Abstract: A method for cerebral cooling is described using a cooling assembly, which includes first and second elongate tubular members adapted for insertion into a nasal cavity of a patient through the patient's nostrils. The elongate tubular members each have a proximal end, a distal end, a lumen extending therebetween, and a plurality of ports in fluid communication with the lumen. The cooling assembly also includes a manifold and a reservoir, which contains a pressurized fluid that includes a propellant having a boiling point less than 22° C. The elongate tubular members are inserted into the nasal cavity through the patient's nostrils and pressurized fluid is delivered onto a surface of the nasal cavity by infusing the pressurized fluid from the reservoir through the manifold, into the lumens and through the plurality of ports of the first and second elongate tubular members.

Abstract: A cooling system for an indwelling heat exchange catheter includes a heat exchange bath that is configured to receive a conduit that carries saline to and from the catheter. A heating/cooling fluid is in the bath and exchanges heat with the saline. The heating/cooling fluid flows through a heat exchanger that includes a refrigerant and two variable speed DC compressor for removing heat from the refrigerant. A gear pump circulates the working fluid to and from the catheter and is removably engaged with a pump support platform.

Abstract: A method of treating a subject in need thereof, is carried out by (a) administering said subject a therapeutic intervention (e.g., an active agent) in a treatment effective amount; and concurrently (b) administering said subject caloric vestibular stimulation in a treatment effective amount, said caloric vestibular stimulation administered so as to enhance the efficacy of said active agent. In some embodiments, the caloric vestibular stimulation is administered as an actively controlled time varying waveform.

Abstract: Catheter devices and methods for intravascular heating and/or cooling of human or veterinary patients. The catheter devices generally comprise catheters having inflow and outflow lumens and at least one curvilinear balloon connected to the inflow and outflow lumens such that heat exchange fluid may be circulated through the balloon(s). The catheter is inserted into the vasculature and heated or cooled fluid is circulated through the balloon(s) to heat or cool blood flowing in heat-exchange proximity to the balloon(s), thereby effecting heating or cooling of all or a portion of the patient's body.

Abstract: Surgical cooling may be implemented by various systems, processes, and techniques. In certain implementations, a surgical cooling device includes a shaft, a cooling assembly, and a mechanical control system. The shaft includes a pair of axial cooling channels extending through its interior. The cooling assembly includes a pair of arms pivotally attached to the shaft and a foldable thermal exchanger coupled to the pair of arms and fluidly coupled to the pair of axial cooling channels. The mechanical control system is adapted to unfold the cooling assembly from a closed position to an open position to allow a coolant to flow through a first of the pair of axial cooling channels, through one or more thermal exchange channels, and out a second of the pair of cooling channels.

Abstract: An automated therapy system having an infusion catheter; a sensor adapted to sense a patient parameter; and a controller communicating with the sensor and programmed to control flow output from the infusion catheter into a patient based on the patient parameter without removing fluid from the patient. The invention also includes a method of controlling infusion of a fluid to a patient. The method includes the following steps: monitoring a patient parameter with a sensor to generate a sensor signal; providing the sensor signal to a controller; and adjusting fluid flow to the patient based on the sensor signal without removing fluid from the patient.

Abstract: Therapy systems for hyperthermic energy delivery and cryogenic cooling and associated methods of use. A treatment device can have a distal portion with a therapeutic assembly including an energy delivery element and a cryogenic applicator. The energy delivery element can be configured to apply therapeutically-effective hyperthermic energy to a treatment site (e.g., for neuromodulation). The cryogenic applicator can be configured to cool tissue at least proximate the treatment site.

Abstract: Methods and apparatus for preventing myocardial infarction, or lessening the size/severity of an evolving myocardial infarction, by cooling at least the affected area of the myocardium using an intravascular heat exchange catheter. The heat exchange catheter may be inserted into the vasculature (e.g., a vein) and advanced to a position wherein a heat exchanger on the catheter is located in or near the heart (e.g., within the vena cava near the patient's heart). Thereafter, the heat exchange catheter is used to cool the myocardium (or the entire body of the patient) to a temperature that effectively lessens the metabolic rate and/or oxygen consumption of the ischemic myocardial cells or otherwise protects the ischemic myocardium from undergoing irreversible damage or infarction.

Abstract: A family of catheter electrode assemblies includes a flexible circuit having a plurality of electrical traces and a substrate; a ring electrode surrounding the flexible circuit and electrically coupled with at least one of the plurality of electrical traces; and an outer covering extending over at least a portion of the electrode. A non-contact electrode mapping catheter includes an outer tubing having a longitudinal axis, a deployment member, and a plurality of splines, at least one of the plurality of splines comprising a flexible circuit including a plurality of electrical traces and a substrate, a ring electrode surrounding the flexible circuit and electrically coupled with at least one of the plurality of electrical traces; and an outer covering extending over at least a portion of the ring electrode. A method of constructing the family of catheter electrode assemblies is also provided.

Abstract: A method of delivering therapy to a vein. In one embodiment, the method includes the following steps: inserting a structural sheath into the vein, the structural sheath being configured to prevent collapse of the vein due to spasm or via the administration of tumescent anesthesia; advancing a vapor delivery shaft into the catheter sheath; positioning a vapor delivery tip of the vapor delivery shaft distally of the catheter sheath; and delivering vapor to the vein through the vapor delivery tip to, e.g., shrink the vein with the vapor. The invention also includes a vapor delivery catheter system adapted to perform the method.

Abstract: A heat exchange fluid supply system for supplying a heat exchange fluid to an intravascular heat exchange catheter includes a disposable cassette having a bulkhead and an external heat exchanger, and which is configured to operate in combination with a reusable master control unit. The bulkhead includes a reservoir section and a pump section. The reservoir section is provided with a means to monitor the amount of heat exchange fluid that is in the system. The bulkhead provides the mechanism for priming the system with heat exchange fluid from an external source and for circulating fluid to the catheter in a closed circuit. The pump section is configured to allow for pumping of heat exchange fluid at a constant pressure.

Abstract: The invention relates to a device for conveying heated air to a person and comprises an air-permeable inner sheet and an air-impermeable outer sheet which are connected to one another by welds in order to form a panel-like shape in the inflated state. The welds produce a main duct having, viewed at the inlet end and in the non-inflated state, a main duct width. The main duct is delimited by at least one first series of elongate first welded strips, the first intermediate spaces which are in line with one another. The length of each of these first intermediate spaces, viewed in the non-inflated state, is in each case smaller than the main duct width. The length of each first welded strip is at least 15% of the main duct width and at most 80% of the main duct width.

Abstract: Devices and methods for cooling vessel walls to inhibit restenosis in conjunction with medical procedures such as coronary artery angioplasty. One catheter device includes a distal tube region having coolant delivery holes radially and longitudinally distributed along the distal region. In some devices, holes spray coolant directly onto the vessel walls. In other embodiments, a balloon or envelope is interposed between the coolant and the vessel walls and the coolant returned out of the catheter through a coolant return lumen. Some direct spray devices include an occlusion device to restrict blood flow past the region being cooled. Pressure, temperature, and ultrasonic probes are included in some cooling catheters. Some cooling catheters are coiled perfusion catheters supporting longer cooling periods by allowing perfusing blood flow simultaneously with vessel wall cooling.

Abstract: An apparatus for treating or preventing a kidney disease includes a delivery device configured for insertion into an urinary tract, wherein the delivery device comprises a section for placement in the urinary tract, and wherein the delivery device comprises a first end configured for coupling to an oxygen source, and a lumen configured for delivering oxygen from the oxygen source to a kidney.

Abstract: Materials and methods for producing localized hypothermia in a patient (e.g., for treatment of acute pancreatitis and pancreatic cancer).

Abstract: Relatively non-invasive devices and methods for heating or cooling a patient's body are disclosed. Devices and methods for treating ischemic conditions by inducing therapeutic hypothermia are disclosed. Devices and methods for inducing therapeutic hypothermia through esophageal cooling are disclosed. Devices and methods for operative temperature management are disclosed.

Abstract: Methods, systems, and devices are disclosed for cooling tissue, and in particular for applying therapeutic hypothermia to the spinal canal, tissue disposed within the spinal canal, and nerve roots extending from the spinal canal. Bone screws, intervertebral implants, stabilization rods, spinous process spacers, and other devices are described which define a chamber through which a chilled fluid, expandable gas, or other coolant means can be circulated, delivered, or activated to cool adjacent tissue. The degree of cooling can be regulated using a controller, which can be configured to increase or decrease the cooling effect based on any of a variety of measured or predicted physiological or thermodynamic properties. Methods are disclosed for implanting cooling instruments and for carrying out various treatment regimens that involve cooling tissue using such instruments.

Abstract: A cerebral cooling device that uses a pressurized source to deliver a fluid that evaporates in the nasal cavity to provide cooling and has a balloon on the distal end that inflates from some of the pressure front the pressurized source. The device includes a nasal catheter having delivery ports located in the distal region and a balloon on the distal end. The proximal end of the catheter is in fluid communication with a pressurized source of a low boiling point fluid. A manifold located between the pressurized source and the catheter distributes the fluid and pressure from the pressurized source to a first lumen of the catheter to inflate the balloon and to a second lumen of the catheter through the delivery ports to cool the nasal cavity. A check valve in the manifold ensures that the fluid and pressure are first delivered to the balloon.

Abstract: The present invention relates to an apparatus for performing heat treatment of a bodily cavity in a mammal. The apparatus comprises a catheter intended for insertion into said bodily cavity, an inflatable balloon surrounding a distal end of said catheter in a liquid tight manner which balloon is adapted in use of said apparatus to be inflated and dilated in said bodily cavity, control means operatively connected to said balloon by at least one oscillation lumen and being provided with an oscillation assembly adapted to drive a heat transmitting fluid within said apparatus, and heating means adapted to heat said heat transmitting fluid. Said control means are adapted to control pressure and temperature of said heat transmitting fluid. The heating means have a heat emitting portion and a heat receiving portion which is use of the apparatus are positioned in thermal contact with each other, and which are separable from each other.

Abstract: A method is described for preventing breast cancer recurrence after surgical removal of a breast cancer mass. Specifically, the method is thermal treatment of breast tissue surrounding a cavity after lumpectomy for breast cancer. Delivery of a heated fluid is through a balloon catheter to the cavity generated after lumpectomy with the goal of ablating the surrounding tissue, including transformed cells that were not removed through surgery. A balloon and controller were designed for this application.

Abstract: Closed loop heat exchange catheters having bi-directional flow heat exchange regions and their methods of manufacture and use. The heat exchange region may be formed of expandable or non-expandable tubular conduit(s) that are configured in a series of loops or coiled configuration defining a supply flow path and a return flow path through which heat exchange medium is circulated. The individual loops of convolutions of the coiled configuration may be the same or different size. In some embodiments, the tubular conduit(s) may be passed through generally transverse bore holes formed in a catheter shaft so that the loops or convolutions of protrude from the catheter shaft.

Abstract: A method for cerebral and systemic cooling by providing a nebulized liquid having a boiling point of 38-300° C. The nebulized liquid is delivered as a mist or a spray via the nasal and/or oral cavities of a patient. The mist causes cooling by direct heat transfer through the nasopharynx and hematogenous cooling through the carotids and the Circle of Willis. Compositions and medical devices for cerebral and systemic cooling are also provided. Cooling assemblies, and methods of use, are also provided that include flexible balloon assemblies that are inserted to various locations in a patient's body. The flexible balloons are then infused with a liquid having a temperature between about ?20° C. and about 37° C. The flexible balloon assemblies can be inserted into the nasal cavity, oral cavity, throat, stomach, and other locations to effect cerebral cooling.

Abstract: A system for affecting a temperature of a patient, the system includes: a nose catheter that is adapted to be inserted into a nose upper channel and to receive a fluid; and a temperature control and fluid supply unit that is adapted to supply the fluid and control a temperature of the fluid so as to affect a temperature of a brain of a patient when the nose catheter is inserted into the nose upper channel of a patient and receives the first fluid; wherein the temperature control and fluid supply unit comprises: a thermoelectric heat pump that is arranged to transfer heat from a cold side to a hot side; a fluid block arranged to be cooled by the cold side and to cool the fluid when the fluid passes through the fluid block; and at least one heat transfer element arranged to transfer heat from the hot side.

Abstract: A heating-type balloon catheter device is provided. The catheter device may include a heating-type balloon at a top end portion of a catheter main body and a vibration imparting device connected to a base end portion of the catheter main body. The vibration imparting device may impart vibration to a liquid for heating in the heating-type balloon and include an elastic tube with a base end portion connected to the catheter main body and with a top end portion thereof closed. The elastic tube may be filled with a liquid for heating. A vibrator device having a roller rotating about a rotary shaft at a position offset to the rotary shaft may be provided. The elastic tube may be set to such a vibrator device so that a predetermined direction of rotation of the roller extends from the side of the base end portion of the elastic tube to the side of the top end portion thereof and a margin volume part which is not pressed with the roller is provided on the side of the top end portion of the elastic tube.

Abstract: A system and method for use with at least one cryoprobe for the treatment of biological tissue controls the energy applied to the tissue. The invention receives live procedure data such as temperature information from locations along the pathway of the cryogenic liquids, and calculates a procedure signature or profile based on the procedure data. In one embodiment, volumetric isotherms are calculated. The procedure signature is compared to a planning signature based on previously acquired image data and estimates of the thermal gradients from models. The system and method are further configured to automatically regulate the application of power based on analysis of the planning data to the procedure data.

Abstract: Apparatus, systems and methods for cooling or warming the temperature of all or a portion of the body of a human or animal subject to treat disorders including but not limited to sepsis, septic shock or other inflammatory or infectious conditions which can result in shock, hypoxia, ischemia and/or multiple organ failure in human or animal subjects.

Abstract: An apparatus and method for the delivery and removal of a biocompatible liquid to and from the lungs of a mammal, comprising an ice water container adapted for containing ice water; a biocompatible liquid tank disposed within the ice water container, with the tank adapted for containing a biocompatible liquid; and a biocompatible liquid infusion reservoir disposed within the biocompatible liquid tank. The apparatus also comprises a pump assembly and tube assembly that are in operable connection to the ice water container, biocompatible liquid tank and biocompatible liquid reservoir so as to provide a volume of biocompatible liquid to and from the lungs of a mammal, while breaths of oxygen are supplied using a manually operated air bag.

Abstract: Methods and apparatuses for temperature modification of a patient, or selected regions thereof, including an induced state of hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette of any one of several disclosed variations is attached to the circulatory conduits of the catheter, the heat exchange cassette being sized to engage a cavity within one of various described re-usable control units. The control units include a heater/cooler device, a user input device, and a processor connected to receive input from various sensors around the body and the system. The heater/cooler device may be thermoelectric to enable both heating and 15? cooling based on polarity. A temperature control scheme for ramping the body temperature up or down without overshoot is provided.

Abstract: A heat exchange fluid supply system for supplying a heat exchange fluid to an intravascular heat exchange catheter includes a disposable cassette having a bulkhead and an external heat exchanger, and which is configured to operate in combination with a reusable master control unit. The bulkhead includes a reservoir section and a pump section. The reservoir section is provided with a means to monitor the amount of heat exchange fluid that is in the system. The bulkhead provides the mechanism for priming the system with heat exchange fluid from an external source and for circulating fluid to the catheter in a closed circuit. The pump section is configured to allow for pumping of heat exchange fluid at a constant pressure.

Abstract: A coolant system for a cryoablation or treatment probe that 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, regulating the cooling rate for a selected mapping or ablation regimen. A coolant reservoir feeds into the low pressure inlet side and receives a return flow of excess fluid from a branch off the outlet side of the compressor.

Abstract: Relatively non-invasive devices and methods for heating or cooling a patient's body are disclosed. Devices and methods for treating ischemic conditions by inducing therapeutic hypothermia are disclosed. Devices and methods for inducing therapeutic hypothermia through esophageal cooling are disclosed. Devices and methods for operative temperature management are disclosed.

Abstract: Methods and apparatus for generating vapor within a catheter are provided which may include any number of features. One feature is generating vapor with a fiber optic, laser fiber optic, or fiber optic bundle within a catheter. Another feature is sensing a temperature of the fiber optic, and adjusting the power delivered to the electrode array to fully generate vapor within the catheter. Another feature is delivering the vapor to a vein of a patient for vein reduction therapy.

Abstract: The invention is directed toward a method of reducing motion sickness comprising the steps of introducing cooled gas into a user's ear canal to reduce the temperature of the user's tympanic membrane and vestibular system. The gas is circulated in the user's inner ear, and then exhausted to the atmosphere. The cooled gas induces nystagmus in the user, promotes vestibular desensitization and resistance to motion sickness. The apparatus contemplated for the prevention of motion sickness has an earpiece having a conduit that dispenses cooled gas into the user's ear canal. Gas is provided by a gas source connected to the earpiece with flexible tubing.

Abstract: A method of providing hypothermia to a patient including the steps of inserting a fluid delivery member into a peritoneal cavity of the patient; delivering hypothermia fluid from a fluid source into the peritoneal cavity through the delivery member; and limiting fluid pressure within the peritoneal cavity without providing feedback control to the fluid source. The invention also provides an apparatus for practicing the method.

Abstract: Methods and devices are disclosed for providing therapeutic hypothermia using irrigation of the aerodigestive tract with cooled liquids. The disclosed method provides much more rapid therapeutic cooling to lower temperatures than could previously be achieved, thereby improving clinical outcomes. Novel cooling liquids and cooling devices are disclosed for carrying out the method. An external turbulent flow of cooling liquid may also be applied to the exterior of the head to further promote heat exchange. Multiple embodiments of devices are disclosed for performing rapid induction and maintenance of therapeutic hypothermia either in a hospital setting or in the field so that hypothermic treatment can be quickly instituted before significant tissue damage occurs. Methods are also disclosed for targeting brain cooling by irrigating the upper airway/aerodigestive tract, and more generalized cooling by irrigating the esophagus and/or stomach.

Abstract: Systems and methods for accurate temperature modification of a patient, or selected regions thereof, including inducing hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette attached to the circulatory flow lines of the catheter, the heat exchange cassette being sized to engage a cavity within a control unit. A temperature measurement scheme for obtaining body core temperature is provided, including methods of obtaining and analyzing temperature data to provide feedback to the control unit for use in controlling the heating and cooling of the heat exchange medium so as to heat or cool a patient to a desired target temperature.

Abstract: The present invention provides a method and device for non-invasive anatomical and systemic cooling. The method and device provide for cooling of various bodily fluid- containing spaces or surfaces, such as mucus-containing spaces or surfaces via delivery of a dry fluid not including a coolant into or upon the mucus-containing space or surface. Exposure of such mucus to the dry fluid results in evaporation and cooling of the anatomical feature and/or systemic cooling, as intended. In this fashion, therapeutic hypothermia may be achieved to provide for neuroprotection of various organs after ischemic insult, such the brain after cardiac arrest.

Abstract: A method for treating acute coronary syndromes (i.e., unstable angina or non-Q-wave MI) or transient ischemic attacks in a human or animal patient by placing a heat exchange apparatus in the patient=s vasculature and using that heat exchange apparatus to cool the patient to a temperature (e.g. 30-36_C) at which platelet inhibition (i.e., inhibition of platelet activation and/or aggregation and/or adhesion) occurs. Anti-shivering drugs or anesthesia may be administered to patients whose body temperature is cooled below that patient=s shivering threshold (typically approximately 35.5 C). If it is determined that platelet inhibition is no longer desirable, such as when the patient is about to undergo a surgical or interventional procedure wherein bleeding could be problematic, the hypothermia-induced platelet inhibition may be rapidly reversed by using the intravascular heat exchange apparatus to re-warm the patient=s body to normothermia or near normothermia.

Abstract: A closed loop catheter useable for heat exchange is manufactured by forming a plurality of generally transverse bore holes though a flexible, multilumen catheter body, lacing a tube trough the bore holes so that loops of the tube protrude from the catheter body, connecting one end of the tube to an inflow lumen of the catheter and connecting the other end of the tube to an outflow lumen of the catheter. A heated or cooled heat exchange medium may then be circulated through the tube while the catheter is inserted in the vasculature of a subject, thereby resulting in heat exchange between the subject's flowing blood and the heat exchange medium being circulated through the tube.

Abstract: Devices and methods for cooling all or part of the body of a human or animal subject by inserting a heat exchange catheter into the subject's body and infusing into or through the catheter a heat exchange medium that contains liquid phase matter and frozen solid phase matter, wherein at least some of the solid phase matter melts while in the catheter.

Abstract: Methods for delivering precise amounts of fluid into cardiac tissue for the purpose of facilitating ablation of the tissue along a desired lesion line. One method injects fluid through a hollow needle. The injected fluid can be a highly conductive fluid injected in conjunction with radiofrequency ablation to create an ablative virtual electrode. The injected conductive fluid can provide deeper and narrower conduction paths and resulting lesions. Radiofrequency ablation can be performed at the same time as the fluid injection, using the injection device as an electrode, or subsequent to the fluid injection, using a separate device. In some methods, the injected fluid is a protective fluid, injected to protect tissue adjacent to the desired lesion line. Fluid delivery can be endocardial, epicardial, and epicardial on a beating heart. The present methods find one use in performing maze procedures to treat atrial fibrillation.

Abstract: Peritoneal heat exchange provides the benefit of extremely rapid cooling of the patient's target organs such as the heart and brain as well as facilitating global patient body temperature reduction to therapeutically effective temperatures. The heat exchange medium of the present invention is a chilled gaseous fluid suspension of frozen ice particles.

Abstract: Catheter devices and methods for intravascular heating and/or cooling of human or veterinary patients. The catheter devices generally comprise catheters having inflow and outflow lumens and at least one curvilinear balloon connected to the inflow and outflow lumens such that heat exchange fluid may be circulated through the balloon(s). The catheter is inserted into the vasculature and heated or cooled fluid is circulated through the balloon(s) to heat or cool blood flowing in heat-exchange proximity to the balloon(s), thereby effecting heating or cooling of all or a portion of the patient's body.

Abstract: An induction heating apparatus includes a first interventional device and a second interventional device. The first interventional device includes an electrically conductive material. The first interventional device is adapted for implantation inside a body and for receiving an alternating current. The second interventional device comprises a magnetically conductive material. The second interventional device is adapted for implantation inside the body in close proximity to the first interventional device. With both devices placed inside the body, the second interventional device magnetically couples with the first interventional device and the second interventional device generates heat upon the application of the alternating current to the first interventional device thereby heating the body site.

Abstract: Devices and methods for cooling vessel walls to inhibit restenosis in conjunction with medical procedures such as coronary artery angioplasty. Stenosed vessel walls can be cooled prior to angioplasty, after angioplasty, or both. The invention is believed to inhibit restenosis through cooling to a temperature near freezing, preferably without causing substantial vessel wall cell death. One catheter device includes a distal tube region having coolant delivery holes radially and longitudinally distributed along the distal region. In some devices, holes spray coolant directly onto the vessel walls, with the coolant absorbed into the blood stream. In other embodiments, a balloon or envelope is interposed between the coolant and the vessel walls and the coolant returned out of the catheter through a coolant return lumen. Some direct spray devices include an occlusion device to restrict blood flow past the region being cooled. Pressure, temperature, and ultrasonic probes are included in some cooling catheters.

Abstract: A catheter includes a working fluid supply path communicating with a source of working fluid. The catheter also includes a working fluid return path communicating with the working fluid supply path to return working fluid from the supply path to the source of working fluid. At least one of the paths is contained in a distal heat exchange region of the catheter, where the distal heat exchange region includes first and second helical paths and is made of a shape memory material.

Abstract: A patient temperature control catheter includes working fluid supply and return lumens through which working fluid circulates to exchange heat with a patient in whom the catheter is positioned. At least one lumen is defined by plural coils axially spaced from each other. At least a first coil is a large coil that inflates with working fluid to seat against a wall of a blood vessel in which the catheter is positioned, with blood flowing through the coil so as not to block blood flow in the vessel.

Abstract: An apparatus for exchanging heat in a patient has a first elongated heat exchange catheter carrying circulating working fluid to and from a heat exchange system and a second elongated heat exchange catheter carrying circulating working fluid to and from the heat exchange system. The apparatus has a connector supporting proximal portions of both catheters while distal portions of the catheters are disposed inside a patient's vasculature to exchange heat with the patient.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include hollow fibers which are adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. The hollow fibers enhance the surface area of contact, as well as the mixing of both the heat exchange fluid and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body or alternatively positioned to systemically cool the entire body system.

Abstract: A catheter has an inner sleeve through which refrigerant circulates to and from a source of refrigerant. The catheter also has an outer sleeve surrounding the inner sleeve, including a distal end thereof. The outer sleeve is filled with a frozen biocompatible substance. The refrigerant is separated from the biocompatible substance by one or more walls of the inner sleeve such that the refrigerant is isolated from a patient in whom the catheter is positioned by both the inner sleeve and the frozen biocompatible substance. The refrigerant circulates through the catheter when the catheter is positioned in the patient to maintain the biocompatible substance frozen as heat is transferred from the patient to the biocompatible substance.