Method and apparatus for contracting, loading or crimping self-expanding and balloon expandable stent devices

• US 6,823,576 B2
• Filed: 10/01/2001
• Issued: 11/30/2004
• Est. Priority Date: 09/22/1999
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Austin, Michael
• Primary Examiner(s): JIMENEZ, MARC QUEMUEL
• Application Number:
  US09/966,686
• Publication Number:
  US 20020035774A1
• Time in Patent Office: 1,156 Days
• Field of Search: 295/05, 295/16, 295/15, 295/08, 292/835, 292/82, 292/37, 297/51, 606/1, 724/02, 721/21, 425/DIG.110, 425/DIG.9, 425/547, 425/551, 425/552
• US Class Current: 29/516
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2/9524 Iris-type crimpers
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61M 25/1029 Production methods of the balloon members, e.g. blow-moulding, extruding, deposition or by wrapping a plurality of layers of balloon material around a mandril
• CPC Class Codes: Y10T 29/4981 Utilizing transitory attached element or associated separate material
• CPC Class Codes: Y10T 29/49865 by temperature differential [e.g., shrink fit]
• CPC Class Codes: Y10T 29/49908 Joining by deforming
• CPC Class Codes: Y10T 29/49913 by constricting outer annulus
• CPC Class Codes: Y10T 29/49925 Inward deformation of aperture or hollow body wall
• CPC Class Codes: Y10T 29/49927 Hollow body is axially joined cup or tube
• CPC Class Codes: Y10T 29/53096 including means to provide a controlled environment
• CPC Class Codes: Y10T 29/5367 Coupling to conduit
• CPC Class Codes: Y10T 29/53717 Annular work
• CPC Class Codes: Y10T 29/53987 Tube, sleeve or ferrule
• CPC Class Codes: Y10T 29/53996 by deforming

Abstract

An apparatus for manipulating a medical device is formed of at least three coupled movable blades which are disposed about a reference circle to form an aperture whose size may be varied. The aperture capable of being sized to contain a medical device. Each blade is in communication with an actuation device which is capable of moving the blade to alter the size of the aperture. Each blade includes a single radial point which a) lies on the circumference of the reference circle prior to movement of the blade, and b) may be moved only along a radius of the reference circle on movement of the blade.

Claims

1. A method of reducing a stent in cross-section comprising the steps of

a) providing a crimper having a plurality of closely spaced movable dies defining an aperture, the dies arranged to form an iris and to move simultaneously with one another, the iris having an aperture which is reducible in size by moving the dies by rotation of an actuation device, the aperture having a center, each of the dies having a longitudinal axis which is tangent to the aperture;

b) placing a stent disposed about a catheter within the aperture;

c) crimping the stent onto the catheter by reducing the size of the aperture.

2. The method of claim 1 wherein the stent is disposed about a medical balloon, the medical balloon disposed about a catheter.

3. The method of claim 1 further comprising the step of cooling the temperature of the dies below ambient temperature.

4. The method of claim 3 wherein the stent is made of nitinol.

5. The method of claim 1 wherein the dies are wedge-shaped.

6. The method of claim 1 wherein at least 8 dies are provided.

7. The method of claim 1 wherein at least 16 dies are provided.

8. The method of claim 1 wherein the dies are moved cooperatively inward during the moving step.

9. The method of claim 1 wherein the entirety of the stent is disposed in the aperture during the placing step.

10. A method of crimping a stent comprising the steps of:

a) providing a crimper having a plurality of movable dies arranged to form an iris having an aperture which is reducible in size, each of the dies having an inward facing straight side which faces the aperture, the dies constructed and arranged such that any radial line extending from the center of the aperture to outside the crimper will encounter a movable die;

b) placing a stent disposed about a catheter within the aperture, the inward facing straight sides of the dies facing the stent, the stent cooled below ambient temperature prior to reducing the size of the aperture;

c) reducing the size of the aperture and contacting the inward facing straight sides of the dies against the stent so as to crimp the stent onto the catheter.

11. The method of claim 10 wherein the stent is disposed about a medical balloon, the medical balloon disposed about a catheter.

12. The method of claim 10 wherein the stent is made of nitinol.

13. The method of claim 10 wherein the dies are wedge-shaped.

14. The method of claim 10 wherein at least 8 dies are provided, the dies being wedge-shaped.

15. The method of claim 10 wherein at least 16 wedge-shaped dies are provided.

16. The method of claim 10 wherein the entirety of the stent is disposed in the aperture during the placing step.

17. A method of reducing a stent in cross-section comprising the steps of

a) providing a crimper having a plurality of movable dies arranged to form an iris, the iris defining an aperture having a center, the dies constructed and arranged such that any radial line extending from the center of the aperture to outside the crimper will encounter a movable die, the dies in mechanical communication with an actuator, rotary motion of the actuator causing the aperture to increase in size or decrease in size;

b) placing a stent disposed about a catheter within the aperture;

c) applying rotary motion to the actuator to reduce the size of the aperture sufficiently to contact the dies against the stent and reduce the stent in cross-section.

18. The method of claim 17 wherein the stent is disposed about a medical balloon, the medical balloon disposed about a catheter.

19. The method of claim 17 further comprising the step of cooling the temperature of the dies below ambient temperature.

20. The method of claim 19 wherein the stent is made of nitinol.

21. The method of claim 17 wherein the dies are wedge-shaped.

22. The method of claim 17 wherein at least 8 dies are provided.

23. The method of claim 17 wherein at least 16 dies are provided.

24. The method of claim 17 wherein the dies are moved cooperatively inward during the moving step.

25. The method of claim 17 wherein the entirety of the stent is disposed in the aperture during the placing step.

26. A method of reducing a stent in cross-section comprising the steps of

a) providing a crimper having eight or more movable dies defining an aperture having a center, the dies constructed and arranged such that any radial line extending from the center of the aperture to outside the crimper will encounter a movable die each die having an inward facing flat portion which faces the center of the aperture, the dies arranged to form an iris comprising at least eight of the inward facing flat portions, the aperture being reducible in size by moving the inward facing flat portions toward the center of the aperture;

b) placing a stent disposed about a catheter within the aperture;

c) cooling the temperature of the dies below ambient temperature;

d) crimping the stent onto the catheter by reducing the size of the aperture, the inward facing flat portions contacting the stent.

27. The method of claim 26 wherein the stent is disposed about a medical balloon, the medical balloon disposed about a catheter.

28. The method of claim 26 wherein the stent is made of nitinol.

29. The method of claim 26 wherein the dies are wedge-shaped.

30. The method of claim 26 wherein at least 16 dies are provided.

31. The method of claim 26 wherein the dies are moved cooperatively inward during the moving step.

32. The method of claim 26 wherein the entirety of the stent is disposed in the aperture during the placing step.