Abstract: A method and apparatus is provided for determining an effective thermal mass of a patient. The effective thermal mass is employed to determine a gain factor used in a feedback control system controlling patient temperature. The method begins by inducing hypothermia or hyperthermia in at least a selected portion of the patient with a device having a heat transfer surface. Next, power is transferred between the device and the patient. A change in temperature over time, which arises in the selected portion of the patient, is measured while performing the step of inducing hypothermia or hyperthermia. Finally, an effective thermal mass is calculated based on the measured power and the measured temperature change over time.

Abstract: The invention provides a device for heating or cooling a surrounding fluid in a feeding vessel and a method of manufacturing the same. The device includes a catheter assembly capable of insertion to a selected blood vessel in the vascular system of a patient. The assembly includes an elongated catheter body, a heat transfer element located at a distal portion of the catheter body and including an interior, an elongated supply lumen adapted to deliver a working fluid to the interior of the heat transfer element and having a hydraulic diameter, an elongated return lumen adapted to return a working fluid from the interior of the heat transfer element and having a hydraulic diameter, and wherein the ratio of the hydraulic diameter of the return lumen to the hydraulic diameter of the supply lumen is substantially equal to 0.75.

Abstract: The invention provides a device for heating or cooling a surrounding fluid in a feeding vessel and a method of manufacturing the same. The device includes a catheter assembly capable of insertion to a selected blood vessel in the vascular system of a patient. The assembly includes an elongated catheter body, a heat transfer element located at a distal portion of the catheter body and including an interior, an elongated supply lumen adapted to deliver a working fluid to the interior of the heat transfer element and having a hydraulic diameter, an elongated return lumen adapted to return a working fluid from the interior of the heat transfer element and having a hydraulic diameter, and wherein the ratio of the hydraulic diameter of the return lumen to the hydraulic diameter of the supply lumen is substantially equal to 0.75.

Abstract: The invention provides a device for heating or cooling a surrounding fluid in a feeding vessel and a method of manufacturing the same. The device includes a catheter assembly capable of insertion to a selected blood vessel in the vascular system of a patient. The assembly includes an elongated catheter body, a heat transfer element located at a distal portion of the catheter body and including an interior, an elongated supply lumen adapted to deliver a working fluid to the interior of the heat transfer element and having a hydraulic diameter, an elongated return lumen adapted to return a working fluid from the interior of the heat transfer element and having a hydraulic diameter, and wherein the ratio of the hydraulic diameter of the return lumen to the hydraulic diameter of the supply lumen is substantially equal to 0.75.

Abstract: A selective organ heat transfer device with a mixing-inducing surface. The device can have a plurality of elongated, articulated segments, each having a mixing-inducing exterior surface. A flexible joint connects adjacent elongated, articulated segments. The device is formed of a mechanical layer such as Ni and a biocompatible layer such as Au. An antithrombogenic and/or lubricious coating may also be employed for hemocompatibility. A protective layer such as Au may be employed to provide a degree of non-corrosiveness when exposed to a working fluid.

Abstract: A method and apparatus is provided for heating or cooling at least a selected portion of a patient's body. The method begins by inserting a catheter through the urethra and into the bladder of the patient. A heated or chilled fluid is conducted through a supply lumen of the catheter and into the bladder. The fluid is evacuated from the bladder through a return lumen of the catheter. Finally, a quantity of urine is monitored which flows out of the bladder and through the return lumen of the catheter.

Abstract: The subject invention is a power supply having an input for receiving a power signal, a DC storage device connected to the input, a primary output connected to the DC storage device and connectable to a battery, a DC to DC converter for converting the voltage at the DC storage device to an auxiliary DC voltage, the converter having a supply voltage input, and a switching circuit. The switching circuit includes first, second and third switches. The first switch is responsive to the power signal for providing the DC storage device voltage to the converter supply voltage input. The second switch is responsive to the voltage on the battery for providing the DC storage device voltage to the converter supply voltage input. The third switch is responsive to an auxiliary voltage on/off signal for overriding the second swtich.