Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within or on a patient's body. In particular, methods and apparatus are provided for resecting, cutting, partially ablating, aspirating or otherwise removing tissue from a target site, and ablating the tissue in situ. The methods and systems of the present invention are particularly useful for removing tissue within joints, e.g., synovial tissue, meniscus, articular cartilage and the like.

Abstract: A high frequency power supply for applying electrical energy to a target site on or within a patient's body includes an electrical output driver, an output current sensor detecting the current output from the driver, and a power limiting device coupled to the current sensor during normal conditions, the power limiting device operates on a continuous basis. When current output exceeds a predetermined threshold level, the power limiting device is adapted to reduce power on the output driver to a standby mode. The power limiting device operates on a periodic detection or duty cycle when in the standby mode. The power limiting device switches into the stand-by mode to prevent excessive power drains. The power supply operates at a low power, pulsatile manner when an attached probe is in conductive or isotonic fluid but is not engaging body tissue or near a high impedance source. In this pulsatile mode, the power supply operates in a cyclical manner, typically at a predetermined duty cycle.

Abstract: Electrode assemblies and associated systems employ a nonporous wall having an exterior for contacting tissue. The exterior peripherally surrounds an interior area. The wall is essentially free of electrically conductive material. The wall is adapted to assume an expanded geometry having a first maximum diameter and a collapsed geometry having a second maximum diameter less than the first maximum diameter. The assemblies and systems include a lumen that conveys a medium containing ions into the interior area. An element free of physical contact with the wall couples the medium within the interior area to a source of electrical energy to enable ionic transport of electrical energy from the source through the medium to the wall for capacitive coupling to tissue contacting the exterior of the wall.

Abstract: A method and apparatus for creating a virtual electrode to ablate bodily tissue. The apparatus includes an outer tube, a first electrode, an inner tube and a second electrode. The outer tube is fluidly connected to a source of conductive fluid and defines a proximal end and a distal end. The distal end includes an opening for delivering conductive fluid from the outer tube. The first electrode is disposed at the distal end of the outer tube for applying a current to conductive fluid delivered from the outer tube. The inner tube is coaxially received within the outer tube and is connected to a source of conductive fluid. The inner tube defines a proximal end and a distal end, with the distal end forming an opening for delivering conductive fluid from the inner tube. Finally, the second electrode is disposed at the distal end of the inner tube for applying a current to conductive fluid delivered from the inner tube.

Abstract: A catheter for delivering energy to a surgical site is disclosed. The catheter includes at a proximal end a handle and at a distal end a probe. The catheter includes at least one energy delivery device and an activation element. The at least one energy delivery device is located at the distal end of the catheter to deliver energy to portions of the surgical site. The activation element is located at the distal end of the catheter, to transition the probe from a linear to a multi-dimensional shape, within the surgical site. Methods for deploying the probe from the linear to multi-dimensional shape are disclosed.

Abstract: The present invention provides an apparatus method for performing rf intraluminal reduction and/or occlusion with a virtual electrode. An apparatus in accord with the present invention includes a catheter and a guide wire. The guide wire includes a conductive core having a proximal end electrically connected to a generator of rf current and an exposed distal end. An insulative material having disposed therein at least one microlumen for providing a conductive fluid to a target site within the lumen encases the guide wire.

Abstract: A disposable esophageal probe having dual temperature elements is connected to a cooling catheter controller via a reusable interconnect line to provide redundancy in temperature feedback to the controller, namely, to provide both a control temperature feedback signal and an alarm temperature feedback signal to the controller.

Abstract: The present invention provides a method of controlling cardiac fibrillation, tachycardia, or cardiac arrhythmia by the use of an electrophysiology catheter having a tip section that contains at least one stimulating electrode, the electrode being stably placed at a selected intravascular location. The electrode is connected to a stimulating means, and stimulation is applied across the wall of the vessel, transvascularly, to a sympathetic or parasympathetic nerve that innervates the heart at a strength sufficient to depolarize the nerve and effect the control of the heart.

Abstract: The present tool and associated methods provide for precisely controlled positioning of an ablative element, or an array of ablative elements, against a tissue targeted for treatment. Such treatment is in the form of a lesion, caused by energy emitted from the ablative element, selectively changing or destroying cells within the target tissue. The tool incorporates an element array. This element array consists of one or more energy emitting (ablative) elements. The energy delivered may be in the form of radio frequency, microwave, ultrasound, light, and cryogenics, among others. The element array may also incorporate one or more temperature sensing elements. Further, this element array may incorporate a fluid system providing recirculative cooling or fluid delivery to cool the element array and/or surrounding tissue. In one use of the tool, the element array, which is located at the distal end of an elongate member, is positioned against cardiac tissue during an open heart procedure.

Abstract: A percutaneous method of repairing a fissure in the annulus pulposus comprises placing an energy source adjacent to the fissure and providing sufficient energy to the fissure to raise the temperature to at least about 45-70° C. and for a sufficient time to cause the collagen to weld. An intervertebral fissure also can be treated by placing a catheter with a lumen adjacent to the fissure and injecting sealant into the fissure via the catheter, thereby sealing the fissure. An intervertebral fissure additionally can be treated by providing a catheter having a distal end, a proximal end, a longitudinal axis, and an intradiscal section at the catheter's distal end on which there is at least one functional element. The next step is applying a force longitudinally to the proximal of the catheter which is sufficient to advance the intradiscal section through the nucleus pulposus and around an inner wall of an annulus fibrosus, but which force is insufficient to puncture the annulus fibrosus.

Abstract: A heat transfer device has first and second elongated, articulated segments, each having a turbulence-inducing exterior surface. A flexible joint connects the first and second elongated, articulated segments. An inner coaxial lumen is disposed within the first and second elongated, articulated segments.

Abstract: The invention provides a method and device for selectively controlling the temperature of a selected organ of a patient for performance of a specified application. The method includes introducing a guide catheter into a blood vessel. The guide catheter may have a soft tip and a retaining flange, and may be used to provide treatments such as administration of thrombolytic drug therapies, stenting procedures, angiographic procedures, etc. A supply tube is provided having a heat transfer element attached to a distal end thereof. The heat transfer element having a plurality of exterior surface irregularities, these surface irregularities having a depth greater than the boundary layer thickness of flow in the feeding artery of the selected organ. The supply tube and heat transfer element may be inserted through the guide catheter to place the heat transfer element in the feeding artery of the selected organ.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within of a patient's body, particularly including tissue in the spine. The present invention applies high frequency (RF) electrical energy to one or more electrode terminals in the presence of electrically conductive fluid to remove, contract or otherwise modify the structure of tissue structures. In one aspect of the invention, a method is provided for treating herniated discs within a patient's spine by applying sufficient electrical energy to the disc tissue to reduce a volume of the disc, thereby relieving pressure on a spinal nerve. In one embodiment, the high frequency voltage is sufficient to ablate a portion of the nucleus pulposis, either the extruded portion outside of the annulus or a portion or all of the pulposis within the annulus.

Abstract: A method and apparatus for performing hypothermia of a selected organ without significant effect on surrounding organs or other tissues. A flexible catheter is inserted through the vascular system of a patient to place the distal tip of the catheter in an artery feeding the selected organ. A compressed refrigerant is pumped through the catheter to an expansion element near the distal tip of the catheter, where the refrigerant vaporizes and expands to cool a flexible heat transfer element in the distal tip of the catheter. The heat transfer element cools the blood flowing through the artery, to cool the selected organ, distal to the tip of the catheter.

Abstract: The present invention involves a selective organ heat transfer device having a flexible coaxial catheter capable of insertion into a selected feeding artery in the vascular system of a patient. A heat transfer element is attached to a distal portion of the catheter as well as a turbulence-enhancing element which is adapted to enhance turbulent blood flow along the heat transfer element. The heat transfer element may include the turbulence-enhancing element and/or a turbulence-enhancing element may be located proximal of the heat transfer element.

Abstract: Microwave heating apparatus for heating fluid or tissue includes an elongated catheter for placement adjacent to high/dielectric high loss organic fluid or tissue in a patient. The catheter has a distal end and a proximal end and includes an antenna adjacent to the distal end and a cable having one end connected to the antenna and a second end. A transmitter provides a transmitter signal capable of heating the fluid or tissue and a first receiver receives a first signal indicative of thermal radiation from a first depth in the fluid or tissue, producing a first output signal in response thereto. There is also a second receiver for receiving a second signal indicative of thermal radiation from a second depth in the fluid or tissue, producing a second output signal in and response thereto. The apparatus also includes active and passive diplexers connected in series between the transmitter and the second end of the cable.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within of a patient's body, particularly including tissue in the spine. The present invention applies high frequency (RF) electrical energy to one or more electrode terminals in the presence of electrically conductive fluid to remove, contract or otherwise modify the structure of tissue structures. In one aspect of the invention, a method is provided for treating herniated discs within a patient's spine by applying sufficient electrical energy to the disc tissue to reduce a volume of the disc, thereby relieving pressure on a spinal nerve. In one embodiment, the high frequency voltage is sufficient to ablate a portion of the nucleus pulposis, either the extruded portion outside of the annulus or a portion or all of the pulposis within the annulus.

Abstract: A coil electrode for use in an electrophysiology probe includes a first material having a relatively high radiopacity and a second material having a relatively high resiliency. This combination provides the necessary levels of durability, resiliency and radiopacity. An electrophysiological probe includes a support structure, at least one first electrode defining a first radiopacity supported on the support structure and at least one second electrode defining a second radiopacity supported on the support structure, the second radiopacity being greater than the first radiopacity. When viewed under a fluoroscope, the pattern of electrodes of varying radiopacities allows the physician to distinguish between individual electrodes.

Abstract: A system for treating a target region in tissue beneath a tissue surface comprises a probe for deploying an electrode array within the tissue and a surface electrode for engaging the tissue surface above the treatment site. Preferably, surface electrode includes a plurality of tissue-penetrating elements which advance into the tissue, and the surface electrode is removably attachable to the probe. The tissue may be treated in a monopolar fashion where the electrode array and surface electrode are attached to a common pole on an electrode surgical power supply and powered simultaneously or successively, or in a bipolar fashion where the electrode array and surface electrode are attached to opposite poles of the power supply. The systems are particularly useful for treating tumors and other tissue treatment regions which lie near the surface.

Abstract: A system for recanalizing an occluded blood vessel including a centering catheter employed to center an ablative guide wire within the blood vessel as the guide wire traverses the occlusion. The centering catheter includes a catheter body with an operative lumen through which the ablative guide wire is slidingly disposed. The centering catheter further includes a distally disposed centering mechanism that, when activated, centers the ablative guide wire within the blood vessel as it traverses the occlusion. The centering mechanism can comprise various embodiments including a single inflatable balloon or segmented inflatable balloon, which is in fluid communication with an inflation lumen. An airless preparation lumen may be disposed within the inflation lumen for ease of centering catheter preparation. The ablative guide wire includes insulation that is preferably formed of heat shrink tubing, which is stretched prior or concurrently with the heating process.

Abstract: A method is provided of localizing a drug action where the drug is present throughout a vascular system. The localization occurs to within a volume of blood in a blood vessel, the vascular system having an initial temperature substantially within a first temperature range. A temperature-specific enzyme is delivered throughout a vascular system including a volume of blood in a blood vessel, the temperature-specific enzyme having a working temperature within a prespecified temperature range that does not substantially overlap the first temperature range. A heat transfer element is delivered to a blood vessel in fluid communication with the volume of blood. The temperature of the heat transfer element is adjusted such that the volume of blood in the blood vessel is heated or cooled to the prespecified temperature range. In this way, the action of the temperature-specific enzyme is substantially limited to the volume of blood heated or cooled.

Abstract: A selective organ heat transfer device with deep irregularities in a turbulence-inducing exterior surface. The device can have a plurality of elongated, articulated segments, each having a turbulence-inducing exterior surface. A flexible joint connects adjacent elongated, articulated segments. The flexible joint may be a rubber tube or a metal tube of a predetermined thickness. An inner lumen is disposed within the heat transfer segments. The inner lumen is capable of transporting a pressurized working fluid to a distal end of the heat transfer element.

Abstract: An ablation device for treating tissues, valvular annulus, valvular organ structure, or atherosclerosis of a patient, the ablation device including a flexible elongate tubular shaft having a deployable spiral wire electrode at its distal end adapted to contact/penetrate the tissue to be treated and to apply high frequency energy to the tissue for therapeutic purposes.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within of a patient's body, particularly including tissue in the spine. The present invention applies high frequency (RF) electrical energy to one or more electrode terminals in the presence of electrically conductive fluid to remove, contract or otherwise modify the structure of tissue structures. In one aspect of the invention, a method is provided for treating herniated discs within a patient's spine by applying sufficient electrical energy to the disc tissue to reduce a volume of the disc, thereby relieving pressure on a spinal nerve. In one embodiment, the high frequency voltage is sufficient to ablate a portion of the nucleus pulposis, either the extruded portion outside of the annulus or a portion or all of the pulposis within the annulus.

Abstract: Systems, apparatus and methods for ablation, resection, aspiration, collagen shrinkage and/or hemostasis of tissue and other body structures in open and endoscopic spine surgery. In particular, the present invention includes a channeling technique in which small holes or channels are formed within spinal discs, and thermal energy is applied to the tissue surface immediately surrounding these holes or channels to cause thermal damage to the tissue surface, thereby stiffening the surrounding tissue structure and for reducing the volume of the disc to relieve pressure on the surrounding nerves. High frequency voltage is applied between one or more active electrode(s) and one or more return electrode(s) to volumetrically remove or ablate at least a portion of the disc tissue, and the active electrode(s) are advanced through the space left by the ablated tissue to form a channel, hole, divot or other space in the disc tissue.

Abstract: A method, simulation, and apparatus are provided that are highly suitable for treatment of benign prostatic hyperplasia (BPH). A catheter is disclosed that includes a small diameter disk loaded monopole antenna surrounded by fusion material having a high heat of fusion and a melting point preferably at or near body temperature. Microwaves from the antenna heat prostatic tissue to promote necrosing of the prostatic tissue that relieves the pressure of the prostatic tissue against the urethra as the body reabsorbs the necrosed or dead tissue. The fusion material keeps the urethra cool by means of the heat of fusion of the fusion material. This prevents damage to the urethra while the prostatic tissue is necrosed. A computer simulation is provided that can be used to predict the resulting temperature profile produced in the prostatic tissue.

Abstract: A catheter system and method are provided which change the temperature of a fluid, such as blood, by heat transfer. Selective cooling or heating of an organ may be performed by changing the temperature of the blood feeding the organ. The catheter system includes an inlet lumen and an outlet lumen structured and arranged to carry a working fluid having a temperature different from the adjacent blood. The outlet lumen is configured to induce turbulence in the adjacent fluid passing adjacent the outlet lumen.

Abstract: A bipolar electrosurgical instrument is described which may be used for heating the inner lining of a lumen or cavity within a patient. In particular, the present invention is directed to an electrosurgical instrument including a flexible elongated tube having a proximal and a distal end, a first balloon electrode attached to the distal end of the flexible elongated tube. The first balloon electrode includes a first expandable sleeve formed from an electrically insulating material and a first electrically conductive fluid in the expandable sleeve. A first electrode is positioned in electrical contact with the first electrically conductive fluid. A return balloon electrode is spaced proximally from the first balloon electrode, wherein the return balloon electrode includes a second expandable formed from an electrically insulating material and a second electrically conductive fluid disposed within the second expandable sleeve.

Abstract: A catheter assembly and method for treatment of cardiac arrhythmia. In one preferred embodiment, the catheter assembly includes a catheter body, at least one electrode, and a fluid source. The catheter body includes a proximal portion, an intermediate portion, a distal portion, a first lumen, and an ablation section. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and forms a helix or coil. The first lumen extends from the proximal portion to the distal portion. Finally, the ablation section is formed along the helix of the distal portion and defines a loop transverse to the longitudinal axis. The ablation section is, in one preferred embodiment, comprised of a microporous material in fluid communication with the first lumen so as to irrigate fluid from the first lumen to an exterior surface of the ablation section. The electrode is associated with the ablation section.

Abstract: A probe that facilitates the creation of lesions in bodily tissue. The probe includes a relatively short shaft and an inflatable therapeutic element.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within or on a patient's body. In particular, methods and apparatus are provided for resecting, cutting, partially ablating, aspirating or otherwise removing tissue from a target site, and ablating the tissue in situ. The methods and systems of the present invention are particularly useful for removing tissue within joints, e.g., synovial tissue, meniscus, articular cartilage and the like.

Abstract: Methods and apparatus for temperature modification of selected body regions including an induced state of local hypothermia of the brain region for neuroprotection. A heat exchange catheter is provided with heat transfer fins projecting or extending outward from the catheter which may be inserted into selected blood vessels or body regions to transfer heat with blood or fluid in the selected blood vessels or body regions. Another aspect of the invention further provides methods and apparatus for controlling the internal body temperature of a patient. By selectively heating or cooling a portion of the catheter lying within a blood vessel, heat may be transferred to or from blood flowing within the vessel to increase or decrease whole body temperature or the temperature of a target region. Feed back from temperature sensors located within the patient's body allow for control of the heat transfer from the catheter to automatically control the temperature of the patient or of the target region within the patient.

Abstract: The invention provides a method and device for selectively controlling the temperature of a selected organ of a patient for performance of a specified application. The method includes introducing a guide catheter into a blood vessel. The guide catheter may have a soft tip and a retaining flange, and may be used to provide treatments such as administration of thrombolytic drug therapies, stenting procedures, angiographic procedures, etc. A supply tube is provided having a heat transfer element attached to a distal end thereof. The heat transfer element having a plurality of exterior surface irregularities, these surface irregularities having a depth greater than the boundary layer thickness of flow in the feeding artery of the selected organ. The supply tube and heat transfer element may be inserted through the guide catheter to place the heat transfer element in the feeding artery of the selected organ.

Abstract: A low profile intravascular electrophysiology (EP) device for the formation of linear lesions which has particular utility in the treatment of atrial fibrillation and flutter. The EP device of the invention has an elongated shaft with a proximal section, a distal section, and a plurality of at least partially exposed electrodes disposed on an outer surface of the distal section. The electrodes are spaced along a length of the distal section with at least one temperature sensor located between adjacent electrodes. High frequency, e.g. RF, electrical energy delivered to the electrodes on the distal shaft section of the EP device will form a linear lesion which terminates the fibrillation or flutter.

Abstract: A method of treating a brain disorder by heat transfer from brain tissue comprising the steps of surgically cutting a heat transfer aperture into a patient's skull, thereby exposing a predetermined portion of patient's brain; surgically implanting into said heat transfer aperture a heat pump having one or more electrical sensor elements and one or more temperature sensor elements; surgically implanting a heat transfer management unit in a body cavity of said patient such that a micro controller of the heat transfer management unit is connected to one or more activity sensor elements and one or more temperature sensor elements contacting brain tissue and connecting the heat transfer management unit to said heat pump via a lead bundle. Optionally, the heat transfer unit may be located external to the patient's body.

Abstract: Relief of urethral obstruction is achieved by heat ablation of prostatic tissue by an ablation instrument passed within the urethra to a position in the prostate near the point of urethral obstruction. An electrode is coupled to a high-frequency power supply to ablatively heat the urethra and the prostatic tissue near the urethra. Guidance of the electrode placement may be monitored by an imaging device. The instrument may consist of a catheter with an inflatable balloon structure for positioning the instrument. The temperature of the tissue may be sensed at the electrode to control the high-frequency heating energy and ablation process.

Abstract: A left atrium ablation catheter (4), including a sheath (8) and a deflectable electrophysiology catheter (10) housed within the sheath, is used to ablate coronary tissue at a target site within the left atrium (LA) of a heart. The electrophysiology catheter has ablation electrodes (24) along the tip (10). The ablation catheter is introduced into the right atrium (RA) through either the superior vena cava (SVC) or the inferior vena cava (IVC). The distal open end of the sheath is guided through a punctured hole in the interatrial septum and into the left atrium. The distal end (20) of the sheath is either precurved or is steerable so the electrode tip can be directed to the coronary target site in the left atrium. The electrode tip is sized and configured to create the desired lesion at the target site without movement of the electrode tip.

Abstract: A selective organ cooling device with a separate warming device for preventing secondary cooling which can result from cooling the selected organ. The cooling device applies cooling to the blood flowing in a selected blood vessel, while the body temperature control device warms the whole body either directly, or by warming blood returning to the heart from the selected organ, via a vein.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within or on a patient's body. In particular, methods and apparatus are provided for resecting, cutting, partially ablating, aspirating or otherwise removing tissue from a target site, and ablating the tissue in situ. The systems and methods of the present invention are particularly useful for ablation and hemostasis of tissue in sinus surgery (e.g., chronic sinusitis and/or removal of polypectomies) and for resecting and ablating soft tissue structures, such as the meniscus and synovial tissue within a joint.

Abstract: A method and apparatus for creating a virtual electrode to ablate bodily tissue. The apparatus includes an outer tube, a first electrode, an inner tube and a second electrode. The outer tube is fluidly connected to a source of conductive fluid and defines a proximal end and a distal end. The distal end includes an opening for delivering conductive fluid from the outer tube. The first electrode is disposed at the distal end of the outer tube for applying a current to conductive fluid delivered from the outer tube. The inner tube is coaxially received within the outer tube and is connected to a source of conductive fluid. The inner tube defines a proximal end and a distal end, with the distal end forming an opening for delivering conductive fluid from the inner tube. Finally, the second electrode is disposed at the distal end of the inner tube for applying a current to conductive fluid delivered from the inner tube.

Abstract: The invention provides a method and device for selectively controlling the temperature of a selected organ of a patient for performance of a specified application. The method includes introducing a guide catheter into a blood vessel. The guide catheter may have a soft tip and a retaining flange, and may be used to provide treatments such as administration of thrombolytic drug therapies, stenting procedures, angiographic procedures, etc. A supply tube is provided having a heat transfer element attached to a distal end thereof. The heat transfer element having a plurality of exterior surface irregularities, these surface irregularities having a depth greater than the boundary layer thickness of flow in the feeding artery of the selected organ. The supply tube and heat transfer element may be inserted through the guide catheter to place the heat transfer element in the feeding artery of the selected organ.

Abstract: A catheter system and method are provided which change the temperature of a fluid, such as blood, by heat transfer. Selective cooling or heating of an organ may be performed by changing the temperature of the blood feeding the organ. The catheter system includes an inlet lumen and an outlet lumen structured and arranged to carry a working fluid having a temperature different from the adjacent blood. The outlet lumen is configured to induce turbulence in the adjacent fluid passing adjacent the outlet lumen.

Abstract: The invention provides a method and device for selectively controlling the temperature of a selected organ of a patient for performance of a specified application. The method includes introducing a guide catheter into a blood vessel. The guide catheter may have a soft tip and a retaining flange, and may be used to provide treatments such as administration of thrombolytic drug therapies, stenting procedures, angiographic procedures, etc. A supply tube is provided having a heat transfer element attached to a distal end thereof. The heat transfer element having a plurality of exterior surface irregularities, these surface irregularities having a depth greater than the boundary layer thickness of flow in the feeding artery of the selected organ. The supply tube and heat transfer element may be inserted through the guide catheter to place the heat transfer element in the feeding artery of the selected organ.

Abstract: The present invention comprises electrosurgical apparatus and methods for maintaining patency in body passages subject to occlusion by invasive tissue growth. The apparatus includes an electrode support disposed at a shaft distal end having at least one active electrode arranged thereon, and at least one return electrode proximal to the at least one active electrode. In one embodiment, a plurality of active electrodes each comprising a curved wire loop portion are sealed within a distal portion of the electrode support. The apparatus and methods of the present invention may be used to open and maintain patency in virtually any hollow body passage which may be subject to occlusion by invasive cellular growth or invasive solid tumor growth. Suitable hollow body passages include ducts, orifices, lumens, and the like, with exemplary body passages including the coronary arteries.

Abstract: A method and apparatus for lowering the body temperature of a patient while reducing shivering by using a heat exchange device in combination with an anti-shivering mechanism that temporarily reduces shivering. The devices disclosed include a catheter having a heat exchange balloon thereon with heat exchange fluid circulating through the interior of the balloon. The heat exchange balloon is placed in the vasculature of a patient, and heat exchange fluid at a temperature other than the temperature of the blood in the vasculature is circulated through the interior of the balloon to add or remove heat from the blood of the patient. Various anti-shivering agents are disclosed including dopamine receptor blockers, dopamine receptor agonists, &kgr; opioid receptor agonists, opioid agonist-antagonist analgesics, seratonin 5 HT1a agonists, and pharmaceutically acceptable salts of any members of this group. Specific examples of each are give.

Abstract: Methods and apparatus are provided for an achieving low-rate collagen shrinkage using an electrode array comprising an elongated insulator strip having at least one pair of spaced-apart bi-polar RF electrodes, and a “channeling” disposed on the strip between the bi-polar electrodes to direct the flow of RF current therebetween. The channeling electrode is not directly coupled to the RF power source, but only indirectly through the tissue in contact with the channeling electrode. The apparatus enables low RF power levels (e.g., 0.5 watts to 25 watts) to be applied over time intervals of 5 seconds to 180 seconds to attain low-rate collagen shrinkage by directing or focusing the path of the RF current.

Abstract: A method using an ablation apparatus for treating tissues or atherosclerosis on a patient having a pre-implanted medical stent, the method including applying RF energy to the tissue lesion site underlying the stent for therapeutic purposes at different energy levels, different post-procedure times, and different modes of energy delivery.

Abstract: An electrosurgical probe (10) comprises a shaft (13) having an electrode array (58) at its distal end and a connector (19) at its proximal end for coupling the electrode array to a high frequency power supply (28). The shaft includes a return electrode (56) recessed from its distal end and enclosed within an insulating jacket (18). The return electrode defines an inner passage (83) electrically connected to both the return electrode and the electrode array for passage of an electrically conducting liquid (50). By applying high frequency voltage to the electrode array and the return electrode, the electrically conducting liquid generates a current flow path between the return electrode and the electrode array so that target tissue may be cut or ablated. The probe is particularly useful in dry environments, such as the mouth or abdominal cavity, because the electrically conducting liquid provides the necessary return current path between the active and return electrodes.

Abstract: Device for hyperthermia treatment in a body cavity comprising a catheter (10) to be introduced into the body cavity and being closed at the distal end thereof. An elastically expandable hose piece (18) is mounted at this end, which is sealingly connected to the catheter at both ends of the hose piece. Two passages (11, 12) extend through the catheter and can be connected each to an associated liquid conduit (26, 27) at the proximal end of the catheter. The passages open under the hose piece through side apertures (21, 22) in the catheter so that the hose piece can be expanded as a balloon by the supply of liquid through one passage liquid being drained off through the other passage. The device comprises external means (28, 31) for circulating liquid through the hose piece on the catheter and heating of the circulating liquid.

Abstract: An apparatus for ablating tissue has an elongate member, at least two electrodes housed within an axial lumen of the elongate member, and an electrode actuator for advancing the electrodes beyond a distal end of the elongate member and into tissue to a site targeted for ablation. The electrode actuator rapidly advances the electrodes beyond the distal end of the elongate member so that the electrodes assume a uniform outwardly everted configuration.