US6458156B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Expansible bioprosthetic valve stent
Assignee: University of Western Ontario
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Filing: 1997-05-30
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Granted: 2002-10-01
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Expires: 2017-05-30
Abstract
Abstract A bioprosthetic valve stent is fabricated from a hydrogel, and a bioprosthetic heart valve comprises such a stent. A method for fabricating a hydrogel bioprosthetic valve stent comprises filling a mold cavity with a solution of a hydrogel, allowing the hydrogel to solidity, removing the solidified hydrogel from the mold cavity and hydrating the hydrogel.
Inventors
- 👤 Wan-Kei Wan
- 👤 Anthony Duncan
- 👤 Gordon Campbell
- 👤 Derek Boughner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:44
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/24; A61F2/2412; A61F2/2418; A61F2/2415; A61L; A61L27/00; A61L27/50; A61L27/52; A61L31/00; A61L31/14; A61L31/145
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
60 words
A bioprosthetic valve stent fabricated from a hydrogel, wherein the hydrogel, when hydrated, has (a) a strain value at ultimate tensile stress (UTS) greater than the maximum strain occurring in a human aortic root under physiological conditions; (b) an elastic modulus similar to that of the aortic root; and (c) a relaxation rate similar to that of the aortic root.
Claim 2
Dependent Claim
60 words
A bioprosthetic valve stent fabricated from a hydrogel, wherein the hydrogel, when hydrated, has (a) a strain value at ultimate tensile stress (UTS) greater than the maximum strain occurring in a human aortic root under physiological conditions; (b) an elastic modulus similar to that of the aortic root; and (c) a relaxation rate similar to that of the aortic root.
Claim 3
Dependent Claim
48 words
The valve stent of claim 1 wherein the hydrogel has (a) a strain at UTS of at least 20%; (b) an elastic modulus in the range of about 0.01 to about 10 Mpa; and (c) a relaxation rate in the range of about 3 to about 9 kPa/sec.
Claim 4
Dependent Claim
13 words
The stent of claim 2 wherein the hydrogel is a polyvinyl alcohol hydrogel.
Claim 5
Dependent Claim
13 words
The stent of claim 4 wherein the stent is an aortic valve stent.
Claim 6
Dependent Claim
38 words
The stent of claim 1 wherein the hydrogel is selected from the group consisting of poly(vinyl alcohol), polyacrylamide, poly(N-vinylpyrolidone), poly(hydroxyethyl methacrylate), poly(ethylene oxide), poly(ethylene glycol), poly(ethylene glycol) monomethyl ether, cellulose, poly(acrylate), polymethacrylate, poly(methylacrylate), poly(methyl methacrylate) and poly(lactic acid).
Claim 7
Dependent Claim
51 words
A bioprosthetic heart valve comprising a) a stent in accordance with claim 1 , (b) leaflet valve means having three generally triangular leaflets defining respective cusps which are adapted to open and close during heart systole and diastole respectively; and (c) means for attaching the leaflet valve means to the stent.
Claim 8
Dependent Claim
27 words
The valve of claim 6 wherein the leaflet valve means is selected from the group consisting of glutaraldehyde-pretreated bovine pericardial tissue or glutaraldehyde-pretreated porcine aortic valve cusps.
Claim 9
Independent Claim
69 words
A method of fabricating a bioprosthetic valve stent comprising the steps of: (a) preparing a mold cavity corresponding in shape to the stent to be fabricated; (b) filling said mold cavity with a solution of a selected hydrogel; (c) allowing the hydrogel to solidify; and (d) directly after step (c) removing the solidified hydrogel from the mold cavity and hydrating the solidified hydrogel for a suitable period of time.
Claim 10
Independent Claim
69 words
A method of fabricating a bioprosthetic valve stent comprising the steps of: (a) preparing a mold cavity corresponding in shape to the stent to be fabricated; (b) filling said mold cavity with a solution of a selected hydrogel; (c) allowing the hydrogel to solidify; and (d) directly after step (c) removing the solidified hydrogel from the mold cavity and hydrating the solidified hydrogel for a suitable period of time.
Claim 11
Dependent Claim
47 words
The method of claim 8 wherein the selected hydrogel is PVA and wherein step (c) comprises subjecting the filled mold cavity to at least one freeze-thaw temperature cycle and wherein the method further comprises step (e) subjecting the hydrated hydrogel to at least three freeze-thaw temperature cycles.
Claim 12
Dependent Claim
38 words
The method of claim 9 wherein each freeze-thaw temperature cycle employs a freezing temperature in the range of about −70° C. to −30° C. and a thaw temperature in the range of about 15° C. to 30° C.
Claim 13
Dependent Claim
17 words
An aortic valve stent fabricated from a hydrogel by a process in accordance with claim 9 .
Claim 14
Dependent Claim
28 words
The method of claim 8 wherein the selected hydrogel is PVA and wherein step (c) comprises subjecting the filled mold cavity to at least four freeze-thaw temperature cycles.
Claim 15
Dependent Claim
38 words
The method of claim 12 wherein each freeze-thaw temperature cycle employs a freezing temperature in the range of about −70° C. to −30° C. and a thaw temperature in the range of about 15° C. to 30° C.
Claim 16
Dependent Claim
17 words
An aortic valve stent fabricated from a hydrogel by a process in accordance with claim 12 .
Claim 17
Dependent Claim
17 words
A bioprosthetic valve stent fabricated from a hydrogel by a process in accordance with claim 8 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-09-30 | 2006-04-01 | 2006-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-09-30 | 2010-04-01 | 2010-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-09-30 | 2014-04-01 | 2014-10-01 | $7700.00 | Window Closed / Lapsed |