Metal medical device

• US 6,497,709 B1
• Filed: 05/05/1997
• Issued: 12/24/2002
• Est. Priority Date: 03/31/1992
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Corporation
• Inventors: Heath, Kevin R.
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US08/851,161
• Time in Patent Office: 2,059 Days
• Field of Search: 600/433-436, 600/585, 604/95, 604/283, 606/127, 606/151, 606/200
• US Class Current: 606/127
• CPC Class Codes: A61B 17/22012 in direct contact with, or very close to, the obstruction or concrement for removing obstructions in blood vessels by laser A61B18/245
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque
• CPC Class Codes: A61M 2025/09166 having radio-opaque features
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: Y10T 29/53909 Means comprising hand manipulatable tool

Abstract

A medical device and method for treatment in which the device has a portion for use within the body that exhibits enhanced properties such as radiopacity for viewing by x-ray fluoroscopy. The portion includes an extended metal outer member having, e.g., a predetermined density and an exposed outer surface and a core, including a metal having, e.g., a density greater than the outer member to enhance radiopacity, substantially enclosed by the outer member.

Claims

1. A medical device, comprising:

a filter for placement within a channel within a body to filter a body fluid flowing through the channel, the filter including a wire-form member which comprises an outer metal member and a core disposed within the outer metal member, the outer metal member comprising a first metal and the core comprising a second metal different than the first metal,

wherein the second metal has a density greater than the first metal, and the core has a thickness sufficient to enhance the radiopacity of the filter when placed within the body.

2. The medical device of claim 1 wherein the second metal has a density greater than a density of the first metal.

3. The medical device of claim 1 wherein the outer metal member is a longitudinal member and the core is positioned along an axis of the longitudinal member.

4. The medical device of claim 1 wherein the second metal has a density of at least about 9.9 grams per cubic centimeter.

5. The medical device of claim 1 wherein the core comprises a material selected from the group consisting of tungsten, tantalum, rhenium, iridium, silver, gold, bismuth, platinum and alloys thereof.

6. The medical device of claim 1 wherein the core has a modulus of elasticity of about 550 GPa or less.

7. The medical device of claim 1 wherein the core has a modulus of elasticity of about 200 GPa or less.

8. The medical device of claim 1 wherein the outer metal member comprises a material selected from the group consisting of superelastic alloys, precursor alloys of superelastic alloys, stainless steel, and titanium and its alloys.

9. The medical device of claim 1 wherein one of the outer metal member or the core comprises nitinol.

10. The medical device of claim 9 wherein the outer metal member comprises nitinol.

11. The medical device of claim 1 wherein the core comprises from about 1% to about 40% of the cross-sectional dimension of the wire-form member.

12. The medical device of claim 11 wherein the core is at least about 25% of the cross-sectional dimension of the wire-form member.

13. The medical device of claim 12 wherein the core comprises at most about 28% of the cross-sectional dimension of the wire-form member.

14. The medical device of claim 1 wherein the cross-sectional dimension of the wire-form member is less than about 0.025 inch.

15. The medical device of claim 14 wherein the outer metal member has a cross-section of about 0.0045 to about 0.008 inch and the core has a cross section of about 0.0014 to 0.00195 inch.

16. The medical device of claim 1 wherein the core comprises a solid metallic member.

17. The medical device of claim 1 wherein the outer metal member and the core are of circular cross-sectional configuration.

18. The medical device of claim 1 wherein the core contacts the sheath.

19. The medical device of claim 1 wherein the filter includes a conical clot capturing portion formed of the wire-form member.

20. The medical device of claims 1 or 19 wherein the filter includes a lumen wall engaging portion formed of the wire-form member.

21. A medical device, comprising:

a vascular filter for placement in a blood vessel to filter clots in blood flowing through the blood vessel within the body, the filter including a wire-form member which comprises an outer metal member and a core disposed within the outer metal member, the outer metal member comprising a first metal having a density less than about 9.9 grams per cubic centimeter, and the core comprising a second metal having a density greater than 9.9 grams per cubic centimeter,

wherein the core has a thickness suffiecient to enhance the radiopacity of the filter when places within the body.

22. The medical device of claim 21 wherein the core comprises from about 10% to about 50% of the cross-sectional dimension of the wire-form member.

23. The medical device of claim 21 wherein the second metal comprises tantalum.

24. The medical device of claim 21 wherein the outer metal member comprises nitinol.

25. The medical device of claim 21 wherein a cross sectional dimension of the wire-form member is at most about 0.025 inch.

26. The medical device of claim 25 wherein the outer metal member has a cross-section of about 0.0045 to 0.008 inch and the core has a cross section of about 0.0014 to 0.00195 inch.

27. The medical device of claim 21 wherein the core contacts the sheath.

28. The medical device of claim 21 wherein the vascular filter includes a conical clot capturing portion formed of the wire-form member.

29. The medical device of claims 21 or 28 wherein the vascular filter includes a lumen wall engaging portion formed of the wire-form member.

30. A medical device, comprising:

a filter for filtering a body fluid flowing through a channel in the body, the filter including a wire-form member which comprises a core and a metal sheath intimately surrounding the core, the core having a first thickness and comprising a first metal and the metal sheath having a second thickness different than the first thickness and comprising a second metal different than the first metal, the second metal having a lower density and a greater elasticity than the first metal,

wherein the core has a thickness sufficient to enhance the radiopacity of the filter when placed within the body.

31. The medical device of claim 30 wherein a combined effect of the thickness of the first and second metals is to enhance radio-opacity of the medical device to provide improved fluoroscopic or x-ray visualization of the medical device in the body while a combined effect of the elasticity of the first and second metals is to impart sufficient elasticity to enable the medical device to elastically self-recover from its characteristic deformed configuration.

32. The medical device of claim 30 wherein the filter includes a conical clot capturing portion formed of the wire-form member.

33. The medical device of claims 30 or 32 wherein the filter includes a lumen wall engaging portion formed of the wire-form member.

34. The medical device of claim 30 wherein the core contacts the metal sheath.

35. A medical device, comprising:

a filter for placement within a channel within a body to filter a body fluid flowing through the channel, the filter comprising an outer metal member and a core disposed within the outer metal member, the outer metal member comprising a first metal and the core comprising a second metal different than the first metal,

wherein the second metal has a density greater than the first metal, and the core has a thickness sufficient to enhance the radiopacity of the filter when placed within the body.