Composite guidewire with a linear elastic distal portion

• US 20040193073A1
• Filed: 03/31/2003
• Published: 09/30/2004
• Est. Priority Date: 03/31/2003
• Status: Abandoned Application

• Current Assignee: Medtronic Interventional Vascular, Inc. (Massachusetts) (Medtronic Plc)
• Original Assignee: Medtronic Interventional Vascular, Inc. (Massachusetts) (Medtronic Plc)
• Inventors: DeMello, Richard M., Flight, Bruce
• Application Number:
  US10/403,848
• Publication Number:
  US 20040193073A1
• Time in Patent Office: Days
• US Class Current: 600/585
• CPC Class Codes: A61M 2025/09083 having a coil around a core
• CPC Class Codes: A61M 25/09 Guide wires

Abstract

A composite guidewire includes a central core that is made out of a “linear elastic” material, which at body temperature does not exhibit a yield point and/or change phase when subjected to the range of stresses that are common to guidewires. A core extension, which is made out of stiffer material, such as stainless steel, attaches to the central core through a coupling tube, which may be made of super elastic material, linear elastic material, or stainless steel. The coupling tube fits over a tapered distal end of the core extension and a proximal end of the central core that may but need not be tapered. The proximal end of the coupling tube abuts the tapered section of the core extension where the section has an outer diameter that is approximately the same size as the inner diameter of the coupling tube, and the tube is thus held against axial movement. The space between the inner diameter of the coupling tube and the ends that fit within the tube are filled with an adhesive, to create a strong yet flexible joint that transmits considerable torque without failure. An elongated coil, which may be radiopaque, fits over the distal portion of the central core. The coil may attach at a proximal end to the distal end of the coupling tube by, for example, adhesive, brazing or welding, such that the coil and the coupling tube provide support for the linear elastic core along the entire length of the core. The coil may instead extend over the coupling tube, such that the coil attaches to the distal end of the core extension. A shaping ribbon which is made of bendable material, such as, for example, stainless steel, is attached to a distal portion of the central core and extends beyond the end of the core, to provide a shapeable distal end to the guidewire. An atraumatic tip fits over the end of the guidewire and attaches to the coil and the shaping ribbon by brazing, welding or adhesive, to provide a cushioned end to the guidewire. As appropriate, a relatively short radiopaque outer coil may be positioned over the elongated coil, to provide visibility to the distal end of the guidewire.

Claims

1. A composite guidewire including:

a central core of linear elastic material, the central core having a distal portion and a proximal portion;

a coupling tube or coil extending over the proximal portion of the central core, the coupling tube or coil having a distal end and a proximal end;

a shaping ribbon of a shapeable material, the ribbon attaching to a distal portion of the central core and extending beyond the distal end of the central core;

an elongated coil engaged over the distal portion of the central core, the elongated coil having a distal end that attaches to the distal end of the shaping ribbon and a proximal end that attaches to the coupling tube or coil, and

an atraumatic tip attached to the distal ends of the coil and the shaping ribbon.

2. The composite guidewire of claim 1 further including a core extension of a relatively stiff material, the core extension having a distal end that joins to a proximal end of the central core through the coupling tube.

3. The composite guidewire of claim 2 wherein the proximal end of the elongated coil attaches to the distal end of the coupling tube.

4. The composite guidewire of claim 3 wherein the central core and the core extension have tapered ends that fit within the coupling tube or coil and the space between the tapered ends and the inner diameter of the coupling tube or coil is filled with an adhesive.

5. The composite guidewire of claim 4 wherein the proximal end of the coupling tube or coil abuts the distal end of the core extension at the point where the end of the core extension tapers to approximately the size of the inner diameter of the coupling tube or coil.

6. The composite guidewire of claim 5 wherein the distal end of the coupling tube or coil abuts the proximal end of the central core at the point where the end of the core tapers to approximately the size of the inner diameter of the coupling tube or coil.

7. The composite guidewire of claim 2 wherein the elongated coil extends over the coupling tube and attaches at the distal end to the core extension.

8. The composite guidewire of claim 7 wherein the core extension has a tapered distal end and the coil attaches to the core extension at a proximal end of the tapered section.

9. The guidewire of claim 1 wherein a distal end segment of the central core is tapered.

10. The guidewire of claim 9 wherein

the elongated coil is non-radiopaque, and

the guidewire further includes a radiopaque coil engaged over the non-radiopaque coil.

11. The guidewire of claim 9 wherein

the elongated coil is non-radiopaque, and

the guidewire further includes a radiopaque cover engaged over the tip and the distal end of the coil.

12. A composite guidewire including:

a core that includes a first section of linear elastic material and a second section of a relatively stiff material;

a flexible coupling member that extends over a distal segment of the second section and a proximal segment of the first section, the member attaching to a proximal section of the first section of the core and a tapered distal section of the second section of the core;

a shaping ribbon of a shapeable material that attaches to a distal portion of the first section of the core, the shaping ribbon extending beyond the distal end of the first section;

a coil engaged over a distal segment of the first core section, the coil having a distal end that attaches to a distal end of the shaping ribbon, and

a tip that attaches to the distal ends of the coil and the wire.

13. The composite guidewire of claim 12 wherein space between the coupling member and the ends of the first and second sections of the core that extend within the coupling member is filled with an epoxy adhesive.

14. The composite guidewire of claim 12 wherein the coil extends over the flexible coupling member, the coil attaching to the core extension at a proximal end of the tapered distal section of the core extension.

15. The composite guidewire of claim 12 wherein the proximal end of the core is tapered.

16. The guidewire of claim 12 wherein the coil is radiopaque.

17. The guidewire of claim 12 wherein

the coil is non-radiopaque, and

the guidewire further includes a radiopaque coil engaged over the non-radiopaque coil.

18. The guidewire of claim 12 wherein

the coil is non-radiopaque, and

the guidewire further includes a radiopaque plastic cover engaged over the tip and the distal end of the coil.

19. The guidewire of claim 15 wherein the ends of the coupling member abut tapered portions of the distal and proximal ends of the first and second sections, respectively.

20. A composite guidewire including:

a central core of a linear elastic material;

a core extension of a relatively stiff material;

a flexible coupling member that extends over a distal segment of the core extension and a proximal segment of the central core, the coupling member

attaching to a tapered proximal section of the central core at a point where the section has an outer diameter that corresponds to the inner diameter of the coupling member,

attaching to a tapered distal section of the core extension at a point where the section has an outer diameter that corresponds to the inner diameter of the coupling member; and

being filled with an adhesive to retain the ends and provide a joint between the central core and the core extension;

a shaping ribbon of a shapeable material that attaches to a distal portion of the central core, the shaping ribbon extending beyond the distal end of the first section;

a coil engaged over a distal segment of the first core section, the coil having a distal end that attaches to a distal end of the shaping ribbon, and

an atraumatic tip that attaches to the distal ends of the coil and the wire.

21. The composite guidewire of claim 20 wherein the linear elastic material is a Nitinol alloy that at body temperature remains in a single phase under the levels of stress associated with guidewire use.

22. The composite guidewire of claim 20 wherein the flexible coupling member is a coupling tube made of linear elastic material, super elastic material, or stainless steel.

23. The composite guidewire of claim 20 wherein the flexible coupling member is a coupling coil made of stainless steel.

24. The composite guidewire of claim 20 wherein the coil attaches at a proximal end to the distal end of the coupling member.

25. The composite guidewire of claim 20 wherein the coil extends over the coupling tube and attaches to the core extension at a proximal end of the tapered distal portion.