GUIDEWIRE WITH VARYING PROPERTIES

• US 20160136396A1
• Filed: 01/26/2016
• Published: 05/19/2016
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Chludzinski, Matthew James, Simpson, John Arthur
• Granted Patent: US 10,335,580 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61M 2025/09108 Methods for making a guide wire
• CPC Class Codes: A61M 2025/09133 having specific material compositions or coatings; Materials with specific mechanical behaviours, e.g. stiffness, strength to transmit torque
• CPC Class Codes: A61M 2205/0216 Materials providing elastic properties, e.g. for facilitating deformation and avoid breaking
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: B21C 1/00 Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
• CPC Class Codes: B21F 45/008 of medical instruments, e.g. stents, corneal rings medical science A61
• CPC Class Codes: B21J 7/145 the hammers being driven by a rotating annular driving member

Abstract

A method of making a core metal element for a medical guidewire comprising providing a wire of nickel titanium alloy having a length that includes a proximal portion having a first diameter and a distal portion having a second diameter. Applying cold work to the distal portion and not applying cold work to the proximal portion, thereby imparting to the distal portion a third diameter that is smaller than the second diameter; and then applying a reducing process to the wire whereby the proximal portion is reduced to have a fourth diameter that is less than the first diameter.

Claims

1. A method of making a core metal element for a medical guidewire comprising:

providing a wire of nickel titanium alloy with superelastic properties having a proximal end and a distal end, wherein a first length separates the proximal end from the distal end, applying cold work to the wire through a rotary swaging machine in a sequence that comprises;

swaging the wire over a second length that includes the distal end by using a die set having a first diameter;

swaging the wire over a third length that includes the distal end by using a die set having a second diameter, the third length being less than the second length, and the second diameter being less than the first diameter.

2. The method of claim 1, wherein swaging the wire over a second length includes swaging the wire over a second length that is between 20 mm and 16 mm, and swaging the wire over a third length includes swaging the wire over a third length that is between 14 mm and 10 mm.

3. The method of claim 1, wherein using a die set having a first diameter includes using a die set having a first diameter that is between 0.436 mm and 0.356 mm, and using a die set having a second diameter includes using a die set having a second diameter that is between 0.425 mm and 0.347 mm.

4. The method of claim 1, further including swaging the wire over a fourth length of the wire that includes the distal end by using a die set having a third diameter, wherein the fourth length is less than the third length and the third diameter is less than the second diameter.

5. The method of claim 1, further including applying a reducing process to the wire, whereby the wire is reduced to having a constant diameter over the first length.

6. The method of claim 5, wherein applying a reducing process to the wire includes applying centerless grinding.

7. The method of claim 1, wherein swaging the wire over a second length includes swaging the wire over a second length that is less than the first length.

8. A method of making a core metal element for a medical guidewire comprising:

providing a wire of nickel titanium alloy with superelastic properties having a proximal end and a distal end, wherein a first length separates the proximal end from the distal end, applying cold work to the wire through a rotary swaging machine in a sequence that comprises;

swaging the wire over a second length between a first distal point and a first proximal point by using a die set having a first diameter;

swaging the wire over a third length between a second distal point and a second proximal point by using a die set having a second diameter, the second diameter being larger than the first diameter, further including selecting the second distal point to coincide with the first proximal point.

9. The method of claim 8, wherein swaging the wire over a second length includes swaging the wire over a second length that is between 8 mm and 4 mm, and swaging the wire over a third length includes swaging the wire over a third length that is between 8 mm and 4 mm.

10. The method of claim 8, wherein using a die set having a first diameter includes using a die set having a first diameter that is between 0.414 mm and 0.338 mm, and using a die set having a second diameter includes using a die set having a second diameter that is between 0.425 mm and 0.347 mm.

11. The method of claim 8, further including selecting the first distal point to coincide with the distal end.

12. The method of claim 8, further including swaging the wire over a fourth length of the wire between a third distal point and a third proximal point by using a die set having a third diameter, the third diameter being larger than the second diameter, and further including selecting the third distal point to coincide with the second proximal point.

13. The method of claim 8, further including applying a reducing process to the wire, whereby the wire is reduced to having a constant diameter over the first length.

14. The method of claim 13, wherein applying a reducing process to the wire includes applying centerless grinding.

15. A method of making a core metal element for a medical guidewire comprising:

providing a wire of nickel titanium alloy with superelastic properties having a proximal end and a distal end, wherein a first length separates the proximal end from the distal end, applying cold work to the wire through a rotary swaging machine in a sequence that comprises;

swaging the wire over a second length that includes the distal end by using a die set having a certain diameter; and

swaging the wire over a third length that eludes the distal end by using the die set, the third length being less than the second length.

16. The method of claim 15, wherein swaging the wire over a second length includes swaging the wire over a second length that is between 20 mm and 16 mm, and swaging the wire over a third length includes swaging the wire over a third length that is between 14 mm and 10 mm.

17. The method of claim 15, wherein using a die set having a certain diameter includes using a die set having a certain diameter that is between 0.414 mm and 0.338 mm.

18. The method of claim 15, further including swaging the wire over a fourth length of the wire that includes the distal end by using the die set, the fourth length being less than the third length.

19. The method of claim 15, further including applying a reducing process to the wire, whereby the wire is reduced to having a constant diameter over the first length.

20. The method of claim 19, wherein applying a reducing process to the wire includes applying centerless grinding.

21. The method of claim 15, wherein swaging the wire over a second length includes swaging the wire over a second length that is less than the first length.

22. A method of making a core metal element for a medical guidewire comprising:

providing a wire of nickel titanium alloy with superelastic properties having a proximal end and a distal end, wherein a first length separates the proximal end from the distal end;

applying cold work to the wire through a rotary swaging machine in a sequence that comprises;

swaging the wire over a second length between a first proximal point and a first distal point, by using a die set having a certain diameter and feeding the wire through the die set at a first feed rate; and

swaging the wire over a third length between a second proximal point and a second distal point by using the die set and feeding the wire through the die set at a second feed rate, the second feed rate being faster than the first feed rate, further including selecting the second distal point to coincide with the first proximal point;

and further including selecting the first distal point to coincide with the distal end of the wire.

23. The method of claim 22, wherein swaging the wire over a second length includes swaging the wire over a second length that is between 8 mm and 4 mm, and swaging the wire over a third length includes swaging the wire over a third length that is between 8 mm and 4 mm.

24. The method of claim 22, wherein using a die set having a certain diameter includes using a die set having a certain diameter that is between 0.414 mm and 0.338 mm.

25. The method of claim 22, wherein feeding the wire through the die set at a first feed rate includes feeding the wire through the die set at a first feed rate that is between 1.25 mm/rev. and 0.750 mm/rev., and feeding the wire through the die set at a second feed rate includes feeding the wire through the die set at a second feed rate that is between 0.625 mm/rev. and 0.375 mm/rev.

26. The method of claim 22 further including swaging the wire between a third proximal point and a third distal point by using the die set and feeding the wire through the die set at a third feed rate, the third feed rate being faster than the second feed rate, further including selecting the third distal point to coincide with the second proximal point.

27. The method of claim 22 further including applying a reducing process to the wire, whereby the wire is reduced to having a constant diameter over the first length.

28. The method of claim 22, wherein applying a reducing process to the wire includes applying centerless grinding.

29. A guidewire for medical use, comprising:

a metal core having a proximal end and a distal end, wherein the metal core includes;

a proximal portion having superelastic properties;

a distal portion having linear elastic properties, wherein the distal portion includes the distal end; and

wherein, the metal core does not include a mechanical joint at any location between the proximal end and the distal end.

30. The guidewire of claim 29, wherein the metal core has a constant diameter between the proximal end and the distal end.

31. The guidewire of claim 29, wherein the distal portion is between 4 mm and 8 mm in length.

32. The guidewire of claim 29, further including an intermediate portion that is positioned between the proximal portion and the distal portion, the intermediate portion having properties that are a combination of superelastic properties and linear elastic properties.

33. The guidewire of claim 32, wherein the intermediate portion is between 4 mm and 8 mm in length.

34. The guidewire of claim 29, wherein the metal core is formed from a nickel titanium alloy.

35. The guidewire of claim 29, wherein the distal portion includes a metal to which the linear elastic properties have been imparted by a process of cold working.