Composite flexible tube for medical applications

• US 20030176849A1
• Filed: 03/11/2003
• Published: 09/18/2003
• Est. Priority Date: 03/08/2000
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Chin, Yem, Wendlandt, Jeffrey Michael
• Granted Patent: US 7,582,079 B2
• Time in Patent Office: Days
• US Class Current: 604/527
• CPC Class Codes: A61M 25/0045 multi-layered, e.g. coated coating materials A61L29/08
• CPC Class Codes: A61M 25/005 with embedded materials for reinforcement, e.g. wires, coils, braids

Abstract

A flexible composite tube for medical applications is described. The tube has the ability to transmit a torque and to resist compression, tension, and kinking. The tube is also very flexible in bending, and has a small wall thickness. Different layers are used to obtain the desired properties. Torsional stiffness is obtained by embedding a braid in an elastomeric material. Resistance to kinks and to compression and tension is obtained by placing coils radially inward or outward of the braid. Smooth plastic layers are used to seal the assembly, and facilitate sliding in a body cavity.

Claims

1. A flexible composite tube for medical applications having a longitudinal axis, comprising:

a tubular braid adapted to transfer a torque along the longitudinal axis, the tubular braid being made of intertwined wire elements;

a coil disposed longitudinally along the tube, adapted to limit radial movement of the tubular braid; and

a tube-like elastic layer, disposed adjacent the tubular braid, forming a composite element with the tubular braid to restrict relative movement of the wire elements.

2. The tube according to claim 1, wherein the tubular braid is fully embedded in the elastic layer.

3. The tube according to claim 1, wherein a flexural modulus of the elastic layer and a braid spacing are selected to obtain a desired bending and torsional stiffness of the composite element.

4. The tube according to claim 1, wherein the coil is disposed radially inward of the tubular braid.

5. The tube according to claim 4, further comprising a second coil disposed radially outward of the tubular braid.

6. The tube according to claim 5, wherein the second coil has lower stiffness than the coil.

7. The tube according to claim 2, wherein the coil is fully embedded in the elastic layer.

8. The tube according to claim 1, wherein the coil is a flat wire coil.

9. The tube according to claim 1, further comprising an inner liner disposed radially inward from the coil and the tubular braid.

10. The tube according to claim 1, wherein the elastic layer has a flexural modulus of no more than about 2000 PSI.

11. The tube according to claim 10, wherein the tube has a diameter of about 20 mm.

12. The tube according to claim 11, wherein the composite element and the coil have a combined thickness of about 1 mm.

13. The tube according to claim 1, further comprising a second tubular braid separated from the tubular braid by the coil.

14. The tube according to claim 1, further comprising an outer smooth coating disposed radially outward of the coil and of the composite element.

22. The tube according to claim 2, further comprising an inner liner disposed radially inward from the coil and the tubular braid.

23. The tube according to claim 2, further comprising an outer smooth coating disposed radially outward of the coil and of the composite element.

15. A flexible composite tube for medical applications, comprising:

a tubular braid adapted to transfer a torque along a longitudinal axis of the tube, the tubular braid being made of intertwined wire elements;

an inner coil disposed longitudinally along the tube, radially inside of the tubular braid, adapted to limit radial contraction of the tubular braid; and

an outer coil disposed longitudinally along the tube, radially outside of the tubular braid, adapted to limit radial expansion of the tubular braid.

16. The tube according to claim 15, further comprising a smooth layer disposed radially inward of the inner coil.

17. The tube according to claim 15, further comprising a smooth layer disposed radially outward of the outer coil.

24. The tube according to claim 15, further comprising an outer smooth coating disposed radially outward of the second coil and of the composite element.

18. A flexible composite tube for medical applications having a longitudinal axis, comprising:

an inner tubular braid disposed along the longitudinal axis;

an outer tubular braid disposed radially outside of the inner tubular braid, said inner and outer tubular braids being adapted to transfer a torque along a longitudinal axis of the tube, and being made of intertwined wire elements; and

a coil disposed longitudinally along the tube, radially inside of the outer tubular braid and radially outside the inner tubular braid, adapted to limit radial contraction of the outer tubular braid and radial expansion of the inner tubular braid.

19. The tube according to claim 18, further comprising a smooth layer disposed radially inward of the inner braid.

20. The tube according to claim 18, further comprising a smooth layer disposed radially outward of the outer braid.

21. A flexible composite tube for medical applications having a longitudinal axis, comprising:

a tubular braid adapted to transfer a torque along the longitudinal axis, wherein the tubular braid is made of intertwined wire elements;

a first coil adapted to limit radial movement of the tubular braid, wherein the coil is disposed longitudinally along the tube and disposed radially inward of the tubular braid;

a second coil disposed radially outward of the tubular braid, wherein the second coil has lower stiffness than the first coil; and

a tube-like elastic layer, disposed adjacent the tubular braid, forming a composite element with the tubular braid to restrict relative movement of the wire elements.