US4915848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Red blood cell filtering system
Assignee: Bayer Corp
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Filing: 1989-01-31
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Granted: 1990-04-10
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Expires: 2009-01-31
Abstract
Abstract Closed filtering system for relatively fast and efficient removal of white blood cells from a red blood cell mixture. System comprises at least two blood bags in closed communication with each other via an intermediate filter assembly comprising a housing containing continuous filtering fiber. A preferred housing is tapered and the fiber preferably has a generally Y-shaped cross sectional area and it is adapted to permit substantial removal of white blood cells from a red blood cell mixture with minimal red blood cell hemolysis when the mixture is diluted with preservative solution and passed from one bag to the other at a relatively high flow rate. Filtration is completed within 24 hours, preferably within 6 hours, of whole blood donation.
Inventors
- 👤 Raleigh A. Carmen
- 👤 Chiyong Chong
- 👤 Barry S. Leng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:44
CPC Classifications
A; A61; A61M; A61M1/00; A61M1/02; A61M1/0209; A61M1/0218; A61M1/36; A61M1/3621; A61M1/3627; A61M1/3633; A61M2202/00; A61M2202/04; A61M2202/0413; A61M2202/0439
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
225 words
A method of processing whole blood for the storage of red blood cells comprising the steps of: (a) collecting whole blood from a donor into a donor bag of a closed multiple blood bag system comprising a donor bag in communication with at least one other bag via connecting tubing, the tubing including an integral white blood cell filter consisting essentially of a single continuous filtering fiber of about 2.2 denier and the at least one other bag including a red blood cell additive solution; (b) centrifuging the whole blood in the donor bag under conditions sufficient to separate the whole blood into an upper plasma component and a lower red blood cell component which includes some white blood cells; (c) removing the plasma component from the donor bag; (d) introducing the additive solution into the donor bag by passing the solution through the filter to prime the filter removing air from the filter and then mixing the solution with the red and white blood cells; and (e) passing the mixture of step (d) through the filter and into the at least one other bag under conditions sufficient to remove substantially all white blood cells from the mixture, thereby providing a red blood cell preparation substantially free of white blood cells and suitable for long term storage without substantial amounts of white blood cell contaminants.
Claim 2
Independent Claim
225 words
A method of processing whole blood for the storage of red blood cells comprising the steps of: (a) collecting whole blood from a donor into a donor bag of a closed multiple blood bag system comprising a donor bag in communication with at least one other bag via connecting tubing, the tubing including an integral white blood cell filter consisting essentially of a single continuous filtering fiber of about 2.2 denier and the at least one other bag including a red blood cell additive solution; (b) centrifuging the whole blood in the donor bag under conditions sufficient to separate the whole blood into an upper plasma component and a lower red blood cell component which includes some white blood cells; (c) removing the plasma component from the donor bag; (d) introducing the additive solution into the donor bag by passing the solution through the filter to prime the filter removing air from the filter and then mixing the solution with the red and white blood cells; and (e) passing the mixture of step (d) through the filter and into the at least one other bag under conditions sufficient to remove substantially all white blood cells from the mixture, thereby providing a red blood cell preparation substantially free of white blood cells and suitable for long term storage without substantial amounts of white blood cell contaminants.
Claim 3
Dependent Claim
18 words
The method of claim 1 where steps (a) through (e) are accomplished within 24 hours of each other.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein steps (a) through (e) are accomplished within 6 hours of each other.
Claim 5
Dependent Claim
17 words
The method of claim 3 wherein the filter housing has a volume of less than about 50cc.
Claim 6
Dependent Claim
36 words
The method of claim 3 wherein the filtration is under conditions capable of filtering a unit of blood comprising a mixture of red and white blood cells in less than about 3 hours at room temperature.
Claim 7
Dependent Claim
25 words
The method of claim 3 wherein the filtration is under conditions capable of removing at least about 80% of white blood cells from the mixture.
Claim 8
Dependent Claim
28 words
The method of claim 1 wherein the white blood cell filter includes filtering fiber of cellulose acetate having a density of about 0.4 to 0.7 grams per cc.
Claim 9
Dependent Claim
46 words
The method of claim 1 wherein the filtration is under conditions capable of filtering the cells and reducing long term hemolysis of the cells such that the amount of hemolysis detectable after five weeks storage of the filtered red blood cells is less than about 0.30%.
References Cited (Backward Citations)
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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) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |