Methods of manufacturing nested balloons utilizing pressurized constrained annealing

Abstract

A nested balloon is provided where each balloon is formed from tubing that optimizes the inner wall stretch thus providing maximum balloon strength. The high pressure, nested balloon is provided with layers that allow for slipping, such that the balloon has a very high pressure rating and toughness, yet excellent folding characteristics. Methods for producing such nested balloons using existing balloon forming equipment are also provided. The nested balloons can have layers with low-friction surfaces. The nested balloons are preferably manufactured using a variety of methods, including pressurized constrained annealing.

What is claimed is: 
     
         1 - 18 . (canceled) 
     
     
         19 . A method of manufacturing a nested balloon, comprising:
 providing a first balloon;   providing a second balloon;   inserting the first balloon into the second balloon to form a nested balloon,   wherein the first balloon layer slides relative to the second balloon layer before annealing;   annealing the nested balloon by pressurized constrained annealing to have a lower average burst pressure and a higher compliance than a balloon not annealed, wherein the first balloon layer slides relative to the second balloon layer after annealing; and   blow-molding the first balloon layer and the second balloon layer prior to annealing.   
     
     
         20 . The method of  claim 19 , wherein annealing the nested balloon by pressurized constrained annealing comprises annealing at a temperature of between about 100° F. and about 300° F. for a time period of at least 30 minutes. 
     
     
         21 . The method of  claim 19 , wherein the first balloon layer comprises nylon. 
     
     
         22 . The method of  claim 19 , wherein the second balloon layer comprises nylon. 
     
     
         23 . The method of  claim 19 , wherein annealing the nested balloon by pressurized constrained annealing comprises annealing at temperature between about 120° F. and about 270° F. 
     
     
         24 . The method of  claim 19 , wherein annealing the nested balloon by pressurized constrained annealing comprises annealing at temperature between about 100° F. and about 200° F. 
     
     
         25 . The method of  claim 19 , wherein annealing the nested balloon by pressurized constrained annealing comprises pressurizing the nested balloon at a pressure of between about 2 atm and about 30 atm. 
     
     
         26 . The method of  claim 19 , wherein annealing the nested balloon by pressurized constrained annealing comprises pressurizing the nested balloon at a pressure of between about 15 atm and about 25 atm. 
     
     
         27 . The method of  claim 19 , further comprising stretching the balloon with a stretch force of between about 1 pound and about 5 pounds. 
     
     
         28 . The method of  claim 19 , wherein annealing the nested balloon by pressurized constrained annealing for ae time period is between 30 minutes and 180 minutes. 
     
     
         29 . The method of  claim 19 , further comprising sterilizing the nested balloon after annealing at a temperature of between about 40° C. and about 60° C. for a time period of between about 1 hour and about 3 hours. 
     
     
         30 . The method of  claim 19 , wherein blow molding occurs no more than about 48 hours prior to annealing. 
     
     
         31 . The method of  claim 19 , wherein blow molding occurs no more than about 24 hours prior to annealing. 
     
     
         32 . The method of  claim 19 , further comprising welding the nested balloon to a catheter shaft to form a balloon catheter. 
     
     
         33 . The method of  claim 19 , wherein the first balloon layer is a co-extruded balloon layer. 
     
     
         34 . The method of  claim 19 , wherein the second balloon layer is a co-extruded balloon layer. 
     
     
         35 . The method of  claim 19 , wherein the first balloon and the second balloon comprise the same material. 
     
     
         36 . The method of  claim 19 , wherein a lubricant is disposed between the first balloon and the second balloon. 
     
     
         37 . A method of manufacturing a nested balloon, comprising:
 providing a first balloon;   providing a second balloon;   inserting the first balloon layer into the second balloon layer to form a nested balloon, wherein a lubricant is disposed between the first balloon layer and the second balloon layer, wherein the first balloon and the second balloon comprise the same material;   blow-molding the first balloon layer and the second balloon layer prior to annealing;   annealing the nested balloon by pressurized constrained annealing to have a lower average burst pressure and a higher compliance than a balloon not annealed, wherein the first balloon layer and the second balloon layer are configured to slide relative to each other after annealing.   
     
     
         38 . The method of  claim 37 , wherein annealing the nested balloon by pressurized constrained annealing comprises applying the temperature between about 100° F. and about 300° F. for between 30 minutes and 90 minutes.