The present application claims the benefit of priority from U.S. c. ≡119, U.S. provisional application No. 63/323,832, previously filed on 25 at 2022, 3, which provisional application is incorporated by reference in its entirety as if fully set forth herein.
Detailed Description
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, and not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve the intended purpose thereof as described herein. More specifically, "about" or "approximately" may refer to a range of values of ±20% of the recited values, for example "about 90%" may refer to a range of values of 71% to 110%.
As used herein, the terms "patient," "subject," "user," and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, but use of the subject invention in a human patient represents a preferred embodiment. Furthermore, the vasculature of a "patient," "subject," "user," and "subject" may be that of a human or any animal. It should be understood that the animal may be of any suitable type including, but not limited to, a mammal, a veterinary animal, a livestock animal or a companion animal, and the like. For example, the animal may be a laboratory animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain characteristics similar to humans. It should be appreciated that the subject may be, for example, any suitable human patient. Likewise, the term "proximal" refers to a location closer to an operator or physician, while "distal" refers to a location further from the operator or physician.
As discussed herein, an "operator" may include a doctor, surgeon, technician, scientist, or any other individual or delivery meter device associated with delivering a multi-electrode catheter for treating drug refractory atrial fibrillation to a subject.
As discussed herein, the term "ablation" when referring to the devices and corresponding systems of the present disclosure refers to components and structural features configured to reduce or prevent the generation of unstable cardiac signals in cells by utilizing non-thermal energy, such as irreversible electroporation (IRE), interchangeably referred to in the present disclosure as Pulsed Electric Field (PEF) and Pulsed Field Ablation (PFA). "ablation" as used throughout the present disclosure, when referring to the devices and corresponding systems of the present disclosure, refers to non-thermal ablation of cardiac tissue for certain conditions, including, but not limited to, arrhythmia, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablation" also includes known methods, devices and systems that implement various forms of body tissue ablation as understood by those skilled in the relevant art.
As discussed herein, the terms "bipolar" and "monopolar" when used in reference to an ablation scheme describe an ablation scheme that differs in terms of current path and electric field distribution. "bipolar" refers to an ablation protocol that utilizes a current path between two electrodes, both of which are positioned at a treatment site; the current density and the current flux density at each of the two electrodes are typically approximately equal. "monopolar" refers to an ablation procedure utilizing a current path between two electrodes, wherein one electrode comprising a high current density and a high electrical flux density is positioned at the treatment site and a second electrode comprising a relatively lower current density and a lower electrical flux density is positioned away from the treatment site.
As discussed herein, the terms "biphasic pulse" and "monophasic pulse" refer to the corresponding electrical signals. A "biphasic pulse" refers to an electrical signal comprising a positive voltage phase pulse (referred to herein as a "positive phase") and a negative voltage phase pulse (referred to herein as a "negative phase"). "monophasic pulse" refers to an electrical signal that includes only a positive or negative phase. Preferably, the system providing biphasic pulses is configured to prevent the application of a direct current voltage (DC) to the patient. For example, the average voltage of the biphasic pulse may be zero volts relative to ground or other common reference voltage. Additionally or alternatively, the system may include a capacitor or other protective component. Voltage amplitudes of biphasic and/or monophasic pulses are described herein, it being understood that the expressed voltage amplitudes are absolute values of the approximate peak amplitudes of each of the positive voltage phase and/or the negative voltage phase. Each phase of the biphasic pulse and the monophasic pulse preferably has a square shape that includes a substantially constant voltage amplitude during most of the phase's duration. The phases of the biphasic pulse are separated in time by an inter-phase delay. The inter-phase delay duration is preferably less than or approximately equal to the duration of the phase of the biphasic pulse. The inter-phase delay duration is more preferably about 25% of the duration of the phase of the biphasic pulse.
As discussed herein, the terms "tubular" and "tube" are to be understood in a broad sense and are not limited to structures that are right circular cylinders or that are entirely circumferential in cross-section or have a uniform cross-section throughout their length. For example, the tubular structure is generally shown as a substantially right circular cylinder structure. However, the tubular structure may have a tapered or curved outer surface without departing from the scope of the present disclosure.
As used herein, the term "temperature rating" is defined as the maximum continuous temperature that a component can withstand during its lifetime without causing thermal damage such as melting or thermal degradation (e.g., charring and chipping) of the component.
The present disclosure relates to systems, methods, or uses and devices utilizing an end effector that includes an electrode attached to a spine. The exemplary systems, methods, and devices of the present invention may be particularly useful for IRE ablation of cardiac tissue to treat cardiac arrhythmias. Ablation energy is typically provided to the heart tissue by an end portion of the catheter that can deliver ablation energy along the tissue to be ablated. Some example catheters include a three-dimensional structure at the tip portion and are configured to apply ablation energy from various electrodes positioned on the three-dimensional structure. Fluoroscopy may be used to visualize the ablation procedure in combination with such exemplary catheters.
Cardiac tissue ablation using thermal techniques such as Radio Frequency (RF) energy and cryoablation to correct for a malfunctioning heart is a well-known procedure. Typically, for successful ablation using thermal techniques, the cardiac electrode potentials need to be measured at various locations in the myocardium. Furthermore, temperature measurements during ablation provide data that enables ablation efficacy. Typically, for ablation protocols using thermal ablation, electrode potential and temperature are measured before, during, and after the actual ablation.
RF methods may have risks that may lead to charring of tissue, burns, steam bursts, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulae. Cryoablation is an alternative to RF ablation, which may reduce some of the thermal risks associated with RF ablation. However, manipulating a cryoablation device and selectively applying cryoablation is generally more challenging than RF ablation; thus, cryoablation is not feasible in certain anatomical geometries that may be reached by an electrical ablation device.
IRE as discussed in this disclosure is a non-thermal cell death technique that may be used for atrial arrhythmia ablation. To ablate using IRE/PEF, biphasic voltage pulses are applied to disrupt the cellular structure of the myocardium. The biphasic pulse is non-sinusoidal and can be tuned to target cells based on the electrophysiology of the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to generate heat at the treatment region, heating all cells indiscriminately in the treatment region. Thus, IRE has the ability to avoid adjacent heat sensitive structures or tissue, which would be beneficial in reducing the possible complications known to be affected by ablation or separation modalities. In addition or alternatively, monophasic pulses may be used.
Electroporation can be induced by applying a pulsed electric field across the biological cells to cause reversible (temporary) or irreversible (permanent) creation of pores in the cell membrane. Upon application of a pulsed electric field, the cell has a transmembrane electrostatic potential that rises above the static potential. Electroporation is reversible when the transmembrane electrostatic potential remains below the threshold potential, meaning that the pores can close when the applied pulsed electric field is removed and the cells can repair and survive themselves. If the transmembrane electrostatic potential rises above the threshold potential, electroporation is irreversible and the cell becomes permanently permeable. Thus, cells die from a loss of homeostasis, typically from programmed cell death or apoptosis, which is believed to leave less scar tissue than other modes of ablation. Typically, different types of cells have different threshold potentials. For example, cardiac cells have a threshold potential of about 500V/cm, whereas for bone, the threshold potential is 3000V/cm. These differences in threshold potential allow IRE to selectively target tissue based on the threshold potential.
The solutions of the present disclosure include systems and methods for applying electrical signals from catheter electrodes positioned near myocardial tissue, preferably by applying a pulsed electric field effective to induce electroporation in myocardial tissue. The systems and methods can effectively ablate targeted tissue by inducing irreversible electroporation. In some examples, the systems and methods are effective to induce reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when the electricity applied with the electrodes is below the electric field threshold of the target tissue that allows cell repair. Reversible electroporation does not kill cells, but allows the physician to view the effect of reversible electroporation on the electrical activation signal near the target site. Exemplary systems and methods for reversible electroporation are disclosed in U.S. patent publication 2021/0162210, the entire contents of which are incorporated herein by reference and attached to the appendix of priority application 63/323,832.
The pulsed electric field and its effectiveness in inducing reversible and/or irreversible electroporation may be affected by the physical parameters of the system and the biphasic pulse parameters of the electrical signal. Physical parameters may include electrode contact area, electrode spacing, electrode geometry, and the like. Examples presented herein generally include physical parameters suitable for effectively inducing reversible and/or irreversible electroporation. Biphasic pulse parameters of an electrical signal may include voltage amplitude, pulse duration, pulse-to-pulse delay, inter-pulse delay, total applied time, delivered energy, and the like. In some examples, parameters of the electrical signal may be adjusted to induce both reversible and irreversible electroporation given the same physical parameters. Examples of various ablation systems and methods including IRE are provided in U.S. patent publications 2021/0169550A1, 2021/0169567A1, 2021/0169568A1, 2021/0161592A1, 2021/0196372A1, 2021/0177503A1 and 2021/0186604A1, the entire contents of each of these patent publications being incorporated herein by reference and attached in the appendix of priority application 63/323,832.
To deliver Pulsed Field Ablation (PFA) in an IRE (irreversible electroporation) procedure, the surface area of the electrode in contact with the tissue being ablated should be sufficiently large. As described below, the medical probe includes a tubular shaft having a proximal end and a distal end, and a basket assembly located at the distal end of the tubular shaft. The basket assembly includes a single unitary structure. The unitary structure may include a plurality of ridges formed from a planar sheet of material and one or more electrodes coupled to each of the ridges. The plurality of ridges may converge at a central ridge intersection comprising one or more cuts. The cutouts may allow each of the ridges to flex such that the ridges form a basket assembly that approximates a sphere or an oblate spheroid. It is noted that the cuts (in the various configurations described and illustrated in this specification) allow the basket to be compressed into a smaller form factor when undeployed (or being retracted into the delivery sheath) without buckling or plastic deformation.
Fig. 1 is a schematic illustration of a medical system 20 including a medical probe 22 and a console 24 according to an embodiment of the present invention. Medical system 20 may be based on, for example, a system produced by Biosense Webster inc (31Technology Drive,Suite 200,Irvine,CA 92618USA)The system. In the embodiments described below, the medical probe 22 may be used for diagnostic or therapeutic treatment, such as for performing an ablation procedure in the heart 26 of the patient 28. Alternatively, the medical probe 22 may be used for other therapeutic and/or diagnostic purposes in the heart or other body organs, mutatis mutandis.
The medical probe 22 includes a flexible insertion tube 30 and a handle 32 coupled to the proximal end of the tubular shaft. During a medical procedure, a medical professional 34 may insert the probe 22 through the vascular system of the patient 28 such that the distal end 36 of the medical probe enters a body cavity, such as a chamber of the heart 26. Upon entry of distal end 36 into the chamber of heart 26, medical professional 34 may deploy basket assembly 38 adjacent distal end 36 of medical probe 22. The basket assembly 38 may include a plurality of electrodes 40 attached to a plurality of ridges 214, as described below with reference to fig. 2A and 2B. To begin performing a medical procedure, such as irreversible electroporation (IRE) ablation, the medical professional 34 can manipulate the handle 32 to position the distal end 36 such that the electrode 40 engages the cardiac tissue at the desired location or locations. Upon positioning distal end 36 such that electrode 40 engages heart tissue, medical professional 34 can activate medical probe 22 such that electrode 40 delivers an electrical pulse to perform IRE ablation.
The medical probe 22 may include an introducer sheath including the flexible insertion tube 30 and the handle 32 and a treatment catheter including the basket assembly 38, the electrode 40, and the tubular shaft 84 (see fig. 2-4). The treatment catheter is translated through the introducer sheath such that basket assembly 38 is positioned within heart 26. The distal end 36 of the medical probe 22 corresponds to the distal end of the introducer sheath when the basket assembly 38 is received within the flexible insertion tube 30, and the distal end 36 of the medical probe 22 corresponds to the distal end of the basket assembly 38 when the basket assembly 38 extends from the distal end of the introducer sheath. Alternatively, the medical probe 22 may be configured to include a second handle on the treatment catheter and other features as would be understood by one of ordinary skill in the relevant art.
In the configuration shown in fig. 1, the console 24 is connected by a cable 42 to a body surface electrode that typically includes an adhesive skin patch 44 attached to the patient 28. The console 24 includes a processor 46 that, in conjunction with a tracking module 48, determines the position coordinates of the distal end 36 within the heart 26. The position coordinates may be determined based on electromagnetic position sensor output signals provided from the distal portion of the catheter when the generated magnetic field is present. Additionally or alternatively, the location coordinates may be based on impedance and/or current measured between the adhesive skin patch 44 and the electrode 40 attached to the basket assembly 38. In addition to functioning as a position sensor during a medical procedure, the electrode 40 may perform other tasks, such as ablating tissue in the heart.
As described above, the processor 46 may be coupled with the tracking module 48 to determine the location coordinates of the distal end 36 within the heart 26 based on the impedance and/or current measured between the adhesive skin patch 44 and the electrode 40. Such determination is typically after a calibration procedure has been performed that correlates the impedance or current with the known position of the distal end. While the embodiments presented herein describe electrodes 40 that are preferably configured to deliver IRE ablation energy to tissue in heart 26, it is considered to be within the spirit and scope of the present invention to configure electrodes 40 to deliver any other type of ablation energy to tissue in any body cavity. Furthermore, while described in the context of electrodes 40 configured to deliver IRE ablation energy to tissue in heart 26, those skilled in the art will appreciate that the disclosed techniques may be applicable to electrodes used to map and/or determine various characteristics of an organ or other portion of the body of patient 28.
The processor 46 may include real-time noise reduction circuitry 50, typically configured as a Field Programmable Gate Array (FPGA), and analog-to-digital (a/D) signal conversion integrated circuitry 52. The processor may be programmed to execute one or more algorithms and use the characteristics of circuitry 50 and 52 and the modules to enable the medical professional 34 to perform an IRE ablation procedure.
The console 24 also includes an input/output (I/O) communication interface 54 that enables the console 24 to communicate signals from and/or to the electrode 40 and the adhesive skin patch 44. In the configuration shown in fig. 1, console 24 also includes IRE ablation module 56 and switching module 58.
IRE ablation module 56 is configured to generate IRE pulses that include peak power in the range of tens of kilowatts. In some examples, electrode 40 is configured to deliver an electrical pulse comprising a peak voltage of at least 900 volts (V). Medical system 20 performs IRE ablation by delivering IRE pulses to electrodes 40. Preferably, medical system 20 delivers biphasic pulses between electrodes 40 on the ridges. Additionally or alternatively, medical system 20 delivers monophasic pulses between at least one of electrodes 40 and the skin patch.
To dissipate heat and improve the efficiency of the ablation process, the system 20 supplies irrigation fluid (e.g., saline solution) to the distal end 36 and to the electrode 40 via a channel (not shown) in the tubular shaft 84 (see fig. 2A-2C). Additionally or alternatively, the irrigation fluid may be supplied through the flexible insertion tube 30. The console 24 includes a flushing module 60 to monitor and control flushing parameters such as pressure and temperature of the flushing fluid. It is noted that while the exemplary embodiment of the medical probe is preferably for IRE or PFA, it is also within the scope of the present invention to use the medical probe alone for RF ablation only (monopolar mode or bipolar mode with external ground electrode), or sequentially (some electrodes in IRE mode and other electrodes in RF mode) or simultaneously (electrode set in IRE mode and other electrodes in RF mode) in combination with IRE ablation and RF ablation.
Based on the signals received from the electrode 40 and/or the adhesive skin patch 44, the processor 46 may generate an electroanatomical map 62 showing the position of the distal end 36 within the patient. During a procedure, the processor 46 may present the map 62 to the medical professional 34 on the display 64 and store data representing the electroanatomical map in the memory 66. Memory 66 may include any suitable volatile memory and/or nonvolatile memory, such as random access memory or a hard disk drive.
In some embodiments, medical professional 34 can manipulate map 62 using one or more input devices 68. In alternative embodiments, display 64 may include a touch screen that may be configured to accept input from medical professional 34 in addition to presenting map 62.
Fig. 2A is a schematic illustration showing a perspective view of a medical probe 22 including a basket assembly 38 in an expanded form when unconstrained, such as by being pushed out of an insertion tube lumen 37 at a distal end 36 of an insertion tube 30. The medical probe 22 shown in fig. 2A lacks the introducer sheath shown in fig. 1. Fig. 2B shows the basket assembly in collapsed form within the insertion tube 30 of the introducer sheath. In the expanded form (fig. 2A), the ridges 214 curve radially outward, while in the collapsed form (fig. 2B), the ridges are generally disposed along the longitudinal axis 86 of the insertion tube 30.
As shown in fig. 2A, basket assembly 38 includes a plurality of flexible ridges 214 formed at and connected at the ends of tubular shaft 84. During a medical procedure, the medical professional 34 may deploy the basket assembly 38 by extending the tubular shaft 84 from the insertion tube 30, causing the basket assembly 38 to exit the insertion tube 30 and transition to the expanded form. The ridges 214 may have an oval (e.g., circular) or rectangular (which may appear flat) cross-section and comprise a flexible, resilient material (e.g., a shape memory alloy such as nickel titanium, also known as nitinol) forming struts, as will be described in more detail herein.
As shown in fig. 2A, a plurality of flexible ridges 214 converge at a central ridge intersection 211. In some examples, the central spine intersection 211 may include one or more cutouts 212 that allow the spine 214 to flex when the respective attachment end 216 of each spine is connected to the spine retention hub 90, as described in more detail below.
In the embodiments described herein, one or more electrodes 40 positioned on ridges 114 of basket assembly 38 may be configured to deliver ablation energy (RF and/or IRE) to tissue in heart 26. Additionally or alternatively, the electrodes may also be used to determine the position of basket assembly 38 and/or measure physiological characteristics, such as local surface potentials at corresponding locations on tissue in heart 26. The electrodes 40 may be biased such that a greater portion of one or more electrodes 40 face outward from the basket assembly 38 such that one or more electrodes 40 deliver a greater amount of electrical energy outward away from the basket assembly 38 (i.e., toward the heart 26 tissue) than inward.
Examples of materials that are ideally suited for forming electrode 40 include gold, platinum, and palladium (and their corresponding alloys). These materials also have a high thermal conductivity that allows the minimal heat generated on the tissue (i.e., by the ablation energy delivered to the tissue) to be conducted through the electrode to the back of the electrode (i.e., the portion of the electrode on the inside of the ridge) and then to the blood pool in heart 26.
As shown in fig. 2A and 2B, basket assembly 38 has a distal end 39. The medical probe 22 may include a ridge retention hub 90 extending longitudinally from the distal end of the tubular shaft 84 toward the distal end 39 of the basket assembly 38. As described above, the console 24 includes a flush module 60 that delivers flush fluid to the basket assembly 38 through the tubular shaft 84.
Turning to fig. 2C, the basket assembly 38 includes a single unitary structure that includes a plurality of ridges 214 (shown more clearly in fig. 9 and 10A) formed from a planar sheet of material 210. The ridge retention hub 90 may be inserted into the tubular shaft 84 and attached to the tubular shaft 84. The ridge retention hub 90 may include a cylindrical member 94 including a plurality of relief grooves 96, a flush hub 97, a plurality of flush openings 98, and at least one ridge retention hub electrode 99, or some combination thereof. Relief grooves 96 may be provided on an outer surface of the cylindrical member 94 and configured to allow a portion of each ridge 214 (such as each ridge attachment end 216) to fit into the corresponding relief groove 96. In particular, each spine attachment end 216 may include an aperture 216a and one or more detents 216b. The eyelets 216a and detents 216b are provided to aid assembly and to physically retain the ridges to the tubular member 84 by the relief grooves 96.
The attachment end 216 may be a generally linear end of the spine 214. The attachment end 216 may be configured to extend outwardly from the spine retention hub 90 such that the basket assembly 38 is positioned outwardly from the spine retention hub 90 and, thus, the tubular shaft 84. In this manner, the ridges 214 may be configured to position the basket assembly 38 away from the distal end of the tubular shaft 84 and away from the distal end of the insertion tube 30 when the basket assembly is deployed.
As described above, the console 24 includes an irrigation module 60 that delivers irrigation fluid to the distal end 36. The plurality of irrigation openings 98 may be angled to spray or otherwise disperse irrigation fluid to tissue in a given electrode 40 or heart 26. Since the electrode 40 does not include irrigation openings that deliver irrigation fluid, the configuration described above enables heat transfer from the tissue to the portion of the electrode on the inside of the ridge 214 (i.e., during an ablation procedure), and the electrode 40 may be cooled by aligning the irrigation fluid with the portion of the electrode 40 on the inside of the ridge 214 via the irrigation openings 98. The spine retention hub electrode 99 disposed at the distal end of the retention hub 90 may be used in combination with the electrode 40 on the spine 214 or, alternatively, may be used independently of the electrode 40 for reference mapping or ablation.
Fig. 2D is an exploded view of the contact force sensor 400 referenced in fig. 2C. As shown in fig. 2D, the contact force sensor 400 is disposed inside the tube 84 (not shown in fig. 2D) and is located proximally relative to the basket assembly 38 and as close as possible to the basket assembly 38 so that contact with the heart tissue by the ridges 214 can be transferred to the contact force sensor 400. The contact force sensor 400 includes a coupler 414 provided with a plurality of notches 414a, 414b, 414c on the outer circumference of the cylindrical member or coupler 414 for corresponding engagement with the protrusions 194a, 194b, 194c of the beam coupling member 190. The ridge retaining hub or coupler 90 is provided with notches 416a, 416b, 416c that mate with the protrusions 192a, 192b, 192c of the beam coupling member 190. The flat surfaces 416d of the ridge-retaining hub or coupler 90 are formed (angled relative to the axis 86 of the ridge-retaining hub or coupler 90), whereby each flat surface 416d is angled relative to the axis 86 such that each flat surface is complementary to the angle (i.e., helix angle) of the beam coupling member 190 defined by the helical path of the protrusions 194a, 194b, 194 c. In a configuration similar to the ridge-retaining hub or planar surface 416d of the coupler 90, three planar surfaces (not shown due to the perspective view) 414d are also provided for the coupler 414 that contact the force sensor 400, as the three planar surfaces 414d are also angled relative to the axis 86 such that each planar surface 414d of the coupler 414 is generally parallel to the angled path of the beam coupling member 190 defined by the helical ramps of the protrusions 194a-194c and the planar surface 416d.
The position sensor coils 422 and 424 are mounted to the coupler 414 (for coupling with the hub 96) in a generally equiangular configuration about the axis 86. It should be noted that while two coils (for the X-axis and Y-axis) are used in the exemplary embodiment to determine the position of these coils (as mounted to the coupler 414, thereby determining the position of the basket ridges, since the distance between the basket ridges and the position sensor is known), in some cases only one position sensing coil may be used if the other two axes are known via other visualization techniques. Also, depending on the packaging constraints of the catheter, three position sensing coils may be used. Details of the contact force sensor are provided in U.S. patent application publication 20210077180A1 published at 2021, 3 and 18, which is incorporated by reference herein and attached to the appendix of priority application 63/323,832.
Fig. 3A is a perspective view of basket assembly 38 in an expanded form wherein a plurality of flexible ridges 214 converge at a central ridge intersection 211 having a single cutout 212. Each ridge 214 may include a plurality of electrodes 40. As shown, each ridge 214 may be insulated from the respective electrode 40 by an insulating sheath 80 covering at least a portion of the ridge 214. In addition, each ridge may also include a frame extrusion 70, as shown more clearly in FIG. 5B. The frame extrusion 70 may be used to maintain the position of the insulating sheath 80 and the electrode 40 by preventing the insulating sheath 80 from sliding or moving around the ridges 214 during deployment. The frame extrusion 70 may also be used to insulate the electrode 40 from the ridges 214.
Fig. 3B shows a cross-sectional view of the corresponding ridge 214, insulating sheath 80, and electrode 40 of fig. 3A. In some examples, the electrode 40 may have a substantially circular or oval cross-sectional shape that matches the cross-sectional shape of the insulating sheath 80, while the ridges 214 may have a substantially rectangular cross-sectional shape. The insulating sheath 80 may also include a substantially rectangular opening such that the corresponding ridge 214 may extend through the insulating sheath 80. As shown in fig. 3B, electrode 40 may include an electrode body thickness T1 substantially similar to ridge thickness T2. In some examples, the plurality of ridges 214 may have a cross-sectional thickness of about 0.05mm (0.002 ") to about 0.15mm (0.006"). Each electrode body 40 may have a wall cross-sectional thickness of about 0.03mm (0.001 ") to about 0.13mm (0.005"). Each electrode body 40 may have a wall cross-sectional thickness of about 0.1mm (0.004 ") to about 0.3mm (0.012").
Referring back to fig. 2A-2C, one or more electrodes 40 may be attached to the spine 214 to form the basket assembly 38. In some examples, each electrode 40 may include a conductive material (e.g., gold, platinum, and palladium (and their respective alloys)).
Turning to fig. 4A-4C, the electrode 40 may have various cross-sectional shapes, curvatures, lengths, number of lumens, and lumen shapes. Electrode 440 is provided to illustrate various configurations of electrode 40 that may be used with medical device 22, but should not be construed as limiting. Those skilled in the art will appreciate that various other configurations of the electrode 40 may be used with the disclosed technology without departing from the scope of the present disclosure.
Each electrode 440 may have an outer surface 474 facing outwardly from the electrode 440 and an inner surface 476 facing inwardly toward the electrode 440, with at least one lumen 470 formed through the electrode 440. The lumen 470 may be sized and configured to receive the spine 214 such that the spine 214 may pass through the electrode 440. The lumen 470 may be a symmetrical opening through the electrode 440 and may be disposed offset relative to the central axis 87 of the respective electrode. In other examples, the lumens 470 may pass through the electrode 440 in a generally transverse direction relative to the central axis 87 of the respective electrode. Further, depending on the particular configuration, the lumen 470 may be positioned in the electrode 440 closer to the bottom surface, closer to the top surface, or closer to the middle of the electrode 440. In fig. 4A and 4B, the top surface (upper side) is oriented toward the top of the drawing, the bottom surface (lower side) is oriented toward the bottom of the drawing, and the middle is located between the top surface and the bottom surface. In other words, each electrode 440 may include an inner lumen 470 that is offset relative to the center of mass of the electrode 440.
In addition, as shown in fig. 4A-4C, the electrode 440 may have a lumen 470 that is large enough to pass the respective ridges 214 and wires through the electrode so that the electrode 440 may be in electrical communication with the console 24. Although not shown, the electrode 440 may also include a wire relief that forms a recess or depression in the electrode 440 adjacent the lumen 470 for passing one or more wires through the lumen 470 along with the corresponding ridges 214. The relief may be sized to provide space for wires of electrode 440 to pass through electrode 440 so that electrode 440 may be in electrical communication with console 24.
Alternatively, or in addition, the wire may be threaded through the wire lumen. Although not depicted, the electrode 40 may include both a wire relief adjacent the lumen 470 and a wire lumen. Such electrodes may allow additional wires to pass through the electrode body.
As shown in fig. 4A-4C, the electrode 440 may include a substantially circular or elliptical cross-sectional shape. In particular, the electrode 440 may include a first portion 441A and a second portion 441B that define a longitudinal direction of the electrode 440 and that are joined together to form a substantially circular shape. The two portions 441A, 441B may each independently be semi-circular or semi-elliptical in shape that curves inwardly relative to the central axis 87 of the respective electrode 440. Although not shown, the two portions 441A, 441B may have independent lengths or curvatures such that the dimensions of the respective electrodes may be more circular, as shown in fig. 4A, or more elliptical or substantially flattened on the first portion 441A or the second portion 441B.
Fig. 5A and 5B are schematic illustrations showing various insulating sheaths 580A-580C of a given medical device 22 according to embodiments of the present invention. Fig. 5A is a front view of insulating sheath 580C, and fig. 5B is a perspective view thereof. The insulating sheath 580A-580C may be made of biocompatible, electrically insulating materials such as polyamide-polyether (Pebax) copolymers, polyethylene terephthalate (PET), polyurethane, polyimide, parylene, silicone. In some examples, the insulating material may include a biocompatible polymer, including, but not limited to: polyether ether ketone (PEEK), polyglycolic acid (PGA), polylactic-co-glycolic acid (PLGA), polycaprolactone (PCL), poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly-L-lactide, polydioxanone, polycarbonate and polyanhydride, wherein the ratio of certain polymers is selected to control the extent of the inflammatory reaction. Insulating jackets 580A-580C may also include one or more additives or fillers, such as Polytetrafluoroethylene (PTFE), boron nitride, silicon carbide, aluminum oxide, aluminum nitride, zinc oxide, and the like. The insulating jackets 580A-580C may help insulate the ridges 214 and/or wires passing through the insulating jackets 580A-580C from the electrode 40 to prevent arcing of the ridges 214 by the electrode 40 and/or mechanical wear of the wires passing through the insulating jackets 580A-580C.
As shown in fig. 5A and 5B, insulating jackets 580A-580C may include a substantially circular or oval cross-sectional shape. The insulating sheath may be comprised of a single lumen (as shown in fig. 5B) or a multiple lumen configuration (as shown in fig. 5A). The multi-lumen sheath may be configured such that the alloy frame and wire share a single lumen, while the second lumen may be used for irrigation. The alloy frame and wire may also occupy separate lumens, as described. The current embodiment does not use an irrigation sheath. For these designs, the insulating sheath may be continuous (individual sleeves extending from near the distal end of each alloy frame strut), segmented (bridging between electrode gaps), or a combination of both. Further, the insulating sheath 580A, 580B may include a first lumen 582A, 582B and a second lumen 584A, 584B, while the insulating sheath 580C includes only the first lumen 582C. In one configuration, the first lumens 582A, 582B may be configured to receive the ridges 214, while the second lumens 584A, 584B may be configured to receive wires, or vice versa. In other examples, the first lumens 582A-582C may each be configured to receive the ridges 214 in addition to one or more wires that may be connected to one or more electrodes 40. Further, as shown in fig. 5B, insulating sheaths 580A-580C may include apertures 586 through which wires may be electrically connected to electrode 40. Although shown in fig. 5B as being near the bottom of insulating sheath 580C, aperture 586 may be positioned near the top or side of insulating sheath 580C. Further, as shown in fig. 5B, insulating sheath 580C may include a plurality of apertures 586, wherein each aperture is disposed on the same side of the insulating sheath (i.e., top, bottom, left, right) or on a different side of the insulating sheath, depending on the application. As shown in fig. 5B, the frame extrusion 570 may be used to maintain the position of the insulating sheath 580 and electrodes (not shown) by preventing the insulating sheath 580C from sliding or moving around the ridges during deployment.
As shown in fig. 5C, the frame extrusion 570 may be composed of two sections, including a distal frame extrusion 570A near the central intersection 211 of the basket assembly and a proximal frame extrusion 570B near the spine attachment end 216. A frame extrusion 570 having two sections may improve the bonding and mechanical properties of the basket assembly 38. Additionally, the frame extrusion 570 may provide electrical insulation between the spine 114 and the electrode 40. The frame extrusion 570 having two sections 570A, 570B and no frame extrusion extending over the center of the associated spine 114 may allow for greater flexibility and shape retention of the basket assembly 38. Although not depicted, the frame extrusion 570 may be a single piece that extends along the entire length of the respective spine. In some examples, the frame extrusion 570 may be uncoated or coated with a material including silicone, polyurethane, parylene, polyether block amide (e.g., known under the trade names PEBAX (armema) and VESTAMID E (Evonik Industries)), or polyethylene terephthalate. The coating may extend along at least a portion of the frame extrusion 570 or over a portion of each section 570A, 570B. The coating may also extend along the entire length of the frame extrusion 570 and/or along the entire length of each section 570A, 570B. The coating may be composed of a heat-shrinkable material for creating very thin wall thicknesses. The coating may provide further electrical insulation and provide a bondable surface that is not easily slipped. In some examples, the frame extrusion 570 may be composed of multiple layers, including multiple full length extrusions combined with one or more segmented (proximal and distal end) extrusions. In some examples, the full length extrusion may be in contact with the patient and may additionally include a second layer or a third layer, depending on the configuration.
Fig. 5D provides a schematic illustration showing a respective distal frame extrusion 570A positioned proximate the central intersection 211. Distal frame extrusion 570A may have a substantially circular cross-sectional shape with proximal lumen 572A sized to loosely fit the spine 214 therethrough. Distal frame extrusion 570A may also include a distal lumen 572B sized to closely fit through ridges 214. In some examples, distal lumen 572B of distal frame extrusion 570A tapers inwardly about spine 214 about central axis 87 and forms a substantially rectangular cross-sectional opening sized to closely fit spine 214 and prevent sliding along spine 214.
Fig. 5E-5G provide schematic illustrations of frame extrusion mounts 573A, 573B positioned on ridges 214 to provide alignment of frame extrusion 570 and/or insulating sheath 580. Each respective ridge 214 may have one or more of a ridge 573A or a via 573B added to the ridge 214 by laser cutting or other suitable method. Ridges 214 with one or both of ridges 573A and/or through holes 573B may improve adhesive bonding and improve mechanical retention of frame extrusion 570. A length of gap between ridges 573B may help minimize "bridging" of the extrusion between the ridges. Although not depicted, each distal frame extrusion 570 may provide a recess within the distal lumen 572B of the distal frame extrusion 570A configured to interact with one or more cuts extending along the length of the spine 214, as shown in fig. 7A-7E.
Fig. 6A and 6B are schematic illustrations showing cross-sectional views of a given line 600, 650 connectable to a given electrode 40 according to embodiments of the invention. Fig. 6A shows a solid core wire 600. Fig. 6B shows a stranded wire 650. Each wire 600, 650 may extend through at least a portion of the tubular shaft 84 and through the tubular shaft 84. The solid core wire 600 may include a conductive core material 602 and a conductive cover material 604 surrounding the conductive core material 602. Similarly, the strand 650 may include strands, each strand including a conductive core material 652 and a conductive cover material 654 surrounding the conductive core material 652. Each wire 600, 650 may include an insulating sheath 606 surrounding the conductor. Wires 600, 650 may be configured to withstand a voltage differential of adjacent wires sufficient to deliver an IRE pulse. Preferably, the wires 600, 650 can withstand at least 900V between adjacent wires and more preferably withstand at least 1,800V between adjacent wires. To reduce the likelihood of dielectric breakdown between conductors of adjacent wires, the conductive cover materials 604, 654 may have a lower conductivity than the core materials 602, 652.
The insulating sheath 606 may be configured to have a temperature rating of between 150 degrees celsius and 200 degrees celsius such that the electrically insulating sheath 606 melts or degrades (e.g., char and chip) during welding of the wire 600 to the electrode 40 (e.g., at a temperature of 300 degrees celsius), and thus the insulating sheath 606 of the wire 600 does not need to be mechanically stripped. In other examples, the insulating sheath 606 may have a temperature rating of greater than 200 degrees celsius to prevent the electrically insulating material 602 from melting or degrading (e.g., charring and chipping) during manufacture and/or during use of the medical probe 22. The insulating sheath 606 may be mechanically stripped from the wire 600 before the wire 600 is electrically connected to the electrode 40.
Fig. 7A-7E are schematic illustrations of top views of basket assembly 38 showing various examples of one or more cutouts 212 on central spine intersection 211. As shown, the intersection 211 may include a single discrete cutout 212A, as shown in fig. 7A and 7B. Alternatively, the intersection 211 may include two or more cutouts 212B, as examples provided in fig. 7C and 7D. The one or more cutouts 212A, 212B may include a variety of patterns, such as centrosymmetric (i.e., symmetrical about a center point) and equiangular (i.e., including equal angles) to allow equal bending between the ridges 214, and disproportionate and asymmetric to allow unequal bending of the ridges 214 to change structural stability. In some cases, when basket assembly 38 includes an even number of ridges 214, the pattern of one or more cutouts 212 may change between every other ridge, as shown in fig. 7B. In some examples, one or more cutouts 212 may extend along a portion of each ridge 214. Each of the designs shown in fig. 7A to 7E will be discussed separately.
In fig. 7A, the distal end of basket assembly 38 has an open cutout 212, which is a combination of a central opening 212A (substantially approximated by a virtual circle 213 having a diameter D1) and a slot 212B for each ridge (giving a total of six slots 212B). Each ridge is disposed generally equiangularly about the longitudinal axis with a predetermined angle a between any two ridges. Each slot 212B has a slot width S extending about a length L1 from the circumference of the virtual circle D1 such that a virtual circle 215 having a diameter D2 abuts the slot 212B. The second virtual circle 215 has a diameter D2 that is about 3.6 times the diameter D1 of the first virtual circle 213. In one embodiment, the cutout 212 (represented by the central cutout 212A and the open slot portion 212B) has a diameter of about 1.9mm2 Wherein the diameter of the virtual circle 213 is about 1.1mm and the diameter of the virtual circle 215 is about 4mm such that each open slot 212B has a width S of about 0.08mm extending about 1.5mm from the virtual circle 213 such that the negative product defined by all of the cuts in the design is about 1.9mm2 。
In fig. 7B, the basket 38 has a distal portion thereof configured with an open center 212A radiating into each of the six ridges 214. The open center 212A has a first area A1 that may be approximated by a virtual circle having a radius r1Like this. Three ridges approximately 120 degrees apart have tapered slots 212B extending rearward toward the proximal portion of basket 38. Three other ridges approximately 120 degrees apart have large apertures 217 of area A3 disposed toward the proximal portion of basket 38. The cut area A3 may be approximated by a virtual circle having a radius r3 and disposed on the ridge 214 such that the orifice 217 abuts the inner circumference of the virtual circle 215 having a radius r 2. In this configuration, each third area A3 is about 1/4 of the open first area A1, while the total negative surface area of the entire incision comprises an area that is about 1.6 times the first open area A1 of the empty space, and the second area A2 (calculated with radius r 2) comprises an area that is about 7 times the first area A1. In addition, the second area A2 includes an area that is about 36 times the third area A3. Radius r3 comprises a radius that is about 0.4 times radius r1, while radius r2 comprises a radius that is about 2.8 times radius r 1. In one exemplary embodiment, the first open area A1 of the empty space is about 2mm2 The method comprises the steps of carrying out a first treatment on the surface of the The second area A2 (defined by radius r 2) is about 15mm2 The method comprises the steps of carrying out a first treatment on the surface of the The third area A3 is about 0.4mm2 The method comprises the steps of carrying out a first treatment on the surface of the The total area of all incisions is approximately 3.5mm2 The method comprises the steps of carrying out a first treatment on the surface of the Radius r1 is about 0.8mm; r2 is about 2.2mm; and r3 is about 0.4mm.
In fig. 7C, the design has a small aperture 212A disposed in the center of the basket 38 (coincident with the longitudinal axis 86) and tadpole-shaped cuts 211 disposed on each of the ridges 214. Each tadpole-shaped cutout 211 is defined by an orifice cutout 212B that merges with a slot cutout 212C. It is noted that although the apertures 212A or 212B are shown as approximately circular, any shape of the cutout openings 212A or 212B are within the scope of the present invention so long as each aperture 212A or 212B has the requisite negative product. In the case where the apertures 212A are configured as circles, the apertures 212A have a central void A0 (having a negative area) that may be approximated by a first virtual circle having a radius r0, while each aperture 212B has a second area A2 that may be represented by a second virtual circle having a radius r 2. The orifices 212B (or "heads" of the tadpole cuts) are radially aligned such that the orifices 212B are contiguous with a first virtual circle having a radius r 1. The second virtual circle may have a radius r0 that is the radius of the first virtual circle representing the aperture 212A 1.2 times the second radius r2, while the first virtual circle r1 may have a radius r1 that is about 1.5 times the radius r0 of the central virtual circle. The tail or "tail" slot-like opening 212C extends a length L1 toward the proximal end of the basket 38 such that each tail abuts the inner circumference of the third virtual circle 215. The slot length L1 includes a length of about 6 to 10 times the first radius r1. The third virtual circle 215 may have a radius r3 extending from the longitudinal axis 86, wherein the radius r3 comprises a radius that is about 10 to 15 times the first radius r1 or the center radius r 0. In exemplary embodiments (in many embodiments), the negative product of each tadpole-shaped cut 211 is about 0.2mm2 While the negative product of the central aperture 212A is about 0.05mm2 Such that the total negative area defined by all of the cuts is about 1.4mm2 . In the same exemplary embodiment, the center radius r0 may be about 0.13mm, the second radius r2 may be about 0.2mm, and the first radius r1 may be about 0.23mm.
In fig. 7D, the design of basket 38 is provided with apertures 212A at approximately the center of ridge 214 (i.e., axis 86). Each ridge 214 is provided with a comet-shaped cut 211 having a head portion 212B and an open tapered slot tail 212C that tapers toward the proximal portion of each ridge 214. The comet-shaped cutout 212B is arranged such that the distal head portion 212B of the cutout 211 abuts the outer circumference of the second virtual circle 213, and the proximal slot-shaped opening 212C of the cutout 211 abuts the inner circumference of the third virtual circle 215. In the case where the aperture 212A is configured as a circular hole having a radius r0 located on the central axis 86, where the first radius r1 includes about 90% of the central radius r0, the second virtual circle 213 may have a second radius r2 that is about 2.5 times the central radius r0, while the third virtual circle 215 has a radius r3 (all measured from the central axis 86) that is about 10 times the central radius r 0. The ridge 214 has a first width W1 that tapers at its narrowest point toward the central axis 86 to a narrower second ridge width W2 that is about 66% of the first ridge width W1 before being subdivided into narrower two ridge arms by the comet cutout 212B, wherein each arm includes a third ridge width W3 of about 1/3 of the width W1. The comet cutout 212B has a length L1 along the ridge that is about 1.8 times the maximum ridge width W1.
In fig. 7E, the center of the radiating ridge 214 of the basket 38 (on the longitudinal axis 86) has no cut-out such that there is no void at the center of the basket to act as a sharp edge surface against biological tissue (at the edge of such a central aperture). To allow the ridges to be folded in unison near the distal portion of the basket 38, each ridge is provided with tadpole-shaped cutouts 211 extending from the head portion 212B to the tail portion 212C. The head portion 212B is arranged such that the head portion 212B abuts the outer circumference of the first virtual circle 213 having the radius r 1. Each head portion 212B has a negative surface area that may be approximated by a second virtual circle having a radius r2 that is about 90% of the first radius r 1. The tail portion 212C is defined by a third virtual circle 215 having a radius r3 that is about 10 times the first radius. The length L1 of each of these tail portions comprises a length that is approximately 1.5 times the width W1 of the ridge 214. In one exemplary embodiment (in many embodiments), the total negative area of the six incisions is about 1.5mm2 。
The ridges 214 may be folded or otherwise bent such that each respective attachment end 216 of the ridges 214 may be inserted into the distal end 85 (shown in fig. 2B) of the tubular shaft 84 and the relief groove 96 (not shown) of the ridge retaining hub 90. Although not shown in fig. 10A and 10B, it should be understood that the electrode 40 may be attached to the ridges 214 prior to insertion into the tubular shaft 84 to form the basket assembly 38. As previously described, the ridges 214 may comprise a flexible, resilient material (e.g., a shape memory alloy, such as nickel titanium (also referred to as nitinol)) that causes the basket assembly 38 to transition to its expanded form (as shown in FIG. 2A) when the basket assembly 38 is deployed from the tubular shaft 84. As will become apparent throughout this disclosure, the ridges 214 may be electrically insulated from the electrode 40 to prevent arcing of the electrode 40 to the corresponding ridge 214.
As will be appreciated by those skilled in the art having the benefit of this disclosure, the basket assembly 38 shown in fig. 2A-2C including the ridges 214 formed from a single planar sheet of material and converging at a central intersection is provided for illustrative purposes only, and the disclosed techniques are applicable to other configurations of basket assembly 38. For example, the described configuration of basket-type ridge assemblies may be obtained via laser cutting of a nitinol tube and heat treating the ridges from the tubular blank into a planar form substantially as shown herein. Likewise, the disclosed techniques may be applicable to basket assemblies 38 formed of a single spine 214 or multiple spines 214, with each spine 214 attached at both ends. In other examples, basket assembly 38 may include a central hub that connects the plurality of ridges 214 together at the distal end 39 of basket assembly 38. In still other examples, basket assembly 38 may include a single ridge 214 configured to form a spiral, a plurality of ridges 214 configured to form one or more tripods or any other shape of basket assembly 38. Thus, while fig. 2A-2C illustrate a particular configuration of basket assembly 38, the disclosed techniques should not be construed as so limited.
In the exemplary embodiment shown herein, the ridge width W may have a nominal width of about 0.6mm, and may be as low as 0.2mm or as high as 1.5mm. The thickness of each ridge may nominally be 0.09mm and may vary from 0.05mm to 0.2 mm. It should be noted that these values of width and thickness may vary depending on the stiffness desired.
Fig. 8A and 8B are schematic illustrations showing cross-sectional profiles 38A, 38B of the basket assembly such that when the basket assembly is deployed, the ridges define a three-dimensional shape comprising the cross-section. The basket assembly may be a generally spherical body comprising a generally circular cross-section as shown in fig. 8A. The basket assembly may have an approximately oblate spheroid shape including an approximately oval cross-section as shown in fig. 8B. Although not every variation of shape is shown or described herein, those skilled in the art will appreciate that the ridges 214 may also be configured to form other various shapes suitable for a particular application.
By including ridges 214 configured to form various shapes when in the expanded form, basket assembly 38 may be configured to position various electrodes 40 attached to ridges 214 at various locations, with each location being closer to or farther from the distal end of tubular shaft 84. For example, when the basket assembly 38 is in the expanded form, the electrode 40 attached to the spine 214 near the middle of the spine 214 shown in fig. 8A will be farther from the distal end of the tubular shaft 84 than the spine 214 shown in fig. 8B. Further, each ridge 214 may have an oval (e.g., circular) or rectangular (which may appear flat) cross-section, and comprise a flexible, resilient material (e.g., a shape memory alloy such as nickel titanium (also known as nitinol), cobalt chromium, or any other suitable material).
Fig. 9, 10A and 10B are schematic illustrations showing views of ridges 214 forming basket assembly 38. Fig. 9 provides one example of how a planar sheet of material 210 may be assembled with a tubular shaft 84 whereby each ridge 214 is curved or curvilinear when the respective attachment end 216 is connected to the ridge retention hub 90. As shown in fig. 10A, the ridges 214 may be formed from a single sheet of planar material 210 to form a generally star shape. In other words, the ridge 214 may be formed from the single piece of planar material such that the ridge 214 converges toward the central intersection 211. The intersection 211 may be a solid piece of material (as shown in fig. 10A) or may include one or more cutouts 212 (as shown in fig. 10B). The basket assembly 38 may include a plurality of ridges 214 ranging from about four ridges to about ten ridges from the single piece of planar material 210.
The spine assembly 210 may be physically connected to the tubular member 84 via a suitable technique, such as adhesive or molding. In one embodiment shown in fig. 10C, perforations 216a and detents 216b may be provided to aid in assembling the ridges to the tubular member 84 and physically retaining the ridges thereto.
As shown in fig. 10D, a balloon BL may be provided within the spine assembly 210 'if desired to ensure that the spine assembly 210' is fully inflated from a cylindrical form factor to a spheroid-like shape as shown in fig. 10C. The balloon BL may comprise a polymeric material. In the embodiment of fig. 10C, the spine assembly may be made from a tubular cylindrical raw material such that the proximal portion 210A and the distal portion 210B are made from a unitary material. As shown in fig. 10E, the tubular blank is cut into the desired shape of the spine assembly 210'. Thereafter, the cut tube may be shaped (or heat set) to provide the spheroid ridge configuration shown in fig. 10F, as known to those skilled in the art.
Fig. 11 is a flow chart illustrating a method 1100 of manufacturing basket assembly 38 in accordance with an embodiment of the present invention. The method 1100 may include aligning 1102 the ridges of the expandable basket assembly 38 with the electrode 40. The electrode may include an electrode body defining a lumen therethrough such that the respective ridges 214 extend through the electrode body. The electrode body may comprise a substantially circular cross-sectional shape. The method 1100 may include inserting 1104 each ridge into the lumen of at least one electrode 40. The electrodes 40 may be positioned such that the electrodes are offset between the electrodes 40 on adjacent ridges 214. The method 1100 may include fitting 1106 the ends of the ridges 216 to a tubular shaft 84 sized to traverse the vasculature such that the central ridge intersection 211 is positioned at the distal end 39 of the medical probe 22 and the respective ridges are movable from a tubular configuration to an arcuate configuration. As will be appreciated by those skilled in the art having the benefit of this disclosure, fitting 1106 the ends of the ridges into the tubular shaft may include attaching the ridges 214 to the ridge-retaining hub 90. In addition, the ridge retention hub 90 and/or the ridge 214 and the tubular shaft 84 may be inserted into the flexible insertion tube 30 to form the medical probe 22.
In some examples, the method may further include forming an approximately spheroid or oblate spheroid shape with ridges. The method 1100 may also include electrically connecting the wire to one or more electrodes. The method 1100 may further include disposing an insulating jacket over the ridge having a substantially rectangular cross-sectional shape. The electrically insulating sheath may comprise a body defining an opening having a substantially rectangular cross-sectional shape such that a respective ridge may extend through the opening.
The method may also include cutting the planar sheet of material 210 to form a plurality of ridges 214 including a central ridge intersection 211. Cutting the plurality of ridges 214 may include cutting from a pattern including longitudinal scores and transverse scores. The planar sheet of elastomeric material may comprise a shape memory alloy, such as nickel titanium (also known as nitinol), cobalt chrome, or any other suitable material. The method 1100 may include cutting discrete cuts 212 at the central ridge intersections 211. As described above, the discrete cutout 212 may be a single cutout or two or more cutouts. Further, the one or more discrete cuts may be cut into a pattern extending along at least a portion of each ridge. In some examples, these steps may occur as simultaneous steps or as a series of steps. Alternatively, the metal strands may be shaped in a pattern similar to that formed by cutting a planar sheet.
As will be appreciated by those of skill in the art, the method 1100 may include any of the various features of the disclosed techniques described herein and may vary depending on the particular configuration. Thus, the method 1100 should not be construed as limited to the specific steps and sequence of steps explicitly described herein. It is noted that while the exemplary embodiment of the medical probe is preferably for IRE or PFA, it is also within the scope of the present invention to use the medical probe alone for RF ablation only (monopolar mode or bipolar mode with external ground electrode), or sequentially (some electrodes in IRE mode and other electrodes in RF mode) or simultaneously (electrode set in IRE mode and other electrodes in RF mode) in combination with IRE ablation and RF ablation.
The disclosed technology described herein may be further understood in light of the following clauses:
clause 1: a medical probe, comprising: a tubular shaft having a proximal end and a distal end, the tubular shaft extending along a longitudinal axis of the medical probe; and an expandable basket assembly coupled to the distal end of the tubular shaft, the basket assembly comprising: a plurality of ridges extending along the longitudinal axis and converging at a central ridge intersection, each ridge of the plurality of ridges comprising: a plurality of electrodes, each electrode comprising an electrode body defining a lumen therethrough such that the respective ridge extends through the electrode body lumen, and an electrically insulating sheath disposed between the respective ridge of the plurality of ridges and the respective electrode of the plurality of electrodes, thereby electrically insulating the plurality of electrodes from the plurality of ridges, wherein a cross-sectional shape of each electrode body and electrically insulating sheath comprises a substantially circular shape.
Clause 2: the medical probe of clause 1, wherein the plurality of ridges comprise a substantially rectangular cross-sectional shape; and wherein the electrically insulating sheath comprises a body defining an opening therethrough such that the respective ridge extends through the electrically insulating sheath body, wherein the opening comprises a substantially rectangular cross-sectional shape.
Clause 3: the medical probe of clauses 1 and 2, wherein the electrically insulating sheath is disposed along at least a portion of the respective ridge.
Clause 4: the medical probe of clauses 1 and 2, wherein the electrically insulating sheath is disposed along the entire length of the respective ridge except for the central ridge intersection.
Clause 5: the medical probe of clauses 1 and 2, wherein the electrically insulating sheath is disposed along the entire length of the respective ridge except for the respective ridge end.
Clause 6: the medical probe of any of clauses 1-5, wherein a cross-sectional thickness of each electrode comprises a dimension substantially similar to a dimension of the ridge, and wherein the cross-sectional thickness of each electrode is configured to flex radially outward from the longitudinal axis when the expandable basket assembly transitions from a collapsed to an expanded form.
Clause 7: the medical probe of any of clauses 1-6, wherein each of the electrically insulating sheaths comprises a first lumen configured to receive the respective ridge.
Clause 8: the medical probe of any of clauses 1-6, wherein each of the electrically insulating sheaths comprises a first opening and a second opening, the first opening configured to receive a first wire and the second opening configured to receive the respective ridge.
Clause 9: the medical probe of clause 1, wherein each of the plurality of ridges further comprises a frame extrusion disposed between the respective ridge and the respective electrically insulating sheath.
Clause 10: the medical probe of clause 9, wherein the frame extrusion is disposed along at least a portion of the respective spine.
Clause 11: the medical probe of clauses 9 and 10, wherein the frame extrusion extends beyond an outlet of the electrically insulating sheath proximate the central ridge intersection.
Clause 12: the medical probe of clauses 9 and 10, wherein the frame extrusion extends beyond an outlet of the electrically insulating sheath proximate the respective ridge end.
Clause 13: the medical probe of clauses 9-12, wherein the frame extrusion maintains the position of the electrically insulating sheath over the respective ridges.
Clause 14: the medical probe of any of clauses 1-13, wherein the plurality of ridges extend from the central ridge intersection in an equiangular pattern such that the respective angles between respectively adjacent ridges are about equal.
Clause 15: the medical probe of any of clauses 1-13, wherein the expandable basket assembly comprises four to ten ridges of the plurality of ridges.
Clause 16: the medical probe of clause 1, wherein each respective ridge of the plurality of ridges comprises two electrodes.
Clause 17: the medical probe of any one of clauses 1-16, further comprising a wire, wherein the electrode body lumen comprises a release configured to receive the wire of the medical probe.
Clause 18: the medical probe of clause 17, wherein the wire is electrically connected to the electrode.
Clause 19: the medical probe of any of clauses 17 and 18, wherein at least a portion of the wire comprises: a conductive core material comprising a first conductivity; a conductive cover material comprising a second conductivity less than the first conductivity, the conductive cover material surrounding the conductive core material; and an insulating sheath surrounding the conductive cover material.
Clause 20: the medical probe of any of clauses 17 and 18, wherein at least a portion of the wire comprises a plurality of strands and an insulating sheath surrounding the plurality of strands, and wherein each strand of the plurality of strands comprises a conductive core material comprising a first conductivity and a conductive cover material comprising a second conductivity less than the first conductivity, the conductive cover material surrounding the conductive core material, respectively.
Clause 21: the medical probe of any of clauses 1-20, wherein the electrode body lumen is symmetrically disposed about a central axis of the electrode.
Clause 22: the medical probe of any of clauses 1-21, wherein the plurality of ridges comprise a material selected from the group consisting of nitinol, cobalt chromium, stainless steel, titanium, and combinations thereof.
Clause 23: the medical probe of any of clauses 1-21, wherein the plurality of ridges comprise a polymer.
Clause 24: the medical probe of any of clauses 1-21, wherein the plurality of electrodes are configured to deliver an electrical pulse for irreversible electroporation, the pulse having a peak voltage of at least 900 volts (V).
Clause 25: the medical probe of any of clauses 1-24, wherein the plurality of ridges are configured to form an approximately spherical basket assembly when in the expanded form.
Clause 26: the medical probe of any of clauses 1-24, wherein the plurality of ridges are configured to form an approximately oblate spheroid basket assembly when in the expanded form.
Clause 27: the medical probe of any one of clauses 1-26, further comprising a spray port configured to deliver irrigation fluid to the plurality of electrodes.
Clause 28: a method of constructing a medical probe, the method comprising: aligning the ridges of the expandable basket assembly with an electrode, the electrode comprising an electrode body defining a lumen therethrough such that the respective ridges extend through the lumen of the electrode, the electrode body comprising a substantially circular cross-sectional shape; inserting the ridge into the lumen of the electrode; and fitting the ends of the ridges to a tubular shaft sized to traverse the vasculature such that the expandable basket assembly is movable from a tubular configuration to an arcuate configuration.
Clause 29: the method of clause 28, further comprising: positioning the ridges of the expandable basket assembly through a first lumen of an electrically insulating sheath; positioning a wire through a second lumen of the electrically insulating sheath; positioning the electrode over the electrically insulating sheath; and electrically connecting the wire to the electrode through an aperture in the electrically insulating sheath, thereby providing a passageway between the second lumen and the electrode.
Clause 30: the method of clause 28, wherein each respective ridge of the plurality of ridges comprises a first electrode and a second electrode, the method further comprising: positioning the ridges of the expandable basket assembly through a first lumen of an electrically insulating sheath; aligning each respective ridge of the plurality of ridges with the first electrode and the second electrode; inserting each respective ridge of the plurality of ridges into the lumen of the first electrode and the lumen of the second electrode; and fitting an end of each respective ridge of the plurality of ridges to the tubular shaft sized to traverse vasculature.
Clause 31: the method of clause 30, further comprising offsetting the electrodes between adjacent ridges.
Clause 32: the method of any of clauses 28-31, wherein the cross-sectional shape of the electrically insulating sheath comprises a substantially circular shape.
Clause 33: the method of any of clauses 29-32, wherein the wire is insulated from the ridge.
Clause 34: the method of any of clauses 29-33, wherein at least a portion of the wire comprises: a conductive core material comprising a first conductivity; a conductive cover material comprising a second conductivity less than the first conductivity, the conductive cover material surrounding the conductive core material; and an insulating sheath surrounding the conductive cover material.
Clause 35: the method of any of clauses 29-33, wherein at least a portion of the wire comprises a plurality of strands and an insulating sheath surrounding the plurality of strands, and wherein each strand of the plurality of strands comprises a conductive core material comprising a first conductivity and a conductive cover material comprising a second conductivity less than the first conductivity, the conductive cover material surrounding the conductive core material, respectively.
Clause 36: the method of any of clauses 28-35, wherein the plurality of ridges comprise a material selected from the group consisting of nitinol, cobalt chromium, stainless steel, and titanium.
Clause 37: the medical probe of any of clauses 28-35, wherein the plurality of ridges comprise a polymer.
Clause 38: the method of any of clauses 28-37, further comprising configuring the electrode to deliver an electrical pulse for irreversible electroporation, the pulse having a peak voltage of at least 900 volts (V).
Clause 39: the method of any of clauses 28-38, further comprising configuring the plurality of ridges to form an approximately spherical basket assembly.
Clause 40: the method of any of clauses 28-38, further comprising configuring the plurality of ridges to form a basket assembly that approximates an oblate spheroid shape.
Clause 41: the method of any of clauses 28-40, further comprising configuring the spray port to deliver irrigation fluid to the electrode.
Clause 42: a spine basket member comprising: a plurality of ridges extending radially from the longitudinal axis; a plurality of electrodes including an electrode body defining a lumen therethrough such that each ridge of the plurality of ridges extends through the lumen; and an electrically insulating sheath disposed between a respective ridge of the plurality of ridges and a respective electrode of the plurality of electrodes, wherein each electrode body and electrically insulating sheath comprises a substantially circular cross-section.
Clause 43: the spine basket member of clause 42, further comprising: a cutout defining a first open area of an empty space proximate the longitudinal axis, the first open area of the empty space approximating a first virtual circle including a first diameter from the longitudinal axis, the cutout extending into each of the plurality of ridges a first length to define an open slot in each of the plurality of ridges, each slot contiguous with a circumference of a second virtual circle that is greater than the first virtual circle.
Clause 44: the spine basket member of clause 43, wherein every other slot of the plurality of spines comprises an aperture defining a third area that is less than the first open area of the empty space.
Clause 45: the spine basket member of clause 44, wherein the second virtual circle defines a second area that is about 36 times the third area.
Clause 46: the spine basket member of clause 45, wherein the second area comprises an area that is about 7 times the first open area of the empty space.
Clause 47: the spine basket component of clause 45 wherein the third area is about 1/4 of the open first area, while the total negative surface area of the cutout comprises an area that is about 1.6 times the first open area of the empty space.
Clause 48: the spine basket member of clause 45, wherein the third area comprises a circle having a radius that comprises a radius that is about 0.4 times a first radius of the first virtual circle and the radius of the second virtual circle comprises a radius that is about 2.8 times the first radius.
Clause 49: the spine basket component of clause 48, wherein the first open area of the void space is about 2mm2 The second area is about 15mm2 And the third area is about 0.4mm2 And the total area of all cuts is about 3.5mm2 。
Clause 50: the spine basket structure of clause 42 further comprising: a tadpole cut on each ridge of the plurality of ridges, each cut including a head portion contiguous with a circumference of a first virtual circle having a first radius disposed about the longitudinal axis, the head portion defining a negative product approximating a second virtual circle having a second radius, the head portion connected to a slot-shaped tail portion extending along the ridge for a first length and contiguous with an inner circumference of a third virtual circle comprising a third radius.
Clause 51: the spine basket member of clause 50, wherein the second radius comprises a radius approximately equal to a radius of the first virtual circle and the third radius comprises a radius approximately 8-15 times the radius of the first virtual circle.
Clause 52: the spine basket member of clause 51 wherein the first length of the slot-shaped tail portion comprises a length that is about 6 to 10 times the length of the radius of the first virtual circle.
Clause 53: the spine basket member of clause 50 further comprising a cutout disposed on the longitudinal axis to define a center negative area approximating a center circle comprising a center radius less than the first radius.
Clause 54: the spine basket member of clause 50, wherein the negative product of each of the tadpole-shaped cuts is about 0.2mm2 While the negative product of the center circle is about 0.05mm2 Such that the total negative area defined by all of the incisions is about 1.4mm2 。
Clause 55: the spine basket component of clause 50, wherein the central void radius is about 0.13mm, the second radius is about 0.2mm, and the first radius is about 0.23mm.
Clause 56: the spine basket member of clause 50 wherein the cutout defines a comet-shaped cutout having a head portion with a slot-shaped tapered tail extending to a proximal portion of each spine.
Clause 57: the spine basket member of clause 56 further comprising a circular aperture located on the longitudinal axis of the spine, the circular aperture having a center radius from the longitudinal axis.
Clause 58: the spine basket structure of clause 57 wherein the first radius is about 90% of the center radius, the second virtual circle comprises a second radius that is about 2.5 times the center radius, and the third virtual circle comprises a radius that is about 10 times the center radius.
Clause 59: the spine basket component of clause 58, wherein each spine comprises a first spine width that tapers toward the longitudinal axis to a smaller second spine width and is further subdivided by a portion comprising the comet-shaped cut into two narrower spine arms extending along the comet-shaped cut, each narrow spine arm comprising a third spine width.
The above embodiments are cited by way of example, and the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described and illustrated above, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.