Catheter core wire

• US 6,669,670 B1
• Filed: 11/13/2000
• Issued: 12/30/2003
• Est. Priority Date: 03/06/1997
• Status: Expired due to Fees

• Current Assignee: Mirage IP LLC (IP Edge LLC)
• Original Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Inventors: Bleam, Jeffrey C., Muni, Ketan P.
• Primary Examiner(s): Le, Long V.
• Assistant Examiner(s): Lam, Ann Y
• Application Number:
  US09/712,407
• Time in Patent Office: 1,142 Days
• Field of Search: 604/164.13, 604/165.01, 604/93.01, 604/96.01, 604/103.04, 604/103.09, 604/164.01, 604/164.02, 604/164.03, 604/164.06, 604/164.1, 604/164.11, 604/264
• US Class Current: 604/164.13
• CPC Class Codes: A61M 2025/09175 having specific characteristics at the distal tip
• CPC Class Codes: A61M 2025/1093 having particular tip characteristics
• CPC Class Codes: A61M 25/09 Guide wires
• CPC Class Codes: A61M 25/09033 with fixed mandrils, e.g. mandrils fixed to tip; Tensionable wires
• CPC Class Codes: A61M 25/104 used for angioplasty
• CPC Class Codes: C22F 1/006 Resulting in heat recoverable alloys with a memory effect

Abstract

Disclosed herein is an improved core wire for use in a medical catheter. In one aspect, a tapering core wire is incorporated into the distal end of a catheter. The catheter has a tubular body. Both ends of an inflatable balloon are mounted to the tubular body. The core wire extends from the distal end of the tubular body. In one embodiment, substantially all of the taper of the core wire occurs in the extending portion of the core wire over a length of at least 15 mm but no more than 60 mm. In another aspect, a core wire with a shapeable tip and method of manufacturing the same are provided. A core wire previously made superelastic is subject to additional processing to remove its superelasticity thereby allowing the material to be shapeable to aid in advancing the core wire through a blood vessel or other body cavities. In another aspect of the present invention, a method is provided for securing the core wire to the distal end of an elongated catheter tubular body. The tubular body is mechanically crimped onto the core wire to secure the core wire in place. This crimping method has been found to increase the strength of the bond between the core wire and the catheter tube so that greater pull force is required to break the core wire off from the catheter.

Claims

1. A medical catheter, comprising:

an elongate tubular body having a proximal end and a distal end and a lumen extending therethrough; and

a core wire having a proximal taper extending into the lumen along the distal end of the tubular body and a distal taper extending from the distal end of the tubular body, the core wire having an intermediate section of substantially constant diameter between the proximal taper and the distal taper, wherein the core wire extends within the lumen of the elongate tubular body only along a distal section of the elongate tubular body and wherein the intermediate section of the core wire is fixedly attached to the distal section of the tubular body.

2. The catheter of claim 1, wherein the core wire has a proximal section of substantially constant diameter proximal to the proximal taper.

3. The catheter of claim 1, wherein the core wire extends into the lumen along the distal section of the elongate tubular body over a length of about 10 to 100 mm to provide additional structural support to the tubular body.

4. A medical catheter, comprising:

an elongate tubular body having a proximal end and a distal end and a lumen extending therethrough; and

a core wire fixedly attached to the distal end of the tubular body, the core wire having a proximal taper extending into the lumen along the distal end of the tubular body and a distal taper extending from the distal end of the tubular body and a section of substantially constant diameter between the proximal taper and distal taper;

wherein the section of substantially constant diameter is crimped to the tubular body.

5. A medical device, comprising:

an elongate tubular body adapted to extend from a location outside a body to a treatment site within a body lumen, the tubular body having a proximal end and a distal end and a lumen extending therethrough; and

a core wire having a proximal end extending inside the lumen of the tubular body and terminating therein in a distal section of the tubular body and a distal end extending distally beyond the distal end of the tubular body;

wherein the core wire includes an intermediate section between its proximal end and its distal end, the cross-sectional size of the core wire in the intermediate section being greater than the cross-sectional size of the core wire at both its proximal end and its distal end, the intermediate section of the core wire being fixedly attached to the tubular body.

6. The medical device of claim 5, wherein the intermediate section includes a section of substantially constant diameter.

7. The medical device of claim 5, wherein the core wire includes a tapered section decreasing the cross-sectional size of the core wire from the intermediate section toward the proximal end of the core wire.

8. The medical device of claim 7, further comprising a section of substantially constant diameter between the tapered section and the proximal end of the core wire.

9. The medical device of claim 5, wherein the core wire includes a first tapered section decreasing the cross-sectional size of the core wire from the intermediate section toward the distal end of the core wire.

10. The medical device of claim 9, further comprising a flattened tip between the tapered section and the distal end of the core wire.

11. The medical device of claim 5, wherein the core wire is made of nitinol.

12. A medical device, comprising:

an elongate tubular body having a proximal end and a distal end and a lumen extending therethrough; and

a core wire fixedly attached to the tubular body, the core wire having a proximal end extending inside the lumen of the tubular body and terminating therein in a distal section of the tubular body, the core wire having a distal end extending distally beyond the distal end of the tubular body, the core wire having an intermediate section between its proximal end and its distal end, the intermediate section having a cross-sectional size that is greater than the cross-sectional size of the proximal and distal ends of the core wire;

wherein the core wire includes a first tapered section decreasing the cross-sectional size of the core wire from the intermediate section toward the distal end of the core wire, the core wire further including a flattened tip between the first tapered section and the distal end of the core wire, the core wire further including a second tapered section decreasing proximally in thickness between the flattened tip and the first tapered section.