Compliant balloon catheter

Abstract

A catheter includes a first expandable membrane having a first pressurization limit and a second expandable membrane, having a second pressurization limit, wherein the second pressurization limit is greater than the first pressurization limit, the first expandable membrane defines a cooling chamber, the second expandable membrane being disposed around the first expandable membrane to define an junction therebetween. The catheter includes a coolant injection lumen in fluid communication with the at least one fluid inlet port and the cooling chamber, and a primary coolant return lumen in fluid communication with the at least one fluid outlet port and the cooling chamber. The coolant injection tube, the cooling chamber, and the primary coolant return lumen define a first fluid pathway. The catheter further includes a secondary coolant return lumen in fluid communication with the at least one fluid outlet port and the junction. The junction and the secondary coolant return lumen define a second fluid pathway. The catheter provides a fail-safe feature by selecting the appropriate first and second pressurization limits for the first and second expandable membranes.

What is claimed is: 
     
         1 . A medical device comprising:
 a first expandable membrane having a first burst pressure mean average and a first standard deviation value, the first burst pressure mean average and first standard deviation value defining a first probability distribution curve including an upper burst pressure and a lower burst pressure;   a second expandable membrane having a second burst pressure mean average and a second standard deviation value, the second burst pressure mean average and second standard deviation value defining a second probability distribution curve including an upper burst pressure and a lower burst pressure; and   the upper burst pressure of the first probability distribution curve being less than the lower burst pressure of the second probability distribution curve.   
     
     
         2 . The medical device of  claim 1 , further comprising a catheter body defining a proximal portion and a distal portion, the distal portion defining at least one fluid port in fluid communication with an interior of the first expandable membrane. 
     
     
         3 . The medical device of  claim 1 , wherein the second expandable membrane substantially surrounds the first expandable membrane to define a junction therebetween. 
     
     
         4 . The medical device of  claim 3 , wherein the first expandable membrane is coupled to the catheter body at an inner bond joint, and the second expandable membrane is coupled to the catheter body at an outer bond joint, and wherein the first burst pressure mean average is determined by the sealing strength of the inner bond joint. 
     
     
         5 . The medical device of  claim 3 , further comprising a pressure sensor in fluid communication with the junction. 
     
     
         6 . The medical device of  claim 1 , further comprising a pressure sensor in fluid communication with an interior of the first expandable membrane. 
     
     
         7 . The medical device of  claim 1 , further comprising a pressure relief valve in fluid communication with an interior of the first expandable membrane. 
     
     
         8 . The medical device of  claim 1 , wherein the first burst pressure mean average is determined by the tensile strength of the first expandable membrane and the second burst pressure mean average is determined by the tensile strength of the second expandable membrane. 
     
     
         9 . The medical device of  claim 1 , further comprising a supply of cryogenic fluid in fluid communication with an interior of the first expandable membrane. 
     
     
         10 . The medical device of  claim 9 , further comprising a vacuum source in fluid communication with an interior of the first expandable membrane. 
     
     
         11 . The medical device of  claim 1 , wherein the second expandable membrane is a compliant balloon. 
     
     
         12 . A medical system, comprising:
 a catheter body defining a fluid flow path;   a first expandable membrane disposed on the catheter body in fluid communication with the fluid flow path, the first expandable membrane having a first burst rating defining an upper burst prediction pressure and a lower burst predication pressure;   a second expandable membrane surrounding at least a portion of the first expandable membrane, the second expandable membrane having a second burst rating defining an upper burst prediction pressure and a lower burst prediction pressure; and   the upper burst prediction pressure of the first expandable membrane not overlapping with the lower burst prediction pressure of the second expandable membrane.   
     
     
         13 . The medical system of  claim 12 , wherein the fluid flow path includes an injection lumen and an exhaust lumen. 
     
     
         14 . The medical system of  claim 13 , further comprising a pressure sensor in fluid communication with the injection lumen. 
     
     
         15 . The medical system of  claim 13 , further comprising a pressure sensor in fluid communication with the exhaust lumen. 
     
     
         16 . The medical system of  claim 13 , further comprising a pressure relief valve in fluid communication with the injection lumen and a pressure relief valve in fluid communication with the exhaust lumen. 
     
     
         17 . The medical system of  claim 13 , further comprising a supply of cryogenic fluid in fluid communication with the injection lumen and a vacuum source in fluid communication with the exhaust lumen. 
     
     
         18 . The medical system of  claim 12 , wherein the first expandable membrane is a non-compliant balloon and the second expandable membrane is a compliant balloon. 
     
     
         19 . The medical system of  claim 18 , wherein the second expandable membrane retains the cryogenic fluid from the first expandable membrane when the first expandable membrane bursts. 
     
     
         20 . A medical device comprising:
 a first expandable membrane having a first burst pressure mean average and a first standard deviation value, the first burst pressure mean average and first standard deviation value defining a first probability distribution curve including an upper burst pressure and a lower burst pressure;   a second expandable membrane having a second burst pressure mean average and a second standard deviation value, the second burst pressure mean average and second standard deviation value defining a second probability distribution curve including an upper burst pressure and a lower burst pressure; and   a burst pressure that is 99.9% of the upper burst pressure of the first probability distribution curve not overlapping a burst pressure that is 99.9% of the lower burst pressure of the second probability distribution curve.