Medical devices utilizing modified shape memory alloy

• US 20040093017A1
• Filed: 11/06/2003
• Published: 05/13/2004
• Est. Priority Date: 11/06/2002
• Status: Abandoned Application

• Current Assignee: NMT Medical Incorporated
• Original Assignee: NMT Medical Incorporated
• Inventors: Chanduszko, Andrzej J.
• Application Number:
  US10/702,717
• Publication Number:
  US 20040093017A1
• Time in Patent Office: Days
• US Class Current: 606/200
• CPC Class Codes: A61B 17/0057 Implements for plugging an opening in the wall of a hollow or tubular organ, e.g. for sealing a vessel puncture or closing a cardiac septal defect sutures A61B17/04; closing rectum or urethra near body surface A61F2/0009
• CPC Class Codes: A61B 17/12022 Occluding by internal devices, e.g. balloons or releasable wires plugging an opening in the wall of an organ A61B17/0057; occluders for the cervical canal A61F6/146; vas deferens occluders A61F6/20
• CPC Class Codes: A61B 17/12109 in a blood vessel
• CPC Class Codes: A61B 17/12172 having a pre-set deployed three-dimensional shape methods of manufacturing A61B2017/00526
• CPC Class Codes: A61B 2017/00575 for closure at remote site, e.g. closing atrial septum defects
• CPC Class Codes: A61B 2017/00592 Elastic or resilient implements
• CPC Class Codes: A61B 2017/00606 Implements H-shaped in cross-section, i.e. with occluders on both sides of the opening
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61F 2/0105 Open ended, i.e. legs gathered only at one side
• CPC Class Codes: A61F 2/012 Multiple filtering units
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2220/0008 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0017 Angular shapes
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0071 spherical
• CPC Class Codes: A61F 2230/008 : paraboloidal
• CPC Class Codes: A61F 2230/0093 : Umbrella-shaped, e.g. mushroom-shaped
• CPC Class Codes: A61F 2250/0042 : differing in shape-memory transition temperatures, e.g. in martensitic transition temperature, in austenitic transition temperature
• CPC Class Codes: A61L 2400/16 : Materials with shape-memory or superelastic properties
• CPC Class Codes: A61L 31/022 : Metals or alloys
• CPC Class Codes: A61L 31/14 : Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials

Abstract

A medical device made from a shape memory alloy has portions with a first recovery force, and other portions with a second recovery force in desired locations, such as ends that contact portions of the body, such that the second recovery force is less than the first recovery force.

Claims

1. A medical device made of at least one wire having first, second, and third sequential sections, the first, second, and third sequential sections having the same material, the first and third sections having a first transition peak temperature, and the second section having a corresponding second transition peak temperature that is greater than the first transition peak temperature by at least about 5°

C.

2. The device of claim 1, wherein the first, second, and third sequential sections are made of nitinol.

3. The device of claim 2, wherein the first and second transition peak temperatures are austenitic peak temperatures.

4. The device of claim 2, wherein the first and second transition peak temperatures are R′

-phase peak temperatures.

5. The device of claim 1, wherein the second transition peak temperature is greater than the first transition peak temperature by at least about 10°

C.

6. The device of claim 5, wherein the second transition peak temperature is greater than the first transition peak temperature by at least about 12°

C.

7. The device of claim 1, wherein the wire is solid.

8. The device of claim 1, wherein the wire is tubular.

9. The device of claim 1, wherein the wire has a polygonal cross-section.

10. The device of claim 1, wherein the wire has a rectangular cross-section.

11. The device of claim 1, wherein the first, second, and third sections form a loop designed to contact tissue of a patient when the device is deployed, the curved portion of the loop being in the second section.

12. The device of claim 11, wherein the device is a stent having multiple loops at an end of the stent, each loop having a curved section with a recovery force that is less than the recovery force of adjacent sections.

13. The device of claim 11, wherein the device is a blood filter.

14. The device of claim 11, wherein the device is an occluder.

15. The device of claim 14, wherein the occluder has a plurality of loops, each of which has a curved section with a recovery force that is less than the recovery force of adjacent sections.

16. The device of claim 1, wherein the device is a guide wire.

17. The device of claim 1, wherein the device includes a spoke having an end for contacting tissue of a patient, the end being part of the third section.

18. A method for making a medical device including treating a wire that is part of the medical device and that has first, second, and third sequential sections with the first, second, and third sequential sections being made of the same material, the treating being provided so that the first and third sections having a first transition peak temperature, and the second section has a corresponding second transition peak temperature that is greater than the first transition peak temperature.

19. The method of claim 18, wherein the first, second, and third sequential sections are made of nitinol.

20. The method of claim 19, wherein the transition peak temperatures are austenitic peak temperatures.

21. The method of claim 19, wherein the transition peak temperatures are R′

-phase peak temperatures.

22. The method of claim 18, wherein the first, second, and third sections form a loop, with the curved portion of the loop being in the second section.

23. The method of claim 22, wherein the device is a stent having multiple loops at an end of the stent, each loop having a curved section with a recovery force that is less than the recovery force of adjacent sections.

24. The method of claim 22, wherein the device is a blood filter.

25. The method of claim 22, wherein the device is an occluder.

26. The method of claim 18, wherein the device is a guide wire.

27. The method of claim 18, wherein the device includes a spoke having an end for contacting tissue of a patient, the end being part of the third section.

28. The method of claim 18, wherein the treating includes providing a heat treatment to the second section different from a treatment provided to the first and second sections.

29. The method of claim 28, wherein the heat is applied by direct contact to the wire.

30. The method of claim 29, wherein the heat is applied with a hot liquid bath.

31. The method of claim 28, wherein the heat is applied by an energy source not in direct contact with the wire.

32. The method of claim 31, wherein the energy source is a laser.

33. The method of claim 28, wherein the heat is applied by an energy source with a computer controlled positioning system.

34. The method of claim 28, wherein the heat is applied to the wire while the wire is in a first shape, the method further comprising bending the wire into a shape suitable for use in the medical device after the treating.

35. The method of claim 34, wherein the heat is applied to the second section while the first, second, and third sequential sections are in a straight line, and thereafter bending the wire to form a loop with the curved portion in the second section.

36. The method of claim 28, wherein the heat is applied in an automated manner.

37. The method of claim 28, wherein the heat is applied with a coil.

38. The method of claim 18, wherein the treating includes using one of ion bombardment and ultrasonic energy.

39. The method of claim 18, wherein the device is treated so that the second transition peak temperature is greater than the first transition peak temperature by at least about 5°

C.

40. The device of claim 39, wherein the second transition peak temperature is greater than the first transition peak temperature by at least about 10°

C.

41. The device of claim 40, wherein the second transition peak temperature is greater than the first transition peak temperature by at least about 12°

C.

42. A medical device for insertion into a patient, the device having one or more wires with a plurality of loops circumferentially arranged and having curved portions for contacting tissue of a patient, wherein the curved portions for contacting the tissue of the patient have a transition peak temperature that is greater than portions immediately adjacent to the curved portions by at least 5°

C.

43. The device of claim 42, wherein the device is a septal defect occluder formed from a single wire.

44. The device of claim 42, wherein the device is an occluder formed from a plurality of wires with loops.

45. The device of claim 42, wherein the device is a filter formed from a plurality of wires with loops.

46. The device of claim 42, wherein the device is a stent a plurality of loops at an end of the stent.

47. The device of claim 42, wherein the device is made of nitinol.

48. The device of claim 42, wherein the transition peak temperature is the austenitic peak temperature.

49. The device of claim 42, wherein the transition peak temperature is the R′

-phase peak temperature.