Patient temperature control catheter with outer sleeve cooled by inner sleeve

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.

What is claimed is: 
     
         1 . A catheter, comprising:
 a first sleeve through which working fluid can circulate to and from a source;   a second sleeve surrounding the first sleeve and filled with a biocompatible substance, the working fluid being separated, from the biocompatible substance by the first sleeve such that when the catheter is disposed in a patient, the working fluid is isolated from the patient by both the first sleeve and the biocompatible substance; and   at least one sensor between the first and second sleeves, wherein the sensor is configured to detect a temperature or state of the biocompatible substance.   
     
     
         2 . The catheter of  claim 1 , comprising the working fluid, wherein the working fluid includes a fluoridated hydrocarbon. 
     
     
         3 . The catheter of  claim 1 , wherein the biocompatible substance is frozen. 
     
     
         4 . The catheter of  claim 1 , wherein the biocompatible substance includes saline. 
     
     
         5 . The catheter of  claim 1 , wherein the sensor is a temperature sensor. 
     
     
         6 . The catheter of  claim 5 , wherein the temperature sensor provides a signal indicating that the biocompatible substance is at a temperature requiring additional cooling. 
     
     
         7 . The catheter of  claim 1 , wherein the sensor is an optical sensor. 
     
     
         8 . The catheter of  claim 7 , wherein the optical sensor provides a signal indicating that the biocompatible substance is in a state requiring additional cooling. 
     
     
         9 . The catheter of  claim 1 , wherein the first sleeve has an opening juxtaposed with a proximal end of the first sleeve and a closed distal end opposite the proximal end such that working fluid may enter the first sleeve only through the proximal end and cannot pass through the distal end. 
     
     
         10 . The catheter of  claim 1 , wherein the first and second sleeves are coaxial with each other. 
     
     
         11 . A system, comprising:
 a catheter including:   a first sleeve through which working fluid from a source of working fluid can circulate to and from the source of working fluid;   a second sleeve surrounding the first sleeve for holding a biocompatible substance in a space between the first and second sleeves, wherein the space is enclosed such that no biocompatible substance may escape from the space;   wherein the working fluid can circulate through the catheter to maintain the biocompatible substance at a designated temperature as heat is transferred to the biocompatible substance; and   
     
     
         12 . The system of  claim 11 , wherein the biocompatible substance is frozen and the second sleeve extends the length of the first sleeve. 
     
     
         13 . The system of  claim 11 , wherein the first sleeve of the catheter has an opening juxtaposed with a proximal end of the first sleeve and a closed distal end opposite the proximal end such that working fluid may enter the first sleeve only through the proximal end and cannot pass through the distal end. 
     
     
         14 . The system of  claim 11 , further comprising at least one control system engageable with, the catheter and configured for, responsive to a signal from the fluorinated hydrocarbon sensor, generating a signal to activate an audible and/or visual alarm. 
     
     
         15 . The system of  claim 11 , wherein the working fluid, can circulate through the catheter to maintain the biocompatible substance below the freezing point of the biocompatible substance as heat is transferred to the biocompatible substance 
     
     
         16 . System comprising:
 an inner chamber configured to receive working fluid therein and an outer chamber surrounding the inner chamber and configured to hold a biocompatible fluid therein, such that the biocompatible fluid can exchange heat with the working fluid, the inner chamber not being in fluid communication with the outer chamber; and   a control system configured for receiving a patient temperature signal and responsive to the patient temperature control signal, selectively circulate working fluid in the inner chamber.   
     
     
         17 . The system of  claim 16 , comprising a working fluid in the inner chamber and a biocompatible fluid in the outer chamber. 
     
     
         18 . The system of  claim 16 , comprising a patient temperature sensor configured to communicate with the control system. 
     
     
         19 . The system of  claim 16 , comprising a working fluid sensor disposed between the sleeves to sense a leak of working fluid out of the inner sleeve. 
     
     
         20 . The system of  claim 16 , comprising a catheter defining the chambers.