Bistable spring construction for a stent and other medical apparatus

• US 6,488,702 B1
• Filed: 01/23/1998
• Issued: 12/03/2002
• Est. Priority Date: 01/24/1997
• Status: Expired due to Term

• Current Assignee: CeloNova Stent, Inc.
• Original Assignee: Jomed GmbH
• Inventors: Besselink, Petrus Antonius
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US09/012,843
• Time in Patent Office: 1,775 Days
• Field of Search: 623/1.19, 623/1.18, 623/1.15, 623/1.2, 606/198, 606/155, 606/156
• US Class Current: 623/1.15
• CPC Class Codes: A61B 17/11 for performing anastomosis; Buttons for anastomosis
• CPC Class Codes: A61B 2017/1107 for blood vessels
• CPC Class Codes: A61F 2/0004 Closure means for urethra or rectum, i.e. anti-incontinence devices or support slings against pelvic prolapse
• CPC Class Codes: A61F 2/0009 placed in or outside the body opening close to the surface of the body plugging an opening in the wall of a hollow or tubular organ A61B17/0057
• CPC Class Codes: A61F 2/0022 placed deep in the body opening occluding blood vessels by internal devices A61B17/12022
• CPC Class Codes: A61F 2/02 Prostheses implantable into the body closure means for urethra or rectum or for artificial body openings therefor A61F2/0004
• CPC Class Codes: A61F 2/042 Urinary bladders
• CPC Class Codes: A61F 2/064 with special features to facilitate anastomotic coupling anastomosis of natural blood vessels A61B17/11
• 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 2002/047 Urethrae
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/9155 Adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: F16K 31/003 operated without a stable intermediate position, e.g. with snap action F16K31/56 takes precedence

Abstract

The present invention is directed to bistable cells and their use in devices, particularly medical devices such as stents, clamps and valves. An expandable stent formed of a plurality of bistable cells is described. The stent has two or more stable configurations, including a first stable configuration with a first diameter and a second stable configuration with a second, larger diameter. A valve comprising a bistable cell for use in eliminating incontinence is also disclosed.

Claims

1. A stent having a plurality of stable configurations, the stent comprised of a plurality of interconnected cells, each cell having a cell structure that includes a first section and a second section, the second section more flexible than the first section, the first and second sections interconnected so that the cell is capable of isothermally assuming either one of only two stable configurations.

2. The stent of claim 1 wherein a first subset of the plurality of interconnected cells comprise second sections exhibiting a first rigidity and a second subset of the plurality of interconnected cells comprise second sections exhibiting a second rigidity, wherein the first rigidity differs from the second rigidity.

3. The stent of claim 2 wherein a first stable configuration of a cell structure is an unexpanded configuration and a second stable configuration of a cell structure is a fully expanded configuration.

4. The stent of claim 2 wherein the first and second subsets of the plurality of interconnected cells are designed and arranged to provide a range of stent diameters in step-wise fashion.

5. The stent of claim 1 wherein the plurality of interconnected cells are constructed and arranged so that the cells may be switched between the two stable configurations by applying a uniform radially directed force to an interior surface of the stent.

6. The stent of claim 1 wherein the first and second sections have a generally wave-like appearance.

7. A tubular stent having a surface comprising a plurality of cells, each one of the plurality of cells having a first stable shape and a second stable shape, the second stable shape encompassing a larger area than the first stable shape, each cell including first and second interconnected sections, the second section more flexible than the first section, wherein each one of the plurality of cells is capable of isothermally assuming either one of only the first or second stable shapes.

8. The stent of claim 7 wherein a first subset of the plurality of cells exhibit a first rigidity and a second subset of the plurality of cells exhibit a second rigidity, and the first rigidity differs from the second rigidity.

9. The stent of claim 8 wherein the first and second subsets of cells are arranged and disposed so that the stent has at least two stable states, including a first stable state in which the stent has a first diameter and a second stable state in which the stent has a second diameter, the second diameter larger than the first diameter.

10. The stent of claim 9 further having a third stable state, the third stable state having a third diameter different from the first and second diameters.

11. The stent of claim 7 wherein the plurality of cells comprises cells of two or more types, each of the two or more cell types requiring differing amounts of force to expand.

12. The stent of claim 7 wherein the first and second sections have a generally wave-like appearance.