Coronary guidewire system

• US 6,579,246 B2
• Filed: 12/22/2000
• Issued: 06/17/2003
• Est. Priority Date: 12/22/1999
• Status: Expired due to Term

• Current Assignee: McDermott Will & Emery LLP
• Original Assignee: SARCOS LC (Sarcos Technology & Robotics Corp.)
• Inventors: Jacobsen, Stephen C., Davis, Clark C., Wells, David L.
• Primary Examiner(s): FOREMAN, JONATHAN M
• Application Number:
  US09/746,738
• Publication Number:
  US 20020013540A1
• Time in Patent Office: 907 Days
• Field of Search: 600/434, 600/435, 600/585
• US Class Current: 600/585
• CPC Class Codes: A61M 2025/0042 Microcatheters, cannula or the like having outside diameters around 1 mm or less
• CPC Class Codes: A61M 2025/09175 having specific characteristics at the distal tip
• CPC Class Codes: A61M 25/0138 having flexible regions as a result of weakened outer material, e.g. slots, slits, cuts, joints or coils
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: A61M 25/09033 with fixed mandrils, e.g. mandrils fixed to tip; Tensionable wires

Abstract

A guidewire system configured for introduction into a body lumen, comprising a core wire having proximal end and a distal end and a tapering profile, and a micromachined tube coupled to the core wire, and a joint where the micromachined tube is joined to the core wire; the location of the joint being at a location on the tapering profile where the torsional force which can be transferred by the core wire and the micromachined tubing are substantially the same.

Claims

1. A guidewire system, wherein a guidewire is configured for introduction into a body lumen, comprising:

a core wire having a proximal end, a distal end, and a tapering profile;

a micromachined tube having a proximal end and a distal end, the micromachined tube being coupled to the core wire;

a joint coupling the micromachined tube to the core wire;

the location of the joint being at a location on the tapering profile where the torsional force which can be transmitted by the core wire and the torsional force which can be transmitted by the micromachined tube are substantially the same.

2. A guidewire system as in claim 1 wherein the micromachined tube further comprises a plurality of axial beams and a plurality of transverse beams.

3. A guidewire system as in claim 2, wherein the axial beams and the transverse beams are configured so that a maximum torsional strain is substantially the same both in the axial beams and the transverse beams.

4. A guidewire system as in claim 2, wherein the axial beams and the transverse beams are configured so that a resistance to fatigue failure is substantially the same in both the axial beams and the transverse beams.

5. A guidewire system as in claim 4, wherein the micromachined tube further comprises a polished surface.

6. A guidewire system as in claim 4, wherein corners of the beams are rounded so as to reduce stress concentrations.

7. A guidewire system as in claim 5, wherein the micromachined tube is electropolished.

8. A guidewire system as in claim 1, wherein the proximal end of the micromachined tube is located adjacent the joint.

9. A guidewire system as in claim 8, wherein the core wire extends distally of the joint and the distal end of the core wire is coupled to the micromachined tube.

10. A guidewire system as in claim 9, wherein the core wire and the micromachined tube are joined at their respective distal ends.

11. A guidewire system as in claim 10, further comprising a plurality of axial beams and a plurality of transverse beams configured so that a maximum torsional strain is substantially the same in both the axial beams and the transverse beams.

12. A guidewire system as in claim 11, wherein resistance to fatigue failure is substantially the same in the axial and transverse beams.

13. A guidewire system as in claim 1, further comprising a coil disposed between the core wire and the micromachined tube.

14. A guidewire system as in claim 1, wherein the micromachined tube is configured so its lateral flexibility varies with position along its length.

15. A guidewire system as in claim 14, wherein the flexibility of the micromachined tube increases toward its distal end.

16. A guidewire system as in claim 14, where the flexibility of the micromachined tube sequentially increases, then decreases, then increases with a change in position along its length.

17. A guidewire system as in claim 1, wherein the joint is located intermediate the proximal and distal ends of the micromachined tube.

18. A guidewire system as in claim 1, wherein the guidewire further comprises a proximal coil having a proximal end and a distal end, the proximal coil being disposed over the core wire and coupled thereto at the proximal end of the proximal coil, at least a portion of the proximal coil being disposed proximally of the micromachined tube.

19. A guidewire system as in claim 18, wherein at least a portion of the proximal wire adjacent its distal end is disposed between the micromachined tube and the core wire.

20. A guidewire system as in claim 19, further comprising a medial coil, said medial coil having a proximal end and a distal end, said medial coil being disposed between the micromachined tube and the core wire.

21. A guidewire system as in claim 20, wherein the medial coil has an unwound portion adjacent its proximal end and the proximal coil has an unwound portion adjacent its distal end, said unwound portions of the respective medial and proximal coils overlapping and being wound together to provide a mechanical interlock between the proximal coil and the medial coil, the micromachined tube overlaying the overlapping portions.

22. A guidewire system as in claim 21, where the overlapping portions are located adjacent the joint.

23. A guidewire system as in claim 22, further comprising a distal coil, the distal coil being coupled to the medial coil and to the core wire, the distal coil being disposed between the core wire and the micromachined tube.

24. A guidewire system as in claim 1, wherein the core wire has a first outer diameter along a substantial portion of its length, and the micromachined tube has an outer diameter substantially the same as the first outer diameter of the core wire over at least a portion of its length.

25. A guidewire system as in claim 1, further comprising a proximal coil disposed over the core wire proximal of the micromachined tube, the core wire having a first outer diameter along a substantial portion of its length, the proximal coil having substantially the same outer diameter as the first outer diameter of the core wire, and the micromachined tube having substantially the same outer diameter as the proximal coil.

26. A guidewire system, wherein a guidewire is configured for introduction into a body lumen, comprising:

a core wire having a proximal end and a distal end and a tapering profile including a transition where a diameter of the core wire changes from a first outer diameter proximally to a second smaller outer diameter distally;

a micromachined tube having a proximal end and a distal end, the micromachined tube being coupled to the core wire adjacent the transition;

a joint coupling the micromachined tube to the core wire;

a location of the joint being adjacent the transition, and wherein the torsional force which can be transmitted by the core wire and the torsional force which can be transmitted by the micromachined tube are substantially the same adjacent the joint.

27. A guidewire system as in claim 26, wherein the core wire has a first outer diameter proximal of the joint and wherein the micromachined tube has an outer diameter substantially the same as the first outer diameter.

28. A guidewire system as in claim 26, wherein the guidewire further comprises a proximal coil having a proximal end and a distal end, and the core wire having a proximal transition located proximal to the transition adjacent the joint, the proximal end of the proximal coil being coupled to the core wire adjacent the proximal transition and the distal end being adjacent the joint, whereby the outer diameter of the guidewire is substantially the same along the guidewire.

29. A guidewire system as in claim 27, wherein the proximal coil further comprises a portion adjacent its distal end having a smaller outer diameter than the first outer diameter, the micromachined tube overlying at least a portion of the proximal coil adjacent the distal end of the proximal coil.

30. A guidewire system as in claim 26, wherein the micromachined tube further comprises a plurality of axial beams and a plurality of transverse beams.

31. A guidewire system as in claim 29, wherein the axial beams and the transverse beams are configured so that a maximum torsional strain is substantially the same in both the axial and the transverse beams.

32. A guidewire system as in claim 29, wherein the axial beams and the transverse beams are configured so that a resistance to fatigue failure is substantially the same in the axial and the transverse beams.

33. A guidewire system as in claim 31, wherein the micromachined tube further comprises a polished surface.

34. A guidewire system as in claim 29, wherein the corners of the beams are rounded so as to reduce stress concentrations.

35. A guidewire system as in claim 26, wherein the core wire extends distally of the joint and the distal end of the core wire is coupled to the micromachined tube.

36. A guidewire system as in claim 34, wherein the core wire and the micromachined tube are joined at their respective distal ends.

37. A guidewire system as in claim 26, further comprising plurality of axial beams and a plurality of transverse beams configured so that a maximum torsional strain is substantially the same in the axial and the transverse beams.

38. A guidewire system as in claim 37, wherein resistance to fatigue failure is substantially the same in the axial and transverse beams.

39. A guidewire system as in claim 26, wherein the micromachined tube is configured so its lateral flexibility varies with position along its length.

40. A guidewire system as in claim 26, wherein the guidewire further comprises a proximal coil having a proximal end and a distal end, the coil being disposed over the core wire and coupled thereto at the proximal end of the proximal coil, at least a portion of the proximal coil being disposed proximally of the micromachined tube.

41. A guidewire system as in claim 28, further comprising a medial coil, said medial coil having a proximal end and a distal end, said medial coil being disposed between the micromachined tube and the core wire.

42. A guidewire system as in claim 41, wherein the medial coil has a proximal unwound portion adjacent its proximal end and the proximal coil has an unwound portion adjacent its distal end, said unwound portions overlapping and being wound together to provide a mechanical interlock between the proximal coil and the medial coil, the micromachined tube overlaying the overlapping portions.

43. A guidewire system as in claim 42, where the overlapping portions are located adjacent the joint.

44. A guidewire system as in claim 43, further comprising a distal coil, the distal coil being coupled to the medial coil and to the core wire, the distal coil being disposed between the core wire and the micromachined tube.

45. A guidewire system, the guidewire being configured for guideably traversing a body lumen, comprising:

a core wire having a proximal end, a distal end, and an outer diameter, and a transition intermediate the proximal and distal ends where the outer diameter changes from a larger diameter proximally to a smaller diameter distally;

a micromachined tube having a proximal end and a distal end, said micromachined tube further comprising a plurality of axial beams and a plurality of transverse beams, the beams being configured so that resistance to fatigue failure of the axial beams and of adjacent transverse beams is substantially the same, the micromachined tube being disposed over the core wire and coupled to the core wire adjacent the transition;

the core wire having a capacity to transmit torsional force that is substantially the same as a capacity to transmit torsional force of the micromachined tube adjacent the transition;

whereby the capacity of the guidewire to transmit torsional forces is substantially maintained from that of the core wire proximal of the transition to that distal of the transition where the core wire has a smaller outer diameter and at least a portion of the torsion forces are carried by the micromachined tube.

46. A guidewire system as in claim 45, wherein the core wire extends distally of the transition to the distal end of the micromachined tube and wherein the micromachined tube is coupled to the core wire adjacent the distal end of each.

47. A guidewire system as in claim 46, further comprising a proximal coil having a proximal end and a distal end, the proximal coil being disposed over the core wire proximally of the micromachined tube.

48. A guidewire system as in claim 47, further comprising a proximal transition, and wherein the proximal end of the proximal coil is coupled to the core wire adjacent the proximal transition, and the distal end of the proximal coil is coupled to the core wire adjacent the transition where the micromachined tube is coupled to the core wire.

49. A guidewire system as in claim 48, wherein an outer diameter of the guidewire is not substantially increased along the length thereof from the proximal end to the distal end.

50. A guidewire system as in claim 45, wherein the axial beams and the transverse beams are configured so that a maximum strain occurring in either of the axial or transverse beams from torsion and bending forces is substantially the same.

51. A method of enhancing performance of a coronary guidewire is given by undertaking steps comprising:

providing a micromachined tube, said tube having a plurality of axial beams and a plurality of transverse beams;

configuring the micromachined tube so that a maximum strain induced in the axial beams from torsion and bending of the micromachined tube is substantially the same as that in the transverse beams;

providing a core wire having a diameter profile and a transition from a first diameter proximally to a second smaller diameter distally,

coupling the micromachined tube to the core wire adjacent the transition;

selecting diameters of the profile and the position of the coupling of the micromachined tube to the core wire so that a torque transmission capacity of the core wire is substantially the same as a torque transmission capacity of the micromachined tube adjacent the location of the coupling.

52. A guidewire system wherein improvement of performance of a coronary guidewire is given by undertaking steps comprising:

providing a micromachined tube, said tube having a plurality of axial beams and a plurality of transverse beams;

configuring the micromachined tube so that resistance to fatigue failure of an axial beam from torsion and bending of the micromachined tube is substantially the same as an adjacent in transverse beams;

providing a core wire having a diameter profile and a transition from a first diameter proximally to a second smaller diameter distally,

coupling the micromachined tube to the core wire adjacent the transition;

selecting diameters of the profile and the position of the coupling of the micromachined tube to the core wire so that a torque transmission capacity of the core wire is substantially the same as a torque transmission capacity of the micromachined tube adjacent the location of the coupling.

53. A guidewire system as in claim 52, further comprising the step of rounding corners of the axial and transverse beams.

54. A guidewire system as in claim 53, further comprising the step of polishing the micromachined tube.