Method and apparatus for regional and whole body temperature modification

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. The disposable heat exchange cassettes may include an integral pump head that engages with a pump drive mechanism within the re-usable control unit. More than one control unit may be provided to receive the same heat exchange cassette so that, for example, a large capacity control unit can be used initially, and a smaller, battery-powered unit can be substituted once the patient reaches the desired target temperature.

1 - 36 . (canceled) 
     
     
         37 . A system for maintaining or changing the temperature of at least a portion of the body of a subject, comprising:
 an extracorporeal heat exchanger configured to be applied to at least a portion of an exterior surface of a subject;   a primary heat exchanger configured to be fluidly coupled to the extracorporeal heat exchanger;   a pump head in fluid communication with the extracorporeal heat exchanger and the primary heat exchanger, the pump head, primary heat exchanger and the extracorporeal heat exchanger forming a fluid circuit through which a heat exchange fluid flows;   a heater/cooler device in thermal communication with the primary heat exchanger, the heater/cooler device configured to add heat to the heat exchange fluid or subtract heat from the heat exchange fluid flowing through the primary heat exchanger;   at least one sensor for monitoring the temperature of at least a portion of the subject's body, the at least one sensor providing signals representative of the monitored temperature of the at least a portion of the subject's body; and   a controller configured to control the heater/cooler device in response to the signals provided by the at least one sensor to maintain or change the temperature of at least a portion of the subject.   
     
     
         38 . The system of  claim 37 , wherein the controller and heater/cooler device are reusable. 
     
     
         39 . The system of  claim 37 , wherein the pump head is selected from the group consisting of a screw pump, a gear pump, diaphragm pump, and a peristaltic roller pump. 
     
     
         40 . The system of  claim 37 , wherein the heat exchange fluid flows through the primary heat exchanger along a serpentine pathway. 
     
     
         41 . The system of  claim 37 , wherein the extracorporeal heat exchanger is a thermal blanket. 
     
     
         42 . The system of  claim 37 , wherein the controller controls the heater/cooler device in response to the signals from the at least one sensor to change the temperature of at least a portion of the subject's body to a target temperature. 
     
     
         43 . The system of  claim 42 , wherein the controller controls the heater/cooler device in response to the signals from the at least one sensor to maintain the temperature of at least a portion of the subject's body at the target temperature. 
     
     
         44 . The system of  claim 37 , wherein the controller is programmed using software commands and selected operating parameters to control the heater/cooler device. 
     
     
         45 . The system of  claim 44 , further comprising an input device for inputting at least one of the selected operating parameters. 
     
     
         46 . The system of  claim 45 , wherein the at least one of the selected operating parameters is a target temperature. 
     
     
         47 . The system of  claim 43 , wherein the controller controls the heater/cooler device to maintain the temperature of the at least a portion of the subject's body within a buffer range of temperatures, the buffer range being based on the target temperature. 
     
     
         48 . The system of  claim 47 , wherein the buffer range includes a upper variance set point temperature and a lower variance set point temperature. 
     
     
         49 . The system of  claim 45 , wherein the input device provides for inputting an upper variance set point temperature and a lower variance set point temperature. 
     
     
         50 . The system of  claim 37 , further comprising a fluid source in fluid communication with the fluid circuit for providing heat exchange fluid to the fluid circuit. 
     
     
         51 . The system of  claim 50 , wherein the fluid source is an IV bag. 
     
     
         52 . The system of  claim 50 , wherein the fluid source is disposed above a horizontal level at least one of the horizontal levels defined by the group consisting of the subject, the extracorporeal heat exchanger and the pump head. 
     
     
         53 . The system of  claim 37 , wherein the fluid circuit, the at least one sensor and the controller are configured for use in a treatment area of a health care institution. 
     
     
         54 . The system of  claim 37 , wherein the fluid circuit, the at least one sensor and the controller are configured for use outside of a treatment area of a health care institution. 
     
     
         55 . The system of  claim 37 , wherein the fluid circuit, the at least one sensor and the controller are configured for use in an ambulance. 
     
     
         56 . The system of  claim 37 , wherein the at least one sensor is selected from the group consisting of a temperature probe for the head, temperature probe for the brain, a rectal temperature probe, an ear temperature probe and a bladder temperature probe. 
     
     
         57 . The system of  claim 37 , wherein the at least one sensor is a solid state thermocouple. 
     
     
         58 . The system of  claim 37 , further comprising at least one other sensor for monitoring a condition selected from the group consisting of a heart rate of the subject, a temperature from a different location that that sensed by the sensor, a pressure within the fluid circuit and a pressure within the subject, the at least one other sensor in operable communication with the controller, and wherein the controller receives signals from the at least one other sensor. 
     
     
         59 . The system of  claim 37 , wherein at least one of the group consisting of the extracorporeal heat exchanger, the fluid circuit, the sensor and the fluid source are disposable. 
     
     
         60 . The system of  claim 37 , further comprising:
 a heat exchange catheter having at least one recirculating-fluid-type intracorporeal heat exchanger, the heat exchange catheter being insertable into the vasculature of the subject such that the heat exchanger is in contact with blood flowing within the vasculature;   a second primary heat exchanger configured to be fluidly coupled to the heat exchange catheter;   a pump head in fluid communication with the heat exchange catheter and the second primary heat exchanger, the pump head, second primary heat exchanger and heat exchange catheter providing a second fluid circuit through which heat exchange fluid flows; and   a second heater/cooler device in thermal communication the second primary heat exchanger, the second heater/cooler device configured to add heat to the heat exchange fluid or subtract heat from the heat exchange fluid flowing through the second primary heat exchanger; and   wherein the controller is configured to control the second heater/cooler device in response to the signals provided by the at least one sensor to maintain or change the temperature of at least a portion of the subject.