US4381775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for low pressure filtration of plasma from blood
Assignee: Asahi Kasei Medical Co Ltd
•
Filing: 1980-08-18
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Granted: 1983-05-03
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Expires: 2000-08-18
Abstract
Abstract A method for carrying out separation of plasma from whole blood, in which whole blood is passed through a filtration membrane means of a material suitable for separating plasma from whole blood and having a pore size from 0.1 to 0.6 microns at positive pressure differential across the membrane in a range up to just below 50 mm Hg. This provides an increased flow as compared to the flow obtained with higher pressures.
Inventors
- 👤 Yukihiko Nose'
- 👤 Paul S. Malchesky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:46
CPC Classifications
B; B01; B01D; B01D61/00; B01D61/14; B01D61/147; A; A61; A61K; A61K35/00; A61K35/12; A61K35/14; A61K35/16; A61M; A61M1/00; A61M1/34; A61M1/3472; A61M1/3486; B01D63/00; B01D63/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
111 words
A method of separating plasma from whole blood, comprising the step of: directing a flow of whole blood across one face of a filtration membrane means which is made of a material suitable for separating plasma from whole blood and having a pore size from 0.1 to 0.6 microns, said flow being at a flow velocity of from 5 to 1500 cm /min and being at a depth sufficient for separating plasma from the flow of blood, and at the same time generating a positive pressure differential across said membrane up to just below 50 mm Hg. for forcing plasma through the membrane, and collecting the plasma separated by the membrane.
Claim 2
Independent Claim
111 words
A method of separating plasma from whole blood, comprising the step of: directing a flow of whole blood across one face of a filtration membrane means which is made of a material suitable for separating plasma from whole blood and having a pore size from 0.1 to 0.6 microns, said flow being at a flow velocity of from 5 to 1500 cm /min and being at a depth sufficient for separating plasma from the flow of blood, and at the same time generating a positive pressure differential across said membrane up to just below 50 mm Hg. for forcing plasma through the membrane, and collecting the plasma separated by the membrane.
Claim 3
Dependent Claim
37 words
A method as claimed in claim 1 in which the step of generating a pressure differential across said membrane comprises generating a pressure in a range from about 8.5 mm Hg. to just below 50 mm Hg.
Claim 4
Dependent Claim
29 words
A method as claimed in claim 1 in which the pressure generating step comprises generating a pressure in a range of from about 20 to about 40 mm Hg.
Claim 5
Dependent Claim
17 words
A method as claimed in claim 1 in which said membrane means is a film type membrane.
Claim 6
Dependent Claim
17 words
A method as claimed in claim 1 in which said membrane means is a hollow fiber membrane.
Claim 7
Dependent Claim
20 words
A method as claimed in claim 1 in which said membrane means is a hollow fiber membrane of hydrophilic material.
References Cited (Backward Citations)
US3705100A
Cited
US4191182A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-02 | 1986-11-01 | 1987-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-02 | 1990-11-01 | 1991-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-02 | 1994-11-01 | 1995-05-03 | $7700.00 | Window Closed / Lapsed |