Heating/cooling system for indwelling heat exchange catheter

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.

We claim: 
     
         1 - 22 . (canceled) 
     
     
         23 . A heat exchanger comprising:
 at least one computer readable storage medium; and   at least one processor configured to execute instructions on the computer readable storage medium to undertake logic comprising:   determining whether pulses from a flow detector of the heat exchanger are being received;   responsive to a determination that pulses are being received, determining whether a timer has expired;   responsive to a determination that the timer has expired, returning an error message; and   responsive to a determination that pulses are not being received, returning an error message.   
     
     
         24 . The heat exchanger of  claim 23 , wherein the pulses represent motion of a paddle wheel through light beams. 
     
     
         25 . The heat exchanger of  claim 24 , wherein the light beams are established by light emitting diodes in the heat exchanger. 
     
     
         26 . The heat exchanger of  claim 23 , wherein the logic further comprises:
 responsive to a determination that pulses are not present, determining whether plural light emitting diode (LED)/infrared transmitter (IRT) pairs are energized;   responsive to a determination that all LED/IRT pairs are energized, determining whether all LED/IRT pairs are operating properly.   
     
     
         27 . The heat exchanger of  claim 26 , wherein the logic when executed by the processor further includes determining whether all LED/IRT pairs are operating properly at least in part by sequentially toggling the LED/IRT pairs on and off. 
     
     
         28 . The heat exchanger of  claim 27 , wherein the logic when executed by the processor further includes responsive to a determination that all LED/IRT pairs are energized, determining whether a subset of the LED/IRT pairs are energized. 
     
     
         29 . The heat exchanger of  claim 28 , wherein the logic when executed by the processor further includes responsive to a determination that the subset of the LED/IRT pairs are energized, determining whether signal pulses are present. 
     
     
         30 . The heat exchanger of  claim 23 , wherein the logic when executed by the processor further includes responsive to a determination that pulses are being received, determining whether all of plural light emitting diode (LED)/infrared transmitter (IRT) pairs are energized. 
     
     
         31 . A heat exchanger comprising:
 at least one computer readable storage medium; and   at least one processor configured to execute instructions on the computer readable storage medium to undertake logic comprising:   periodically energizing a heater of the heat exchange system;   determining whether an increase in temperature satisfying a threshold is indicated;   responsive to a determination that an increase in temperature satisfying a threshold is indicated, returning a message indicating an error in circulation of a glycol circuit of the heat exchanger.   
     
     
         32 . The heat exchanger of  claim 31 , wherein the logic when executed by the processor further includes responsive to a determination that an increase in temperature satisfying a threshold is indicated, deenergizing the heater.