Patent US4596728A successfully refreshed from Google Patents.
US4596728A
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Low temperature heat shrinkable polymer material
Assignee: Johns Hopkins University
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Filing: 1985-02-01
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Granted: 1986-06-24
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Expires: 2005-02-01
Abstract
Abstract A heat shrinkable polymer material is particularly adapted for implanted biomedical use. A polycrystalline polymer is irradiated to produce crosslinking of its intramolecular structure to thereby impart viscoelasticity. The material is biocompatible and suitable for implanted use, from the standpoints of very low toxicity, ability to retain structural integrity and being non-carcinogenic and, moreover, is heat shrinkable at a temperature compatible with such implanted use.
Inventors
- 👤 Hou-Ching Yang
- 👤 Joseph Silverman
- 👤 John J. Wozniak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:56
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/14; A61L27/16; A61L27/165; A61B; A61B17/00; A61B17/11; A61L31/00; A61L31/04; A61L31/048; A61L31/049; B; B29; B29C; B29C61/00; B29C61/003; B29C61/06; B29C71/00; B29C71/0009; B29C71/02; B29C71/04; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2002/30001; A61F2002/30003; A61F2002/3006; A61F2002/30092; A61F2210/00; A61F2210/0014; B29C35/00; B29C35/02; B29C35/08; B29C35/0866; B29C2035/0877; B29C2071/0027; B29C2071/022; B29K; B29K2009/00; B29K2105/00; B29K2105/24; B29L; B29L2023/00; B29L2031/00; B29L2031/753; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1331
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
106 words
An article of manufacture comprising, a polycrystalline trans-1,4 polyisoprene having a crystalline melt temperature substantially 130° F. and produced by the sequential steps of: exposing the material to ionizing radiation sufficient to create intramolecular crosslinks within the material, heating the material to substantially 130° F., altering the shape of the material from a first configuration to a second configuration, and cooling the material while in said second configuration to reform the crystalline structure, whereby said material will remain in said second configuration until subsequent reheating of the material to substantially 130° F. to cause the material to revert from said second configuration to said first configuration.
Claim 2
Dependent Claim
106 words
An article of manufacture comprising, a polycrystalline trans-1,4 polyisoprene having a crystalline melt temperature substantially 130° F. and produced by the sequential steps of: exposing the material to ionizing radiation sufficient to create intramolecular crosslinks within the material, heating the material to substantially 130° F., altering the shape of the material from a first configuration to a second configuration, and cooling the material while in said second configuration to reform the crystalline structure, whereby said material will remain in said second configuration until subsequent reheating of the material to substantially 130° F. to cause the material to revert from said second configuration to said first configuration.
Claim 3
Dependent Claim
22 words
The article of manufacture specified in claim 1 wherein said trans-1,4 polyisoprene is composed of a trans constituent in excess of 90%.
Claim 4
Dependent Claim
24 words
A polycrystalline trans-1,4 polyisoprene, radiation-crosslinked to produce a viscoelastic memory therein and having a crystalline melt temperature of substantially 130° F. and being biocompatible.
Claim 5
Dependent Claim
24 words
A polycrystalline trans-1,4 polyisoprene, radiation-crosslinked to produce a viscoelastic memory therein and having a crystalline melt temperature of substantially 130° F. and being biocompatible.
Claim 6
Dependent Claim
20 words
The polycrystalline polymeric material specified in claim 3 wherein said trans-1,4 polyisoprene has a trans constituent in excess of 90%.
Claim 7
Dependent Claim
29 words
The polycrystalline polymeric material specified in claim 3 wherein the biocompatibility of said material is represented by a low-level toxicity and a retention of structural integrity while in vivo.
Claim 8
Dependent Claim
43 words
A heat shrinkable polymer material comprising, radiation-crosslinked, polycrystalline trans-1,4 polyisoprene characterized by a crystalline melt temperature of substantially 130° F. and pre-stretched to a first configuration, said polymer material shrinking to a second configuration upon the heating thereof to said crystalline melt temperature.
Claim 9
Dependent Claim
43 words
A heat shrinkable polymer material comprising, radiation-crosslinked, polycrystalline trans-1,4 polyisoprene characterized by a crystalline melt temperature of substantially 130° F. and pre-stretched to a first configuration, said polymer material shrinking to a second configuration upon the heating thereof to said crystalline melt temperature.
Claim 10
Dependent Claim
28 words
The heat shrinkable polymer material specified in claim 6 wherein said second configuration corresponds to a configuration of said material prior to stretching thereof to said first configuration.
Claim 11
Dependent Claim
31 words
The heat shrinkable polymer material specified in claim 7 wherein said second configuration is tubular and said first configuration is also tubular, but of a diameter larger than said second configuration.
Claim 12
Dependent Claim
22 words
The heat shrinkable polymer material specified in claim 6 wherein the trans-1,4 polyisoprene is synthetic and defined by the structural equation: ##STR2##
Claim 13
Dependent Claim
21 words
The heat shrinkable polymer material specified in claim 9 wherein said trans-1,4 polyisoprene has a trans constituent in excess of 90%.
Claim 14
Dependent Claim
36 words
The heat shrinkable polymer material specified in claim 6 having a viscoelastic memory characteristic causing said trans-1,4 polyisoprene to shrink from a first to a second configuration upon heating said polymer material to substantially 130° F.
Claim 15
Dependent Claim
106 words
The heat shrinkable polymer material specified in claim 11 wherein said viscoelastic memory is produced by the sequential steps of exposing the trans-1,4 polyisoprene to ionizing radiation sufficient to create intramolecular crosslinks within the material while the shape of said material is a first configuration, heating the material to substantially 130° F. to dissolve the crystalline structure of the material, stretching the heated material to a second configuration, and cooling the stretched material to reform the crystalline structure, whereby the material retains said stretched second configuration and whereby subsequent heating of the material to substantially 130° F. causes the material to return to its first configuration.
Claim 16
Dependent Claim
44 words
The heat shrinkable polymer material specified in claim 12, further comprising the step of annealing the material following said exposure to ionizing radiation and prior to stretching the material, by subjecting the material to a temperature of approximately 60° C. for substantially two minutes.
Claim 17
Dependent Claim
95 words
A heat shrinkable, biocompatible member useful for performing vascular anastomosis and like surgical procedures in vivo, comprising, a biocompatible, radiation-crosslinked polycrystalline trans-1,4 polyisoprene characterized by a crystalline melt temperature of substantially 130° F., said member being pre-stretched to a first configuration and capable of being movably disposed to encircle in sleeve-like fashion the vascular members to be interconnected and having a viscoelastic memory, whereby said pre-stretched member upon being heated to substantially 130° F. shrinks to a second configuration forming a sleeve of smaller diameter to engage and maintain said vascular members in interconnected relationship.
Claim 18
Dependent Claim
95 words
A heat shrinkable, biocompatible member useful for performing vascular anastomosis and like surgical procedures in vivo, comprising, a biocompatible, radiation-crosslinked polycrystalline trans-1,4 polyisoprene characterized by a crystalline melt temperature of substantially 130° F., said member being pre-stretched to a first configuration and capable of being movably disposed to encircle in sleeve-like fashion the vascular members to be interconnected and having a viscoelastic memory, whereby said pre-stretched member upon being heated to substantially 130° F. shrinks to a second configuration forming a sleeve of smaller diameter to engage and maintain said vascular members in interconnected relationship.
Claim 19
Dependent Claim
20 words
The heat shrinkable biocompatible member specified in claim 14 wherein said trans-1,4 polyisoprene is characterized by the structural equation: ##STR3##
Claim 20
Dependent Claim
23 words
The heat shrinkable biocompatible member specified in claim 15 wherein the trans-1,4 polyisoprene is characterized by a trans constituent in excess of 90%.
Claim 21
Dependent Claim
30 words
The heat shrinkable biocompatible member specified in claim 15 wherein said trans-1,4 polyisoprene has a biocompatibility characterized by a low-level toxicity and a retention of structural integrity while in vivo.
Claim 22
Dependent Claim
20 words
The heat shrinkable biocompatible member specified in claim 14 wherein the first and second configurations of said member are tubular.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-23 | 1989-12-23 | 1990-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-23 | 1993-12-23 | 1994-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-23 | 1997-12-23 | 1998-06-24 | $7700.00 | Window Closed / Lapsed |