Catheter and catheter fabrication method

• US 7,331,948 B2
• Filed: 06/18/2004
• Issued: 02/19/2008
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Skarda, James R.
• Primary Examiner(s): Lucchesi; Nicholas D.
• Assistant Examiner(s): BOUCHELLE, LAURA A
• Application Number:
  US10/871,588
• Publication Number:
  US 20050283136A1
• Time in Patent Office: 1,341 Days
• Field of Search: 604523-527
• US Class Current: 604/527
• CPC Class Codes: A61M 2025/0081 Soft tip
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/0045 multi-layered, e.g. coated coating materials A61L29/08
• CPC Class Codes: A61M 25/0069 Tip not integral with tube
• CPC Class Codes: A61M 25/008 Strength or flexibility characteristics of the catheter tip

Abstract

A catheter is fabricated by joining a first catheter body segment, the first segment including a braided or coiled filament reinforcing layer contained within an outer layer, to a second catheter body segment by thermal fusion in a zone including an interface between the first segment and the second segment and at a temperature causing ends of the filament reinforcing layer in the zone to extend outward within the outer layer. Following thermal fusion, the extending ends of the filament reinforcing layer are removed.

Claims

1. A catheter fabrication method, comprising the steps of:

joining a first catheter body segment, the first segment including a braided or coiled filament reinforcing layer contained within an outer layer, to a second catheter body segment by thermal fusion in a zone including an interface between the first segment and the second segment and at a temperature causing ends of the filament reinforcing layer in the zone to extend outward within the outer layer; and

removing the extending ends of the filament reinforcing layer.

2. The method of claim 1, wherein the step of removing the extending ends creates a channel in an outer surface of the outer layer.

3. The method of claim 1, wherein the step of removing the extending ends creates a channel in an outer surface of the outer layer and in an outer surface of the second catheter segment.

4. The method of claim 1, wherein the step of removing the extending ends comprises grinding away the extending ends.

5. The method of claim 1, further comprising the step of filling a void left by the removed extending ends with a material.

6. The method of claim 2, further comprising the step of filling the channel with a material to create a smooth transition between the outer surface of the outer layer and an outer surface of the second catheter segment.

7. The method of claim 6, wherein the material is an epoxy.

8. The method of claim 6, wherein the material is a polymer.

9. The method of claim 6, further comprising the step of curing the material filling the channel.

10. The method of claim 9, wherein the material is a UV light curable polymer.

11. The method of claim 6, wherein the material has a hardness greater than that of the second segment.

12. The method of claim 6, wherein the material has a hardness less than that of the outer layer of the first segment.

13. The method of claim 1, wherein:

the outer layer of the first segment is formed of a polyether block amide having a hardness between approximately 70 and approximately 75 on a Shore D scale and the second segment is formed of a polyether block amide having a hardness between approximately 50 and approximately 70 on a Shore D scale; and

the thermal fusion temperature is between approximately 300°

F. and approximately 400°

F.

14. A catheter fabrication method, comprising the steps of:

joining a first catheter body segment, the first segment including a braided or coiled filament reinforcing layer contained within an outer layer, to a second catheter body segment by thermal fusion in a zone including an interface between the first segment and the second segment and at a temperature causing ends of the filament reinforcing layer in the zone to extend outward within the outer layer;

removing the extending ends of the filament reinforcing layer and thereby creating a channel in an outer surface of the outer layer; and

filling the channel with a material to create a smooth transition between an outer surface of the outer layer and an outer surface of the second catheter segment.

15. The method of claim 14, wherein the step of removing the extending ends comprises grinding away the extending ends.

16. The method of claim 14, wherein the material is an epoxy.

17. The method of claim 14, wherein the material is a polymer.

18. The method of claim 14, further comprising the step of curing the material filling the channel.

19. The method of claim 18, wherein the material is a UV light curable polymer.

20. The method of claim 14, wherein the material has a hardness greater than that of the second segment.

21. The method of claim 14, wherein the material has a hardness less than that of the outer layer of the first segment.

22. The method of claim 14, wherein:

the outer layer of the first segment is formed of a polyether block amide having a hardness between approximately 70 and approximately 75 on a Shore D scale and the second segment is formed of a polyether block amide having a hardness between approximately 50 and approximately 70 on a Shore D scale; and

the thermal fusion temperature is between approximately 300°

F. and approximately 400°

F.

23. A catheter, comprising:

a first catheter body segment including a braided or coiled filament reinforcing layer contained within an outer layer;

a second catheter body segment joined to the first catheter body segment by thermal fusion; and

a zone, in close proximity to the junction of the first segment and the second segment, including a channel, the channel having been formed by removing ends of the filament reinforcing layer and being filled with a material to create a smooth transition between an outer surface of the outer layer and an outer surface of the second catheter segment;

wherein the ends of the filament reinforcing layer were caused to extend outward within the outer layer by the thermal fusion.

24. The catheter of claim 23, wherein the material is a UV light curable polymer.

25. The catheter of claim 23, wherein the material has a hardness greater than that of the second segment.

26. The catheter of claim 23, wherein the material has a hardness less than that of the outer layer of the first segment.

27. The catheter of claim 23, wherein the outer layer of the first segment is formed of a polyether block amide having a hardness between approximately 70 and approximately 75 on a Shore D scale and the second segment is formed of a polyether block amide having a hardness between approximately 50 and approximately 70 on a Shore D scale.

28. A catheter fabrication method, comprising the steps of:

joining a first catheter body segment, the first segment including a braided or coiled filament reinforcing layer contained within an outer layer, to a second catheter body segment by thermal fusion in a zone including a butt joint between the first segment and the second segment and at a temperature causing ends of the filament reinforcing layer in the zone to extend outward within the outer layer;

removing the extending ends of the filament reinforcing layer and thereby creating a channel spanning a portion of an outer surface of the first segment and a portion of an outer surface of the second segment; and

filling the channel with a material to create a smooth transition between the outer surface of the first segment and the outer surface of the second segment;

wherein the joining comprises

placing a heat-resistant tube spanning the butt joint prior to the thermal fusion process to promote intimate contact of the first and second segments; and

removing the tube subsequent to the thermal fusion process.

29. A catheter fabrication method, comprising the steps of:

joining a first catheter body segment, the first segment including a braided filament reinforcing layer contained within an outer layer, to a second catheter body segment by thermal fusion in a zone including an interface between the first segment and the second segment and at a temperature causing ends of the filament reinforcing layer in the zone to extend outward within the outer layer; and

removing a portion of the braided filament reinforcing layer.