US5327774A
Expired / Lapsed
US
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Method for testing venous valves
Assignee: Edwards Lifesciences Corp
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Filing: 1993-10-08
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Granted: 1994-07-12
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Expires: 2013-10-08
Abstract
Abstract A method and device for testing artificial or natural venous valves. The device comprises chamber (10) a sample for mounting a test valve (V) on a liquid flow path and a muscle pump component (16) and/or respiratory pump component (50) and/or capacitance reservoir (58) and/or vertical hydrostatic column component (102) fluidly connected to the flow path to mimic the muscle pump, respiratory pump, capacitance and hydrostatic impedance effects on venous circulation in the mammalian body. Included in the invention are methods of testing venous valves by mimicking known hemodynamic flow conditions within a mammalian body.
Inventors
- 👤 Than Nguyen
- 👤 Aws Nashef
- 👤 Amir H. Abolfathi
- 👤 David W. Wieting
- 👤 Denis Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:30
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/24; A61F2/2472; A61B; A61B17/00; A61B2017/00681; A61B2017/00707
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
A method for testing the function of venous valves, said method comprising: (a) holding a venous valve sample in a substantially fixed position; (b) fluidly connecting an inflow conduit in relation to said venous valve to pass a flow of liquid through said venous valve; (c) fluidly connecting an outflow conduit in relation to said venous valve such that liquid passing through said venous valve will then flow through said outflow conduit; (d) pumping a pulsatile flow of liquid through said inflow conduit to mimic the effect of a physiological muscle pump on venous return in a human being; (e) creating cyclic variations in pressure on liquid exiting said venous valve through said outflow conduit to mimic the effect of intrathoracic variations in pressure which occur in a human being during respiration.
Claim 2
Independent Claim
132 words
A method for testing the function of venous valves, said method comprising: (a) holding a venous valve sample in a substantially fixed position; (b) fluidly connecting an inflow conduit in relation to said venous valve to pass a flow of liquid through said venous valve; (c) fluidly connecting an outflow conduit in relation to said venous valve such that liquid passing through said venous valve will then flow through said outflow conduit; (d) pumping a pulsatile flow of liquid through said inflow conduit to mimic the effect of a physiological muscle pump on venous return in a human being; (e) creating cyclic variations in pressure on liquid exiting said venous valve through said outflow conduit to mimic the effect of intrathoracic variations in pressure which occur in a human being during respiration.
Claim 3
Dependent Claim
34 words
The method of claim 1 further comprising: (f) attaching a variable capacitance reservoir to said outflow conduit and varying the capacitance within said reservoir to mimic changes in venous capacitance within a human being.
Claim 4
Dependent Claim
62 words
The method of claim 2 further comprising the steps of: selecting a target venous pressure waveform; and adjusting the pulsatile flow of liquid created in step (d), the cyclic variations in pressure created in step (e) and the capacitance within the variable capacitance reservoir of step (f) to cause the liquid flowing through said venous valve to mimic the pre-selected target waveform.
Claim 5
Dependent Claim
35 words
The method of claim 1 further comprising: (f) attaching a vertically inclined tubular conduit to said outflow conduit such that liquid passing through said outflow conduit must flow against hydrostatic impedance created by said column.
Claim 6
Dependent Claim
36 words
The method of claim 4 further comprising the step of: (g) varying the height of said vertically inclined column to mimic variations in hydrostatic impedance venous flow resulting from various postural positions of a human being.
Claim 7
Dependent Claim
49 words
The method of claim 5 further comprising the steps of: selecting a target waveform; and adjusting the pulsatile flow of liquid created in step (d) and the amount of hydrostatic impedance created in step (g) to cause the liquid flowing through said venous valve to mimic the pre-selected waveform.
Claim 8
Dependent Claim
118 words
The method of claim 1 wherein the venous valve sample to be tested is positioned within a harvested segment of vein and wherein: step (a) further comprises holding the segment of vein wherein said venous valve sample is located in a substantially fixed position; step (b) further comprises fluidly connecting an inflow conduit to the first end of said segment of vein to pass a flow of liquid through said segment of vein and through said venous valve; and step (c) further comprises fluidly connecting an outflow conduit to an opposite end of said segment of vein such that liquid passing through said segment of vein and through said venous valve will then flow through said outflow conduit.
Claim 9
Dependent Claim
20 words
The method of claim 1 further comprising the step of: controlling the temperature of liquid passing through said venous valve.
Claim 10
Dependent Claim
20 words
The method of claim 1 further comprising the step of: monitoring the pressure of liquid passing through said venous valve.
Claim 11
Dependent Claim
54 words
The method of claim 1 further comprising the steps of: selecting a target venous pressure waveform; and adjusting the pulsatile flow of liquid created in step (d) and the cyclic variations in pressure created in step (e) so as to cause the liquid flowing through said venous valve to mimic the selected target waveform.
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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) | 1997-07-11 | 1998-01-10 | 1998-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-11 | 2002-01-10 | 2002-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-11 | 2006-01-10 | 2006-07-12 | $7700.00 | Window Closed / Lapsed |