SELF CONSTRAINING RADIALLY EXPANDABLE MEDICAL DEVICES

• US 20110166637A1
• Filed: 01/19/2011
• Published: 07/07/2011
• Est. Priority Date: 07/15/2009
• Status: Active Grant

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Silverman, James D., Irwin, Craig W.
• Granted Patent: US 8,936,634 B2
• Time in Patent Office: Days
• US Class Current: 623/1.13
• CPC Class Codes: A61F 2/01 Filters implantable into blood vessels
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61M 2025/0024 Expandable catheters or sheaths

Abstract

The current invention comprises tubes that can be constrained and expanded by either axial or torsional strain. By torsionally displacing the tube in a direction counter to the biased helices and angularly displacing the lower angle helix to an angle equal to, but opposite, the starting angle, the tube is expanded diametrically with no significant change in length after expansion of the tube. These tubes find utility in medical and non medical applications.

Claims

1. A tubular structure having a longitudinal axis comprising a first element oriented at a first angle of θ

and a second element oriented at a second angle of γ

, wherein;

a. θ

does not equal γ

;

b. θ and

γ

are formed at an angle of between about +/−

90 degrees relative to the axis of the tubular structure; and

c. wherein when a first length section of the tubular structure is displaced rotationally relative to a second length section of the tubular structure, both θ and

γ

change relative to the longitudinal axis and produce a change in diameter of at least a portion of the tubular structure.

2. The tubular structure of claim 1, wherein said tubular structure has about the same length before and after expansion.

3. The tubular structure of claim 1, wherein at a given small diameter and a given large diameter the lengths are equal.

4. The tubular structure of claims 3, wherein the length changes between a given small diameter and a given large diameter.

5. The tubular structure of claim 2, wherein the angle of θ

before expansion and angle of θ

after expansion is equal.

6. The tubular structure of claim 2, wherein the angle of γ

before expansion and angle of γ

after expansion is equal and opposite in sign.

7. The tubular structure of claim 1, wherein said first and second elements comprise metal, polymer or a combination thereof.

8. The tubular structure of claim 1, wherein said tubular structure comprises a helically wrapped film.

9. The tubular structure of claim 8, wherein said tubular structure is a constraining sheath.

10. The tubular structure of claim 9, wherein said constraining sheath can be everted.

11. The tubular structure of claim 10, wherein as said constraining sheath is everted, the outer layer of the tube grows radially.

12. The tubular structure of claim 1, wherein said tubular structure is a stent.

13. The tubular structure of claim 12, wherein said stent further comprises a graft.

14. The tubular structure of claim 12, wherein said stent comprises stent rings.

15. The tubular structure of claim 1, wherein said tubular structure is a filter.

16. A tubular construct comprising:

a first helical element having a first pitch angle;

a second helical element having a second pitch angle;

said second helical element being attached in part to the first helical element;

wherein when a portion of the tubular construct is rotated, the first pitch angle and the second pitch angle change relative to each other.

17. The tubular structure of claim 16, wherein said tubular construct has about the same length before and after expansion.

18. The tubular structure of claim 16, wherein said first and second elements comprise metal, polymer or a combination thereof.

19. The tubular structure of claim 16, wherein said tubular structure is a stent.

20. The tubular structure of claim 19, wherein said stent further comprises a graft.

21. The tubular structure of claim 16, wherein said tubular structure is a filter.

22. The tubular construct of claim 16, wherein at least a segment of the tubular construct has a given diameter, and wherein when a portion of the tubular construct is rotated so as to change the first pitch angle and the second pitch angle relative to each other, the diameter of the at least a segment of the tubular construct changes.

23. The tubular construct of claim 16, wherein at least a segment of the tubular construct has a given longitudinal stiffness, and wherein when a portion of the tubular construct is rotated so as to change the first pitch angle and the second pitch angle relative to each other, the longitudinal stiffness of the at least a segment of the tubular construct changes.

24. The tubular construct of claim 16, wherein at least a segment of the tubular construct has a given length, and wherein when a portion of the tubular construct is rotated so as to change the first pitch angle and the second pitch angle relative to each other, the length of the at least a segment of the tubular construct changes.