Variable stiffness angioplasty guide wire

• US 6,183,420 B1
• Filed: 12/05/1997
• Issued: 02/06/2001
• Est. Priority Date: 06/20/1997
• Status: Expired due to Term

• Current Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Inventors: Choh, Richard, Douk, Nareak, Gambale, Richard A.
• Primary Examiner(s): YU, JUSTINE ROMANG
• Application Number:
  US08/985,799
• Time in Patent Office: 1,159 Days
• Field of Search: 600/585, 600/434, 600/462, 600/550, 600/439, 600/463, 600/466, 600/467, 604/95, 604/280, 604/282, 606/198
• US Class Current: 600/462
• CPC Class Codes: A61M 2025/0915 having features for changing the stiffness
• CPC Class Codes: A61M 2025/09175 having specific characteristics at the distal tip
• CPC Class Codes: A61M 25/09 Guide wires

Abstract

An angioplasty guidewire includes a proximal shaft formed with an axial passage and a variable stiffness intermediate section extending axially from the tubular shaft and having a corridor aligned axially with the passage and terminating at a distal joint. The intermediate section comprises a plurality of stiffening elements. A core element is slidably disposed axially through the passage and includes a distal end projecting into the corridor and attached to the distal joint while a flexible distal tip is mounted to the end of the intermediate portion and projects axially therefrom.

Claims

1. A guidewire comprising:

a proximal tubular shaft for insertion into a patient'"'"'s body and formed with an axial passage;

a variable stiffness intermediate section extending axially away from said proximal tubular shaft and having a corridor aligned axially with said passage and terminating at a distal joint, said intermediate section comprising a plurality of stiffening elements;

a core element slidably disposed axially through said passage and having a distal end projecting into said corridor and attached to said distal joint; and

a flexible distal tip mounted to a distal end of said intermediate portion and projecting axially therefrom.

2. A guidewire according to claim 1 wherein:

said core element distal end is splined at said distal joint.

3. A guidewire according to claim 1 wherein:

said intermediate section comprises at least one spring element.

4. A guidewire according to claim 3 wherein:

said intermediate section comprises a first inner spring and a second outer spring disposed coaxially around said first inner spring.

5. A guidewire according to claim 4 wherein:

said first inner spring is formed with a wire having a kidney-shaped cross-section.

6. A guidewire according to claim 3 wherein:

said at least one spring element comprises an inner spring formed with wire having a kidney-shaped cross-section.

7. A guidewire according to claim 1 wherein:

said plurality of stiffening elements are disposed along said core element distal end; and

said guidewire further including

an outer spring positioned in coaxial relationship with said inner elements.

8. A guidewire according to claim 7 wherein:

said inner elements are formed substantially spherical with respective concave portions to complementally engage the convex surface of adjacent elements and including respective central bores for receiving said core element.

9. A guidewire according to claim 7 wherein:

said inner elements comprising respective spherically formed beads with throughbores for receiving said core element and respective spacers formed with oppositely facing concave recesses to complementally engage respective pairs of spherical beads in interposed relationship.

10. A guidewire according to claim 1 wherein:

said passage is formed oversize with respect to said core element to receive hydraulic fluid and said guide wire further including

an annular piston sealably disposed coaxially between said core element and said tubular shaft and responsive to said hydraulic fluid to alter the stiffness of said intermediate section.

11. A catheter system comprising:

an angioplasty catheter having an expandable element for dilating radially outwardly inside a blood vessel; and

a controllably variable guidewire including

a proximal tubular shaft for insertion into a patient'"'"'s body and formed with an axial passage;

a variable stiffness intermediate section extending axially away from said proximal tubular shaft and having a corridor aligned axially with said passage and terminating at a distal joint, said intermediate section comprising a plurality of stiffening elements;

a core element slidably disposed axially through said passage and having a distal end projecting into said corridor and attached to said distal joint; and

a flexible distal tip mounted to a distal end of said intermediate portion and projecting axially therefrom.

12. A catheter system according to claim 11 wherein:

said expandable element comprises a stent.

13. A catheter system according to claim 11 wherein:

said expandable element comprises a balloon.

14. A guidewire comprising:

a proximal tubular shaft for insertion into a patient'"'"'s body and formed with an axial passage;

a variable stiffness intermediate section extending axially away from said proximal tubular shaft and having a corridor aligned axially with said passage and terminating at a distal joint, said intermediate section comprising a plurality of stiffening elements;

a core element slidably disposed axially through said passage and having a distal ends projecting into said corridor; and

a flexible distal tip mounted to a distal end of said intermediate portion and projecting axially therefrom.

15. A guidewire according to claim 14 wherein:

said intermediate section comprises a hypotube having an interiorbore closed at the distal extremity of said intermediate section; and

said core element comprises a relatively stiff core wire.

16. A guidewire according to claim 15 wherein:

said hypotube is fixed; and

said core wire is moveable within said internal bore.

17. A guidewire according to claim 15 wherein:

said internal bore is of a constant diameter; and

said core wire is of a constant diameter.

18. A guidewire according to claim 14 wherein:

said intermediate section comprises a tapered tubular member having an interior bore closed at the distal extremity of the intermediate section, and said core element is moveable within said internal bore.

19. A guidewire according to claim 18 wherein:

said internal bore is formed with a relatively constant diameter.

20. A guidewire according to claim 18 wherein:

said core element comprises an untapered core wire.

21. A guidewire according to claim 14 wherein:

said intermediate section comprises a spring coil and a flexible member, said flexible member being coaxially disposed over said core element and said flexible member and said core element being slidable relative to each other to cooperatively impart a variable stiffness to said intermediate section, said variable stiffness being increased by advancing said core element within said flexible member toward said distal joint, said variable stiffness being reduced by moving said core element within said flexible member away from said distal joint.

22. A guidewire according to claim 21, wherein:

said core element comprises a core wire; and

said flexible member comprises a hypotube.

23. A guidewire according to claim 22, wherein said hypotube is fixed to said distal tip.

24. A guidewire according to claim 14 wherein:

said intermediate section comprises a spring coil and a flexible hypotube associated with said proximal shaft;

wherein said core element is slidably received within said hypotube to cooperatively impart a variable stiffness to said intermediate section, said hypotube being anchored to said distal joint, said variable stiffness being increased by advancing said core element toward said distal joint within said hypotube, said variable stiffness being reduced by moving said core element away from said distal joint within said hypotube.