Patent US4753733A successfully refreshed from Google Patents.
US4753733A
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US
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Plasmapheresis method and apparatus for overcoming membrane fouling
Assignee: EIDP Inc
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Filing: 1986-07-18
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Granted: 1988-06-28
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Expires: 2006-07-18
Abstract
Abstract Plasmapheresis by filtration can be carried out with high efficiency for long periods by conducting blood over a surface of a membrane and passing plasma at an accelerating rate until the threshold level is attained, maintaining the rate of passing plasma until the ceiling system transmembrane pressure difference is attained and then reducing the passing of plasma and the system transmembrane pressure difference and allowing the membrane to clear before repeating the cycle.
Inventors
- 👤 Joseph M. Ramstack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:45
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/14; B01D61/147; A; A61; A61M; A61M1/00; A61M1/34; A61M1/3496; B01D61/22; B01D65/00; B01D65/08; A61M1/36; A61M1/3621; A61M1/3639; B01D2321/00; B01D2321/20; B01D2321/2066
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
97 words
Improved plasmapheresis comprising conducting blood over the first surface of a microporous membrane having first and second surfaces, while collecting plasma-depleted blood from the first surface and plasma which flows through the membrane (plasma flow) from the second surface, the improvement characterized in that, when the system transmembrane pressure (STMP) reaches the ceiling STMP which is the pressure above which membrane fouling and blood trauma occur, membrane fouling is cleared by substantially terminating the plasma flow while continuing the conducting of blood over the first surface, and thereafter restarting plasma flow and continuing the collection of plasma.
Claim 2
Dependent Claim
97 words
Improved plasmapheresis comprising conducting blood over the first surface of a microporous membrane having first and second surfaces, while collecting plasma-depleted blood from the first surface and plasma which flows through the membrane (plasma flow) from the second surface, the improvement characterized in that, when the system transmembrane pressure (STMP) reaches the ceiling STMP which is the pressure above which membrane fouling and blood trauma occur, membrane fouling is cleared by substantially terminating the plasma flow while continuing the conducting of blood over the first surface, and thereafter restarting plasma flow and continuing the collection of plasma.
Claim 3
Dependent Claim
18 words
Process of claim 1 which further comprises conducting blood over the surface of the membrane using fouling-reducing techniques.
Claim 4
Dependent Claim
19 words
Process of claim 1 which further comprises conducting blood over the surface of the membrane by reciprocatory pulsatile flow.
Claim 5
Dependent Claim
19 words
Process of claim 1 which further comprises electronically controlling the plasma flow in response to the system transmembrane pressure.
Claim 6
Dependent Claim
91 words
Improved apparatus for carrying out plasmapheresis by filtration, which apparatus comprises means for conducting blood over the first surface of a microporous membrane having first and second surfaces, said means operably connected to means for collecting plasma-depleted blood from the first surface and plasma which flows through the membrane (plasma flow) from the second surface, sadi means operably connected to means for measuring system transmembrane pressure (STMP), said means operably connected to means for substantially terminating the plasma flow while blood is conducted over the first surface of the microporous membrane.
Claim 7
Dependent Claim
91 words
Improved apparatus for carrying out plasmapheresis by filtration, which apparatus comprises means for conducting blood over the first surface of a microporous membrane having first and second surfaces, said means operably connected to means for collecting plasma-depleted blood from the first surface and plasma which flows through the membrane (plasma flow) from the second surface, sadi means operably connected to means for measuring system transmembrane pressure (STMP), said means operably connected to means for substantially terminating the plasma flow while blood is conducted over the first surface of the microporous membrane.
Claim 8
Dependent Claim
19 words
Apparatus of claim 5 which includes means for conducting blood over the surface of the membrane using fouling-reducing techniques.
Claim 9
Dependent Claim
20 words
Apparatus of claim 5 which includes means for conducting blood over the surface of the membrane by reciprocatory pulsatile flow.
Claim 10
Dependent Claim
21 words
Apparatus of claim 5 which includes an electronic device which controls the plasma flow in response to the system transmembrane pressure.
References Cited (Backward Citations)
GB1381410A
Cited
US4075091A
Cited
US3853756A
Cited
US4001117A
Cited
US4191182A
Cited
US4212743A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |