypertonic saline. The electrode can be configured to monitor the temperature at thetip400 of the electrode. The electrode andstylet460 can be configured for stimulation-guided epidural anesthesia, such as lysis of adhesions. The electrode can be configured to be radiopaque. Thestylet shaft462 can be configured to be radiopaque. An advantage of the electrode being radiovisible is that x-ray guidance, such a fluoroscopy, can be used to position the electrode in the human body. An advantage of thestylet460 being radiovisible is that x-ray guidance, such a fluoroscopy, can be used to position the electrode in the human body. The construction of thestylet460 can be that of epidural catheters. Thestylet shaft462 can be a stainless steel rode. Thestylet shaft462 can have outer diameter that is a value in the range 0.001 inches to 0.018 inches. Thestylet shaft462 can have outer diameter greater than 0.018 inches. Thestylet shaft462 can have outer diameter that is 0.010 inches. Thestylet shaft462 can be configured to be flexible enough to move through thecables430,shaft410, andtip400. Thestylet shaft462 can be configured to maintain a bent configuration. An advantage of thestylet460 holding a bend is that a bend can be imposed in the electrode shaft when thestylet460 is in place. An advantage of a bent electrode shaft is that the bend can maneuvering of the electrode in the human body, such as in the epidural space.
• Referring now toFIG. 4A, an external view of a unitized injection electrode andstylet460 is shown.
• Referring now toFIG. 4B, a cross-section of the unitized injection electrode is presented and shows one embodiment of its construction. Theshaft462 of thestylet460 is within the inner lumen of thecoil401, which appears as a series of substantially circular elements in the cross-sectional view. The tip of thestylet463 can touch the inner surface of the electrode'sdistal end405 when the stylet is fully inserted. The tip of thestylet463 can be configured so that is cannot touch the inner surface of the electrode'sdistal end405 when the stylet is fully inserted. One advantage of the distal tip of the stylet's463 not being able to touch the inner surface of the electrode's distal end when fully inserted is that it ensures the distal end of thecoil401, for instance theregion404, is less stiff than the rest of thetip400 andshaft410 at all times.
• Pin442 ofconnector440 can be configured to connect to the electrical output of a medical electrical generator, such as an RF generator or a nerve stimulator.Pin442 is connected to wire436.Wire436 is connector to thecoil401 and thesafety strap480 atjunction484.Safety strap480 is connected to thecoil401 at itsdistal end405 atjunction481.Pin442,wire236,coil401,strap480 can be configured to carry electrical signals, such as RF generator output, to theactive tip400 of the electrode from a medical generator connected to pin442. In another example, thesafety strap480 can be electrically insulative. Thewire436 can include a conductive metal, such as copper. Thesafety strap480 can include a conductive metal, such as stainless steel. Thesafety strap480 can be a stainless steel flat wire. The cross-section of the safety strap can be substantially rectangular with dimension substantially similar to 0.005 inches by 0.010 inches. One advantage of thesafety strap480 being a flat wire is that thesafety strap480 has a low profile. One advantage of thesafety strap480 being a flat wire is that thesafety strap480 obstructs less of the fluid flow path within the lumen of thecoil401. One advantage of thesafety strap480 being a flat wire is that a largerdiameter stylet shaft462 can passed into the inner lumen of thecoil401. Thesafety strap480 can be configured to help prevent thecoil401 from changing length and/or uncoiling within the body. In another embodiment, thesafety strap480 can be omitted, in whichcase junction484 is betweenwire436 andcoil401, and thecoil401 itself carries electrical signals to itsactive tip400.
• In oneembodiment pin443 connects to one pole of temperature-monitoring circuit and pin442 connects to the other pole of said temperature-monitoring circuit. In this embodiment,wire437 connects to pin443 and is electrically-insulated constantan wire, and thesafety strap480 andcoil401 can both be stainless steel. The distal end of thecoil405 can be a weld that connects thecoil401, thestrap480, and theconstantan wire237 to form a thermocouple junction from which the said temperature-monitoring circuit measures temperatures. In another embodiment,pin443 has two electrically-isolated prongs that connect to both poles of a temperature-monitoring circuit, thewire437 is a bifilar of dissimilar metals, such as copper-constantan thermocouple wire, thejunction482 is the thermocouple formed by connection of the two wires of the bifilar437 to form a thermocouple, and the temperature-monitoring circuit measures temperature from thethermocouple482; thethermocouple482 can be connected to thecoil401 within the length of the tip or to its closeddistal end405.
• It is understood, that thewire437 can be positioned outside the coil for all or part of the length of thehub420 andshaft411. It is understood, that thewire437 can pass into and out of thecoil401 along its length by passing between adjacent loops of thecoil401. One advantage of thewire437 being outside the inner lumen of thecoil401 is that it is like likely to be damaged by themovable stylet shaft462.
• FIG. 5 presents a unitized injection electrode with moveable stylet in accordance several aspects with the present invention.FIG. 5A shows an external view of the unitized injection electrode.FIG. 5B shows one embodiment of the internal construction of the unitized injection electrode in a cross-section view. In one embodiment, the embodiments presented inFIG. 5A andFIG. 5B are analogous to the embodiments presented inFIG. 4A andFIG. 4B, with the difference that inFIG. 5, the injection cable branch, labeled532 inFIG. 5 and labeled432 inFIG. 4, and the generator cable branch, labeled533 inFIG. 5 and labeled433 inFIG. 4, are connected directly to the hub, labeled520 inFIG. 5 labeled420 inFIG. 4, whereas inFIG. 4 the injection cable branch and generator cable branch connect to aroot cable branch431 that connects to thehub420. In one embodiment, the injection electrode with moveable stylet is configured for RF therapy. In one embodiment, the injection electrode with moveable stylet is configured to be placed in the epidural space. In one embodiment, the injection electrode withmoveable stylet560 is configured for injection of fluid through thetip500. In one embodiment, thestylet560 can be removed from the electrode to allow for delivery of fluids from thetip500 by means of injection intoport550. In one example, theelectrode shaft510 andtip500 are flexible. In one embodiment, the injection electrode is configured to measure the temperature of tissue in contact with theactive tip500 of the electrode. In one embodiment, the injection electrode is configured to effect temperature-controlled radiofrequency treatment, including pulsed radiofrequency therapy, of nerves by means of placement of the electrode in the epidural space of a human patient in order to manage said patient's pain. In one embodiment, the unitized injection electrode with moveable stylet is configured to apply radiofrequency electric fields, including pulsed radiofrequency electric fields, to spinal nerves, spinal nerve roots, dorsal spinal nerve roots, and/or dorsal root ganglia, by placement of the electrode in the epidural space and/or the spinal foramina.
• The distal end of the electrode is the end of theactive tip500, and the proximal end of the electrode is end of the cables530. Electrode structures that are more distal are closer to thedistal tip505. Electrode structures that are more proximal are closer to thegenerator connector540 and/or to theinjection port550. The distal end of thestylet560 is thedistal tip563. The proximal end of thestylet560 is thehandle561.
• The unitized injection electrode hastip500 comprising ametallic coil501 withdistal end505,shaft510 comprisingelectrical insulation511 covering themetallic coil501,hub520,generator cable533,connector540 comprisingbody541 and pins542 and543,injection cable532,injection port550, andmovable stylet560 comprisinghub561 andshaft562. In one embodiment,elements500,510,520,533,540,532, and550 are inseparably connected. In oneembodiment injection tube532 is straight. In oneembodiment injection tube532 is curved. In oneembodiment injection tube532 is flexible. In oneembodiment injection tube532 is rigid. In oneembodiment generator cable533 is flexible. In oneembodiment generator cable533 is rigid. In one embodiment, thestylet shaft562 is a metal rod. In one embodiment, thestylet shaft562 is a stainless steel rod. In one embodiment, thestylet shaft562 is a nitinol rod. One advantage of amoveable stylet560 is that the flexibility of theelectrode shaft510 andtip500 can be adjusted by movement of thestylet560.
• In another embodiment, theinjection tubing532 can be omitted and theinjection port550 directly connected to thehub520. In another embodiment, thegenerator cable533 can be omitted and theconnector540 directly connected to thehub520. In another embodiment, thehub520 can be omitted, and theinjection cable532 and thegenerator cable533 directly connected to theelectrode shaft510. In another embodiment, thehub520 can be omitted, theinjection tube532 omitted, theinjection port550 directly connected to theelectrode shaft510, and thegenerator cable533 directly connected to theelectrode shaft510. In another embodiment, thehub520 can be omitted, theelectrode cable532 omitted, theinjection tube532 directly connected to theelectrode shaft510, and thegenerator connector540 directly connected to theelectrode shaft510. In another embodiment, thehub520 can be omitted, theelectrode cable532 omitted, theinjection tube532 omitted, theinjection port550 directly connected to theelectrode shaft510, and thegenerator connector540 directly connected to theelectrode shaft510. In another embodiment, theinjection tube532 and theinjection port550 can be omitted, thestylet560 can be inserted directly into the inner lumen of thecoil501, and a separate injection port, such as a tuohy-borst adaptor, can be connected to the shaft when thestylet560 is withdrawn from electrode to provide for injection of fluid through the electrode into tissue in which the electrode tip is placed.
• Referring now toFIG. 5A specifically, an external view of the electrode is shown with thestylet560 in place within the electrode.
• Referring now toFIG. 5B specifically, a cross-sectional view of one embodiment of the internal construction of the electrode is shown with thestylet560 in place within the inner lumen of the electrode. In one embodiment, thestylet shaft562 is configured so that when it fully inserted into the electrode, thedistal tip563 of thestylet shaft562 contacts the inner surface of thedistal tip505 of the electrode. In another embodiment, thestylet shaft562 is configured so that when it fully inserted into the electrode, thedistal tip563 of thestylet shaft562 is does not contact the inner surface of thedistal tip505 of the electrode.Element535 is configured to limit or prevent the flow of fluid into thegenerator cable533.Wire536 and537 pass throughelement535. In one embodiment,element535 includes the wall of theinjection tube532. In one embodiment,element535 includes glue, such as a glue plug. In one embodiment,element535 includes the wall of theshaft insulation511. In one embodiment,wire537 can passes into the inner lumen of thecoil501 via its proximal end, as illustrated inFIG. 5B. In another embodiment,wire537 can enter the inner lumen ofcoil501 by passing between links of thecoil501.Pin542 is electrically connected to wire536, which is electrically connected tocoil501 atjunction583, which can be, for example, a weld or solder joint. In one embodiment, electrical output from a generator connected to pin542 is conducted to theactive tip500 of the electrode viawire536,junction583, andcoil501.Pin543 is electrically connected to wire537, which is connected to thedistal end505 of the electrode atjunction582. In one embodiment,distal end505 is a weld that incorporates thewire537. In one embodiment,distal end505 is a solder joint that incorporates thewire537. In one embodiment,distal end505 is a glue joint that connects to thewire537. In one embodiment,wire537 is a constantan wire, thecoil501 is stainless steel, the connection between thecoil501 and thewire537 is a thermocouple junction,pin542 is configured to be attached to a temperature-measurement circuit,pin542 is configured to be attached to the same temperature-measurement circuit, and thereby the temperature of tissue in contact with thedistal tip505 of the electrode. In another embodiment,wire537 comprises insulated constantan and copper wires whosejunction582 is a thermocouple junction,pin543 comprises two electrically-isolated pins of which each is connected tone of the twowires comprising wire537, said two electrically-isolated pins are configured to be connected to a temperature-measurement system, and thereby the temperature of tissue in contact with theelectrode tip500 can be measured. Thesafety strap580 can connect to the distal and proximal end of thecoil501 atjunctions581 and584, respectively. One advantage of thesafety strap580 is that it makes theshaft510 and tip500 more robust. In one embodiment, thesafety strap580 can be metallic, such as a stainless steel flat wire. One advantage of ametallic safety strap580 is that it reduces the electrical impedance between the proximal and distal ends of thecoil501. One advantage of ametallic safety strap580 is that electrical signals are conducted with less distortion fromwire536 to theactive tip500 of the electrode. In another embodiment, thesafety strap580 can be omitted. In another embodiment, thewire537 can include elements, such as a wire, that is configured to serve as a safety strap.
• FIG. 6 presents a unitized injection electrode with moveable stylet, in accordance with several aspects of the present invention.FIG. 6A shows an external view of the unitized injection electrode.FIG. 6B shows one embodiment of the internal construction of the unitized injection electrode in a cross-section view, with the exterior of thestylet660 shown. In one embodiment, the embodiments presented inFIG. 6A andFIG. 6B are equivalent to the embodiments presented inFIG. 5A andFIG. 5B, with the difference that the injection cable branch labeled532 inFIG. 5 is omitted inFIG. 6, and the injection port, labeled550 inFIG. 5 and labeled650 inFIG. 6, is directly connected to thehub620 inFIG. 6. One advantage of the direct connection of theinjection port650 to thehub620 the pathway for fluid injection can be reduced.
• The unitized injection electrode hastip600 comprising ametallic coil601 withdistal end605,shaft610 comprisingelectrical insulation611 covering themetallic coil601,hub620,generator cable633,connector640 comprisingbody641 and pins642 and643,injection port650, andmovable stylet660 comprisinghub661 andshaft662. In one embodiment,elements600,610,620,633,640, and650 are inseparably connected. Thetip600 can have aregion603 for which the coil loops are more loosely spaced than in other regions, such asregion601 and602. The distal end of the electrode is the end of theactive tip600, and the proximal end of the electrode is end of the cables630. Electrode structures that are more distal are closer to thedistal tip605. Electrode structures that are more proximal are closer to thegenerator connector640 and/or to theinjection port650. The distal end of thestylet660 is thedistal tip663. The proximal end of thestylet660 is thehandle661.
• Referring now toFIG. 6B specifically, the electrode haswire636,wire637, andsafety strap680.Wire637 can be a constantan wire that connects to pin643, and that connects to thedistal end605 of thecoil601 at junction682 to form a thermocouple junction.Wire637 can be a thermocoupe bifilar terminated by a thermocouple junction682 that connects to twopins composing pin643.Pin643 is configured to provide for monitoring of the tip temperature by connection to a temperature-measurement device.Wire637 connects to pin642 and tocoil601 to provide for conduction of electrical signals from a electrosurgical generator attached to pin642 to theactive tip600 of the electrode. In embodiments where a thermocouple junction is formed between aconstantan wire637 and thedistal end605 or thecoil601, thepin642 can connect to a temperature-measuring device to provide for monitoring of the temperature of tissue in contact with theactive tip600.
• Wire637 can enter thelumen coil601 by passing between two loops ofcoil601. In another embodiment, thewire637 can enter the lumen of thecoil601 be passing into the proximal end of thecoil601. In another embodiment, thewire637 can enter the inner lumen of thecoil601 at a more distal point along the shaft than pictured inFIG. 6B; an advantage of this embodiment is that thestylet shaft662 and thewire637 can touch each other over a shorter length. It is understood that a structure can be added to the end of thegenerator cable633 where it connects to thehub620 that is configured to limit flow of fluids into thegenerator cable633, such as a glue plug.
• FIG. 7 presents a unitized injection electrode with moveable stylet in an external view, in accordance with several aspects of the present invention. In one embodiment, the embodiments presented inFIG. 7 are equivalent to the embodiments presented inFIG. 6A andFIG. 6B, with the difference that the generator cable branch labeled633 inFIG. 6 is omitted inFIG. 7, and the injection port, labeled650 inFIG. 6 and labeled750 inFIG. 7, is directly connected to thehub720 inFIG. 7. The unitized injection electrode hastip700 comprising ametallic coil701 with distal end705,shaft710 comprisingelectrical insulation711 covering themetallic coil701,hub720,connector740 comprisingbody741 and pins742 and743,injection port750, andmovable stylet760 comprisinghub761 andshaft762. In one embodiment,elements700,710,720,740, and750 are inseparably connected. Thetip700 can have aregion703 for which the coil loops are more loosely spaced than in other regions, such asregion701 and702.
• FIG. 8 present an injection electrode system comprising acatheter890 and separate,movable stylet electrode860, in accordance with several aspects of the present invention.FIG. 8A presents one embodiment of the injection electrode system in an external view.FIG. 8B presents one embodiment of the internal construction of the injection electrode system, wherein thecatheter890 is shown in a cross-sectional view and theelectrode860 is shown from its exterior, positioned within thecatheter890. Referring to bothFIG. 8A andFIG. 8B, thecatheter890 comprises atip comprising coil801 anddistal end805,shaft810 comprisinginsulation811 outside thecoil801,hub820, andinjection port850. Theelectrode860 comprisesshaft862,hub860,cable830,generator connector840 comprisingbody841 and pins842 and843. The distal end of the catheter is the end of thedistal point805, and the proximal end of the electrode is end of thehub820. Catheter structures that are more distal are closer to thedistal tip805. Catheter structures that are more proximal are closer to theport850. The distal end of thestylet electrode860 is thedistal tip863. The proximal end of thestylet electrode860 is thehandle861. In certain embodiments, thedistal end805 can be open; one advantage of an opendistal end805 is that injected fluid can exit the distal end of thecatheter890. In certain embodiments, thedistal end805 can be closed; one advantage of a closed end is that tissue cannot enter the distal end of thecatheter890.
• In one embodiment, when theelectrode860 is positions within the inner lumen of thecatheter890 and electrical signals are delivered to theelectrode shaft862 by connecting the electrode to an electrical signal generator viaconnector840, contact between theelectrode shaft862 and the inner surfaces of themetallic coil801, said electrical signals are conducted to theactive tip800 of thecatheter890 and thereby delivered to tissue in contact with theactive tip800. In one embodiment, the injection electrode system inFIG. 8 can be used in the embodiments presented inFIG. 1A andFIG. 1B. The injection electrode system can provide for radiofrequency therapy by means ofcatheter890 placement in the spinal canal. The injection electrode system can provide epidural anesthesia. The injection electrode system can provide stimulation-guided RF and pulsed RF treatment of nervous structures, such as the DRG, via placement of thecatheter890 within the spinal canal. The injection electrode system can provide for stimulation-guided epidural anesthesia, such a lysis of adhesions. The injection electrode system can provide for temperature-monitoring of thecatheter tip800 during medical use.
• Theport850 can be integrated inseparably into thehub820. In one embodiment, thehub820 andinjection port850 can be inseparably connected to theshaft810. In another embodiment, aunitized hub820 andinjection port850 can be separable from the shaft; for example. Theunitized hub820 andinjection port850 can take the form of a tuohy-borst adaptor or another common type of injection adaptor that is familiar to one skilled in the art of epidural anesthesia. The electrode can be moveable within the catheter. The electrode can be fully removed from the catheter. The electrode can be fully removed from the catheter to provide access to theinjection port850 for the injection of fluid through the catheter and outflowing from thecatheter tip800, for example, for the purpose of effective epidural anesthesia.
• In certain embodiments, theshaft810 and tip800 of thecatheter890 can have the same construction to the shaft and tip of electrodes presented inFIGS. 2, 3, 4, 5, 6, and 7. In one embodiment, thecoil801 can be a stainless steel spring coil of round wire. In one embodiment, thecoil801 can be a stainless steel spring coil of flat wire. In one embodiment, thecoil801 can be a laser cut stainless steel tube. It is understood that in other embodiments, thecoil801 is not present over the entire length of theshaft810; for example, the proximal end of thecoil801 can be connected to metal tubing, such as stainless steel hypotube, to provide for a stiffer proximal part of the shaft. It is understood that multiple pieces of coil can be connected to form thecoil801. In certain embodiments, the catheter electrode system presented inFIG. 8A andFIG. 8B has the same construction and function as the injection electrode system presented inFIG. 9A andFIG. 9B.
• Theelectrode890 can have constructions that are familiar to one skilled in the art of RF pain management. For example,electrode890 can have a construction similar to that of the Cosman CSK electrode. For example,electrode890 can have a construction similar to that of the Cosman TCD electrode. For example,electrode890 can have a construction similar to that of the Cosman TCN electrode, whose shaft includes nitinol. Theelectrode890 can be a temperature-sensing electrode. Theelectrode890 can have a thermocouple temperature sensor at its distal863. Theelectrode860 can be configured to provide for the delivery of radiofrequency current to thecatheter890. Theconnector840 can be configured to connect to a radiofrequency generator.
• Referring toFIG. 8A andFIG. 8B, thecatheter890 can be an epidural catheter. Thecatheter890 can be an intravascular catheter. Thecatheter890 can be configured for epidural anesthesia. Thestylet electrode860 can be configured act as a stylet for thecatheter890. Thestylet electrode860 can be configured to deliver electrical signals to theactive tip800 of thecatheter890. Thestylet electrode860 can be configured to deliver RF signals to theactive tip800 of thecatheter890. Thestylet electrode860 can be configured to deliver nerve stimulation signals to theactive tip800 of thecatheter890. The injection electrode system presented inFIG. 8 can be configured to effect radiofrequency treatment, such as pulsed radiofrequency treatment, on nerve structures by means of placement of the electrode system in the epidural space of a human body. One advantage of the injection electrode system presented inFIG. 8 is that manufacture of theelectrode860 and thecatheter890 can proceed in parallel. Another advantage of the injection electrode system presented inFIG. 8 is that standard epidural methods can be used in addition to RF methods in the same medical procedure. Another advantage of the injection electrode system presented inFIG. 8 wherein the unitizedhub820 andinjection port850 is separable fromshaft810 of thecatheter890, is that the needle used to introduce thecatheter890 can be removed from the patient while thecatheter890 is in place within the patient, by sliding said needle over the distal end of theshaft810, as is familiar one skilled in the art of epidural anesthesia.
• Referring now specifically toFIG. 8B, in one embodiment of the injection electrode system, thecatheter890 has asafety strap880 connected to the proximal end of thecoil801 atjunction884 and to the distal end of thecoil801 atjunction881. Thejunction884 can be a weld, such as a laser weld. Thejunction881 can be part of the weld, such as a laser weld or an electrical discharge weld, that forms theclosed end805 of thecatheter890. Thesafety strap880 can be configured to prevent thecoil801 from uncoiling during use. The safety strap can be a metal wire. The safety strap can be a flat wire. The safety strap can be configured to have a low profile to allow entry of the stylet electrode'sshaft862 into the inner lumen of thecoil801. The safety strap can be configured to have a low profile to maintain an open cross-sectional area within the inner lumen of the coil for the flow of injected and aspirated fluid. In embodiments where thesafety strap880 is a metal wire, the safety strap can improve faithful conduction of electrical signals delivered by theelectrode860 to theactive tip800 of thecatheter890. In some embodiments, theelectrode shaft862 contacts thestrap880 and thereby conducts electrical signals to thetip800.
• Referring toFIG. 8A andFIG. 8B, the length of thecatheter890 can be in the range 12-33 inches. The length of thecatheter890 can be less than 12 inches. The length of thecatheter890 can be greater than 33 inches. The length of thecatheter890 can be 12 inches. The length of thecatheter890 can 33 inches. The length of thecatheter890 can be 16 inches. The length of thecatheter890 can be 24 inches. The outer diameter of thecatheter890 can in the range 18 to 21 gauge. The outer diameter of thecatheter890 can be greater than 18 gauge. The outer diameter of thecatheter890 can be less than 21 gauge. The outer diameter of thecatheter890 can be 20 gauge. The outer diameter of thecatheter890 can be 19 gauge. The diameter of theelectrode860 can be configured to produce a desired stiffness of the assembledcatheter shaft810. Thestiffness catheter shaft810 andtip800 can be configured to facilitate safe placement of thecatheter890 in the spinal canal. The introducer needle for the catheter can be 15 gauge. The introducer needle for the catheter can be 16 gauge. The introducer needle for the catheter can be 17 gauge. The introducer needle for the catheter can be 18 gauge. The introducer needle can be an epidural needle, such as a tuohy needle.
• For embodiments where thehub820 andinjection port850 are attached to the catheter shaft810 (either separably as in the case wherehub820 andport850 are an injection adaptor port, or inseparably as in the case where thehub820 andport850 are inseparable attached to the catheter shaft810), the length of theelectrode860 can be configured so that when theelectrode860 is fully inserted into thecatheter890, the electrode'sdistal end863 contacts the inner surface of thedistal end805 of thecoil801. One advantage of this configuration is that it provides tactile physical feedback the user that theelectrode860 is fully inserted in thecatheter890. For embodiments where thehub820 andinjection port850 are attached to the catheter shaft810 (either separably as in the case wherehub820 andport850 are an injection adaptor port, or inseparably as in the case where thehub820 andport850 are inseparable attached to the catheter shaft810), the length of theelectrode860 can be configured so that when theelectrode860 is fully inserted into thecatheter890, the electrode'sdistal end863 cannot contact the inner surface of thedistal end805 of thecoil801. For example, as shown inFIG. 8B, thehub861 of theelectrode860 can abut a surface of theport850 to prevent further advancement of theelectrode shaft862 to thecatheter shaft810. One advantage of this configuration is that it ensures the distal end of thecatheter890 remains floppy irrespective of the position of theelectrode860 in thecatheter890. For embodiments where thehub820 andinjection port850 are not attached to thecatheter shaft810 and theelectrode860 is inserted directly in the proximal end of thecatheter shaft810, the length of theelectrode860 can be configured so that when theelectrode860 is fully inserted into thecatheter890, the electrode'sdistal end863 contacts the inner surface of thedistal end805 of thecoil801. One advantage of this configuration is that it provides tactile physical feedback the user that theelectrode860 is fully inserted in thecatheter890. For embodiments where thehub820 andinjection port850 are not attached to thecatheter shaft810 and theelectrode860 is inserted directly in the proximal end of thecatheter shaft810, the length of theelectrode860 can be configured so that when theelectrode860 is fully inserted into thecatheter890, the electrode'sdistal end863 cannot contact the inner surface of thedistal end805 of thecoil801. One advantage of this configuration is that it ensures the distal end of thecatheter890 remains floppy irrespective of the position of theelectrode860 in thecatheter890.
• FIG. 9 presents a catheter electrode system comprising acatheter990 and separate,movable stylet electrode960, in accordance with several aspects of the present invention. Thestylet electrode960 is inserted into an opening at theproximal end912 of thecatheter990.FIG. 9A presents one embodiment of the injection electrode system in an external view.FIG. 9B presents one embodiment of the internal construction of the injection electrode system, wherein thecatheter990 is shown in a cross-sectional view and theelectrode960 is shown from its exterior, positioned within thecatheter990. Referring to bothFIG. 9A andFIG. 9B, thecatheter990 comprises atip comprising coil901 anddistal end905, aproximal end912, and ashaft910 comprisinginsulation911 outside thecoil901. Theelectrode960 comprisesshaft962,hub960,cable930,generator connector940 comprisingbody941 and pins942 and943. In certain embodiments, theelectrode960 can be fully withdrawn from thecatheter990. The distal end of thecatheter990 is the end of thedistal point905, and the proximal end of thecatheter990 is end into which theelectrode960 can be inserted. Catheter structures that are more distal are closer to thedistal tip905. Catheter structures that are more proximal are closer to the end into which theelectrode960 can be inserted. The distal end of thestylet electrode960 is thedistal tip963. The proximal end of thestylet electrode960 is thehandle961. In certain embodiments, thedistal end905 can be open; one advantage of an opendistal end905 is that injected fluid can exit the distal end of thecatheter990. In certain embodiments, thedistal end905 can be closed; one advantage of a closed end is that tissue cannot end the distal end of thecatheter990.
• In one embodiment, thedistal tip963 of the stylet is enlarged to reduce the likelihood that thestylet960 will exit the inner lumen of thecoil901 by passing between adjacent loops of thecoil901, such as the spaces of theopen coil section903, for example when thestylet960 is moved and the catheter'stip900 is in a bent conformation. In one embodiment, the enlargeddistal stylet tip963 is substantially spherical. In another embodiment, the enlargeddistal stylet tip963 has other shapes matched to the physical characteristics of the coil and physician needs. It is understood that an enlarged distal stylet tip can be used for other embodiments that include a moveable stylet, including these presented inFIGS. 4, 5, 6, 7, 8, 10, and 11.
• In one embodiment, the system presented inFIG. 9 contains more than onestylet960. In one more specific embodiment, one stylet is an electrode and another stylet is a conventional catheter stylet consisting of a rod and a handle. In another more specific embodiment, the said more than one stylet have distinguishing physical characteristics, including without limitation differing lengths, differing stiffnesses, and differing shapes. In certain embodiments, thecatheter990 is configured such that two stylets can be placed in its inner lumen at the same time. In certain embodiments, thecatheter990 is configured such that a straight stylet and a curved stylet can be inserted into thecatheter990 at the same time; one advantage of these embodiments is that the tip of thecatheter990 can be steered by moving the two stylets relative to thecatheter990 and to each other.
• In certain embodiments, the catheter electrode system presented inFIG. 9A andFIG. 9B has the same construction and function as the injection electrode system presented inFIG. 8A andFIG. 8B. In certain embodiments, the construction and function of the system presented inFIG. 9 is the same as that presented inFIG. 8 with the difference that thehub820 andport850 are not explicitly shown inFIG. 9. It is understood that in certain embodiments, an injection adaptor, for instance a tuohy-borst adaptor or removable injection hub, such as820 and850, can be attached to theproximal end912 of thecatheter990 to provide for injection of fluids. In one embodiment, thecatheter990 is an epidural catheter, familiar to one skilled in the art of epidural anesthesia. In one embodiment, thecatheter990 is an epidural catheter constructed using a metal coil. In one embodiment, theelectrode960 is a radiofrequency electrode configured to move through the inner lumen of thecatheter990. In one embodiment, theelectrode960 is configured to deliver electrical signals, such as radiofrequency, pulsed radiofrequency, and stimulation signals, to theactive tip900 of the catheter. In one embodiment, electrical signals delivered to theelectrode960 by connection of itsgenerator connector940 to an electrical generator, are in turn conducted to theactive tip900 ofcatheter990 by contact between theelectrode shaft962 with the inner surface of thecoil901.
• Referring now specifically toFIG. 9B, in one embodiment of the injection electrode system, thecatheter990 has asafety strap980 connected to the proximal end of thecoil901 atjunction984 and to the distal end of thecoil901 at junction981. Thejunction984 can be a weld, such as a laser weld. The junction981 can be part of the weld, such as a laser weld or an electrical discharge weld, that forms theclosed end905 of thecatheter990. Thesafety strap980 can be configured to prevent thecoil901 from uncoiling during use. The safety strap can be a metal wire. The safety strap can be a flat wire. The safety strap can be configured to have a low profile to allow entry of the stylet electrode'sshaft962 into the inner lumen of thecoil901. The safety strap can be configured to have a low profile to maintain an open cross-sectional area within the inner lumen of the coil for the flow of injected and aspirated fluid. In embodiments where thesafety strap980 is a metal wire, the safety strap can improve faithful conduction of electrical signals delivered by theelectrode960 to theactive tip900 of thecatheter990. In some embodiments, theelectrode shaft962 contact thestrap980 and thereby electrical signals are conducted to thetip900; one advantage of the safety strap is that the distal end of theelectrode963 does not need to touch thecatheter tip905 in order that electrical signals are conducted to thetip900. In one embodiment, theelectrode960 can be long enough that itsdistal end963 contacts the innerdistal surface905 of thecatheter990 when it is fully inserted into thecatheter990. In one embodiment, theelectrode960 is configured such that itsdistal end963 does not contact the inner surface of thedistal end905 of thecatheter990, when theelectrode960 is fully inserted into thecatheter990. For example, as shown inFIG. 9B, thehub961 of theelectrode960 can be constructed to abut the proximal end of thecatheter890 and thereby prevent thedistal end963 of theelectrode shaft962 from contacting the distal end of the inner lumen of thecoil901.
• Referring now toFIGS. 10A, 10B, 10C, 10D, and 10E,FIG. 10 presents certain embodiments of a system that includes acatheter1015, aninjection adaptor1020, astylet1080, and anelectrode1060, in accordance with several aspects of the present invention. Thecatheter1015 includesproximal end1012,shaft1010,plastic sheath1011,tip1001,spring coil1001,proximal aspect1002 of thetip1000,middle aspect1003 of thetip1000,distal aspect1004 of thetip1000, anddistal end1005. Theinjection adaptor1020 includesproximal port1032, aproximal clamp1031, amiddle body1043, aninjection port1042, adistal clamp1041,distal body1051, anddistal port1052. Thestylet1080 includesproximal handle1081,shaft1082, anddistal tip1083. Theelectrode1060 includesproximal hub1061,shaft1062,distal tip1063,cable1064, andgenerator connector1065. Thegenerator connector1065 includesbody1066,output connection1067, andtemperature connection1068.
• In certain embodiments, thecatheter1015 is an epidural catheter. In certain embodiments, thecatheter1015 is an intravascular catheter. In certain embodiments, thecatheter1015 is an intraurethral catheter. In certain embodiments, theplastic sheath1011 is electrical insulation. In certain embodiments, the spring coil is a stainless steel spring coil. In certain embodiments, thedistal end1005 is a closed end. In certain embodiments, thedistal end1005 includes an opening. Thecatheter tip1000 can include openings, for example on the middle aspect of thetip1003, configured for outflow of fluid from the inner lumen of thecatheter1015. In certain embodiments, thecatheter1015 can have a maximum external diameter of 0.042 inches. In certain embodiments, thetip1000 of thecatheter1015 has a maximum diameter of 0.034 inches. In certain embodiments, thetip1000 of thecatheter1015 has a length in the range 0-20 mm. In certain embodiments, thecatheter1015 is one of the embodiments ofcatheter890. In certain embodiments, thecatheter1015 is one of the embodiments of the catheter embodiments described in relation toFIG. 8. In certain embodiments, thecatheter1015 is one of the embodiments ofcatheter990. In certain embodiments, thecatheter1015 is one of the embodiments of the catheter embodiments described in relation toFIG. 9.
• In certain embodiments,port1042 can accept a syringe. In certain embodiments, theinjection port1042 can include a luer port.Injection port1042 can include a luer lock.Injection port1042 can be a male luer.Injection port1042 can include a flexible tube and a luer port.Port1032 can be a luer port. In certain embodiments, theinjection adaptor1020 can have dimensions similar to a tuohy-borst adaptor for guidewires. In certain embodiments, theclamp1031 is a tuohy-borst adaptor. In certain embodiments, theclamp1031 includes a tube and block, wherein the block includes a slot with narrowing cross section that is configured to close down the tube when the block is relative to the tube. In certain embodiments, theclamp1031 can provide for the repeated attachment and separation of theadaptor1020 and theelectrode1060. In certain embodiments, theclamp1031 can provide for the repeated attachment and separation of theadaptor1020 and thestylet1080. In certain embodiments, theclamp1041 is a tuohy-borst adaptor. In certain embodiments, theclamp1041 includes a tube and block, wherein the block includes a slot with narrowing cross section that is configured to close down the tube when the block is relative to the tube. In certain embodiments, theclamp1041 can provide for the repeated attachment and separation of theadaptor1020 and thecatheter1015.
• In certain embodiments, theelectrode1060 includes a temperature sensor, for example in itsdistal end1063, andtemperature connection1068 conducts temperature signals from the temperature sensor. In certain embodiments, the electrode does not include a temperature sensor and does not include atemperature connection1068. In certain embodiments, theelectrode1060 is an RF electrode. In certain embodiments, the electrode is a temperature-sensing RF electrode. In certain embodiments, the electrode is an internally-cooled RF electrode. In certain embodiments, theelectrode1060 is a unitized injection electrode. In certain embodiments, theelectrode1060, theelectrode1060 includes an injection port configured such that when fluid is injected into the electrode's injection port, that fluid flows into the catheter's inner lumen. In certain embodiments, theelectrode shaft1062 has an outer diameter 0.014 inches. Theshaft1062 of theelectrode1060 can be composed of a conductive metal, for example, stainless steel or nitinol. Thedistal end1063 of theelectrode1060 can have an outer diameter larger than the outer diameter of theshaft1062; one advantage of an enlargeddistal end1063 is that the electrode is less likely to exit the inner lumen of thecatheter1015 through fluid-outflow holes in thecatheter1015, particularly when the catheter is in a curved configuration within a living body and theelectrode1060 is moved relative to thecatheter1015. In another embodiment, thedistal end1063 of theelectrode1060 can have the same outer diameter as theshaft1062.
• In certain embodiments, thestylet1080 includes a RF generator connection in itshandle1081. In certain embodiments, theelectrode shaft1082 has an outer diameter in the range 0.008 to 0.014 inches. In certain embodiments, theshaft1080 is a metal rod, such as a stainless steel rod or a nitinol rod. Thedistal end1083 of thestylet1080 can have an outer diameter larger than the outer diameter of theshaft1082; one advantage of an enlargeddistal end1083 is that the stylet is less likely to exit the inner lumen of thecatheter1015 through fluid-outflow holes in thecatheter1015, particularly when the catheter is in a curved configuration within a living body and thestylet1080 is moved relative to thecatheter1015. In another embodiment, thedistal end1083 of thestylet1080 can have the same outer diameter as theshaft1082. In certain embodiments, thestylet1080 can include an injection port in thehub1081 and ashaft1082 that includes a hollow lumen and one or more openings in itsdistal end1083; one advantage of these embodiments is that fluid injection into the catheter can be effected via thestylet1080.
• Referring now specifically toFIG. 10A, thecatheter1015,electrode1060, andhub adaptor1020 are shown in external views. Thecatheter1015 can be inserted intoport1052 as shown byarrow1091, andclamp1041 can be actuated to fix the injection adaptor to the catheter. Theclamp1041 can provide a fluid seal between thecatheter1015 and theinjection adaptor1020, so that, for example, fluid injected into theinjection adaptor1020 does not leak from thedistal port1052 when the catheter is clamped inside theport1052. In certain embodiments, theclamp1041 can be released non-destructively so that theinjection adaptor1020 can be separated from the catheter; one advantage of aseparable injection adaptor1020 is that if the catheter has been introduced into the living body by means of a metal tube, such as the metal tube an epidural needle, the needle can be removed from the living body by sliding the needle off of the proximal end, even if the catheter is still placed in the living body. Thecatheter stylet1080 can be inserted intoport1032 as shown byarrow1093, andclamp1031 can be actuated to fix thestylet1080 to theinjection adaptor1020. Theclamp1031 can provide a fluid seal between thestylet1060 and theinjection adaptor1020; one advantage of this fluid seal is that fluid injected into theadaptor1020 is prevented from leaking out ofport1032. When thecatheter1015 is placed inside thedistal port1052, thestylet1080 can pass through the injection adaptor fromport1032 and out ofport1052 into the inner lumen of thecatheter1015. Theclamp1031 can be released non-destructively to release thestylet1080 from theadaptor1020, thereby allowing thestylet1080 to move freely into theinjection adaptor1020 and thecatheter1015 and to be removed from theinjection adaptor1020 andcatheter1015. Theelectrode1060 can be inserted intoport1032 as shown byarrow1093, andclamp1031 can be actuated to fix theelectrode1060 to theinjection adaptor1020. Theclamp1031 can provide a fluid seal between theelectrode1080 and theinjection adaptor1020; one advantage of this fluid seal is that fluid injected into theadaptor1020 is prevented from leaking out ofport1032. When thecatheter1015 is inserted intoport1052, theelectrode1060 can pass through thehub adaptor1020 and into the inner lumen of thecatheter1015. Theclamp1031 can be released to release theelectrode1060 from theadaptor1020, thereby allowing it to move freely into theinjection adaptor1020 and thecatheter1015, and to be removed from theinjection adaptor1020 andcatheter1015.
• Referring now specifically toFIG. 10B, one embodiment of an assembly of thecatheter1015, theinjection adaptor1020, and theelectrode1060 is presented in an external view. The proximal end of thecatheter1015 is clamped in thedistal opening1052 of theinjection adaptor1020, thereby effecting a fluid seal between an outer surface of thecatheter1015 and an inner surface of theadaptor1020. Theelectrode1060 is clamped in theproximal opening1032 of theinjection port1020, thereby creating a fluid seal between an outer surface of theelectrode1060 and an inner surface of theadaptor1020. In certain embodiments, a mark is provided on the shaft of the catheter to indicate the proper positioning of thecatheter1015 within theadaptor1020. In certain embodiments, theadaptor1020 includes a stop within theopening1052 that is configured to engage with thecatheter1015, thereby indicating the proper position of thecatheter1015 within thehub1020. Theshaft1062 of theelectrode1060 passes through an inner lumen of theadaptor1020 and into the inner lumen of thecatheter1015. In certain embodiments, thedistal end1063 of theelectrode1060 is mechanically prevented from touching adistal surface1005 of thecatheter1015, if present, for example, by means of mechanical engagement of theelectrode hub1061 and theport1032. In certain embodiments, the distal end of theelectrode1063 can touch the distal end of thecatheter1015, if present. In certain embodiments, the adaptor hub provides a fluid pathway betweenport1042 and the inner lumen ofcatheter1015. One advantage of said fluid pathway is that fluid injected intoport1042 can flow into thecatheter1015 and out of holes in either theshaft1010, thetip1000, or both. One advantage of the twofluid clamps1031 and1041 is that fluid injected intoport1042 does not leak out ofports1032 and1052. One advantage of the twofluid clamps1031 and1041 is that fluid, such as anesthetic, radiocontrast, alcohol, biological material, and drugs, can be injected intoport1042 when theelectrode1060 is positioned in the inner lumen ofcatheter1015 without said fluid leaking out of theelectrode port1032 and thecatheter port1052. In certain embodiments, the internal construction of the assembly shown inFIG. 10B is that of the assembly shown inFIG. 10D.
• Referring now specifically toFIGS. 10C, 10D, and 10E, one embodiment of the construction ofinjection adaptor hub1020 is presented. InFIG. 10C, theadaptor1020 is presented in an exploded, external view. InFIGS. 10D and 10E, theadaptor1020 and the catheter are each presented in a cross sectional view, and theelectrode1060 is presented in an external view. In this embodiment, theinjection adaptor1032 includes five pieces. The first piece includesport1032,proximal clamp1031, andinternal threads1034, and a central through hole, all of which can be composed of a single piece of a hard material, such as a hard plastic, ABS, PVC, polycarbonate, or a metal. Thesecond piece1035 is a compressible ring, which can be composed of a soft plastic such as polyurethane. The third piece includes theexternal threads1044, amiddle body1043,injection port1042,distal clamp ring1041, and a central through hole. The fourth piece is a compressive ring, which can be composed of a soft plastic such as polyurethane. The fifth piece is adistal body1051 that includesexternal threads1054,distal port1052, and a central through hole. As is familiar to those skilled in the art of tuohy-borst adaptors, whenring1031 is tightened ontomiddle body1043 by engagement ofthreads1034 and1044, thegasket1035 is compressed and the diameter of the central through hole ofgasket1035 is reduced. Thegasket1035 can be configured such that when theelectrode1060 passes through thegasket1035 and the gasket is compressed betweenring1031 andbody1043, the gasket compresses theelectrode shaft1062 thereby creating a fluid seal among thering1031, thering1015, and theshaft1062. As is familiar to those skilled in the art of tuohy-borst adaptors, whenring1041 is tightened ontodistal body1051 by engagement ofthreads1046 and1054, thegasket1045 is compressed and the diameter of the central through hole ofgasket1045 is reduced. Thegasket1045 can be configured such that when thecatheter1015 passes through thegasket1045 and the gasket is compressed betweenring1041 andbody1051, the gasket compresses thecatheter shaft1010 thereby creating a fluid seal among thering1041,ring1045, andring1051. Whengaskets1035 and1045 are both compressed to create two fluid seal, fluid injected intoport1042 flows into the inner lumen of theinjection adaptor1020, into the inner lumen of thecatheter1015, and out fromgaps1003 in thespring coil1001 of thetip1000. One advantage of the electrode catheter system presented inFIG. 10 is that fluid can be injected into a living body through the catheter while theelectrode1060 is positioned in the inner lumen of thecatheter1015. One advantage of the embodiments of aninjection adaptor1020 presented inFIG. 10 is that fluid can be injected into a living body through acatheter1015 while the catheter'sstylet1080 is positioned in the inner lumen of thecatheter1015. One advantage of the embodiments of aninjection adaptor1020 presented inFIG. 10 is that anelectrode1080 or astylet1060 can pass straight through theadaptor1020 and into the catheter.
• In certain embodiments of theinjection adaptor1020, thering1031 and the injection port can be separate pieces; for example, the1031 can be rotate about its central axis relative to theport1032. In certain embodiments of theinjection adaptor1020, thering1041 can be separate pieces; for example, the1041 can be rotate about its central axis relative to themiddle body1043. In certain embodiments, thering1031 andmiddle body1043 are a single solid piece, and the inner diameter of thering1035 and the outer diameter of theelectrode shaft1062 are configured such a fluid seal is created when theelectrode shaft1062 passes through the inner lumen of thering1035; for example, the inner diameter of thering1035 can be slightly smaller than the outer diameter of theelectrode shaft1062 so that theelectrode shaft1062 compresses thering1035 when theelectrode1062 passes through thering1035. In certain embodiments, thering1041 anddistal body1051 are a single solid piece, and the inner diameter of thering1045 and the outer diameter of thecatheter shaft1010 are configured such a fluid seal is created when thecatheter shaft1010 passes through the inner lumen of thering1045; for example, the inner diameter of thering1045 can be slightly smaller than the outer diameter of thecatheter shaft1010 so that thecatheter shaft1010 compresses thering1045 when thecatheter shaft1010 passes through thering1045. In certain embodiments of theinjection adaptor hub1020, theadaptor1020 is constructed by connecting a two touhy-borst adaptors and one T-shaped tube, wherein the first touhy-borst adaptor has a male luer-lock its distal end, the first tuohy-borst adaptor distal end is attached to the female luer-lock port at the proximal end of the T-shaped tube, the T-shaped tube has a side port for injection of fluid, the distal end of the T-shaped tube has a male luer-lock, the distal end of the T-shaped tube is attached to the female luer-lock of the cap of the second touhy-borst adaptor, the first touhy-borst adaptor is configured to create a fluid seal around anelectrode1060 orstylet1080 passing through the first touhy-borst adaptor's center lumen, and the second touhy-borst adaptor is configured to create a fluid seal around acatheter1015 passing into itsdistal opening1052; in one more specific embodiment, the said two tuohy-borst adaptors and one T-shaped tube are standard guidewire components. In other embodiment, a Y-shaped tube replaces the said T-shaped tube. In other embodiments, at least one of the fluid clamps inadaptor1020 is not a touhy-borst adaptor. In another embodiment, both fluid clamps inadaptor1020 are not touhy-borst-type clamps. In other embodiments, a fluid clamp inadaptor1020 can be a structure that pinches a tube around theelectrode1060 or thestylet1080 passing through the tube. In another embodiment, at least one fluid clamp inadaptor1020 can be an annular structure whose inner diameter is interferes with the object passing through it. In another embodiment of inadaptor1020, the fluid clamp around thestylet1080 orelectrode1060 can be a plastic ring whose inner diameter is equal to or smaller than the stylet's outer diameter, so that the stylet can be moved through the ring and fluid is substantially restrained from passing between the ring and the stylet. In other embodiments, theinjection port1042 can include a fluid clamp.
• Referring now specifically toFIG. 10D, one embodiment of an assembled catheter electrode system is presented that includes acatheter1015, aseparable hub1020, and anelectrode1060, wherein thecatheter1015 andadaptor1020 are shown in a cross-sectional view, and theelectrode1060 is shown in an external view. In certain embodiments, the system can be configured for application of radiofrequency therapy, such as pulsed radiofrequency therapy, to nerve in the epidural space.
• Referring now specifically toFIG. 10E, one embodiment of an assembled catheter electrode system is presented that includes acatheter1015, aseparable injection hub1020, and anelectrode1060, in which theelectrode1060 includes agenerator connector1066 that is directly attached to theshaft1062. In one embodiment, thegenerator connector hub1066 only contains onepin1067 for connection to an electrical signal, such as the output of an RF generator or the output of a nerve stimulator. One advantage of acoaxial generator connector1066 is that the connector can be used to manipulate theelectrodes1060.
• In other embodiments ofFIGS. 10B, 10D, and 10E, thestylet1080 can replace theelectrode1060 in the assembly.
• Referring toFIG. 10, in certain embodiments,catheter1015 does not include a spring coil. In certain embodiments, thecatheter1015 is a plastic catheter. In certain embodiments, thecatheter1015 has an opendistal end1005. In certain embodiments, the catheter includes one or more holes on the side of its shaft or tip to provide for the outflow of injected fluid. In certain embodiments, thespring coil1001 is completely covered by theinsulation1011. In certain embodiments, thecatheter1015 has an exterior surface that is entirely plastic and a closed distal end. In certain embodiments, thecatheter1015 can be steerable. In certain embodiments thecatheter1015 can include a connection to an RF generator. In certain embodiments, the catheter can be a unitized catheter injection electrode. In certain embodiments, theinjection hub1020 can be inseparably connector thecatheter1015.
• Referring toFIG. 10, in certain embodiments, the system includes only thecatheter1015, theelectrode1060, and theinjection adaptor1020, and does not include astylet1080. In certain embodiments, the system includes only thecatheter1015, thestylet1080, and theinjection adaptor1020, and does not include anelectrode1060. In certain embodiments, theinjection adaptor1020 is provided separately. In certain embodiments, theinjection adaptor1020 is configured to be adapted to a variety of catheters. In certain embodiments, a standard epidural needle can be included in the system and used to penetrate tissue, such as the skin, to provide for introduction of thecatheter1015 into the human body. In certain embodiments, an epidural needle that includes electrical insulation covering a part of its shaft can be included in the system and used to penetrate tissue, such as the skin, to provide for introduction of thecatheter1015 into the human body. In certain embodiments, and RF generator can be included in the system.
• Referring now toFIGS. 11A, 11B, 11C, 11D, 11E, and 11F,FIG. 11 presents certain embodiments of a system that includes acatheter1115, aninjection adaptor1120, and aninjection stylet1180, in accordance with several aspects of the present invention. Thecatheter1115 includesproximal end1112,shaft1111,plastic sheath1111,tip1101,spring coil1101,proximal aspect1102 of thetip1100,middle aspect1103 of thetip1100,distal aspect1104 of thetip1100, anddistal end1105. Theinjection adaptor1120 includesproximal port1132, aproximal clamp1131, amiddle body1143, an injection port1142, adistal clamp1141,distal body1151, anddistal port1152. Theinjection stylet1180 includes aninjection port1184,proximal handle1181,injection tube1185,shaft1182,distal tip1183. In certain embodiments, the injection adaptor can be one of the embodiments of aninjection adaptor1020 presented in relation toFIG. 10, wherein theinjection port1042 is omitted. In certain embodiments, the injection adaptor can be one of the embodiments of aninjection adaptor1020 presented in relation toFIG. 10, wherein themiddle body1043 is a tubular structure that does not have a hole in one of its side walls. In certain embodiments thecatheter1115 can be one of the embodiments ofcatheter1015 presented in relation toFIG. 10. In certain embodiments thestylet1180 can be one of the embodiments ofstylet1080 presented in relation toFIG. 10. In certain embodiments thestylet1180 can be one of the embodiments of anelectrode1060 presented in relation toFIG. 10.
• Theproximal port1132 can be a female luer port. Theproximal port1132 can configured to admit theinjection tube1185 and theshaft1182. Theproximal clamp1131 can be a tuohy-borst type port. Theproximal clamp1131 can be configured to create a fluid seal around theinjection tube1185 when thetube1185 is inserted into theport1132. Themiddle body1143 is a tubular structure that includes a central lumen through which theshaft1182 can pass. Thedistal clamp1141 can be configured to create a fluid seal around the proximal end of thecatheter1112. Thedistal clamp1141 can be a tuohy-borst-type clamp. Thedistal body1151 has adistal opening1152 that into which the catheter's proximal end can enter. Thestylet shaft1182 can pass into theport1132, through themiddle body1143, and into an inner lumen of acatheter1115 that inserted inport1152. In certain embodiments, theinjection tube1185 can pass into the middle body. In certain embodiments, thetube1185 can pass through the middle body. In certain embodiments, thetube1185 can pass through the injection adaptor and into the inner lumen of the catheter.
• Theport1184 can be a female luer port. Theport1184 can be a male luer. Theport1184 can be a port configured for the injection of fluids. Theport1184 can include a luer lock. Theport1184 can be a non-luer port. Theport1184 can include a flexible extension tube. Theinjection tube1185 has an inner lumen through which fluids can be injected. Theinjection tube1185 can be a metal hypotube; the metal can be stainless steel. Theinjection tube1185 can have a circular cross section. Theinjection tube1185 can have a non-circular cross section. Theinjection tube1185 can have a diameter in the range 25 to 20 gauge. Theshaft1182 can be the shaft of a catheter stylet, such as the shaft of an epidural catheter's stylet. Theshaft1182 can be a metal rod; the metal can be stainless steel or nitinol. Theshaft1182 can be a metal tube. Theshaft1182 can be straight. Theshaft1182 can be curved. Theshaft1182 can be bendable to meet a physician's needs. Theshaft1182 can be bendable to facilitate steering of thecatheter1115 within the living body. Thedistal tip1183 can have the same diameter as theshaft1182. Thedistal tip1183 can have a diameter that is larger than the diameter of the1182; one advantage of this configuration is that theshaft1182 is less likely to exit holes in the side barrel of thecatheter1115 when thecatheter1115 is bent within a living body and thestylet1180 is moved relative to thecatheter1115. In certain embodiments, thedistal tip1183 has a substantially spherical shape. In certain embodiments, thedistal tip1183 has a non-spherical shape. Theinjection tube1185 andshaft1182 can be fixedly connected byjunction1186.Junction1186 can be a solder joint.Junction1186 can be a glue joint.Junction1186 can be an electrically conductive connection; one advantage of an electricallyconductive connection1186 is that an electrical signal connected toinjection tube1185 is transmitted toshaft1182. In certain embodiments, theinjection stylet1180 can be an RF electrode. In certain embodiments, theinjection stylet1180 can include a temperature sensor. In certain embodiments, theinjection stylet1180 can have an integral connector for an RF generator. In certain embodiments, an RF connection can attached to thestylet1180, for example, by means of an alligator clip.
• Whenclamp1141 creates a fluids seal around thecatheter1115 andclamp1131 creates a fluid seal around theinjection tube1185, fluid injected intoport1184 flows through theadaptor1120, into the inner lumen of thecatheter1115, and out of holes in the shaft of thecatheter1115, such as widely-spacedcoil loops1103 of thecatheter tip1100. One advantage of theinjection adaptor1120 and theinjection stylet1184 is that fluid can be injected into a living body through acatheter1115 when thestylet shaft1182 is within the inner lumen of the catheter.
• One advantage of a system that includes aninjection stylet1180 configured for acatheter1115 and aninjection adaptor1120 that includes afluid clamp port1131 for acatheter1115, afluid clamp port1141 for a stylet, and a central lumen connecting the two ports, is that it provides for injection of fluid injection into thecatheter1115 without an injection port that is not substantially coaxial with thecatheter1115. One advantage of a system that includes aninjection stylet1180 configured for acatheter1115 and aninjection adaptor1120 that includes afluid clamp port1131 for acatheter1115, afluid clamp port1141 for a stylet, and a central lumen connecting the two ports, is that it provides for enhanced ergonomics for manual rotation of the catheter by means of theadaptor hub1020.
• Referring specifically toFIG. 11A, one embodiment of thecatheter1115,adaptor1120, andstylet1180 are presented as separate pieces.Catheter1115 can be inserted intoadaptor1120 as shown byarrow1191.Injection stylet1180 can be inserted intoinjection adaptor1120 as shown byarrow1193. In certain embodiments, the proximal end of theshaft1182 is fixed within the inner lumen ofinjection tube1185 and does not fully occlude the flow path of theinjection tube1185; one example of a cross-sectional view of this embodiment is shown inFIG. 10D. One advantage of embodiments in which theshaft1182 is placed within the inner lumen of theinjection tube1185 is that it provides a cylindrical exterior surface around which clamp1131 can create a fluid seal.
• Referring specifically toFIG. 11B, one embodiment of the assembly of acatheter1115,adaptor1120, andstylet1180 is presented in an external view. In one embodiment, assembly shown inFIG. 10B can be effected as indicated by thearrows1191 and1193 shown inFIG. 10A. In this assembly, theclamp1131 creates a substantially fluid-tight seal around theinjection tube1185, andclamp1141 creates a substantially fluid-tight seal around thecatheter1115. One advantage of this assembly is that fluid injected intoport1184 does not substantially leak out ofports1132 and1152.
• Referring specifically toFIGS. 11D, 11E, and 11F, certain embodiments of the assembly of acatheter1115,adaptor1120, andstylet1180 are presented, wherein thecatheter1115 andadaptor1120 are presented in a cross-sectional view, and thestylet1180 is presented in a cross sectional view, except for theshaft1182, if present, which is presented in an external view.
• Referring specifically toFIGS. 11C, 11D, 11E, and 11F, one embodiment of the construction of aninjection adaptor1120 is presented. InFIG. 11C, the construction is shown in an exploded view. InFIGS. 11D, 11E, and 11F, the construction is shown is an assembled, cross-sectional view. The adaptor is constructed from five pieces, each of which is substantially axially-symmetric around the proximal-distal axis. The first piece includes theproximal port1132 and theclamp ring1031, which can be constructed from a substantially incompressible substance, such as a hard plastic. The second piece is antubular structure1035, which can be constructed from a compressible substance such as a soft plastic. The third piece includes themiddle body1043 andclamp ring1041, which can be constructed from a substantially incompressible substance, such as a hard plastic. The fourth piece istube1045, which can be constructed from a compressible substance such as a soft plastic. The fifth piece is thedistal body1051, which can be constructed from a substantially incompressible substance, such as a hard plastic. Thering1131 includesthreads1134 that can engage with thethreads1144 that are included onbody1143; this engagement can compresstube1135 and reduce its internal diameter, thereby creating a substantially fluid-tight seal among thebody1143, thering1131, thegasket1135, and the astylet1180 positioned in the inner lumen of thetube1135. Thering1141 includesthreads1146 that can engage with thethreads1154 that are included onbody1151; this engagement can compresstube1145 and reduce its internal diameter, thereby creating a substantially fluid-tight seal among thebody1151, thering1141, thegasket1145, and the acatheter1115 positioned in the inner lumen of thetube1145. One advantage of the embodiment of theinjection adaptor1120 presented inFIGS. 11C, 11D, 11E, and 11F is that the two fluid clamps prevent leaking a fluids from theinjection hub1120 when theinjection hub1120 is engaged with thestylet1180 and thecatheter1115 and said fluids are injected intoport1184 of the stylet.
• In certain embodiments, theinjection adaptor hub1120 can be constructed from more than five pieces. In certain embodiments, theadaptor1120 can be constructed from fewer than five pieces. In certain embodiments, the components of theadaptor1120 shown inFIGS. 11C, 11D, 11E, and 11F can be constructed from multiple pieces. In certain embodiments, the threadedring1131 can rotate aroundport1132. In certain embodiments, the threadedring1141 can rotate aroundbody1143. In certain embodiments,middle body1143 can be constructed from two pieces. In some embodiment of theinjection adaptor1120, a different type of fluid clamp can be included. In certain embodiments of theinjection adaptor1120 andcatheter1115, the adaptor and catheter can be inseparably connected.
• Referring specifically toFIG. 11D, one embodiment of aninjection stylet1180 is presented in a cross-sectional view. In this embodiment, theshaft1182 is fixed inside the inner lumen ofinjection tube1185. Theshaft1182 does not block the flow path through theinjection tube1185. Thegasket1135 clamps around the smooth, cylindrical outer diameter of theinjection tube1185. In certain embodiments, the proximal end of theshaft1182 can extend up to or proximal to the proximal end of theinjection tube1185, and thejunction1186 can be on the proximal end of the shaft. In certain embodiments, theshaft1182 can extend proximal to thetube1185 and thejunction1186 can be between thehandle1181 and theshaft1182. In embodiments where theinjection tube1185,junction1186,shaft1182 are electrically conductive, an electrically signals, such as an RF signal or a nerve stimulation signal, can be attached to a portion of the injection tube proximal toport1132, and thereby the electrical signal can be transmitted to thecatheter1115 by contact between an inner metal surface of the catheter and theshaft1182. One advantage of embodiments that include aninjection tube1185 that does not extend into the inner lumen of thecatheter1115 and astylet rod1182 that does extend into the inner lumen of thecatheter1115, is that the flow of fluids injected intoport1184 are not blocked by flexing of the catheter shaft which could close down the inner lumen of theinjection tube1185 were it positioned within the inner lumen of thecatheter1115 and kinked by the flexing.
• Referring specifically toFIG. 11E, one embodiment of aninjection stylet1180 is presented in a cross-sectional view. In this embodiment, theshaft1182 is fixed outside theinjection tube1185. In certain embodiments, as shown inFIG. 11E, theshaft1182 is fixed to the outer surface of theinjection tube1185. In certain embodiments, theshaft1182 is fixed to thehandle1181, for example, by gluing both theshaft1182 and theinjection tube1185 into a distal opening of thehandle1181. In some embodiment, as shown inFIG. 11E, an integral connection to anelectrical generator1190, such as an RF generator, is attached to theinjection stylet1180. The connection can provide for delivery of electrical signals to thestylet1180, and thereby to acatheter1115 into which theinjection stylet1180 is placed, and it can provide for conduction of measurement signals from thestylet1115 to a generator, such as temperature signals. Thecable1189 of theconnection1190 can be flexible.
• Referring now toFIG. 11F, one alternative embodiment of the assembly of acatheter1115,injection adaptor1120, andinjection stylet1180 is presented, wherein theinjection stylet1180 includes aninjection tube1185 that is configured to function as a stylet for acatheter1115. In this embodiment, theinjection tube1185 has a length that is configured to pass through thehub1120 and into the inner lumen of thecatheter1115. In certain embodiments, thetube1185 is configured to align with thedistal end1105 of the catheter in the assembly. In certain embodiments, thetube1185 is configured not to reach thedistal end1105 of the catheter in the assembly. In certain embodiments, thetube1185 is straight. In certain embodiments, thetube1185 is curved. In certain embodiments, thetube1185 has a circular cross-section. In certain embodiments, thetube1185 has a non-circular cross section. In certain embodiments, thetube1185 has a rectangular cross section. In certain embodiments, thetube1185 is reinforced with a rod fixed inside its inner lumen. One advantage of theinjection stylet1180 presented inFIG. 11F is ease of construction.
• Referring now toFIGS. 12A, 12B, 12C, 12D, 12E, 12F, 12G, 12H, 12I, 12J, 12K, 12L, 12M, 12N, 12O, 12P, 12Q, 12R, 12S, 12T, 12U,12V,12W,12X, and12Y,FIG. 12 presents certain embodiments of an epidural RF cannula, which includes ahollow needle1200 and astylet1250, in accordance with several aspects of the present invention. In certain embodiments, thecannula system1200 and1250 can be configured for the systems and methods related to catheter systems presented in the embodiments presented inFIG. 1.
• Referring toFIGS. 12A, 12B, and 12C, 12F, and 12G, certain embodiments of an epidural RF cannula system are presented in several views. The epidural RF cannula system includes ahollow needle1200 and astylet1250. Thecannula1200 includes aport1245 at its proximal end, ahub1240, amarker1247 that indicates the orientation of thebevel1230, ahollow metal shaft1210,electrical insulation1215 covering a proximal length of theshaft1210, anactive tip1220 at the distal end of theshaft1210 that is not covered by electrical insulation, and anepidural bevel1230. Thestylet1250 includes aproximal cap1280, analignment feature1285 that is configured to engage with thecannula hub1240 and thereby align thebevel1260 of thestylet1250 and thebevel1230 of theneedle1200, ashaft1255, and abevel1260 at the distal end of theshaft1255.FIG. 12A presents thecannula1200 andstylet1250 separately in an external view from the side of the bevel; herein this view is referred to this view as a “side view” of the system.FIG. 12B presents the cannula and stylet engaged, with the stylet within the inner lumen of the cannula, from the same external side view as presented inFIG. 12A.FIG. 12C presents a second external view of the assembledcannula1200 andstylet1250, wherein the view is rotated 90 degrees around the proximal-to-distal axis of thecannula1200 starting from the view inFIG. 12B; herein, this view is referred to as a “top view” of the needle system.FIG. 12F presents a detailed side view of theneedle bevel1230 andstylet1260 wherein thecannula1200 andstylet1250 are fully engaged as shown inFIG. 12B.FIG. 12G presents a detailed top view of theneedle bevel1230 andstylet1260 wherein thecannula1200 andstylet1250 are fully engaged as shown inFIG. 12C.
• In certain embodiments, thecannula port1245 can be a female luer port. Theport1245 can be configured for injection of fluids. Theport1245 can include a luer lock. In certain embodiments, thehub1240 can be metal, such as stainless steel. In certain embodiments, thehub1240 can be plastic. Thehub1240 can include theport1245. Thehub1240 has an inner lumen which provides for fluid communication between theport1240 and the inner lumen of theshaft1210. In certain embodiments, the hub can be configured to engage with detachable “wings” to facilitate manipulation of the needle, as is familiar to one skilled in the art of needles for epidural anesthesia. In certain embodiments, the hub can include fixed wings that are inseparable from the hub. In certain embodiments, thehub marker1247 can be rotationally with the opening of thebevel1230. In other embodiments, thehub marker1247 can be on the opposite side of the shaft relative to the cut or cuts of thebevel1230. Thecannula shaft1210 can include stainless steel hypotube. Thecannula shaft1210 can be constructed from a metal hypotube selected from among the following sizes 18TW, 18RW, 17TW, 17RW, 16TW, 16RW, 15TW, 15RW, 14TW, 14RW, and other sizes. Theshaft1210 can include depth markers, including bands that indicate lcm lengths along the shaft. The length of theshaft1210 can be 5 cm. The length of theshaft1210 can be 6 cm. The length of theshaft1210 can be 10 cm. The length of theshaft1210 can be 15 cm. The length of theshaft1210 can be 20 cm. The length of theshaft1210 can be 3.5 inches. The length of theshaft1210 can be 4.5 inches. The length of theshaft1210 can be 6 inches. In certain embodiments theshaft1210 of theneedle1200 can be cylindrical. In certain embodiments theshaft1210 of theneedle1200 can be substantially axially symmetric. The inner lumen of thecannula1200 can be configured to allow a catheter, including a catheter-style electrode system, to pass into theport1245, through theshaft1210, and out from thebevel1230. The inner lumen of thecannula1200 can be configured for fluid to be injected into theport1245, through theshaft1210, and out from thebevel1230. The inner lumen of thecannula1200 can be configured for fluid to be injection into theport1245, through theshaft1210, and out from thebevel1230. The inner lumen of thecannula1200 can be configured so that an RF electrode can be inserted into theport1245, pass into the inner lumen of themetal shaft1210, and contact an inner surface of themetal shaft1210, thereby providing for the delivery and control of RF signal output to living tissue in contact with theactive tip1220. In certain embodiments, the length of theshaft1210 can be configured such that an RF electrode's distal end aligns with thedistal bevel1230 when the electrode is fully engaged with thecannula1200. Theelectrical insulation1215 can be a plastic tube, such as shrink tube, covering and adhered to themetal shaft1210. Theelectrical insulation1215 can be a plastic coating. Theelectrical insulation1215 can be fixedly attached to theunderlying metal shaft1210. Theelectrical insulation1215 can be a proximal plastic tube attached to a distal metal tube that forms thetip1220. Theelectrical insulation1215 can be configured to prevent RF current from flowing from electrically-insulated areas of the shaft. In certain embodiments, theinsulation1215 covers the proximal end of theshaft1210, leaving thedistal end1220 uninsulated. In certain embodiments, theinsulation1215 leaves multiple regions of the shaft uninsulated. Theactive tip1220 can be en electrically-uninsulated length of themetal shaft1210. The length of theactive tip1220 can be 1 mm. The length of theactive tip1220 can be 2 mm. The length of theactive tip1220 can be 4 mm. The length of theactive tip1220 can be 5 mm. The length of theactive tip1220 can be 6 mm. The length of theactive tip1220 can be 10 mm. The length of theactive tip1220 can be 15 mm. The length of theactive tip1220 can be 20 mm. The length of theactive tip1220 can be 30 mm. The length of theactive tip1220 can be in the range 1-30 mm. The length of theactive tip1220 can be less than 1 mm. The length of theactive tip1220 can be greater than 30 mm. In certain embodiments, thebevel1230 can be an epidural bevel, such as a tuohy bevel, an RX bevel, a Cath Glide bevel, a Higuchi bevel. In certain embodiments, thebevel1230 can be configured to limit damage to a catheter that passes through it. In certain embodiments, the bevel can be configured for insertion into the epidural space. In certain embodiments, thebevel1230 can be configured to prevent damage to the dura mater of the spinal cord. In certain embodiments, thebevel1230 can provide by penetration of skin and tissue of the posterior spine. In certain embodiments, thecannula1200 is configured to introduce a catheter that includes an outer surface that is plastic. In certain embodiments, thecannula1200 is configured to introduce a catheter that includes a shaft that is constructed from a spring coil that is covered by electrical insulation. In certain embodiments, thecannula1200 is configured to introduce a catheter that includes a shaft that is constructed from a spring coil that includes an outer surface and an inner lumen, wherein the outer surface is surrounded by a plastic tube.
• Thestylet1250 can be configured to occlude a portion of the inner lumen of thecannula1200. Thestylet1250 can be configured to reduce coring of tissue when thecannula1200 penetrates solid tissue. Thestylet1250 can be configured to reduce insertion force required to advance thecannula1200 into living tissue. Thestylet1250 can be configured to stiffen the shaft of thecannula1200. In certain embodiments, thestylet cap1280 can be configured to engage with thehub1240 for the purpose of fixing a longitudinal distance between the distal end of thestylet1250 and the distal end of thecannula1200. In certain embodiments, the alignment tab can engage with a feature of thehub1240 to provide for fixing the rotational alignment thecannula bevel1230 and thestylet bevel1260. In certain embodiments, engagement of thehub1240 and thecap1280 can provide for a particular, substantially solid tip geometry when thestylet1250 is fully engaged with thecannula1200. In certain embodiments, thecap1280 can engage with thehub1240 by means of an interference fit. In certain embodiments, thecap1280 can engage with thehub1240 in a locked configuration. In certain embodiments, thecap1280 can engage with thehub1240 by means of a luer lock. Thestylet shaft1255 can be a solid rod. Thestylet shaft1255 can be a metal rod, such as stainless steel. Thestylet shaft1255 can be a plastic rod, such as nylon. The stylet shaft can be a hard, flexible plastic rod. One advantage of aplastic stylet rod1255 is that it can bend to pass through acurved cannula shaft1210. The length of thestylet shaft1255 can be equal to the length of thecannula shaft1210. The length of thestylet shaft1255 can be larger than the length of thecannula shaft1210. The length of thestylet shaft1255 can be shorter than the length of thecannula shaft1210. Thebevel1260 of the stylet can have a similar geometry to that of thecannula bevel1230. The outer diameter of thestylet shaft1255 can be configured to provide for smooth movement of theshaft1255 within the inner lumen of thecannula shaft1210. In certain embodiments, thestylet shaft1255 can completely occlude the inner lumen of thecannula shaft1210. In certain embodiments theshaft1255 of thestylet1255 can be cylindrical. In certain embodiments theshaft1255 of thestylet1255 can be substantially axially symmetric. Thebevel1260 of the stylet can have an similar geometry to that of thecannula bevel1230. The bevel of1260 of the stylet can be formed from the same cutting surfaces as those that formed thecannula bevel1230. The bevel of1260 of the stylet can have a shape shaped such that when thestylet1250 is inserted into thecannula1200, and thehub1240 and thecap1280 are fully engaged, the assembled needle has a substantially smooth combined bevel.
• Referring toFIG. 12A,arrow1290 shows the way in which thestylet1250 can be inserted into thecannula1200.
• Referring toFIGS. 12B, 12C, 12G, and 12H, thebevel1230 of thecannula1200 and thebevel1260 of thestylet1250 are aligned longitudinally and rotationally when thecannula hub1240 is fully engaged with thestylet cap1280.
• Referring toFIGS. 12F and 12G, thecannula bevel1230 includes two curved surfaces, adistal surface1233 and aproximal surface1231. In certain embodiments, theproximal bevel surface1231 is a concave cylindrical cut. In certain embodiments, theproximal bevel surface1233 is a convex cylindrical cut. In certain embodiments, the proximal1231 and distal1233 are cylindrical cuts. Thestylet bevel1260 includes one flat surface whoseangle1265 relative to the long axis of thestylet1250 is configured to be substantially parallel to the average angle of distal aspect of thedistal cannula bevel1233. In one example theangle1265 is substantially equal to 35 degrees. In certain embodiments, theangle1265 is within the range 35-55 degrees.Surface1211 is the inner surface of theshaft1210 that is on the same side of the shaft as thebevel opening1230.Surface1212 is the inner surface of theshaft1210 that is on the opposite side of the shaft relative to thebevel opening1230. The transition from the inner surface of the shaft to the outer surface can be rounded to prevent damage to a catheter passing through thebevel1230, when the stylet is removed. Theproximal portion1234 of thebevel1230, which can be referred to as the “heel”1234 of the bevel, can be rounded on both its inner and outer edges to reduce the likelihood of damage to a flexible catheter that bends over theheel1234. For example, theheel1234 can be full radiused. For example, theheel1234 can have edges whose radius of curvature is no smaller than 0.002 inches. The distal,inner edge1235 of thebevel1230 can be smoothed to minimize cutting edges and thereby provide for smooth, damage-free passage of a catheter through thebevel1230, when thestylet1250 is removed. Theinner edge1237 of thebevel1230 can radiused, for instance by polishing, sand blasting, or grinding, to minimize cutting edges that can damage a catheter. The junction between thedistal bevel1233 and theproximal bevel1231 can be smoothed and/or filleted, as appropriate, to reduce sharp edges. In certain embodiments, thedistal aspect1239 of theouter edge1236 of thebevel1230 can be sharpened. In certain embodiments, thedistal aspect1239 of theouter edge1236 of thebevel1230 be configured to penetrate solid tissue, such as skin and muscle. In the embodiment presented inFIGS. 12F and 12G, thecannula1200 and thestylet1250 are configured to produce a combined bevel that is sufficiently a solid, flat bevel. One advantage of an epidural bevel that includes a curved proximal surface and a curved distal surface is that the bevel opening is enlarged, the distal bevel angle is less sharp, and the bevel can be free of sharp junctions between the multiple surfaces that are included in the bevel.
• One advantage of the embodiments of an epidural RF cannula system presented inFIGS. 12A, 12B, 12C, 12F, and 12G is that the system can provide for percutaneous access to the epidural space, delivery of epidural anesthesia through theneedle1200, insertion of a catheter into the epidural space through theneedle1200, and delivery of targeted high-frequency electrotherapy to nerves in the epidural space via the active tip of thecannula1220. One advantage of the present invention is that electrical signals, such as nerve stimulation, radiofrequency, pulsed radiofrequency, PENS, TENS, muscle stimulation, and neuromodulation signals, can be applied to human body in a targeted manner by thesame needle1200 by means of which a catheter is introduced into the human body.
• In certain embodiments, theshaft1210 can include echogenic markers. Echogenic markers can be configured to enhance visibility of an object when imaged using an ultrasound apparatus. In certain embodiments, the tip can include echogenic markers. In certain embodiments, the echogenic markers can be indentations into the metal surface of the metal of theshaft1210. In certain embodiments, the echogenic markers can be solid objects insertion between theinsulation1215 and themetal shaft1210. In certain embodiments, the echogenic markers can be a roughing of the surface of theshaft1210, for example, roughing as produced by sand blasting. In certain embodiments, echogenic markers can be positioned only at theactive tip1220. In certain embodiments, echogenic markers can be positioned at a distal aspect for theactive tip1220 and at a proximal aspect of theactive tip1220; one advantage of such embodiments is that the distal and proximal extent of theactive tip1220 can be discerned more easily using ultrasound. In certain embodiments, one echogenic marker is positioned at a distal aspect of theactive tip1220, and a second echogenic marker is positioned at the distal aspect of theinsulation1215; one advantage of this configuration is that the distal and proximal ends of theactive tip1220 can be viewed using ultrasound imaging.
• Referring toFIGS. 12D and 12E, certain embodiments of an epidural RF cannula are presented in which theshaft1210 includes abend1217. Thebend1217 can deflect the distal end of theshaft1210 by anangle1285 with respect to the proximal end of theshaft1210. Thecurve1217 can be configured to provide for improved steerability of theneedle1200 through solid tissue. Thebend1217 can be configured to facilitate positioning of theneedle1200 within the living body. One advantage of thebend1217 is that theshaft1210 can approach a vertebra at a steep angle and the distal aspect of theshaft1210 can direct a catheter out of thebevel1230 at a more shallow angle, for example, more parallel to the epidural space. One advantage ofcurve1217 is that a catheter's initial trajectory can be adjusted by rotating thecannula1200 about its central axis. Thebend1217 can be positioned at the distal aspect of theinsulation1215. Thebend1217 can be positioned proximal to the distal end of theinsulation1215. Thebend1217 can be positioned distal to the distal end of theinsulation1215. Thebend1217 can be positioned 5 mm from the distal tip of thecannula1200. Thebend1217 can be positioned 10 mm from the distal tip of thecannula1200. Thebend1217 can be positioned 15 mm from the distal tip of thecannula1200. Thecurve1217 can extend from 10 mm proximal to the distal tip of thecannula1200 to the distal tip of thecannula1200. Theangle1285 can be 5 degrees. Theangle1285 can be 10 degrees. Theangle1285 can be 15 degrees. Theangle1285 can be 20 degrees. Theangle1285 can be in the range 5 to 20 degrees. Theangle1285 can be greater than 20 degrees. One advantage of aplastic stylet shaft1255 is that thestylet1250 can follow thebend1217 as is passes through the inner lumen of theshaft1210. One advantage of an undercutmetal stylet shaft1255 is that is can pass by thebend1217, through the inner lumen of theshaft1210, more easily.
• Referring toFIG. 12E, certain embodiments of an epidural RF cannula are presented in which the distal end of thestylet1250 extends beyond the distal end of thecannula1200 when thestylet1250 is seated within thecannula1200. In certain embodiments, thestylet1250 can have a bluntdistal end1270. Thetip1270 can be full radiused. In certain embodiments, thebevel1230 of thecannula1200 and thetip1270 of the stylet can be configured to form a substantially blunt-tip, solid needle, when thecannula1200 andstylet1250 are fully engaged. Theshaft1255 of thestylet1250 can be a flexible, hard plastic, such as nylon. Theshaft1255 can be constructed of a material that can both easily pass throughbend1217 and extend beyond thebevel1230 in a substantially straight configuration when in tissue. In one example, the distal end of thestylet shaft1255 can extend beyond the distal end of thecannula shaft1210 by 0.050 inches. In one embodiment, a first stylet with aflat bevel1260 that aligns withbevel1230 is placed within thecannula1200 to facilitate penetration of thecannula1200 through the thicker tissue and into a sensitive bodily position, and then the first stylet is replaced by a second stylet that have a roundedtip1270 that extends beyond the distal end of thecannula1200 to prevent cutting of the internal structures when thecannula1200 is manipulated in the said sensitive bodily position; in one example the tougher tissue can be skin and muscle overlying the spine, and the sensitive bodily position can be the epidural space.
• Referring toFIGS. 12H and 12I, certain embodiments of abevel12301 for anepidural needle1200 and abevel12601 for anepidural stylet1250 are presented in a side view inFIG. 12H and in a top view inFIG. 12I. Thecannula bevel12301 includes two surfaces, a flatproximal surface12311 that is angled relative to the transverse plane of theshaft1210 at the position of thesurface12311, and a curveddistal surface12331. In one example, thedistal surface12331 has substantially one curvature when viewed from the side, as inFIG. 12H. In one embodiment, the angle ofsurface12311 relative to the transverse plane of theshaft1210 is 15 degrees. Thestylet bevel12601 includes one flat surface whose angle12651 relative to the long axis of thestylet1250 is configured to be substantially parallel to the average angle of distal aspect of thedistal cannula bevel12331. In one example the angle12651 is substantially 35 degrees. In certain embodiments, the angle12651 is within the range 35-55 degrees.Surface1211 is the inner surface of theshaft1210 that is on the same side of the shaft as thebevel opening12301.Surface1212 is the inner surface of theshaft1210 that is on the opposite side of the shaft relative to thebevel opening12301. Theheel12341 can be rounded to prevent damage to a catheter passing through the bevel. The inner edge of thebevel12371 can be smoothed to prevent damage to a catheter passing through the bevel. The junction between thedistal bevel1233 and theproximal bevel1231 can be smoothed and/or filleted, as appropriate, to reduce sharp edges. In certain embodiments, thedistal aspect1239 of theouter edge1236 of thebevel1230 can be sharpened, for example, for the purpose of penetrating solid tissue. Thebevels12301 and12601 are configured to form a combined bevel that is sufficiently flat and solid. One advantage of an epidural bevel that includes a flat proximal surface and a curved distal surface is that the bevel opening is enlarged, the distal bevel angle is less sharp, and radius of the bevel heel can be enlarged, and the bevel can be free of sharp junctions between the multiple surfaces that are included in the bevel.
• Referring toFIGS. 12J and 12K, certain embodiments of abevel12302 for anepidural needle1200 and abevel12602 for anepidural stylet1250 are presented in a side view inFIG. 12J and in a top view inFIG. 12K. Thecannula bevel12302 includes two surfaces, a flatproximal surface12312 that is parallel to the transverse plane of theshaft1210 at the location of thesurface12312, and a curveddistal surface12331. In certain embodiments, the embodiments presented inFIGS. 12J and 12K can be special cases of the embodiments presented inFIGS. 12H and 12I, wherein the angle ofsurface12311 relative to the transverse plane of theshaft1210 is zero. One advantage of an epidural bevel that includes a flat proximal surface formed from a transverse cut, and a curved distal surface is that the bevel opening is enlarged, the distal bevel angle is less sharp, and radius of the bevel heel is maximized, and the bevel can be free of sharp junctions between the multiple surfaces that are included in the bevel.
• Referring toFIGS. 12L and 12M, certain embodiments of abevel12303 for anepidural needle1200 and abevel12603 for anepidural stylet1250 are presented in a side view inFIG. 12L and in a top view inFIG. 12M. Thecannula bevel12303 includes three flat surfaces, a flatproximal surface12313, a flatmiddle surface12323, and a flatdistal surface12333. In certain embodiments, thesurface12323 can be parallel to the central axis of theshaft1210. In certain embodiments thesurface12323 can form a non-zero angle relative to the longitudinal axis of theshaft1210 at the location of thesurface12323. In certain embodiments, theheel12343 andinner edge12373 can be rounded to prevent damage to a flexible catheter passing through thebevel12303. In certain embodiments, the distalouter edge12393 of the bevel can be sharp to penetrate solid tissue.
• Referring toFIGS. 12N and 12O, certain embodiments of abevel12304 for anepidural needle1200 and abevel12604 for anepidural stylet1250 are presented in a side view inFIG. 12N and in a top view inFIG. 12O. Thecannula bevel12304 includes three surfaces, a flatproximal surface12314, a flatmiddle surface12324, and a curveddistal surface12333. In certain embodiments, thesurface12324 can be parallel to the central axis of theshaft1210. In certain embodiments thesurface12324 can form a non-zero angle relative to the longitudinal axis of theshaft1210 at the location of thesurface12324. In certain embodiments, theheel12344 andinner edge12374 can be rounded to prevent damage to a flexible catheter passing through thebevel12304. In certain embodiments, the distalouter edge12394 of the bevel can be sharp to penetrate solid tissue. One advantage of thebevel12304 of anepidural needle1200 wherein the bevel includes a curved distal surface is that the junction between the distal surface and the proximal surface adjacent can have low curvature.
• Referring toFIGS. 12P and 12Q, certain embodiments of abevel12305 for anepidural needle1200 and abevel12605 for anepidural stylet1250 are presented in a side view inFIG. 12P and in a top view inFIG. 12Q. Thecannula bevel12305 includes three surfaces, a curvedproximal surface12315, a flatmiddle surface12325, and a flatdistal surface12335. In certain embodiments, thesurface12325 can be parallel to the central axis of theshaft1210. In certain embodiments thesurface12325 can form a non-zero angle relative to the longitudinal axis of theshaft1210 at the location of thesurface12325. In certain embodiments, theheel12345 andinner edge12375 can be rounded to prevent damage to a flexible catheter passing through thebevel12305. In certain embodiments, the distalouter edge12395 of the bevel can be sharp to penetrate solid tissue.
• Referring toFIGS. 12R and 12S, certain embodiments of abevel12306 for anepidural needle1200 and abevel12606 for anepidural stylet1250 are presented in a side view inFIG. 12R and in a top view inFIG. 12S. Thecannula bevel12306 includes three surfaces, a curvedproximal surface12316, a flatmiddle surface12326, and a curveddistal surface12336. In certain embodiments, thesurface12326 can be parallel to the central axis of theshaft1210. In certain embodiments thesurface12326 can form a non-zero angle relative to the longitudinal axis of theshaft1210 at the location of thesurface12326. In certain embodiments, theheel12346 andinner edge12376 can be rounded to prevent damage to a flexible catheter passing through thebevel12306. In certain embodiments, the distalouter edge12396 of the bevel can be sharp to penetrate solid tissue.
• Referring toFIGS. 12T and 12U, certain embodiments of abevel12307 for anepidural needle1200 and abevel12607 for anepidural stylet1250 are presented in a side view inFIG. 12T and in a top view inFIG. 12U. Thecannula bevel12307 includes two surfaces, a curvedproximal surface12317 and a curveddistal surface12337. In certain embodiments, theheel12347 andinner edge12377 can be rounded to prevent damage to a flexible catheter passing through thebevel12307. In certain embodiments, the distalouter edge12397 of the bevel can be sharp to penetrate solid tissue. Theshaft1210 can include agentle bend12387 at the position of thebevel12307. In certain embodiments, thestylet bevel12607 can be a flat surface that is aligned with and substantially parallel to the average orientation of thecannula bevel12307.
• Referring toFIGS. 12V and 12W, certain embodiments of abevel12308 for anepidural needle1200 and abevel12608 for anepidural stylet1250 are presented in a side view in FIG.12V and in a top view inFIG. 12W. Thecannula bevel12308 is a flat surface that has an angle relative to the transverse plane of theshaft1210 at the location of thebevel12308. Theshaft1210 includes agentle bend12388 at the position of thebevel12308. In certain embodiments, thestylet bevel12608 can be a flat surface that is substantially parallel and aligned with thecannula bevel12308. In certain embodiments, thebevels12308 and12608 can be a touhy bevel. In certain embodiments, theheel12348 andinner edge12378 can be rounded to prevent damage to a flexible catheter passing through thebevel12308. In certain embodiments, the distalouter edge12398 of the bevel can be sharp to penetrate solid tissue.
• Referring toFIGS. 12X and 12Y, certain embodiments of abevel12309 for anepidural needle1200 and abevel12609 for anepidural stylet1250 are presented in a side view inFIG. 12X and in a top view inFIG. 12Y. Thecannula bevel12309 includes a curvedproximal surface12319 and a flatdistal surface12329. In certain embodiments, theproximal surface12319 can be flat. In certain embodiments, thedistal surface12329 can be parallel to the central axis of theshaft1210. Theshaft1210 includes agentle bend12389 opposite thebevel12309. In certain embodiments, theheel12349 andinner edge12379 can be rounded to prevent damage to a flexible catheter passing through thebevel12309. In certain embodiments, the distalouter edge12399 of the bevel can be sharp to penetrate solid tissue. Thestylet bevel12609 is a flat surface. Thestylet bevel12609 can be configured to occlude the opening in the distal end of theshaft1210. The stylet bevel can be aligned with the opening at the distal end of theshaft1210. In certain embodiments, theneedle1200 does not includeelectrical insulation1215. In certain embodiments, theneedle1200 is an epidural needle. In certain embodiments, the bevel geometries presented inFIGS. 12F, 12G, 12H, 12I, 12J, 12K, 12L, 12M, 12N, 12O, 12P, 12Q, 12R, 12S, 12T, 12U, 12V, 12W, 12X, and 12Y can be included in an epidural needle that does not include electrical insulation. In certain embodiments, the bevel geometries presented inFIGS. 12F, 12G, 12H, 12I, 12J, 12K, 12L, 12M, 12N, 12O, 12P, 12Q, 12R, 12S, 12T, 12U, 12V, 12W, 12X, and 12Y can include addition cut surfaces, such as a blunted distal tip.
• Referring now toFIG. 13,FIG. 13 presents certain embodiments of an epidural RF cannula system, which includes ahollow needle1300 and astylet1350, wherein theneedle1300 includes aproximal length1325 of theshaft1310 that is uninsulated, in accordance with several aspects of the present invention. In certain embodiments, thecannula system1300 and1350 can be configured for the systems and methods related to catheter systems presented in the embodiments presented in relation toFIG. 1. In certain embodiments, thecannula system1300 and1350 can be configured for the systems and methods related to catheter systems presented in the embodiments presented in relation toFIG. 1D. In certain embodiments, thecannula1300 is configured to provide for connection to one output pole of an RF generator, such as the reference jack.
• Thecannula1300 includes aport1345 at its proximal end, ahub1340, amarker1347 that indicates the orientation of thebevel1330, ahollow metal shaft1310, aproximal portion1325 of theshaft1310 that is not covered by electrical insulation, adepth stop1327,electrical insulation1315 covering a middle portion of theshaft1310, anactive tip1320 at the distal end of theshaft1310 that is not covered by electrical insulation, and anepidural bevel1330. Thestylet1350 includes aproximal cap1380, analignment feature1385 that is configured to engage with thecannula hub1340 and thereby align thebevel1360 of thestylet1350 and thebevel1330 of theneedle1300, a shaft1355, and abevel1360 at the distal end of the shaft1355.FIG. 13 presents thecannula1300 andstylet1350 separately in an external view from the side of the bevel, andarrow1390 shows how thestylet1350 can be engaged with thecannula1300. One output pole of an electrical power supply, such as the reference pole of an RF generator can be attached to theconnection section1325, for example, by means of an alligator clip. The depth stop can prevent theconnection section1325 from being advanced into living tissue when thecannula1300 is used to penetrate said living tissue, such as the human body. The depth stop can be constructed from an electrically-insulative material, such as plastic, to prevent electrical signals applied tosection1325 from being conducted to living tissue through thedepth stop1325. In certain embodiments, the depth stop is electrically-isolated from theconnection point1325. Electrical signals applied to theconnection point1325 conduct through theshaft1310 to theactive tip1320. Theneedle1300 can be used as theneedle170 inFIG. 1D, andconnection175 can be the junction between theuninsulated length1325 and a cable connected to one output pole of an RF generator; in this example, when a catheter electrode passing through theneedle1300 is connected to the opposite output pole of the RF generator, the active tip of the electrode is not in contact with theshaft1310, and both the active tip of the electrode and theactive tip1320 of theneedle1300 are in contact with the human body, electrical current flows between theactive tip1320 of theneedle1300 and the active tip of the catheter electrode.
• Referring now toFIG. 14,FIG. 14 presents certain embodiments of an epidural RF cannula system, which includes ahollow needle1400 and astylet1450, wherein theneedle1400 include as connection to anelectrical power supply1425, in accordance with several aspects of the present invention. In certain embodiments, thecannula system1400 and1450 can be configured for the systems and methods related to catheter systems presented in the embodiments presented in relation toFIG. 1. In certain embodiments, thecannula system1400 and1450 can be configured for the systems and methods related to catheter systems presented in the embodiments presented in relation toFIG. 1D. In certain embodiments, thecannula1400 is configured to provide for connection to one output pole of an RF generator, such as the reference jack.
• Thecannula1400 includes aport1445 at its proximal end, ahub1440, amarker1447 that indicates the orientation of thebevel1430, a hollowconductive shaft1410, aconductive connector1425, electrically-insulative housing for theconnector1423, aflexible cable1424 that can conduct electricity between theconnector1423 and theshaft1410,electrical insulation1415 covering a middle portion of theshaft1410, anactive tip1420 at the distal end of theshaft1410 that is not covered by electrical insulation, and anepidural bevel1430. Thestylet1450 includes aproximal cap1480, analignment feature1485 that is configured to engage with thecannula hub1440 and thereby align thebevel1460 of thestylet1450 and thebevel1430 of theneedle1400, ashaft1455, and abevel1460 at the distal end of theshaft1455. Theconductive shaft1410 can be constructed from a metal, such as stainless steel.FIG. 14 presents thecannula1400 andstylet1450 separately in an external view from the side of the bevel, andarrow1490 shows one method by which thestylet1450 can be engaged with thecannula1400. One output pole of an electrical power supply, such as the reference pole of an RF generator can be attached to theconnector1423, for example, by means of an alligator clip. Electrical signals applied to theconnector1423 conduct through thecable1424 to theshaft1410, and from theshaft1410 to theactive tip1420. Theneedle1400 can be used as theneedle170 inFIG. 1D, andconnection175 can be the junction between thepin1423 and a cable connected to one output pole of an RF generator; in this example, when a catheter electrode passing through theneedle1300 is connected to the opposite output pole of the RF generator, and the active tip of the electrode is not in contact with theshaft1410, and both the electrode's active tip and the needleactive tip1420 are in contact with the human body, electrical current flows between theactive tip1420 of theneedle1400 and the active tip of the catheter electrode.
• In certain embodiments, the invention presented here can relate to medical catheters in general, including catheters configured for placement in a particular bodily location or locations, such as the epidural space, bodily spaces, bodily cavities, bodily potential spaces, between layers of tissue, blood vessels, the urinary tract, the urethra, the ureter, the renal pelvis, the vagina, the uterus, the fallopian tubes, the digestive tract. The invention presented here can relate to medical electrodes, including RF electrodes and stimulation electrodes, including electrodes configured for placement in the epidural space, in bodily spaces, in bodily cavities, in bodily potential spaces, between layers of tissue, in blood vessels, in the urinary tract, in the urethra, in the ureter, in the renal pelvis, in the vagina, in the uterus, in the fallopian tubes, in the digestive tract. Although the present invention is described with several particular embodiments, various changes and modifications can be suggested by one skilled in the art. In particular, the present invention is described with reference to certain polymers and materials and methods of processing those materials, but can apply to other types of processing and materials with little alteration and similar results. Furthermore, the present invention contemplates several process steps that may be performed either in the sequence described or in an alternative sequence without departing from the scope and the spirit of the present invention. The present invention is intended to encompass such changes and modification as they fall within the scope and the spirit of the appended claims.

Claims (2)

1.-21. (canceled)

22. An injection electrode comprising:

a flexible, metallic coil comprising coil windings, an insulated proximal end, an uninsulated distal end, and a lumen extending therealong;

a metallic guide rod disposed within the lumen of the metallic coil;

an injection port configured such that fluid injected into the port flows through the lumen of the metallic coil;

a connector in electrical communication with the metallic coil and configured to energize the uninsulated distal end;

a thermocouple in electrical communication with the metallic coil and configured to measure temperature at the uninsulated distal end;

wherein electrical conductors of the connector, the thermocouple, or both, extend within the lumen of the metallic coil; and

wherein a portion of the uninsulated distal end comprises a plurality of the coil windings spaced apart to allow the fluid injected through the lumen to flow out therebetween around a full exterior circumference of the lumen of the metallic coil.

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