BALLOON EXPANDABLE BIOABSORBABLE STENT WITH A SINGLE STRESS CONCENTRATION REGION INTERCONNECTING ADJACENT STRUTS

• US 20100249905A1
• Filed: 03/29/2010
• Published: 09/30/2010
• Est. Priority Date: 12/19/2007
• Status: Active Grant

• Current Assignee: Cardinal Health Switzerland 515 GmbH (Cardinal Health, Inc.)
• Original Assignee: Advanced Technologies and Regenerative Medicine, LLC
• Inventors: Zhang, Qiang, Contiliano, Joseph H.
• Granted Patent: US 7,981,149 B2
• Time in Patent Office: Days
• US Class Current: 623/1.160
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0019 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir

Abstract

An expandable, implantable medical device, such as an intraluminal stent (10) fabricated from polymeric materials, includes a plurality of elongated struts (16) in consecutive series and alternating stress concentration junctions (18) interconnecting ends of adjacent struts (16). When the stent (10) is in an expanded condition, the adjacent struts (16) form expanded substantial V-shapes and stresses are concentrated within the junctions (18). The junctions (18) define pivot points (P) for the respective attached, adjacent struts (16). Each of the pivot points (P) is located substantially on a line bisecting the V-shapes formed by the struts (16), when the stent (10) is expanded.

Claims

1. An expandable, implantable medical device comprising:

a frame structure having a plurality of hoop components interconnected by a plurality of flexible connectors and joined together to form a substantially cylindrical device expandable from a cylinder having a first diameter to a cylinder having a second diameter, wherein the hoop components are formed as a continuous series of substantially longitudinally oriented radial struts and alternating stress concentration junctions, wherein adjacent ones of the struts are substantially parallel when the cylinder is at the first diameter and the adjacent struts form substantial V-shapes when the cylinder is at the second diameter; and

wherein each of the junctions defines a pivot point for the attached, adjacent struts and wherein each of the pivot points is located substantially on a line bisecting the V-shapes formed by the struts when the cylinder is at the second diameter.

2. The device of claim 1, wherein the junctions are ductile hinges.

3. The device of claim 1, wherein, when the cylinder is at the second diameter stresses are concentrated within the junctions.

4. The device of claim 3, wherein the concentrated stresses in the junctions exceed the yield point of the frame structure.

5. The device of claim 4, wherein the concentrated stresses in the junctions are below the ultimate stress levels of the frame structure.

6. The device of claim 1, wherein the frame structure is comprised of a polymer having a predetermined molecular orientation.

7. The device of claim 1, wherein the alternating junctions have a smaller cross-sectional area relative to the adjacent geometry.

8. The device of claim 1, wherein the adjacent struts rotate substantially symmetrically and uniformly away from each other, about the pivot point, when the stent is expanded.

9. The device of claim 1, wherein the frame structure includes polymeric materials.

10. A method of using an expandable, implantable medical device in a surgical procedure comprising:

implanting, into a body passageway, a frame structure having a plurality of hoop components interconnected by a plurality of flexible connectors and joined together to form a substantially cylindrical device expandable from a cylinder having a first diameter to a cylinder having a second diameter, wherein the hoop components are formed as a continuous series of substantially longitudinally oriented radial struts and alternating stress concentration junctions, wherein adjacent ones of the struts are substantially parallel when the cylinder is at the first diameter; and

expanding the frame structure from the first diameter to the second diameter, wherein the adjacent struts form substantial V-shapes when the cylinder is at the second diameter, wherein each of the junctions defines a pivot point for the attached, adjacent struts and wherein each of the pivot points is located substantially on a line bisecting the V-shapes formed by the struts when the cylinder is at the second diameter.

11. The method of claim 10, wherein the junctions are ductile hinges.

12. The method of claim 10, wherein, when the cylinder is at the second diameter stresses are concentrated within the junctions.

13. The method of claim 12, wherein the concentrated stresses in the junctions exceed the yield point of the frame structure.

14. The method of claim 13, wherein the concentrated stresses in the junctions are below the ultimate stress levels of the frame structure.

15. The method of claim 10, wherein the frame structure is comprised of a polymer having a predetermined molecular orientation.

16. The Method of claim 10, wherein the alternating junctions have a smaller cross-sectional area relative to the adjacent geometry.

17. The method of claim 10, wherein the adjacent struts rotate substantially symmetrically and uniformly away from each other, about the pivot point, when the stent is expanded.

18. The method of claim 10, wherein the frame structure includes polymeric materials.