Process for producing steerable sheath catheters

• US 20010049491A1
• Filed: 04/12/2001
• Published: 12/06/2001
• Est. Priority Date: 04/24/2000
• Status: Active Grant

• Current Assignee: Biotran Corporation Incorporated
• Original Assignee: Biotran Corporation Incorporated
• Inventors: Shimada, Jin
• Granted Patent: US 6,582,536 B2
• Time in Patent Office: Days
• US Class Current: 604/95.04
• CPC Class Codes: A61M 25/0012 with embedded structures, e.g. coils, braids, meshes, strands or radiopaque coils
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires

Abstract

The invention is a method for manufacturing a steerable catheter having a distal end, proximal end, an outer jacket, a pull wire and a central lumen. The central lumen is maintained in a circular shape without bulges diminishing the useful inter-diameter by using an outer jacket with an elliptical shape and uneven thickness to encase a pull wire. The pull wire friction is also reduced by using one wire of larger diameter to create the lumen for the pull wire of smaller diameter, thus reducing the friction on the pull wire and reducing the locking of the catheter body around the pull wire at bends preventing movement of the pull wire. The distal end of the catheter also has a smooth tip due to heat treating of steel wire braid reinforcement that does not require the addition of bulge forming additional material to control tip shape.

Claims

1. A method to manufacture a steerable sheath catheter, the catheter including an outer jacket and a pull wire embedded into the outer jacket, comprising:

laminating the outer jacket to surround the lumen defining wire;

removing the lumen defining wire thereby forming a lumen; and

inserting a pull wire into the lumen, wherein the pull wire has a smaller diameter than the lumen.

2. A method of

claim 1

wherein the catheter includes an inner liner.

3. A method of

claim 1

wherein the lumen defining wire has a diameter of preferably approximately 0.010 inches.

4. A method of

claim 1

wherein the pull wire has a diameter of preferably approximately 0.008 inches.

5. The method of

claim 1

wherein the lumen defining wire is covered with a lubricious material.

6. The method of

claim 1

wherein the outer jacket is made of a heat flowable polymer.

8. The process of

claim 6

wherein the braided wire is disposed between the lumen and the outer wall.

9. The process of

claim 6

wherein the inner liner is composed of fluorocarbon polymer.

14. The method of

claim 1

wherein the braided wire accommodates the pull wire, preventing deformation of the inner liner.

7. In a process for making a steerable catheter wherein the catheter has an inner liner, a braided wire, an outer jacket and a pull wire, the improvement comprising:

inserting a lumen defining wire between the inner liner and the outer jacket;

annealing the inner liner, the braided wire and the outer jacket into a catheter sheath;

removing the lumen defining wire thereby forming a lumen; and

inserting a pull wire into the lumen, wherein the pull wire has a diameter smaller than the diameter of the lumen defining wire.

10. A method to manufacture a steerable sheath catheter, the method including placing an inner liner over a mandrel, placing a pull wire on the inner liner, placing a wire braid over the inner liner and pull wire, placing an outer jacket over the wire braid, pull wire and liner, deforming the outer jacket with heat into a uniformly circular outer cross-sectional shape, the improvement comprising:

utilizing an outer jacket wherein the outer jacket is thicker at one cross-sectional portion and thinner at another cross-sectional portion;

positioning the outer jacket over the wire braid and pull wire so that the thicker cross-sectional portion is over the pull wire.

11. The method of

claim 10

wherein the outer jacket is thicker at one cross-sectional portion and thinner at another cross-sectional portion approximately 180°

therefrom.

12. In a process for making a steerable catheter wherein the catheter has an inner liner, a wire braid, an outer jacket and a pull wire, the improvement comprising:

extruding the outer jacket, wherein the jacket is thicker at one cross-sectional portion and thinner approximately 180°

therefrom;

disposing a pull wire between the inner liner and the thicker cross-sectional portion of the outer jacket;

deforming the outer jacket with heat into a circular outer cross-sectional shape.

13. A method to manufacture a steerable sheath catheter, the catheter including an inner liner, a pull wire, a wire braid surrounding the inner liner, and an outer jacket surrounding the wire braid, the improvement comprising:

placing the wire braid on a core material,

heat treating an end portion of the wire braid,

removing the core material.

15. A method to manufacture a steerable sheath catheter, the catheter including:

an inner liner, a wire braid surrounding the inner liner, an outer wall laminated to surround the wire braid and a pull wire;

the improvement comprising;

heat treating an end portion of the wire braid.

16. In a process for making a steerable sheath catheter, the process including:

placing an inner liner over a mandrel, placing a pull wire longitudinally along the inner liner, placing a wire braid over the inner liner and pull wire, placing an outer jacket over the wire braid, and laminating the catheter by applying heat, the improvement comprising;

placing the wire braid onto a core material,

heat treating an end portion of the wire braid,

removing the core material,

placing the wire braid over the inner liner and pull wire.

17. A steerable sheath catheter, the catheter including a pull wire, a wire braid and an outer jacket surrounding the wire braid and pull wire,

wherein the end portions of the wire braid are heat treated.