Medical devices configured from deep drawn nickel-titanium alloys and nickel-titanium clad alloys and method of making the same

• US 6,830,638 B2
• Filed: 05/24/2002
• Issued: 12/14/2004
• Est. Priority Date: 05/24/2002
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Magrini, Kevin M., Huter, Scott J., Boyle, William J., Boylan, John F.
• Primary Examiner(s): WYSZOMIERSKI, GEORGE P
• Application Number:
  US10/155,910
• Publication Number:
  US 20030217794A1
• Time in Patent Office: 935 Days
• Field of Search: 148/402, 148/563, 148/670, 148/671, 148/676, 148/677, 623/1.18, 623/1.19
• US Class Current: 148/563
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 2017/2212 having a closed distal end, e.g. a loop
• CPC Class Codes: A61F 2/013 Distal protection devices, i.e. devices placed distally in combination with another endovascular procedure, e.g. angioplasty or stenting
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2002/821 Ostial stents
• CPC Class Codes: C22F 1/006 Resulting in heat recoverable alloys with a memory effect
• CPC Class Codes: C22F 1/10 of nickel or cobalt or alloys based thereon

Abstract

Nickel-titanium alloys that have been deep drawn in a cold working process have linear pseudoelastic behavior without a phase transformation or onset of stress-induced martensite. A medical device made from a structural element which has been deep drawn and subsequently formed into a desired medical device geometry will experience such linear pseudoelastic behavior.

Claims

1. A medical device, comprising:

a structural element having a particular medical device geometry formed from nickel-titanium alloy and being collapsible to be placed in a delivery position and self-expandable from the delivery position to a deployed position, where the nickel-titanium alloy has been processed in a deep drawing process which forms hollow-shaped structural element and cold works the nickel-titanium alloy so that it remains in a martensitic phase only regardless of stress that may be applied to the structural element to maintain the structural element in the delivery position, the hollow-shaped structural element being formed into the desired medical device geometry which includes a hollow structure.

2. The medical device of claim 1, wherein the structural element is laser cut to form the medical device geometry.

3. The medical device of claim 1, wherein the nickel titanium alloy is clad with a metallic element.

4. The medical device of claim 3, wherein the metallic element clad onto the nickel-titanium alloy is selected from the group consisting of palladium, platinum, chromium, iron, cobalt, vanadium, manganese, boron, copper, aluminum, tungsten, gold, tantalum and zirconium.

5. The medical device of claim 1, wherein the structural element has been heat treated and a hysteresis curve of the nickel-titanium alloy does not include a stress plateau.

6. The medical device of claim 1, wherein the structural element assumes a shape imparted by cold forming.

7. The medical device of claim 6, wherein the deep drawing occurs below the recrystallization temperature of the nickel-titanium alloy.

8. The medical device of claim 1, wherein the nickel-titanium alloy has an ingot transformation temperature which is set above 37 degrees C.

9. The medical device of claim 1, wherein the structural element forms a component of a composite medical device.

10. The medical device of claim 1, wherein the nickel-titanium alloy contains a third element.

11. The medical device of claim 10, wherein the third element is selected from a group consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium or hafnium.

12. A method for manufacturing a medical device for use in a body lumen, comprising:

providing nickel-titanium stock;

deep drawing the nickel-titanium alloy stock into a structure element having a hollow shape; and

forming the structural element into a desired medical device geometry which includes a hollow structure, the structural element being capable of assuming a first position when a stress is applied to it and movable to a second position when the stress is removed.

13. The method for manufacturing a medical device of claim 12, wherein the deep drawing of the nickel-titanium alloy produces a material which remains in a martensitic phase regardless of stress that may be applied to the structural element.

14. The method for manufacturing a medical device of claim 12, wherein the deep drawing of the nickel-titanium stock is performed by a punch and die operation.

15. The method for manufacturing a medical device claim 12, wherein method includes low temperature heat treat of the nickel-titanium alloy.

16. A self-expanding medical device, comprising:

a structural element having a particular medical device geometry formed from a nickel-titanium alloy and being collapsible to be placed in a delivery position and self-expandable from the delivery position to a deployed position, wherein the nickel-titanium alloy has been processed in a deep drawing process which forms hollow-shaped structural element and cold works the nickel-titanium alloy and heat treated so that the alloy remains in a martensitic phase only regardless of stress that may be applied to the structural element to maintain the structural element in the delivery position, the hollow-shaped structural element being formed into the desired medical device geometry which includes a hollow structure.

17. The medical device of claim 16, wherein the structural element is laser cut to form the medical device geometry.

18. The medical device of claim 16, wherein the nickel-titanium alloy is clad with a metallic element.

19. The medical device of claim 16, wherein the structural element assumes a shape imparted by cold forming.

20. The medical device of claim 16, wherein the nickel-titanium alloy contains a third element.