Abstract: An apparatus and method for automatic operation of a refrigeration system to provide refrigeration power to a catheter for tissue ablation or mapping. The primary refrigeration system can be open loop or closed loop, and a precool loop will typically be closed loop. Equipment and procedures are disclosed for bringing the system to the desired operational state, for controlling the operation by controlling refrigerant flow rate, for performing safety checks, and for achieving safe shutdown.

Abstract: A cryogenic catheter system provides safe and effective treatment of tissue. The system includes a catheter that is coupled to a console via fluid and electrical umbilicals. The console controls the overall operation of the system based to provide and maintain a predetermined temperature at the catheter tip. The console also controls and monitors operating parameters for providing warning indications to the user and terminating operation of the system in the event of a failure that may compromise patient safety.

Abstract: A method and apparatus to treat Barrett's tissue, a pre-cancerous condition, by removing the epithelium above the lower esophageal sphincter through cryo-ablation. An endoscope with fiber optics is used to view the operation, and a catheter for supplying liquid nitrogen is passed through the lumen of the endoscope. Liquid nitrogen at low pressure is sprayed directly onto the Barrett's tissue through the catheter while the physician views the operation through the fiberoptics of the endoscope and controls the spray via a valve. Freezing is indicated by whiteness and shows that the epithelium has been cryoablated. The apparatus can also be used to treat various other gastrointestinal tract lesions. The catheter is insulated to withstand extremely cold temperatures without becoming stiff and without affecting the inherent flexibility and maneuverability of the endoscope.

Abstract: A method for selective heating of subsurface structures in material such as tissue includes a cooling device for thermally quenching or removing heat from the top surface of tissue during or just after delivering pulsed energy to target or subsurface structures or tissue, a preferred embodiment of the invention using dynamic cooling, to quench the thermal energy conducted from the targeted structure into surrounding tissue.

Abstract: The invention is a technique for dynamic measurements of the heat transfer coefficient to the outer layer of the skin surface using a high thermal conductivity metal in an insulating block as the standardized target. The coefficient is dependent on the specific design of the cryogen valve and nozzle, and values up to 11 500 W/m2K values were measured for a 100 ms long spurts. The values for longer spurts are dependent on air humidity, as ice/snow formation then tends to form a thermally insulating layer. The average value of the heat transfer coefficient for a 200 ms long spurt was determined to 8000 W/m2K for conditions of normal room humidity and temperature. The technique enables an improved prediction of the temperature profile and cooling efficiency during therapy, and may thereby contribute to an improved therapeutic outcome.

Abstract: A cryocatheter system includes a first handle portion having a proximal end, a distal end, a first fluid flow path, and a second fluid flow path; a second handle portion having a proximal end, a distal end, a first fluid flow path, and a second fluid flow path; and a catheter having a proximal end, a distal end, a first fluid flow path, and a second fluid flow path. The distal end of the first handle portion is matable with the proximal end of the second handle portion to place the respective first and second fluid flow paths of each handle portion in fluid communication; and the distal end of the second handle portion is matable with the proximal end of the catheter to place the respective first and second fluid flow paths of the second handle portion and the catheter in fluid communication.

Abstract: A coolant system for a cryoablation or treatment probe such as a mapping or ablation catheter, or a treatment wand, includes a compressor and condenser having a low pressure inlet side and a high pressure outlet side, wherein the outlet side passes through a heat exchanger and is cooled by the inlet side and conditioned for injection to a catheter inlet. A vacuum return system connectable to the catheter outlet draws thermally expended coolant from the catheter and returns it to the low pressure inlet side. A motorized pressure regulator between the heat exchanger and the catheter inlet determines the pressure of coolant passing into the catheter and thus regulates the cooling rate for a selected mapping or ablation regimen. The low pressure compressor inlet supply preferentially conditions the pressurized coolant to ambient temperature or lower before injection into the catheter, allowing the coolant to travel through the body at ambient before expansion in the tip.

Abstract: Improved systems, devices, and methods for delivering cryogenic cooling fluid to cryosurgical probes such as cryosurgical endovascular balloon catheters take advantage of the transients during the initiation and termination of cryogenic fluid flow to moderate the treatment temperatures of tissues engaged by the probe. A flow limiting element along a cryogenic fluid path intermittently interrupts the flow of cooling fluid, often cycling both the fluid flow and treatment temperature. This can maintain the tissue treatment temperature within a predetermined range which is above the treatment temperature provided by a steady flow of cryogenic fluid. In another aspect, room temperature single-use cooling fluid cartridges are filled with a sufficient quantity of cryosurgical fluid to effect a desired endovascular cryosurgical treatment.

Abstract: The invention provides techniques and devices for treating atherosclerotic disease using controlled cryogenic cooling, often in combination with angioplasty. The efficacy of endoluminal cryogenic cooling is enhanced by limiting cooling of target tissues using an insulated cryogenic balloon, the insulation ideally comprising a fluid which undergoes a phase change at a predetermined temperature. A combination cryogenic/angioplasty catheter avoids exchange procedures between dilation of a stenotic region within a vessel wall and the application of cryogenic cooling. The combination angioplasty/cryogenic cooling catheter may cool the diseased blood vessel before, during, and/or after dilation. Controlled cooling of the vessel wall may change its mechanical properties, weakening the vessel and allowing it to be expanded at a much lower pressure than with conventional uncooled angioplasty.

Abstract: Partial or total occlusions of fluid passages within the human body are removed by positioning an array of optical fibers in the passage and directing treatment radiation pulses along the fibers, one at a time, to generate a shock wave and hydrodynamics flows that strike and emulsify the occlusions. A preferred application is the removal of blood clots (thrombin and embolic) from small cerebral vessels to reverse the effects of an ischemic stroke. The operating parameters and techniques are chosen to minimize the amount of heating of the fragile cerebral vessel walls occurring during this photo acoustic treatment. One such technique is the optical monitoring of the existence of hydrodynamics flow generating vapor bubbles when they are expected to occur and stopping the heat generating pulses propagated along an optical fiber that is not generating such bubbles.

Abstract: A confocal microscope is provided including a confocal imaging system having an objective lens, and a device which can be an attachment to the confocal imaging system, or a part thereof. The device has a housing with an interior cavity and two opposite ends, where one end of the housing receives the objective lens, and at the other end of the housing which is attached to, or is a part of, the housing which forms that other end. The chamber has first and second plates presenting two opposing sides of the chamber, where the first plate lies adjacent the tissue to be treated, and the second plate is attached to the housing. The interior cavity of the housing has a window defining a first volume between the window and the objective lens, and a second volume between the window and the chamber. The first volume has an immersion liquid optically matched to the objective lens, and the second volume is approximately evacuated.

Abstract: An apparatus for compressing a gas and its uses are disclosed. The apparatus comprises a fixed-volume container having a hollow and a moveable element subdividing said hollow into a first variable-volume portion and a second variable-volume portion, the second variable-volume portion having an opening for introducing therein a hydraulic and/or pneumatic fluid under pressure, for causing an increase in the volume of said second variable-portion by moving said moveable element, thereby, consequently, decreasing the volume of the first variable-volume portion and compressing a gas contained therein.

Abstract: There is disclosed a laser treatment apparatus including: a handpiece internally including an irradiation optical system for irradiating a laser beam for treatment; a lens disposing unit which can dispose a lens in the irradiation optical system, the lens being selectable from among a plurality of lenses of different types having different focal lengths; and a lens detecting unit which detects the type of the lens disposed in the irradiation optical system.

Abstract: A cryogenic catheter includes an outer flexible member having at least one cryogenic fluid path through the flexible member. The at least one fluid path is defined by a plurality of flexible members disposed within the outer flexible member.

Abstract: A method and apparatus to treat Barrett's tissue, a pre-cancerous condition, by removing the epithelium above the lower esophageal sphincter through cryo-ablation. An endoscope with fiber optics is used to view the operation, and a catheter for supplying liquid nitrogen is passed through the lumen of the endoscope. Liquid nitrogen at low pressure is sprayed directly onto the Barrett's tissue through the catheter while the physician views the operation through the fiberoptics of the endoscope and controls the spray via a valve. Freezing is indicated by whiteness and shows that the epithelium has been cryoablated. The apparatus can also be used to treat various other gastrointestinal tract lesions. The catheter is insulated to withstand extremely cold temperatures without becoming stiff and without affecting the inherent flexibility and maneuverability of the endoscope.

Abstract: A coolant system for a cryoablation or treatment probe such as a mapping or ablation catheter, or a treatment wand, includes a compressor and condenser having a low pressure inlet side and a high pressure outlet side, wherein the outlet side passes through a heat exchanger and is cooled by the inlet side and conditioned for injection to a catheter inlet. A vacuum return system connectable to the catheter outlet draws thermally expended coolant from the catheter and returns it to the low pressure inlet side. A motorized pressure regulator between the heat exchanger and the catheter inlet determines the pressure of coolant passing into the catheter and thus regulates the cooling rate for a selected mapping or ablation regimen. The low pressure compressor inlet supply preferentially conditions the pressurized coolant to ambient temperature or lower before injection into the catheter, allowing the coolant to travel through the body at ambient before expansion in the tip.

Abstract: The present invention is directed towards a combined electrosurgical-cryosurgical instrument for tissue ablation. The instrument comprises a shaft having a proximal end and a distal end, the distal end being electrically and thermally conductive; a radiofrequency insulation sheath surrounding the outer surface of the shaft; a cryo-insulation sheath surrounding a surface of the shaft; a radiofrequency power supply source; a cryogen supply tube within the shaft; and a cryogen supply source connected to the cryogen supply tube. The power source provides electrical energy to the distal end of the shaft, and the cryogen supply tube provides a cryogen to the distal end of the shaft.

Abstract: The invention provides a method and apparatus for producing reversible focal hypothermia of the nervous system to control chronic pain. Nerve conduction is blocked by mild cooling (0 to 25° C.), or hypothermia. At these temperatures, nerve tissue is not destroyed and recovers completely when cooling is terminated, such that the treatment is reversible. By blocking conduction in pain nerves, pain sensation is eliminated in a manner analogous to drugs such as lidocaine that also block nerve conduction to provide anesthesia. The invention can be applied to a variety of conditions such as urge incontinence, muscle spasticity, and epilepsy. Many of these disorders are mediated by nerve and nervous tissue that could be interrupted by cooling. In addition, neurologic dysfunction found in multiple sclerosis may improve by cooling of the nerves. The method and apparatus may be used to cool areas of the nervous system affected by multiple sclerosis to allow more normal functions.

Abstract: A method and apparatus for transmural ablation using an instrument containing two electrodes or cryogenic probes. A clamping force is exerted on the two electrodes or probes such that the tissue of the hollow organ is clamped therebetween. Bipolar RF energy is then applied between the two electrodes, or the probes are cryogenically cooled, thus ablating the tissue therebetween. A monitoring device measures a suitable parameter, such as impedance or temperature, and indicates when the tissue between the electrodes has been fully ablated.

Abstract: Post-angioplasty hyperplasia in blood vessels is treated using a cryosurgical balloon catheter. The balloon catheter is positioned at a target region within the blood vessel, and the balloon inflated by expanding a cryogenic fluid, such as liquid nitrogen, across an expansion orifice into a balloon. The balloon will be constructed so that cooling is achieved primarily in the central regions of the balloon, with the proximal and distal regions being less cold and acting to insulate adjacent regions of the blood vessel from excessive cooling.

Abstract: A cryogenic catheter includes an outer flexible member having at least one cryogenic fluid path through the flexible member. The at least one fluid path is defined by a plurality of flexible members disposed within the outer flexible member.

Abstract: A spray catheter includes a flexible member having a spray tip and a fluid path through the flexible member to the spray tip. The catheter can be deformable and may include a mechanism for varying the spray geometry of the spray tip.

Abstract: A cryogenic medical system includes a medical device and a console connectable to the medical device at a connection point. The console controls the temperature of the medical device. The console includes a first cooling system directing coolant to the medical device at a first temperature along a coolant supply line and a second cooling system chilling the coolant within the coolant supply line to a temperature below the first temperature before the coolant reaches the connection point.

Abstract: A sheath for use on a closed loop Joule-Thomson cryosurgical probe, and the combination of the sheath and the closed loop probe. The sheath is slipped over the probe, thereby separating the probe from the environment. The sheath has a grip which fits over the handle of the cryosurgical probe, and an extendible shroud which can be longitudinally extended to cover tubing and which are attached to the handle. The sheath has a hollow multi-lumen catheter shaped and sized to fit snugly over the cannula of the cryosurgical probe. The catheter is not thermally conductive, preventing transfer of heat from the ambient to the gas mixture, and preventing the freezing of tissues at undesired locations along the catheter. A thermally conductive cap or tip is attached to the distal end of the hollow catheter. The thermally conductive cap or tip is biased against the cold tip on the probe by a biasing element in the sheath assembly, to promote heat transfer.

Abstract: A cooling head for attachment a skin treatment laser has a metal body with a mount at one end for attachment to a laser head to secure the metal body to the head. A cooling surface at the other end is for application to a patient's skin and has an aperture therethrough. A bore extends from the mount through the body to the aperture in the cooling surface to allow a laser beam to be passed therethrough to a treatment area of the patient's skin. An extraction port enables removal of debris from the treatment area and for connection to a vacuum source. An optically transparent window is disposed in the body to allow the treatment area at the aperture in the cooling surface to be viewed by a surgeon using the laser. A cooling means such a liquid flow heat exchanger or Peltier device enables heat removal from the body in use in order to cool the cooling surface.

Abstract: A cryoprobe system with a vented high pressure gas supply line. Venting of the gas supply line upon cut-off of high pressure gas quickens the warming process of the cryoprobe.

Abstract: A cryogenic catheter having an elongate outer member and a plurality of inner members disposed within the elongate outer member is provided. The inner members define at least one cryogenic path through the outer member. At least one of the inner members has at least one controllable opening formed thereon to selectively release cryogenic fluid. The inner members also include an overtube and an injection tube slideably disposed to one another.

Abstract: A device is described that uniformly cools a surface to a specified temperature using a mist of cryogenic fluid. The device comprises a cryogenic fluid reservoir, a valve for controllably releasing the fluid through an atomizing nozzle, a non-contact temperature sensor, and a control unit to display the measured temperature and optionally pre-set the desired surface temperature and control the valve. The application of mist can be controlled manually or electronically. This invention provides a portable tool for safely cooling skin for dermatological applications.

Abstract: A group of multiple hollow fibers may be shaped to introduce angular divergence among the fibers, or to introduce a selected longitudinal oscillation into the fibers. In one shaping technique, the fibers are held in parallel while upper and lower crimping assemblies of parallel crimping bars are drawn together on opposite sides of the parallel fibers. When bars of the opposing assemblies draw sufficiently close, they sandwich the fibers in between them, causing each fiber to assume a shape that oscillates as the fiber repeatedly goes over and then under successive bars. Since the crimping bars are aligned at oblique angles to the fibers, the peaks and troughs of successive fibers are offset. While in this position, the fibers are heated and then cooled to permanently retain their shapes. A different shaping technique utilizes a lattice of crisscrossing tines defining multiple apertures. In this technique, the lattice and fibers are positioned so that each fiber passes through one of the apertures.

Abstract: A self-contained portable cryogenic apparatus that operates at the temperature (of the order of -78.degree. C. at atmospheric pressure) reached by reducing the pressure of carbon dioxide (CO.sub.2) or equivalent in liquid/solid phase, comprising a reservoir of pressurized liquefied CO.sub.2, the drawing off head being connected to a liquid/solid CO.sub.2 pressure reduction and ejection system, and comprising a control device, a pressure reduction device and a device for checking the temperature in the area to which it is applied, remarkable in that the top of the CO.sub.2 reservoir is arranged on the apparatus such that during the entire usage period, only the liquid part of the CO.sub.2 inside the reservoir comes into contact with the head so that it is drawn off and forced towards the application area through a pressure reduction and ejection system. The apparatus is particularly suitable for use in sports medicine in the form of a spray gun.

Abstract: The invention relates to a medical cryo-surgical device. Hitherto, such devices have employed the Joule-Thompson cooling effect, liquid nitrogen, or a sprayed volatile liquid. All such devices will serve the required purpose of cooling tissue to the level that will cause ice crystal formation, but all are relatively inefficient. The invention seeks to provide an improved device, an objective met by a construction comprising a primary heat extraction means (1), a secondary heat extraction means (12) associated with a part to be applied to a patient, and a coolant circuit (14) connecting the primary and secondary heat extraction means. The heat extraction means may be thermo-electric devices that can be sequentially or concurrently activated.

Abstract: An energy supply system for implantable medical devices generates an energy supply by a photovoltaic converter which transforms the light coming from outside of the body. The light is carried to the converter by an optical fiber. This system allows the implanted devices to work without the time restrictions of batteries and opens the door to the development of new devices with much higher power ratings. The system includes a light source (1) external to the patient's body, an optical fiber (3) which runs from a point on the surface of the patient to the implantable device (4) and a photovoltaic converter (5) placed inside the device where the optical fiber ends. Finally, a power conditioning stage (6) ensures that the electrical power generated suits the needs of the other components (7) of the implantable device.

Abstract: Cryocoolers for use in cryosurgery and other applications comprising dual finned tube helical coil heat exchangers. The size and shape of iceballs created by the probes is controlled by the location of the gas outlets within the cryocooler outer sheath.

Abstract: The present invention pertains to an apparatus for cryosurgery. The apparatus comprises a cryoneedle having a diameter less than 3.2 mm. The apparatus is also comprised of a thermal insulation shell disposed about a portion of the cryoneedle for reduction of heat transfer from surrounding tissues or freezing prevention of surrounding tissues during application of the cryoneedle with the shell. The cryoneedle and shell are configured for insertion into a body of a patient. The present invention pertains to a method for freezing tissues. The method comprises the steps of bringing into contact a cryoneedle having a diameter of less than 3.2 mm with a patient's body. Next, there is the step of flowing the cryofluid through the cryoneedle.

Abstract: A hand-held cryosurgical instrument is provided with an insulating, cold-resistive, non-slip grip, which fits onto the neck of a cryosurgical instrument by means of machined threads. The grip has a lip for the users hand to rest against to protect it from the cold metal of the instrument.

Abstract: A method and apparatus to treat Barrett's tissue, a pre-cancerous condition, by removing the epithelium above the lower esophageal sphincter through cryo-ablation. An endoscope with fiber optics is used to view the operation, and a catheter for supplying liquid nitrogen is passed through the lumen of the endoscope. Liquid nitrogen is sprayed directly onto the Barrett's tissue through the catheter while the physician views the operation through the fiberoptics of the endoscope and controls the spray via a valve. Freezing is indicated by whiteness and shows that the epithelium has been cryoablated. The apparatus can also be used to treat various other gastrointestinal tract lesions. A most important and significant feature of this invention is the fact that the liquid nitrogen spray is applied in the esophagus at low pressure.

Abstract: A liquid coolant supply system for supplying a liquid coolant to a thermal therapy catheter includes a sensor control unit, a liquid coolant containment unit and mounts. The sensor control unit includes a pump, a cooling device, a temperature sensor and a pressure sensor. The liquid coolant containment unit includes a sealed reservoir, a coolant-sensor interface module and a pump interface fluidly coupled to the thermal therapy catheter. The coolant-sensor interface module includes a body defining a fluid chamber, a temperature interface supported adjacent the fluid chamber within the body, and a pressure interface supported adjacent the fluid chamber within the body. The mounts removably support the sealed reservoir, pump interface, temperature interface and pressure interface of the containment unit adjacent the cooling device, the pump, the temperature sensor and the pressure sensor.

Abstract: Cryosurgery method and device for performing trans myocardial revascularization are provided. The method includes: forming trans myocardial channels by cryoablating selected portions of the myocardial tissue.

Abstract: The cap which is threaded onto the dewar of a cryosurgical instrument has a vent hole therethrough which is normally closed off by a gasket when the cap is secured to the dewar, but which can allow the venting of gaseous cryogen therethrough when the cap is loosened. The threads of the cap have a scalloped region in which the threads have been machined away so as to provide a passage for gaseous cryogen, whereby, when the cap is loosened on the dewar, pressure therein is released by gas escaping either through the hole or through the scalloped region of the threads.

Abstract: The present invention relates to a portable, hand held, self-contained cryosurgical probe system. In particular, the present invention relates to an improved portable, hand held cryosurgical probe system having easily changeable probes and cryogen sources wherein the cryogen can be provided in precharged cylinders mountable on the hand held unit and/or supplied from remote sources and which is capable of serving a plurality of probes via a multiprobe adapter. The present invention provides the flexibility of easily changeable probes and cryogen sources in a lightweight hand unit whereby different cryogens may be employed at different stages within a procedure or the cryogens may be mixed to vary the effective freeze capacity of the device.

Abstract: A cryotherapy method for reducing tissue injury after balloon angioplasty or stent implantation contemplates use of a well insulated, low profile catheter designed to transport a low temperature medium such as gas, fluid or a mixture thereof at a particular temperature over a guide wire to the site of a lesion. The lesion may or may not have undergone previous procedure for balloon angioplasty or stent implantation. The cryo-medium is introduced from a well insulated storage chamber having a small nozzle to which a conduit may be attached to allow conveyance of the fluid to a point of use. A handheld valve is incorporated into the conduit to allow the surgeon to closely control the flow of the cryo-medium to the point of use. The conduit extends downstream of the valve and is fluidly connected to the catheter that is positioned at the point of the lesion in the body. If desired, antibiotics, anticoagulants, antiproliferative agents, gene materials, etc.

Abstract: A cryosurgery mask permits the continuous application of coolant during cryosurgery. Cryosurgery employs the application of a coolant, such as liquid nitrogen (LN), to a target tissue to effect the removal thereof. The target tissue normally includes diseased tissue, along with a safety margin of adjacent tissue. The cryosurgery mask includes a flexible sheet having a non-adhesive upper surface and a lower skin-facing surface of a silicone gel composition which remains adherent to skin at cryosurgery temperature. A release film is releasably affixed to the skin-facing surface to protect against contamination. In operation, a hole, dimensioned to encircle both the diseased tissue and a safety margin of adjacent normal tissue, is removed from the sheet. The release film is removed and the hole is positioned over the target tissue. The gel layer adjacent to and surrounding the hole is pressed against the skin. A constant spray of LN may then be applied to the target tissue to effect freezing.

Abstract: A cryogenic catheter includes a flexible member having an elongate, thermally-transmissive region and a cryogenic fluid path through the flexible member to the thermally-transmissive region. The thermally-transmissive region can be deformable from a linear configuration to an arcuate configuration and can include multiple thermally-transmissive elements having a first side exposed to the cryogenic fluid path and a second side exposed to points exterior to the flexible member. The thermally-transmissive elements can be rigid or flexible longitudinal strips. Alternatively, annular, cylidrical, or wedge-shaped metallic structures disposed in a spaced-apart relationship can define the thermally-transmissive region. In other embodiments the thermally-transmissive region is defined by a helical coil that is at least partially embedded in the flexible member. The helical coil can also define at least a portion of the cryogenic fluid path through the flexible member and include a gas expansion or boiling chamber.

Abstract: A cryogenic catheter includes a flexible member having an elongate, thermally-transmissive region and a cryogenic fluid path through the flexible member to the thermally-transmissive region. The thermally-transmissive region can be deformable from a linear configuration to an arcuate configuration and can include multiple thermally-transmissive elements having a first side exposed to the cryogenic fluid path and a second side exposed to points exterior to the flexible member. The thermally-transmissive elements can be rigid or flexible longitudinal strips. Alternatively, annular, cylindrical, or wedge-shaped metallic structures disposed in a spaced-apart relationship can define the thermally-transmissive region. In other embodiments the thermally-transmissive region is defined by a helical coil that is at least partially embedded in the flexible member. The helical coil can also define at least a portion of the cryogenic fluid path through the flexible member and include a gas expansion or boiling chamber.

Abstract: Cryosurgery method and device for performing trans myocardial revascularization are provided. The method includes: forming trans myocardial channels by cryoablating selected portions of the myocardial tissue.

Abstract: Apparatus is described for feeding a cryosurgical device by passing a liquid cryogen (e.g. liquid nitrogen) through the device to produce cooling by vaporization, and to enable thawing of the device by passing a heated inert thaw gas (e.g. nitrogen gas) through the device when the liquid cryogen is turned off. The thaw gas is passed through the device in the same direction of flow as the liquid cryogen. The apparatus can supply a plurality of cryosurgical devices, and provide independent control of cryogen and thaw for each probe. Novel valve arrangements are also disclosed for controlling the supply of liquid cryogen and the supply of the thaw gas.

Abstract: The cryo-ablation catheter comprises a generally tubular body having a proximal end and a distal end. The distal end includes a hollow closed head made of a thermally conductive material. A pressure line is received in and extends in the catheter from a location near the proximal end to a location near the head. The catheter includes a discharge channel extending from the head to the proximal end. The pressure line is made of a synthetic material which has, compared to metal, a low modulus of elasticity and a high thermal resistance coefficient.

Abstract: Cryocoolers for use in cryosurgery and other applications comprising finned tube helical coil heat exchangers and warming gas flow through a warming gas supply line fitted Joule-Thomson nozzle. The cryocoolers use helium, hydrogen or neon as a warming gas which is expanded from the Joule-Thomson nozzle to heat the probes.

Abstract: A surgical instrument in which a surgical tool is carried distally of a bend region in a stationary support member by an assembly that transmits proximally applied forces through the bend region to both operate the surgical tool and selectively change the rotational orientation of the surgical tool with respect to the stationary member. In another aspect, in which the stationary member does not include a bend region, a rotatable member supported by the stationary member transmits rotational force to the surgical tool to selectively change the rotational orientation of the tool, and a driver member supported by the stationary member transmits axial force to the surgical tool to operate it.

Abstract: A cryosurgical instrument incorporates a heat transfer zone, which abuts against the portion of the cryosurgical instrument near the input refrigerant entrance, and which receives pure input refrigerant at the coldest temperature for quickly and effectively cooling this portion of the cryosurgical instrument. The cryosurgical instrument includes a shaft portion and a handle portion. The shaft portion includes an outer jacket tube having both an open and closed end. The closed end surrounds the freezing zone for freezing live tissue. A middle tube is disposed within the outer jacket tube. An inner tube is disposed within the middle tube. The inner tube is adapted for routing input cryogenic refrigerant therethrough to the freezing zone. The channel between the inner tube and middle tube forms a cryogenic refrigerant exhaust path for exhausting cryogenic refrigerant from the freezing zone.