Sterilization process for a distensible dilatation balloon with elastic stress response
AssigneeMedtronic AVE, Inc.
InventorsJere R. Anderson, Louis J. Jandris, Michael D. Barbere, Richard T. Murphy
Life of this patent
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Abstract
Balloons and balloon catheters with a superior overall combination of distensibility, elastic stress response and strength. The improved properties of the balloons result from the method or process used to form the balloons, as well as the polymeric materials used in said balloon forming process. Additionally, the enhanced combination of properties of the balloons will not be adversely affected by the novel sterilization process contemplated by this invention.
Claims17
A balloon characterized by an improved overall combination of distensibility, elastic stress response and wall tensile strength made by the process comprising:
- a. providing a parison of a block copolymer having regions of inter-molecular chain interaction separated by regions in which those individual portions of the polymer chains have the ability to uncoil, said parison having a predetermined original outer diameter, a predetermined wall thickness and a predetermined length;
- b. subjecting said parison to at least one axial stretch step and at least one radial expansion step at temperature T1 which is below the melting temperature of said block copolymer to increase the diameter and length of said parison to at least 3 times the original diameter and 2 times the original length and to decrease the original wall thickness to at least 20% of the original wall thickness to form an expanded parison;
- and
- c. heating said expanded parison to a temperature of T2 which is above T1 but below the melting temperature of said block copolymer.
A process of forming a balloon characterized by an improved overall combination of distensibility, elastic stress response and wall tensile strength comprising:
- a. providing a parison of a block copolymer having regions of inter-molecular chain interaction separated by regions in which those individual polymer portion of chains have the ability to uncoil, said parison having a predetermined original outer diameter, a predetermined wall thickness and a predetermined length;
- b. subjecting said parison to at least one axial stretch step and at least one radial expansion step at temperature T1 which is below the melting temperature of said block copolymer to increase the diameter and length of said parison to at least 3 times the original diameter and 2 times the original length and to decrease the original wall thickness to at least 20% of the original wall thickness to form an expanded parison;
- and
- c. heating said expanded parison to a temperature of T2 which is above T1 but below the melting temperature of said block copolymer.
A process for sterilizing balloons and balloon catheters comprising:
- a. subjecting said balloons and balloon catheters to a temperature of about 35 to about 45° C. and a relative humidity of about 55% for about 15 hours;
- b. treating said balloons and balloon catheters at a temperature of about 35 to about 45° C. and a relative humidity of about 55% with ethylene oxide for about 15 hours;
- and
- c. discontinuing treatment with ethylene oxide and subjecting said balloons and balloon catheters to a temperature of about 35 to about 45° C. for about 22 hours.
Dependencies are inferred from the claim text.