EP0095940A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in synthetic vascular grafts and methods of manufacturing such grafts
Assignee: University of Liverpool
•
Filing: 1983-06-01
•
Granted: —
•
Expires: 2003-06-01
Abstract
Abstract A synthetic vascular graft of internal diameter in the range of 0.1 mm to 20 mm and wall thickness between 0.075 mm and 2.0 mm is preferably made by electrostatic spinning of polymeric material. Under an elongation of between 5% and 25% over its unstressed state, the change in internal pressure from a first pressure to a second pressure, the difference between the first and second pressures lying in the range between 20 mm Hg and 75 mm Hg, undergoes a change in internal diameter substantially equal to the change in internal diameter experienced when a corresponding natural artery stretched to an extend experienced in vivo is subjected to the same change in internal pressure. The graft is made by electrostatically spinning an organic polymer material.
Inventors
- 👤 Thien Voon How
- 👤 Roy Malcolm Clarke
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-22 23:34
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/04; A61F2/06; A61F2240/00; A61F2240/001
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
113 words
A synthetic vascular graft of internal diameter in the range 1.0 mm to 20 mm, wall thickness between 0.075 mm and 2.0 mm said graft having anisotropic properties and, which graft, under an elongation of between 5% and 25% over its unstressed state, for a change in internal pressure from a first pressure to a second pressure, the difference between the first and second pressures lying in the range between 20 mm HG and 75 mm Hg, undergoes a change in internal diameter substantially equal to the change in internal diameter experienced when a corresponding natural artery stretched to an extent experienced in vivo is subjected to the same change in internal pressure.
Claim 2
Dependent Claim
113 words
A synthetic vascular graft of internal diameter in the range 1.0 mm to 20 mm, wall thickness between 0.075 mm and 2.0 mm said graft having anisotropic properties and, which graft, under an elongation of between 5% and 25% over its unstressed state, for a change in internal pressure from a first pressure to a second pressure, the difference between the first and second pressures lying in the range between 20 mm HG and 75 mm Hg, undergoes a change in internal diameter substantially equal to the change in internal diameter experienced when a corresponding natural artery stretched to an extent experienced in vivo is subjected to the same change in internal pressure.
Claim 3
Dependent Claim
22 words
A synthetic vascular graft as claimed in claim 1 wherein the internal diameter is in the range 2.5 mm to 12 mm.
Claim 4
Dependent Claim
23 words
A synthetic vascular graft as claimed in claim 1 or claim 2 wherein the internal diameter is between 3 mm and 10 mm.
Claim 5
Dependent Claim
20 words
A synthetic vascular graft as claimed in claim 1 wherein the wall thickness is between 0.2 mm and 1.2 mm.
Claim 6
Dependent Claim
20 words
A synthetic vascular graft as claimed in claim 1 wherein the wall thickness is between 0.3 mm and 1 mm.
Claim 7
Dependent Claim
58 words
A synthetic vascular graft as claimed in claim 1 wherein the variation of internal diameter of the synthetic graft with change in internal pressure over the range between the first and second pressures approximates to the variation of internal diameter of the natural artery stretched to an extent experienced in vivo under the same conditions of pressure change.
Claim 8
Dependent Claim
33 words
A synthetic vascular graft as claimed in claim 1 wherein the first and second pressures are the minimum and maximum pressures experienced in the body at the location of the corresponding natural artery.
Claim 9
Dependent Claim
15 words
A synthetic vascular graft as claimed in claim 7 wherein the polymeric material is polyurethane.
Claim 10
Dependent Claim
28 words
A synthetic vascular graft as claimed in claim 1 or 8 wherein the strength properties of the graft are greater in the longitudinal direction than the circumferential direction.
Claim 11
Dependent Claim
28 words
A synthetic vascular graft as claimed in claim 1 or 8 wherein the strength properties of the graft are greater in the circumferential direction than the longitudinal direction.
Claim 12
Dependent Claim
20 words
A synthetic vascular graft as claimed in claims 1 or 8 wherein the strength properties of the graft are isotropic.
Claim 13
Independent Claim
56 words
A method of manufacturing a synthetic vascular graft by electrostatically spinning an organic polymeric material or a precursor thereof and collecting the spun fibres on a rotating mandrel, which method comprises the step of controlling the speed of rotation of the mandrel such that a desired degree of anisotropy is present in the synthetic vascular graft.
Claim 14
Independent Claim
56 words
A method of manufacturing a synthetic vascular graft by electrostatically spinning an organic polymeric material or a precursor thereof and collecting the spun fibres on a rotating mandrel, which method comprises the step of controlling the speed of rotation of the mandrel such that a desired degree of anisotropy is present in the synthetic vascular graft.
Claim 15
Dependent Claim
21 words
A method as claimed in claim 12 wherein the speed of rotation of the mandrel is between 0 and 25000 r.p.m.
Claim 16
Dependent Claim
22 words
A method as claimed in claim 13 wherein the speed of rotation of the mandrel is between 2000 r.p.m. and 20000 r.p.m.
Claim 17
Dependent Claim
23 words
A method as claimed in claim 12 wherein the speed of rotation of the mandrel is kept uniform during production of a graft.
Claim 18
Dependent Claim
17 words
A method as claimed in claim 12 wherein the speed of rotation of the mandrel is varied.
Claim 19
Dependent Claim
51 words
Apparatus for manufacturing a synthetic vascular graft by an electrostatic spinning method which apparatus comprises a mandrel, means for-rotating the mandrel, means for electrostatically charging the mandrel, means for directing organic polymeric material or a precursor thereof towards the mandrel, and means for controlling the speed of rotation of the mandrel.
Claim 20
Dependent Claim
51 words
Apparatus for manufacturing a synthetic vascular graft by an electrostatic spinning method which apparatus comprises a mandrel, means for-rotating the mandrel, means for electrostatically charging the mandrel, means for directing organic polymeric material or a precursor thereof towards the mandrel, and means for controlling the speed of rotation of the mandrel.
Claim 21
Dependent Claim
27 words
Apparatus as claimed in claim 17 comprising means for varying the rotational speed of the mandrel in accordance with the traverse position of the fluid directing means.
Claim 22
Dependent Claim
23 words
Apparatus as claimed in claim 17 or claim 18 wherein the mandrel is tapered to form a graft having a tapering cross section.
Claim 23
Dependent Claim
19 words
Apparatus as claimed in claim 17 wherein the mandrel has an external diameter between 1 mm and 20 mm.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.