Heat exchange and temperature sensing device and method of use

Abstract

A method and apparatus are disclosed for preventing injury to an esophagus caused by heat or cold being delivered to the left atrium, the method including altering a heat exchange device from an insertable configuration to a heat exchanging configuration which has an inflated generally flattened cross section (e.g. capsule-shaped, elliptical) corresponding with the cross section of the inside of the esophagus such that the esophagus is maintained in its natural shape and location. In some embodiments the heat exchange device has a heat exchanger which is inflated to be in the heat exchanging configuration.

We claim: 
     
         1 . A heat exchanging device for regulating a temperature of an esophagus when heat or cold is delivered to a left atrium of a heart, comprising:
 an elongated shaft comprising a distal end and a proximal end, the elongated shaft defining at least a first lumen and a second lumen;   a heat exchanger attached proximal to and spaced apart from the distal end of the elongated shaft, the heat exchanger comprising a distal end, a proximal end, and a cavity therebetween, at least a portion of said cavity being in fluid communication with the first lumen and the second lumen of the elongated shaft, the heat exchanger comprising an insertable configuration and a heat exchanging configuration,
 wherein a cross-section of the heat exchanger in the insertable configuration is smaller than a cross-section of the heat exchanger in the heat exchanging configuration, and 
 wherein said cross-section of the heat exchanger in the heat exchanging configuration has an inflated generally flattened cross section which substantially conforms to and corresponds with a cross-section of an inside surface of the esophagus such that the esophagus is substantially maintained in its natural shape and location when the heat exchanger is in its heat exchanging configuration. 
   
     
     
         2 . The heat exchanging device of  claim 1 , wherein the cross-sectional shape of the heat exchanger is substantially oblong. 
     
     
         3 . The heat exchanging device of  claim 1 , wherein the cross-sectional shape of the heat exchanger is substantially elliptical. 
     
     
         4 . The heat exchanging device of  claim 1  further comprising a temperature sensor attached to the distal end of the elongated shaft for measuring a core body temperature. 
     
     
         5 . The heat exchanging device of  claim 1 , wherein the heat exchanger further comprises temperature sensors for measuring the temperature of a target site within the esophagus. 
     
     
         6 . The heat exchanging device of  claim 1 , wherein the shape of the heat exchanger is constrained by a weld pattern, wherein the weld pattern comprises at least one weld, wherein said at least one weld attaches at least part of an anterior surface of the heat exchanger and a posterior surface of the heat exchanger. 
     
     
         7 . The heat exchanging device of  claim 1 , wherein the heat exchanger comprises an anterior surface and a posterior surface, wherein the anterior surface is positioned proximate an anterior wall of the esophagus and the posterior surface is positioned proximate a posterior wall of the esophagus, and wherein the posterior wall of the heat exchanger comprises a heat insulating layer for insulating the posterior wall of the esophagus from heat exchange fluid circulating through the heat exchanger, an anterior wall of the heat exchanger and the posterior wall of the heat exchanger defining a heat exchanging lumen, and the anterior wall of the heat exchanger and the heat insulating layer being comprised of the same material. 
     
     
         8 . The heat exchanging device of  claim 1  further comprising a radiopaque material positioned on the heat exchanger. 
     
     
         9 . The heat exchanging device of  claim 8 , wherein the radiopaque material is configured to indicate which side of the heat exchanger is facing a heart of a patient. 
     
     
         10 . The heat exchanging device of  claim 8 , wherein the heat exchanger comprises an anterior surface and a posterior surface, the posterior surface including at least a pair of outer markers and the anterior surface including at least a pair of inner markers, wherein each of the inner markers corresponds and aligns with an outer marker when the heat exchanger is fully unfolded in the heat exchanging configuration. 
     
     
         11 . The heat exchanging device of  claim 8 , wherein the heat exchanger comprises an anterior surface and a posterior surface, the anterior surface including at least a pair of outer markers and the posterior surface including at least a pair of inner markers, wherein each of the inner markers corresponds and aligns with an outer marker when the heat exchanger is fully unfolded in the heat exchanging configuration. 
     
     
         12 . The heat exchanging device of  claim 10  or  11 , wherein each of the inner markers do not align with the outer marker which it corresponds with when the heat exchanger is not fully unfolded. 
     
     
         13 . The heat exchanging device of  claim 10  or  11 , further comprising an asymmetrically located marker for indicating a direction the heat exchanger is facing. 
     
     
         14 . The heat exchanging device of  claim 1 , wherein the heat exchanger comprises a pair of lateral portions, with each of the lateral portions defining a sharp edge, and each sharp edge is covered by layer of material which defines a bumper which protects the esophagus from the sharp edge which is covered by the bumper. 
     
     
         15 . The heat exchanging device of  claim 14 , wherein each bumper is comprised of a portion of a circumference of a tubing. 
     
     
         16 . The heat exchanging device of  claim 1 , wherein the heat exchanger comprises at least one heat exchanger material, the heat exchanging device further comprising at least one temperature sensor imbedded in the at least one heat exchanger material to provide a non-abrasive outer surface. 
     
     
         17 . The heat exchanging device of  claim 16 , wherein a surface of the at least one temperature sensor is exposed to outside of the heat exchanger. 
     
     
         18 . The heat exchanging device of  claim 16 , wherein at least one temperature sensor is covered by at least one heat exchanger material so that the at least one temperature sensor is not exposed to outside of the heat exchanger. 
     
     
         19 . The heat exchanging device of  claim 1 , further comprising at least one temperature sensor attached to an inside surface of the at least one heat exchanger material to provide a non-abrasive outer surface. 
     
     
         20 . The heat exchanging device of one of  claims 16  to  19 , wherein the at least one temperature sensor comprises at least one thermistor. 
     
     
         21 . The heat exchanging device of  claim 1 , wherein the heat exchanger comprises an anterior surface of an anterior wall and a posterior surface of a posterior wall, and the anterior wall and the posterior wall are attached to the elongated shaft to define a dual lobed heat exchanger with a first lobe and a second lobe on opposite sides of the elongated shaft.