System and Method for Management of Body Temperature

Abstract

A system and method for adding or removing heat from a heat exchange fluid circulating between an external heat exchanger and an intravascular heat exchange catheter is described. The system includes a two stage cooling system providing for a high rate of cooling in one stage and a lower rate of cooling in a second stage. Both stages may be used to provide maximal cooling while the second stage is used to provide improved control of the cooling rate as a target temperature is approached. The second stage may also be used to provide heat to the heat exchange fluid.

I claim: 
     
         1 . A system for managing the temperature of a person using an intravascular heat exchanger inserted into the lumen of a body vessel of a patient, comprising:
 an intravascular heat exchanger having a fluid input port and a fluid output port;   an external heat exchanger having an input and an output port, the input and output ports, the intravascular heat exchanger and the external heat exchanger forming a fluid circuit;   a pump disposed within the fluid circuit for pumping heat exchange fluid through the fluid circuit;   a heater/cooler configured to engage the external heat exchanger in a thermal transfer relationship, the heater/cooler including a primary cooling portion and a reversible secondary portion capable of heating or cooling, the primary cooling portion including a refrigeration circuit including a compressor, a condenser, an expansion valve, and a cold block in thermal communication with the reversible secondary portion; and   a controller having a processor configured by software commands to receive temperature indications related to the temperature of a patient and to control operation of the heater/cooler in accordance with a target temperature.   
     
     
         2 . The system of  claim 1 , wherein the fluid input and the fluid output of the intravascular heat exchanger each have releasable couplings, and wherein the input and output ports of the external heat exchanger have releasable couplings, the releasable coupling of the input port configured to engage the releasable coupling disposed on the fluid output of the intravascular heat exchanger and the releasable coupling of the output port configured to engage the releasable coupling of the fluid input of the intravascular heat exchanger 
     
     
         3 . The system of  claim 1 , wherein the reversible secondary portion is a T/E cooler. 
     
     
         4 . The system of  claim 1 , wherein the controller activates the primary cooling portion to remove heat from the heat exchange fluid when the difference between the sensed patient temperature and the target temperature exceeds a selected value. 
     
     
         5 . The system of  claim 1 , wherein the controller activates the primary cooling portion and the reversible secondary portion to remove heat from the heat exchange fluid when the difference between the sensed patient temperature and the target temperature exceeds a selected value. 
     
     
         6 . The system of  claim 1 , wherein the controller activates the reversible secondary portion to remove heat from the heat exchange fluid when the difference between the sensed patient temperature and the target temperature is less than a selected value. 
     
     
         7 . The system of  claim 1 , wherein the controller activates the reversible secondary portion to add heat to the heat exchange fluid when the sensed patent temperature is less than the target temperature. 
     
     
         8 . The system of  claim 4 , wherein the controller deactivates the primary cooling portion and activates the reversible secondary portion when the difference between the sensed patient temperature and the target temperature is less than a selected value. 
     
     
         9 . The system of  claim 5 , wherein the controller deactivates the primary cooling portion when the difference between the sensed patient temperature and the target temperature is less than a selected value. 
     
     
         10 . The system of  claim 1 , further comprising a communication module configured to communicate information related to the sensed temperature and the operation of the system to a display remote from the system. 
     
     
         11 . The system of  claim 1 , further comprising a communication module configured to communicate information related to the sensed temperature and the operation of the system to a data management system. 
     
     
         12 . The system of  claim 11 , wherein the information communicated to the data management system is associated with an electronic medical record of the patient. 
     
     
         13 . The system of  claim 1 , further comprising:
 a communication module configured to communicate with a device monitoring a health parameter of the patient; and   a display controlled by the processor of the controller to display information related to the operation of the system and information received from the monitoring device related to the monitored health parameter of the patient.   
     
     
         14 . The system of  claim 1 , further comprising a secondary cooling circuit disposed between the refrigeration circuit and the fluid circuit, the secondary cooling circuit comprising a pump for pumping secondary heat exchange fluid through the secondary cooling circuit, a secondary cold block configured to engage the cold block of the refrigeration circuit in a heat exchange configuration, and a third cold block configured to engage the external heat exchanger of the fluid circuit in a heat exchange configuration. 
     
     
         15 . The system of  claim 14 , wherein the reversible secondary portion of the heater cooler is disposed in the secondary cooling circuit rather than the primary cooling circuit. 
     
     
         16 . The system of  claim 14 , wherein the third block is a container having an input and an output, the container configured to receive the external heat exchanger such that the external heat exchanger is immersed in the secondary heat exchange fluid flowing through the container.