Medical balloon
View Patent ↗Low polymer stress balloons are made by expanding a tube radially while allowing the ends of the tube to move axially in response to the radial expansion.
1. A method of making a medical balloon, comprising:
providing a polymer tube suitable for being formed into the medical balloon, the tube having two ends;
drawing the tube axially; and
expanding the tube radially while allowing the ends of the tube to move axially in response to said radial expansion.
2. The method of claim 1 , wherein the tube is below a glass transition temperature of a material of the tube during drawing.
3. The method of claim 2 , wherein the tube is below about 100° C. during drawing.
4. The method of claim 1 , wherein the tube is internally pressurized during drawing.
5. The method of claim 1 , wherein expanding the tube comprises heating the tube.
6. The method of claim 5 , wherein the tube is heated to a temperature about equal to or greater than a glass transition temperature of a material of the tube.
7. The method of claim 1 , wherein the tube is expanded to an expanded diameter about 5 to 9 times larger than an unexpanded diameter of the tube.
8. The method of claim 1 , wherein expanding the tube comprises simultaneously heating and pressurizing the tube.
9. The method of claim 1 , wherein expanding the tube comprises:
positioning the tube into a mold; and
simultaneously heating and pressurizing the tube.
10. The method of claim 1 , wherein expanding the tube comprises contacting the tube with a liquid.
11. The method of claim 10 , wherein the liquid comprises water.
12. The method of claim 1 , wherein the ends of the tube are allowed to move axially a distance between about 5 and about 30 percent of an original length of the tube.
13. The method of claim 1 , wherein the tube is formed of a polymer having regions of different hardnesses.
14. The method of claim 1 , wherein the tube comprises a block copolymer including hard segments and soft segments.
15. The method of claim 14 , wherein the block copolymer comprises a material selected from a group consisting of a polyether-ester elastomer, a polyester elastomer, and a polyether block amide.
16. The method of claim 14 , wherein the block copolymer comprises a polyether-ester elastomer.
17. The method of claim 1 , wherein the tube comprises a material selected from a group consisting of a polyester and a polyamide.
18. The method of claim 1 , wherein the tube is a multilayer tube.
19. The method of claim 1 , wherein the tube is a coextruded tube having layers of different hardnesses.
20. The method of claim 1 , further comprising characterizing the balloon by birefringence.
21. The method of claim 1 , further comprising attaching the balloon to a catheter to form a balloon catheter device.
22. The method of claim 1 , further comprising sterilizing the balloon by heating between about 32° C. and about 60° C.
23. The method of claim 1 , wherein expanding the tube radially comprises allowing the ends of the tube to move inwardly in response to said radial expansion.
24. A method of making a medical balloon, comprising:
providing a polymer tube suitable for being formed into the medical balloon, the tube having two ends; and
expanding the tube radially while allowing the ends of the tube to move axially in response to said radial expansion.
25. The method of claim 24 , further comprising axially orienting a material of the tube.
26. The method of claim 25 , wherein axially orienting the material comprises axially drawing the tube.
27. The method of claim 26 , wherein axially orienting the material further comprises internally pressurizing the tube.
28. The method of claim 24 , wherein expanding the tube comprises contacting the tube with a liquid.
29. The method of claim 28 , wherein the liquid comprises water.
30. The method of claim 24 , wherein expanding the tube comprises:
heating the tube to a temperature about equal to or greater than a glass transition temperature of a material of the tube; and
introducing a gas into the tube.
31. The method of claim 24 , wherein expanding the tube further comprises placing the tube into a mold.
32. The method of claim 24 , wherein the tube comprises a block copolymer.
33. The method of claim 24 , further comprising characterizing the balloon by birefringence.
34. The method of claim 24 , further comprising attaching the balloon to a catheter to form a balloon catheter device.
35. The method of claim 1 , further comprising positioning a stent on the balloon.
36. The method of claim 24 , further comprising positioning a stent on the balloon.