Shaft for medical catheters

• US 6,273,878 B1
• Filed: 08/25/1999
• Issued: 08/14/2001
• Est. Priority Date: 02/19/1998
• Status: Expired due to Fees

• Current Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Original Assignee: Percusurge Inc. (Medtronic Plc)
• Inventors: Muni, Ketan P.
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US09/383,103
• Time in Patent Office: 720 Days
• Field of Search: 604/265, 604/264, 604/523
• US Class Current: 604/265
• CPC Class Codes: A61M 2025/0046 Coatings for improving slidability
• CPC Class Codes: A61M 2025/1079 having radio-opaque markers in the region of the balloon
• CPC Class Codes: A61M 25/1036 Making parts for balloon catheter systems, e.g. shafts or distal ends A61M25/1029 takes precedence
• CPC Class Codes: A61M 25/104 used for angioplasty

Abstract

Several improvements are provided in the design of a catheter shaft to reduce costs and improve performance. In one aspect, a small notch is fabricated into a catheter tube by a nonlaser process such as electric discharge machining (EDM) or mechanical grinding. This notch in the catheter tube is necessary for fluid communication between the catheter lumen and a balloon or other element in communication with the tube. Use of a nonlaser process reduces the costs of fabrication while ensuring a high degree of structure integrity. In another aspect, a method is provided to produce a nonuniform polymer coating on a catheter shaft to reduce friction and to maintain a catheter with a low profile. In another aspect, the catheter is provided with a radiopaque marker which is more visible and is more effective at identifying the location of a balloon. The marker is moved closer to a distal balloon by placing it within an adhesive taper adjacent the balloon.

Claims

1. A catheter, comprising:

an elongate shaft; and

a nonuniform polymer coating formed onto at least a portion of the shaft to provide a substantially frictionless surface;

wherein the nonuniform coating is of varying thickness around the circumference of the shaft.

2. The catheter of claim 1, wherein the nonuniform polymer coating is produced by sputter coating.

3. The catheter of claim 1, wherein the nonuniform coating is produced by selectively spraying a polymer coating onto the shaft.

4. The catheter of claim 1, wherein the elongate shaft is substantially cylindrical.

5. The catheter of claim 2, wherein the nonuniform coating formed onto at least a portion of the shaft provides a coating substantially 360 degrees around the shaft.

6. The catheter of claim 2, wherein the nonuniform coating formed onto at least a portion of the shaft provides a coating less than 360 degrees around the shaft.

7. The catheter of claim 1, wherein the nonuniform coating is formed by providing coated and uncoated portions on the shaft.

8. The catheter of claim 1, wherein the polymer coating is made of a polytetrafluoroethylene.

9. The catheter of claim 1, further comprising an expandable device on a distal end portion of the shaft.

10. The catheter of claim 9, wherein the expandable device is a balloon.

11. A medical device, comprising:

an elongate shaft having a proximal end and a distal end;

an expandable member connected to the distal end of the shaft; and

a nonuniform polymer coating formed onto at least a portion of the shaft to provide a substantially frictionless surface, the coating being provided proximal to the expandable member;

wherein the nonuniform coating is formed by varying the thickness of the coating both around the circumference of the shaft and along the length of the shaft.

12. The medical device of claim 11, wherein the nonuniform polymer coating is produced by sputter coating.

13. The medical device of claim 11, wherein the nonuniform coating is produced by selectively spraying a polymer coating onto the shaft.

14. The medical device of claim 11, wherein the elongate shaft is substantially cylindrical.

15. The medical device of claim 14, wherein the nonuniform coating formed onto at least a portion of the shaft provides a coating less than 360 degrees around the shaft.

16. The medical device of claim 11, wherein the polymer coating is made of a polytetrafluoroethylene.

17. The medical device of claim 11, further comprising a proximal marker on the shaft, the coating provided between the proximal marker and the expandable device.

18. The medical device of claim 11, wherein the expandable device is a balloon.

19. The medical device of claim 11, wherein the coating has a thickness of less than about 0.01 inches.

20. The medical device of claim 19, wherein the coating has a thickness of less than about 0.0035 inches.

21. The medical device of claim 11, wherein the thickness of the coating is varied by providing coated and uncoated portions around the circumference and along the length of the shaft.