Method for forming an inflatable balloon for use in a catheter

Claim 1

A method of forming a stretched tubing element used for forming a balloon portion of a balloon dilatation catheter from a tubing element having a first outer diameter wherein the tubing element has a first end segment, an intermediate segment, and a second end segment, the method including the steps of: positioning a first internal support mandrel having a first diameter within the second end and intermediate segments of the tubing element; attaching a body clamp about the first support mandrel and intermediate segment of the tubing adjacent a distal end of the first support mandrel; attaching an end clamp to the first end segment adjacent an outer end thereof; heating the first end segment; urging the body clamp and end clamp longitudinally apart thereby stretching the first end segment longitudinally to lengthen said first end segment and reduce the outer diameter thereof to a second, smaller outer diameter; cooling the first stretched end segment; positioning a second internal support mandrel, having a second diameter which is smaller than the first support mandrel, within the stretched first end and intermediate segments of the tubing element; attaching the body clamp about the second support mandrel and intermediate segment of the tubing element adjacent a distal end of the second support mandrel; attaching the end clamp to the second end segment adjacent an outer end thereof; heating the second end segment; urging the body clamp and end clamp longitudinally apart thereby stretching the second end segment longitudinally to lengthen said second end segment and reduce the outer diameter thereof to a third outer diameter smaller than the second outer diameter; and cooling the second stretched end segment to form the stretched tubing element, wherein a major extent of the intermediate segment has not been stretched.

Claim 2

A method of forming a stretched tubing element used for forming a balloon portion of a balloon dilatation catheter from a tubing element having a first outer diameter wherein the tubing element has a first end segment, an intermediate segment, and a second end segment, the method including the steps of: positioning a first internal support mandrel having a first diameter within the second end and intermediate segments of the tubing element; attaching a body clamp about the first support mandrel and intermediate segment of the tubing adjacent a distal end of the first support mandrel; attaching an end clamp to the first end segment adjacent an outer end thereof; heating the first end segment; urging the body clamp and end clamp longitudinally apart thereby stretching the first end segment longitudinally to lengthen said first end segment and reduce the outer diameter thereof to a second, smaller outer diameter; cooling the first stretched end segment; positioning a second internal support mandrel, having a second diameter which is smaller than the first support mandrel, within the stretched first end and intermediate segments of the tubing element; attaching the body clamp about the second support mandrel and intermediate segment of the tubing element adjacent a distal end of the second support mandrel; attaching the end clamp to the second end segment adjacent an outer end thereof; heating the second end segment; urging the body clamp and end clamp longitudinally apart thereby stretching the second end segment longitudinally to lengthen said second end segment and reduce the outer diameter thereof to a third outer diameter smaller than the second outer diameter; and cooling the second stretched end segment to form the stretched tubing element, wherein a major extent of the intermediate segment has not been stretched.

Claim 12

A method of forming a balloon for use on a balloon dilatation catheter form a tubing element having a first outer diameter wherein the tubing element has a first end segment, an intermediate segment, and a second end segment, the method including the steps of: positioning a first internal support mandrel having a first diameter within the second end and intermediate segments of the tubing element; attaching a body clamp about the first support mandrel and intermediate segment of the tubing element adjacent a distal end of the first support mandrel; attaching an end clamp to the first end segment adjacent an outer end thereof; heating the first end segment; urging the body clamp and end clamp longitudinally apart to lengthen the first end segment and reduce the outer diameter thereof to a second, smaller outer diameter to form a stretched first end segment without stretching the intermediate segment; cooling the stretched first end segment; positioning a second internal support mandrel having a second diameter within the stretched first end segment and the intermediate segment of the tubing element; attaching the body clamp about the second support mandrel and intermediate segment of the tubing element adjacent a distal end of the second support mandrel; attaching the end clamp to the second end segment adjacent an outer end thereof; heating the second end segment; urging the body clamp and end clamp longitudinally apart to lengthen the second end segment and reduce the outer diameter thereof to a third outer diameter smaller than the second outer diameter without stretching the intermediate segment to form a stretched tubing element having stretched first and second end segments and a non-stretched intermediate segment; cooling the second stretched end segment; containing the stretched tubing element in a mold cavity so that the intermediate segment of the stretched tubing element is positioned within an enlarged portion of the mold cavity corresponding in shape to a desired inflated profile for the balloon; heating the stretched tubing element; pressurizing the stretched tubing element to expand the intermediate segment thereof radially outwardly into the enlarged portion of the mold cavity thereby forming the balloon; and cooling the balloon.

Claim 13

A method of forming a balloon for use on a balloon dilatation catheter form a tubing element having a first outer diameter wherein the tubing element has a first end segment, an intermediate segment, and a second end segment, the method including the steps of: positioning a first internal support mandrel having a first diameter within the second end and intermediate segments of the tubing element; attaching a body clamp about the first support mandrel and intermediate segment of the tubing element adjacent a distal end of the first support mandrel; attaching an end clamp to the first end segment adjacent an outer end thereof; heating the first end segment; urging the body clamp and end clamp longitudinally apart to lengthen the first end segment and reduce the outer diameter thereof to a second, smaller outer diameter to form a stretched first end segment without stretching the intermediate segment; cooling the stretched first end segment; positioning a second internal support mandrel having a second diameter within the stretched first end segment and the intermediate segment of the tubing element; attaching the body clamp about the second support mandrel and intermediate segment of the tubing element adjacent a distal end of the second support mandrel; attaching the end clamp to the second end segment adjacent an outer end thereof; heating the second end segment; urging the body clamp and end clamp longitudinally apart to lengthen the second end segment and reduce the outer diameter thereof to a third outer diameter smaller than the second outer diameter without stretching the intermediate segment to form a stretched tubing element having stretched first and second end segments and a non-stretched intermediate segment; cooling the second stretched end segment; containing the stretched tubing element in a mold cavity so that the intermediate segment of the stretched tubing element is positioned within an enlarged portion of the mold cavity corresponding in shape to a desired inflated profile for the balloon; heating the stretched tubing element; pressurizing the stretched tubing element to expand the intermediate segment thereof radially outwardly into the enlarged portion of the mold cavity thereby forming the balloon; and cooling the balloon.