Inflatable balloon catheter seal and method
View Patent ↗An improved balloon catheter seal which may be used for attaching an inflatable balloon to a catheter body, especially when the balloon and catheter body are formed from dissimilar materials. The seal is formed by applying a layer of adhesive material between the inflatable balloon and the catheter body, and crimping a retaining ring over each seal junction. The invention is especially useful when joining a compliant balloon made from silicone to a catheter body made from polyurethane.
1. A method of manufacturing a balloon catheter which includes an outer tubular member having proximal and distal ends; an inner tubular member having proximal and distal ends, said inner tubular member being coaxial with said outer tubular member, said inner tubular member running longitudinally through said outer tubular member and extending distally beyond the distal end of said outer tubular member; an inflatable balloon having a main body portion and proximal and distal portions extending from said main body portion, said proximal and distal portions each having an inner and outer surface; wherein the method includes the steps of:
applying a first layer of adhesive material to the distal end of the outer tubular member;
inserting the proximal portion of the balloon over a portion of the outer tubular member covered by the first layer of adhesive material such that the balloon and outer tubular member are coaxially oriented;
positioning a first retaining ring over the proximal portion of the balloon;
crimping the first retaining ring onto the proximal portion of the balloon;
positioning a proximal retaining ring sleeve over at least a half of the first retaining ring and extending over a proximal portion of the first retaining ring;
heat fusing the proximal retaining ring sleeve to the outer tubular member and the first retaining ring;
inserting the inner tubular member inside the balloon;
positioning a second retaining ring over the balloon;
applying a second layer of adhesive material onto the distal end of the inner tubular member at a location beneath the distal portion of the balloon;
crimping the second retaining ring onto the distal portion of the balloon;
positioning a distal retaining ring sleeve distally adjacent to the second retaining ring; and,
heat fusing the distal retaining ring sleeve to the inner tubular member.
2. A method of manufacturing a balloon catheter as described in claim 1 , wherein at least a portion of the distal end of the outer tubular member is tapered prior to applying the first layer of adhesive material over the portion of the distal end which is tapered.