DUAL BRAIDED SHAFT

• US 20080161762A1
• Filed: 12/29/2006
• Published: 07/03/2008
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Original Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Inventors: Johnson, Michael J., Tegg, Troy T., Stehr, Richard E., Fuentes, Allan M.
• Granted Patent: US 8,182,466 B2
• Time in Patent Office: Days
• US Class Current: 604/264
• CPC Class Codes: A61M 2025/0059 having means for preventing the catheter, sheath or lumens from collapsing due to outer forces, e.g. compressing forces, or caused by twisting or kinking
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids
• CPC Class Codes: A61M 25/0053 having a variable stiffness along the longitudinal axis, e.g. by varying the pitch of the coil or braid
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility

Abstract

A dual braided catheter shaft includes a flat wire forming the inner braid, thereby potentially allowing for reduced radial thickness of the shaft. In one embodiment, the shaft (100) includes an inner polymer jacket (104), an inner braid (106) formed on the inner jacket (104), an intermediate jacket (108) formed over the inner braid (106), an outer braid (110) formed on the intermediate jacket (108) and an outer jacket (112) formed on the outer braid (110). A preferred construction process involves extruding polymer material directly onto each of the inner and outer braids (106 and 110) so that little or no air gaps remain between the polymer material and the braids (106 and 110). The braiding parameters of the inner and outer braids (106 and 110) can be varied along the length of the catheter to provide varying mechanical properties.

Claims

1. A catheter apparatus, comprising:

a first wire wound to form an inner cylindrical braid structure;

a second wire wound to form an outer cylindrical braid structure, said inner cylindrical braid structure being disposed substantially inside of said outer cylindrical braid structure; and

a intermediate layer polymer material disposed at least between said inner cylindrical braid structure and said outer cylindrical braid structure;

said first wire being a flat wire having a minor cross-sectional dimension and a major cross-sectional dimension, where said major dimension is greater than said minor dimension.

2. The apparatus of claim 1, wherein said first wire is oriented such that said major dimension is substantially aligned with a longitudinal axis of said inner braid structure.

3. The apparatus of claim 1, wherein said first wire is oriented such that said minor axis is substantially aligned with a radial axis of said inner cylindrical braid structure.

4. The apparatus of claim 1, wherein said inner and outer structures are substantially coaxial.

5. The apparatus of claim 1, wherein an inner layer of polymer material is disposed at least partially inside of said inner braid structure and an outer polymer layer is disposed at least partially outside of said outer braid structure.

6. The apparatus of claim 1, wherein said second wire is a flat wire having a minor cross-sectional dimension and a major cross-sectional dimension, where said major dimension is greater than said minor dimension.

7. The apparatus of claim 5, wherein said inner layer, inner braid structure, intermediate layer, outer braid structure and outer layer define an integral laminar shaft.

8. The apparatus of claim 1, wherein inner braid structure and intermediate layer cooperate to provide desired incompressibility properties.

9. The apparatus of claim 8, wherein said properties are a function of said major cross-sectional dimension and a braiding parameter.

10. The apparatus of claim 8, wherein said properties are a function of material properties of said intermediate layer of polymer material.

11. The apparatus of claim 5, wherein said outer braid structure and outer layer cooperate to provide desired torque properties.

12. The apparatus of claim 11, wherein said properties are a function of a cross-sectional dimension of said second wire and a braiding parameter.

13. The apparatus of claim 11, wherein said properties are a function of material properties of said outer polymer layer.

14. The apparatus of claim 1, wherein said catheter apparatus has mechanical properties that vary along a length of said catheter apparatus.

15. The apparatus of claim 14, wherein said mechanical properties vary at least in part due to a changing braiding parameter of at least one of said inner and outer braid structures.

16. A catheter apparatus, comprising:

a first cylindrical layer of polymer material defining at least one internal lumen;

a first wire wound to form an inner cylindrical braid structure substantially on an outer surface of said first layer;

a second cylindrical layer of polymer material substantially on an outside of said inner cylindrical braid structure; and

a second wire wound to form an outer cylindrical braid structure substantially on an outer surface of said second layer.

17. The apparatus of claim 16, wherein said first wire is a flat wire having a minor cross-sectional dimension and a major cross-sectional dimension, where said major dimension is greater than said minor dimension.

18. The apparatus of claim 17, wherein said first wire is oriented such that said minor axis is substantially aligned with a radial axis of said inner cylindrical braid structure.

19. The apparatus of claim 16, wherein second wire is a flat wire having a minor cross-sectional dimension and a major cross-sectional dimension, where said major dimension is greater than said minor dimension.

20. The apparatus of claim 16, further comprising an outer cylindrical layer of polymer disposed at least partially outside of said outer braid structure.

21. The apparatus of claim 16, wherein said catheter apparatus has mechanical properties that vary along the length of said catheter apparatus.

22. The apparatus of claim 21, wherein said mechanical properties vary at least in part due to a changing braiding parameter of at least one of said inner and outer braid structures.

23. A method for use in constructing a catheter shaft, said catheter shaft including an inner braid and an outer braid outside of said inner braid, said method comprising the steps of:

braiding a first wire to form said inner braid; and

extruding a melt processable polymer over said braided first wire.

24. The method of claim 23, wherein said step of braiding comprises applying a first braiding parameter to a first section of said inner braid and a second braiding parameter, different than said first braiding parameter, to a second section of said inner braid.

25. The method of claim 23, further comprising the step of forming an inner layer of melt processable polymer and said step of braiding comprises braiding said first wire on an outer surface of said inner layer.

26. The method of claim 23, further comprising the step of braiding a second wire on said polymer to form said outer braid.

27. The method of claim 23, further comprising the step of forming an outer layer of melt processable polymer over said outer braid.

28. A method for use in constructing a catheter shaft, comprising:

forming a first cylindrical layer of polymer material;

braiding a first wire on a first outside surface of said first cylindrical layer;

forming a second cylindrical layer of polymer material over said braided first wire; and

braiding a second wire on a second outside surface of said second cylindrical layer.

29. The method of claim 28, further comprising the step of forming a third cylindrical layer of polymer material over said braided second wire.

30. The method of claim 28, wherein one of said steps of braiding comprises applying a first braiding parameter at a first section of said catheter shaft and applying a second braiding parameter, different than said first braiding parameter, at a second section of said catheter shaft.