US20030181890A1 - Medical device that removably attaches to a bodily organ - Google Patents

Abstract

The present invention is a medical device for use on a bodily organ of a patient. The medical device includes a concave support element that is removably attachable to the surface of the bodily organ, thereby defining an enclosed space adjacent to the bodily organ. The enclosed space is fluidly connected to a fluid management system for circulating a fluid inside of the enclosed space. The medical device also has an energy transfer element mounted to the concave support element and electrically connected to a control unit. In some embodiments, the energy transfer element transmits intense ultrasound energy in a frequency range of 1-30 megahertz, and the fluid acoustically couples the energy transfer element to the bodily organ, and the fluid also cools the energy transfer element.

Description

FIELD OF THE INVENTION
• The present invention relates, in general, to a medical device that removably attaches to a bodily organ and, more particularly, to such a medical device that transmits energy to tissue in or near the bodily organ.[0001]
BACKGROUND
• Physicians have been treating cancerous liver tumors that are up to about five centimeters in diameter using numerous methods including electrosurgery, cryosurgery, and ethanol injection. Another option for treating liver tumors is the application of intense ultrasound energy (IUS). Investigators have been developing IUS devices and methods for several years, especially for treating diseased tissue in the prostate gland and liver. The frequency regime for IUS devices is generally in the range of 1-30 MHz. An inherent challenge when using IUS is maintaining a focused beam of acoustic energy from the ultrasonic energy transfer element onto the diseased tissue for a sufficient number of seconds to raise the temperature of the tissue high enough (at least 43 degrees C.) to cause tissue necrosis. It is then necessary to move the focus of the beam, which may be the size of a grain of rice, to a new, adjacent location to continue the ablation process. These steps are repeated until the entire volume of diseased tissue has been ablated. The time required to effectively treat this volume of tissue with IUS may exceed 20-30 minutes. It is critical, therefore, that the relative movement between the IUS energy transfer element and the tissue being treated is small to ablate selectively the tumor and a desired margin of healthy tissue in minimal time. During procedures for destroying diseased tissue within the liver, the physician must contend with movement of the liver due to the patient's breathing and the heart beating. When the diseased tissue is a cancerous tumor, it is obviously critical that as much of the cancerous cells as possible be destroyed to achieve the maximal therapeutic effect and to lengthen the patient's life.[0002]
• Methods for stabilizing organs or for compensating for organ movement during medical procedures are well known in the art. For example, stabilization devices and methods developed for beating heart surgery include compression and/or vacuum attachment to immobilize a portion of heart while suturing together blood vessels. Enclosed platforms or dome-like structures for creating a workspace for endoscopic access and visualization have also been devised for vein harvesting and cardiac surgery. In addition, electrodes that attach to the skin of the patient for diagnoses or therapy of underlying tissue are also well known. These include electromyography (EMG) electrodes for monitoring muscular activity or functional electrical stimulation (FES) electrodes for stimulating muscular contraction. These electrodes move freely with the movements of the patient, thus minimizing relative movement between the electrode and the relevant tissue.[0003]
• External, non-invasive IUS instruments developed for liver treatment require sufficient energy to offset losses of energy through the abdominal wall and to compensate for the movement of the liver. An alternate approach is to introduce a therapeutic IUS energy transfer element through a small incision in the abdomen and to attach it directly to the surface of the liver, and allow the energy transfer element to “ride” with the movement of the liver during the treatment. For example, a physician would position the IUS treatment energy transfer element on the anterior surface of the liver near a tumor with the aid of an intracorporeal, ultrasonic imaging device. The same imaging device would provide monitoring data to a control system in order to develop a “tool path” program for the energy beam focus. Then using electronic and mechanical focusing/directioning means, the IUS treatment energy transfer element would automatically ablate the tumor as the physician monitored the progress displayed on the control system.[0004]
• Sometimes it is necessary to position the IUS energy transfer element apart from the organ surface so that the underlying tissue to be treated is in the focal range of the energy transfer element. Therefore, the IUS energy transfer element may be enveloped in a fluidic media such as, for example, a saline solution, having relatively the same acoustic energy transmission characteristics as the underlying tissue to provide acoustic coupling between the energy transfer element and the tissue. Also the IUS energy transfer elements generate a significant amount of heat. Since the efficiency of the IUS energy transfer element may decrease rapidly with temperature increase, the fluidic media also serves as a coolant for the energy transfer element. Devices having a water-filled balloon attached over the IUS energy transfer element, and maintained with a fresh water flow, have been effectively devised primarily for these purposes.[0005]
• A multi-element, linear array IUS energy transfer element transmits acoustic energy from the energy transfer element face in an approximately two-dimensional plane, focusing at some distance away from the energy transfer element face. The focal depth and angular directivity within that plane of the focus may be set by the type of acoustic lens attached to the face of the energy transfer element, or electronically controlled within certain ranges. It may also be necessary, however, to physically move the energy transfer element to position the acoustic focus. For example, the energy transfer element may be rotated on its longitudinal axis to sweep the acoustic plane through a volume sector. It may also be vertically adjusted closer or nearer to the tissue.[0006]
• What is needed, therefore, is a medical device that attaches directly to an internal bodily organ and moves freely with the movement of the organ in order to minimize the relative motion between the energy transfer element and the organ during treatment of underlying tissue. What is further needed is such a medical device that also incorporates energy transfer element coupling, cooling, and orienting/positioning means. What is further needed is also such a medical device that may be used minimally invasively on a surgical patient. The present invention addresses these needs and overcomes numerous deficiencies of the prior art.[0007]
SUMMARY OF THE INVENTION
• The present invention is a medical device for use on a bodily organ of a patient that enables diagnostic or therapeutic instrumentation to be securely positioned relative to the bodily organ. The medical device generally comprises a concave support element, wherein the open side is removably attachable to the surface of the bodily organ, thereby defining an enclosed space adjacent to the bodily organ. The enclosed space is fluidly connected to a fluid management system for circulating a fluid inside of the enclosed space. The medical device also has an energy transfer element mounted to the concave support element. The energy transfer element is positioned and oriented for transmitting energy to the bodily organ. The medical device includes a cable for electrically connecting the energy transfer element to a control unit. Preferably, the energy transfer element transmits intense ultrasound energy in a frequency range of 1-30 megahertz. The fluid acoustically couples the energy transfer element to the bodily organ, and the fluid also cools the energy transfer element. Although the description of the invention will be discussed relating specifically to ultrasound energy, it will be appreciated by those knowledgeable in the art that various energy platforms may be used, such as, by example only, RF, microwave and laser.[0008]
• In at least one embodiment, the fluid management system includes a vacuum source for adjustably creating an operating pressure within the enclosed space that is lower than the pressure external to the concave support element, for removably attaching the concave support element to the bodily organ.[0009]
• In at least one embodiment, the medical device has an annular chamber circumventing the open side of the concave support element. The annular chamber is fluidly connected to a vacuum source for removably attaching the medical device to the bodily organ.[0010]
• In another embodiment, the medical device has a plurality of hooking elements mounted on the concave support element. The hooking elements are remotely operable for removably attaching the concave support element to the bodily organ.[0011]
• In at least one embodiment, the medical device also includes remotely controllable positioning means for adjusting the position of the energy transfer element with respect to the bodily organ.[0012]
• In at least one embodiment described herein, the medical device includes a controllable orienting means for adjusting the orientation of the energy transfer element with respect to the bodily organ.[0013]
• In another embodiment, the medical device is collapsible into a collapsed configuration for insertion and removal through a surgical incision, and the medical device is expandable to a full configuration for attachment to a bodily organ.[0014]
• In another embodiment, the medical device has a concave support element that is conformable to the shape of the bodily organ.[0015]
• In at least one embodiment, the medical device includes a flexible membrane attached to the open face of the concave support element. This flexible membrane hermetically separates the enclosed space from the bodily organ when the medical device is attached to the bodily organ. The flexible membrane permits the bodily organ to protrude into the enclosed space when the fluid is at an operating pressure that is lower than the external pressure, thereby removably attaching the medical device to the bodily organ.[0016]
• One example of an application of the present invention is removably attaching the medical device to the anterior surface of the liver of a patient, wherein the energy transfer element of the medical device transmits intense ultrasound energy to ablate a volume of diseased tissue within the liver.[0017]
• These and other features and advantages of the present invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.[0018]
BRIEF DESCRIPTION OF THE DRAWINGS
• We specifically present the novel features of this invention in the appended claims. The reader may best understand, however, the organization and the methods of operation of this invention, by referring to the following description, taken in conjunction with the accompanying drawings.[0019]
• FIG. 1 is a schematic representation of an[0020]IUS device30 introduced into asurgical patient10 through anincision18 and attached to anorgan12, with visualization through alaparoscope16.
• FIG. 2A is an end view of an[0021]energy transfer element102.
• FIG. 2B is a side view of[0022]energy transfer element102 attached to acable104.
• FIG. 3A is an end view of a fluid filled[0023]balloon106 containingenergy transfer element102 shown in FIG. 2B.
• FIG. 3B is a side view of fluid filled[0024]balloon106 containingenergy transfer element102 shown in FIG. 3A.
• FIG. 4A is an end view of a[0025]first embodiment100 ofIUS device30 shown in FIG. 1.
• FIG. 4B is a side view of[0026]first embodiment100 shown in FIG. 4A, and includes aconcave support element112 containing fluid filledballoon106 andenergy transfer element102.
• FIG. 5 is a sectional view taken at line[0027]5-5 offirst embodiment100 shown in FIG. 4B.
• FIG. 6 is a top view of a[0028]second embodiment200 ofIUS device30 shown in FIG. 1.
• FIG. 7 is a side view of[0029]second embodiment200 shown in FIG. 6.
• FIG. 8 is a sectional view taken at line[0030]8-8 ofsecond embodiment200 of FIG. 6, and includes anenergy transfer element202 mounted in aconcave support element212 having a plurality ofprojections214.
• FIG. 9 is a top view of a[0031]third embodiment300 ofIUS device30 shown in FIG. 1.
• FIG. 10 is a side view of[0032]third embodiment300 shown in FIG. 9, showing abellows306 vertically extendable by a distance Z.
• FIG. 11 is a sectional view of[0033]third embodiment300 taken at line11-11 in FIG. 9, and includes avolume307 containing a fluid108 and anannular chamber308 connected to avacuum source39.
• FIG. 12 is a top view of a[0034]fourth embodiment400 ofIUS device30 shown in FIG. 1.
• FIG. 13 is a side view of[0035]fourth embodiment400 shown in FIG. 12.
• FIG. 14 is a sectional view of[0036]fourth embodiment400 taken at line14-14 of FIG. 12, and includes anenergy transfer element402 rotatably mounted in aconcave support element412 with amembrane413, and also including avent417 open during the inflow offluid108.
• FIG. 15 is a sectional view of[0037]fourth embodiment400 of FIG. 14, showingvent417 closed as a hydraulic vacuum is applied tofluid108.
• FIG. 16 is a top view of a[0038]fifth embodiment500 ofIUS device30 of FIG. 1, and includes aninflatable housing512.
• FIG. 17 is an end view of[0039]fifth embodiment500 shown in FIG. 16.
• FIG. 18 is a side view of[0040]fifth embodiment500 shown in FIG. 16.
• FIG. 19 is a sectional view of[0041]fifth embodiment500 taken at line19-19 of FIG. 18.
• FIG. 20 is a sectional view of[0042]fifth embodiment500 taken at line20-20 of FIG. 16, and includes anannular chamber508 connected to avacuum line39.
• FIG. 21 is an end view of[0043]fifth embodiment500 shown in a collapsed configuration.
• FIG. 22 is a side view of[0044]fifth embodiment500 shown in a collapsed configuration.
• FIG. 23 is a top view of a[0045]sixth embodiment600 ofIUS device30 shown in FIG. 1, and includes a plurality offluid chambers614.
• FIG. 24 is an end view of[0046]sixth embodiment600 shown in FIG. 23.
• FIG. 25 is a side view of[0047]sixth embodiment600 shown in FIG. 23, shown in a straight position.
• FIG. 26 is a side view of[0048]sixth embodiment600 shown in FIG. 25, shown conformed to the shape of anorgan12.
• FIG. 27 is a bottom view of a[0049]seventh embodiment700 ofIUS device30 shown in FIG. 1.
• FIG. 28 is a sectional view taken at line[0050]28-28 ofseventh embodiment700 shown in FIG. 27, and includes anactuation cable710 for actuating a plurality ofhook elements720.
• FIG. 29 is an end view of[0051]seventh embodiment700 shown in FIG. 28.
• FIG. 30 is a side view of[0052]seventh embodiment700.
• FIG. 31 is an enlarged, sectional view of a portion of[0053]seventh embodiment700 of FIG. 29, showinghook element720 in a retracted position.
• FIG. 32[0054]shows hook element720 of FIG. 31 in an extended position.
• FIG. 33 is a sectional view taken at the curvilinear axis of a[0055]flexible shaft800 attached toIUS device30, whereinflexible shaft800 includes a plurality ofshaft elements808 that are lockable into a fixed position.
DETAILED DESCRIPTION OF THE INVENTION
• Before explaining the present invention in detail, it should be noted that the invention is not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description The illustrative embodiments of the invention may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments of the present invention for the convenience of the reader and are not for the purpose of limiting the invention.[0056]
• FIG. 1 is a schematic representation of the present invention, a[0057]medical device30, as it may be used on abodily organ12 of asurgical patient10.Medical device30 preferably incorporates intense ultrasound energy and is therefore also referred to as anIUS device30.IUS device30 is not limited to open or endoscopic surgical procedures, but may also be used for external, noninvasive medical procedures as will be described. As shown in FIG. 1, the physician passesIUS device30 through anincision18. If desired, the physician may use alaparoscope16 through atrocar port14 at anentry point20 ofsurgical patient10 to facilitate placement ofIUS device30 onorgan12. For the example shown in FIG. 1,organ12 is the liver.
• A[0058]bundle32 connectsIUS device30 to acontrol unit2 and afluid management system7, which comprises afluid pump4, afluid reservoir6, and avacuum source8. Asuitable fluid pump4 is a Masterflex L/S Compact, Low-Flow, Variable Speed Drive Model No. 77200-00 coupled with a standard pump head Model No. 7016-21 having a flow capacity in the range of 2.1 to 560 ml/min. Asuitable vacuum source8 is an Air Cadet Vacuum Pressure Pump Model No. SD-0753040 (−508 mm Hg max vacuum) available from Cole-Parmer Instrument Company. General purpose laboratory vinyl tubing having an inner diameter in the range of approximately 1.6 to 6.4 mm may be used for fluid interconnections offluid management system7. For the example in FIG. 1,fluid management system7 is a closed system so that fluid pressure may be adjusted to be less than atmospheric pressure. The partial vacuum operating pressure provided byvacuum source7 is approximately in the range of −10 to −200 mm Hg.Bundle32 contains acontrol cable34, afluid supply line38, and afluid return line36.Bundle32 may be flexible and permitted to lay on top of the supine, draped patient, and perhaps taped tosurgical patient10 nearincision18. Segmental portions ofbundle32 may also be rigid or semi-rigid to aid the physician in placement ofIUS device30 onorgan12. The physician may also use readily available ancillary devices not shown to support and holdbundle32 during the procedure, as long asIUS device30 is permitted to move freely with the movement oforgan12. Afluid output line40 fluidly connectsfluid reservoir6 tofluid pump7. Avacuum line42 fluidly connectsvacuum source8 tofluid reservoir6.
• In one embodiment of the present invention for which[0059]medical device30 is an IUS device,control unit2 of FIG. 1 controls the transmission of IUS energy fromenergy transfer element102 and performs automated control of IUS focal depth and directivity.Control unit2 generally comprises a function generator with operator-controlled activation, a power amplifier, and an electrical matching network. A suitable function generator is Hewlett Packard Corporation Model No. 33120A Function/Arbitrary Waveform Generator with input provided by a Wavetek 50 MHz Pulse/Function Generator Model No. 81. A suitable amplifier is the Amplifier Research Amplifier Model 150A 100A.Control unit2 may also include conventional devices for transducer characterization and feedback measurement, such as a Thruline Wattmeter Model No. 4410A available from Bird Corporation, an Ultrasonic Power Meter Model UPM-DT-1 E available from Ohmic Instruments Company, aLeCroy LC534AL 1 GHz Oscilloscope, and a Hewlett Packard HP4194A Impedance/Gain-Phase Analyzer.Control unit2 may further include a host personal computer with an IEEE-488 interface to allow program-based control of function generators and other clinical/laboratory apparatuses. The aforementioned devices are offered by way of example only; other devices or combinations of devices are well known by those skilled in the art for controlling the transmission of ultrasound energy fromenergy transfer element102.
• FIGS. 2A and 2B show a generic representation of an[0060]energy transfer element102, which transmits energy from aface103. For the embodiments disclosed herein,energy transfer element102 transmits intense ultrasonic energy and has approximately a 10 mm square by 50 mm long cylindrical shape. The size and shape ofenergy transfer element102, however, may vary significantly.Energy transfer element102 may also have a circular or other cross sectional shape.Cable104 electrically connectsenergy transfer element102 to controlunit2 shown in FIG. 1.Cable104 may comprise, for example, a single bundle containing a plurality of wires.Cable104 may alternately comprise a plurality of separated wires or a ribbon cable containing a plurality of wires so thatcable104 is relatively flexible. Flexible, printed circuits may also be used in this application.Energy transfer element102 contains one or more piezoelectric elements, which may be arranged in any one of the various arrays that are well known in the art.Energy transfer element102 may also include various combinations of matching layers, absorptive layers, reflective layers, lens configurations, air gap layers, encapsulation materials, seals, and internal cooling, again as is well known in the art.Control unit2 controls the transmission of IUS energy fromenergy transfer element102 for treating tissue, butcontrol unit2 may also be used withenergy transfer element102 to image tissue or to monitor the progress of tissue treatment.
• The present invention is not limited to the use of intense ultrasonic energy for treating tissue, but may also incorporate other energy modalities to accomplish other therapeutic or diagnostic effects. For example,[0061]energy transfer element102 may comprise one or more radio frequency (RF) electrosurgical electrodes that are electrically connected to a conventional monopolar or bipolar RF generator.Medical device30 then is a platform for holding the electrodes against tissue during highly controlled ablation. In another example,energy transfer element102 comprises an electrically induced heat element for locally warming the underlying tissue. In another example,energy transfer element102 may comprise an electromyography transducer for detecting electric potentials developed in underlying muscle tissue.
• FIGS. 3A and 3B show[0062]energy transfer element102 inside of aballoon106 filled with afluid108.Balloon106 may be made of an elastomer such as silicone rubber, for example, which is practically transparent to IUS energy.Balloon106 may also be made of a thin-wall plastic such as PET so thatballoon106 assumes a predetermined shaped when pressurized withfluid108.Fluid supply line38 and returnline36, together withcable104, pass through a sealedneck110 ofballoon106.Fluid108 may be water, saline, oil, or any one of the well-known IUS coupling fluids. Circulation offluid108 inside ofballoon106 also coolsenergy transfer element102, thus maintaining the efficiency and life ofenergy transfer element102 and protecting adjacent tissue.
• FIGS. 4A, 4B, and[0063]5 show views of anembodiment100 ofIUS device30 in FIG. 1.Balloon106 andenergy transfer element102 mount inside aconcave support element112 having anopen side113.Concave support element112 includes a concavesupport element neck114 that sealingly retainscable104,fluid supply line38,fluid return line36, and avacuum line116 for creating a partial pneumatic vacuum inside aspace120 betweenballoon106 andconcave support element112. Face103 ofenergy transfer element102 faces downward againstorgan12 in order to transmit energy throughopen side113 ofconcave support element112. Whenvacuum line116 is connected to vacuum source8 (FIG. 1),embodiment100 may be attached toorgan12 as shown in FIG. 5. The physician may use a surgical forceps or the like to hold onto agrasping pin118 during positioning ofembodiment100 ontoorgan12.Concave support element112 may be made of a rigid, biocompatible material such as injection molded polycarbonate, or may also be made of a relatively flexible, biocompatible elastomer such as a molded polyurethane rubber. Optionally,cable104 may be rotationally mounted in concavesupport element neck114 and mechanically engaged to an external rotation apparatus such as a stepper motor (not shown) inside of control unit2 (FIG. 1), thus comprising an orientation means.Energy transfer element102 may then be rotated about its longitudinal axis within a limited arc sector (+/−45 degrees for example). Rotatingenergy transfer element102, together with electronically moving the IUS energy beam within a plane that contains the longitudinal axis ofenergy transfer element102 and is perpendicular to face103, allows treatment of a volume of tissue inorgan12.
• FIGS.[0064]6-8 show anembodiment200 ofIUS device30 of FIG. 1.Embodiment200 comprises aconcave support element212, aenergy transfer element202 mounted within a energytransfer element enclosure205 ofconcave support element212 with aface203 transmitting IUS energy toward anopen side213 that attaches toorgan12.Embodiment200 further comprises acable204,fluid supply line38, andfluid return line36. A plurality ofprojections214 extends from aninside surface209 ofconcave support element212 in a direction towards concave support elementopen side213.Fluid supply line38 andfluid return line36 fluidly connect tofluid management system7 depicted in FIG. 1. The operator positionsembodiment200 ontoorgan12, thus defining aspace220 betweenconcave support element212 andorgan12. The operator then actuatesfluid management system7 to fillspace220 withfluid108, purging all air fromspace220. Once filled withfluid108, a hydraulic vacuum withinspace220 is created whenvacuum source8 offluid management system7 is actuated so thatembodiment200 attaches atraumatically toorgan12.Projections214 preventorgan12 from being drawn intospace220 and help to maintain communication of vacuum to the surface oforgan12 underconcave support element212. The operator may then actuatecontrol unit2 to activateenergy transfer element202 and begin treating the tissue. When treatment of the tissue stops, the operator orcontrol unit2 turns off the hydraulic vacuum and the operator removesembodiment200 fromorgan12.Concave support element212 and energytransfer element enclosure205 may be integrally molded as one piece from a variety of rigid or semi-rigid, biocompatible plastics or elastomers as described earlier. As shown forembodiment200, energytransfer element enclosure205 may easily be constructed so thatenergy transfer element202 andcable204 may be detached for cleaning, sterilization, and reuse on another patient.Concave support element212, concavesupport element enclosure205,fluid supply line38, andfluid return line36 are optionally disposable.
• FIGS.[0065]9-11 show anembodiment300 ofIUS device30 of FIG. 1.Embodiment300 includes a positioning means that comprises aconcave support element312 having abellows306 that is extendable between a first position and a second position. This enables the operator to adjust vertically the distance between energy transfer element302 (FIG. 11) and the tissue being treated.
• The operator may use this mechanical positioning to center initially the focal point of[0066]IUS device30 within the electronically adjustable range ofIUS device30. This facilitates treatment of diseased tissue located several centimeters deep in the organ as well as diseased tissue located just below the surface of the organ. Acable304 extends fromenergy transfer element102 in the same axis as the direction of extension ofbellows306.
• [0067]Embodiment300 further comprises aenergy transfer element302 mounted tobellows306 so that aface303 ofenergy transfer element302 may be positioned next toorgan12 or spaced apart fromorgan12 at a desired distance. In FIG. 10, “z” indicates movement ofbellows306 from the first position to the second position. When a first pressure is supplied tovolume307, bellows306 extends to the first position as shown in FIG. 11. When a second pressure, which is greater than the first pressure, is supplied tovolume307, bellows306 extends to the second position as shown by the phantom lines in FIG. 11. Intermediate positions are possible by variation of the pressure offluid108 between the first and second pressures.Embodiment300 further comprises anannular chamber308 that fluidly connects viavacuum line39 to a pneumatic or hydraulic vacuum source for attachingembodiment300 toorgan12.Fluid supply line38 andfluid return line36 maintain fluid flow involume307 for coupling and coolingenergy transfer element302, in addition to pressurizing bellows306.
• FIGS.[0068]12-15 shown anembodiment400 ofIUS device30 of FIG. 1.Embodiment400 comprises aconcave support element412, acable404 attached to aenergy transfer element402 having aface403.Fluid supply line38 andfluid return line36 fluidly connect tofluid management system7 depicted in FIG. 1.Embodiment400 further comprises avalve416 covering avent417, and amembrane413 covering anopening415 ofconcave support element412.Concave support element412 is preferably made of a rigid, biocompatible plastic or a semi-rigid, biocompatible elastomer as for the previous embodiments.Membrane413 is made of a thin, elastic, fluid sealing material, such as silicone rubber, that is effectively transparent to the acoustic energy emitted byenergy transfer element402.
• The operator positions[0069]embodiment400 ontoorgan12 over the tissue to be treated and actuatesfluid system7 to fill afluid chamber407 defined byconcave support element412 andmembrane413 withfluid108. The pressure of the air or other fluids inside offluid chamber407 pushopen valve416, which is normally closed, allowing the air or other fluids to escape throughvent417. Oncefluid chamber407 is filled withfluid108, the operator may actuatefluid system7 to create a hydraulic vacuum inside offluid chamber407 while firmly holdingconcave support element412 againstorgan12.
• [0070]Organ12 is drawn partway intofluid chamber407 only to the extent permitted by the diaphragmatic resistance provided bymembrane413. In essence,membrane413 behaves much like another thin tissue layer onorgan12, and the hydraulic vacuum inside offluid chamber407 causesembodiment400 to attach toorgan12 atraumatically, while still containingfluid108. Variation of the hydraulic vacuum pressure also allows adjustment of the distance betweenface403 ofenergy transfer element402 andorgan12.Embodiment400 allows the operator the option of using a fluid media forfluid108 that the operator prefers not to spill ontoorgan12 and into the body cavity. This primarily helps to conserve fluid108 (which may contain, for example, expensive therapeutic agents) and minimizes the need for aspirating fluid from the body cavity during the procedure.Embodiment400 further includes apivot block420 projecting fromconcave support element412 to support a post424 extending fromenergy transfer element402, and aneck422 for rotationally supportingcable404.Energy transfer element402 may be pivoted about its longitudinal axis, either manually or under control ofcontrol unit2 as described earlier, in order to sweep IUS energy throughorgan12.
• FIGS.[0071]16-22 show anembodiment500 ofIUS device30 of FIG. 1.Embodiment500 comprises aninflatable housing512, which has a full configuration (FIGS.16-20) when aninterior space507 is filled withfluid108, and which has a collapsed configuration (FIGS.21-22) whenfluid108 and/or air have been evacuated frominterior space507.Fluid supply line38 andfluid return line36 communicate fluid under the desired pressure tofluid management system7 shown in FIG. 1. When in the full configuration,embodiment500 may be attached toorgan12 for treatment of tissue. When in the collapsed configuration,embodiment500 may be easily passed through a minimally invasive incision in the abdominal wall of the patient, or through an appropriately sized trocar cannula, thus reducing postoperative pain and recovery time for the patient.Inflatable housing512 may be molded, for example, from a tough and resiliently flexible, biocompatible polymer such as polyurethane or polyethylene. Aenergy transfer element502 is attached, for example with an adhesive, to aninterior surface522 ofinflatable housing512, so thatface503 faces towardbottom side515. Acable504 exits through a tight-fitting,housing neck524.Embodiment500 further comprises anannular chamber508 disposed onbottom side515 ofinflatable housing512.Annular chamber508 fluidly connects to a vacuum source byvacuum line39. Amembrane513 coversannular chamber508 and contains a plurality ofports520 spaced apart overannular chamber508. A multiplicity ofbumps518 onannular chamber508 help to maintain vacuum communication withinannular chamber508. The operator positionsembodiment500 onorgan12 whileinflatable housing512 is inflated. The operator then may supply vacuum toannular chamber508 to attachembodiment500 toorgan12.Energy transfer element502 may next be activated to treat tissue.
• FIGS.[0072]23-26 show anembodiment600 ofIUS device30 of FIG. 1.Embodiment600 is very similar toembodiment200 shown in FIGS.6-8, except that aconcave support element612 comprises a plurality offluid chambers614 that fluidly communicate viacommon lumen613 and that may flex relative to each other. This allows abottom surface616 to become non-planar as shown in FIG. 26 so thatembodiment600 may easily conform to a curved portion oforgan12.
• FIGS.[0073]27-32 show anembodiment700 ofIUS device30 of FIG. 1.Embodiment700 is also very similar toembodiment200 shown in FIGS.6-8 except that anattachment mechanism730 is provided to further facilitate attachment ofembodiment700 toorgan12.Embodiment700 comprises aconcave support element712, aenergy transfer element702, acable704,fluid supply line38, andfluid return line36.Concave support element712 has abottom side713 and afluid chamber705.Attachment mechanism730 includes a plurality ofhook elements720 spaced apart and mounted on anactuation cable710 that is rotatable about acurvilinear axis726.Attachment mechanism730 is outside the “field of view” ofenergy transfer element702 so that energy transmitted fromenergy transfer element702 to tissue passes only throughfluid108.
• As shown in FIG. 31,[0074]hook elements720 are retractable from tissue so that the operator may slide andposition embodiment700 onorgan12. Aperipheral shelf722 extending from aninside surface713 ofconcave support element712 supports hookelements720. Once positioned, the operator uses a remotely located control (not shown) to rotateactuation cable710 as shown in FIG. 32, thus rotatinghook elements720 simultaneously and penetrating the superficial tissue oforgan12. The hooks are approximately the same size, for example, as surgical vascular needles. The depth of penetration of the needles may be about in the range of 1-3 mm. Many more or less needles than shown may be used.Attachment mechanism730 may be used alone or in combination with a hydraulic vacuum influid chamber705 to attachembodiment700 toorgan12. Laboratory experiments on live porcine liver show that bleeding from many tiny superficial punctures as created byhook elements720 can be easily managed during the procedure.
• FIG. 33 shows a[0075]flexible shaft800 for holdingIUS device30 of FIG. 1.Flexible shaft800 comprises a plurality ofshaft elements808, atensioning element810, atensioning mechanism812, afluid line814, and acable804.IUS device30 may be embodied as any one ofembodiments200,300,400,500,600, and700 described in the previous FIGS.2-32. Eachshaft element808 has aball806 and a joiningconcave support element802. Eachball806 mates into joiningconcave support element802 ofadjacent shaft element808 except for aproximal ball807 that fits into aframe815 oftensioning mechanism812, and a distal joiningconcave support element809 that fits onto amount820 attached toIUS device30.Shaft elements808 are retained to each other and tohousing815 and mount820 by tensioningelement810 passing through alumen816.Lumen816 fluidly connects tofluid line814. Tensioningelement810 anchors to a retainingelement822 inside ofmount820. Aproximal end824 oftensioning element810 attaches to alever817 oftensioning mechanism812. Whenlever817 is in a lock position,flexible shaft800 rigidly assumes the configuration it is in. Whenlever817 is in a release position,flexible shaft800 is flexible. The operator may positionIUS device30 on an organ while using the rigid configuration offlexible shaft800 as a handle. Once the operator attachesIUS device30 toorgan12 via any one of the embodiments disclosed herein, the operator convertsflexible shaft800 to its flexible configuration so that movement oforgan12 is not significantly hindered.
• The present invention effectively minimizes relative motion between an IUS energy transfer element and underlying tissue of the bodily organ, but may have applicability to other therapeutic or diagnostic energy modalities, including radio frequency electrosurgical energy, laser energy, conventional electrical heating elements, and others. Some of these energy modalities may be operable in a wireless mode, that is, without the need for electrical cables attached to the device, thus allowing the device to move even more freely with the movements of the organ. Further, the present invention has equal application in robotic-assisted surgical applications. In addition, the present invention may be useful for the administration of pharmaceutical agents or for the removal of fluids, toxins, or other substances from the patient. The present invention may be used for internal surgical procedures on various organs including the liver, stomach, and lungs, or may also be used externally and attached to the patient's skin to treat or diagnose underlying tissues.[0076]
• We have shown numerous alternate embodiments of the present invention, but it will be obvious to those skilled in the art that such embodiments are only examples. Those skilled in the art will also realize numerous variations and substitutions without departing from the invention. We intend that the invention be limited only by the spirit and scope of the appended claims.[0077]

Claims (12)

What is claimed is:

1. A medical device for use on a bodily organ of a patient, the medical device comprising:

a) a support element having an open portion that is removably attachable to the surface of the bodily organ, thereby defining an enclosed space adjacent to the bodily organ; and

b) an energy transfer element mounted to the support element, the energy transfer element positioned and oriented for transmitting energy to the bodily organ.

2. The medical device ofclaim 1, wherein the enclosed space is fluidly connected to a fluid management system for circulating a fluid inside of the enclosed space

3. The medical device ofclaim 2, wherein the energy transfer element transmits intense ultrasound energy in a frequency range of 1-30 megahertz, and the fluid acoustically couples the energy transfer element to the bodily organ.

4. The medical device ofclaim 2, wherein the fluid management system includes a vacuum source for adjustably creating an operating pressure within the enclosed space that is lower than the pressure external to the support element, for removably attaching the support element to the bodily organ.

5. The medical device ofclaim 1 further comprising an annular chamber circumventing the open portion of the support element, the annular chamber fluidly connected to a vacuum source for removably attaching the medical device to the bodily organ.

6. The medical device ofclaim 1 further comprising a plurality of attachment elements mounted on the support element for removably attaching the support element to the bodily organ.

7. The medical device ofclaim 6, wherein the attachment elements are hooks.

8. The medical device ofclaim 1 further comprising positioning means for adjusting the position of the energy transfer element with respect to the bodily organ.

9. The medical device ofclaim 1, wherein the medical device is collapsible into a collapsed configuration for insertion into a body cavity and is expandable to a expanded configuration for attachment to a bodily organ.

10 The medical device ofclaim 1, wherein the support element is conformable to the shape of the bodily organ.

11. The medical device ofclaim 1, further comprising a flexible membrane attached to the support element and hermetically separating the enclosed space from the bodily organ.

12. A method of attaching a medical device for use in treating tissue in a bodily organ, the method comprising:

providing a medical device comprising a support element having an open side adjacent to the bodily organ, thereby defining an enclosed space adjacent to the bodily organ;

providing a fluid inside of the enclosed space; and

mounting an energy transfer to the support element, the energy transfer element positioned and oriented for transmitting energy to the bodily organ.

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