US4767538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Washing of semipermeable membrane
Assignee: Baxter International Inc
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Filing: 1985-11-25
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Granted: 1988-08-30
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Expires: 2005-11-25
Abstract
Abstract A method of preparing a dialyzer unit having a plurality of coextending hollow fibers includes washing interior fiber surfaces with an acetic acid both, flushing the interior surfaces with an aqueous glycerin solution, and removing the residual water while retaining a substantial quantity of absorbed glycerin in the fibers. The dialyzer can then be sealed and sterilized.
Inventors
- 👤 George M. Jakubowski
- 👤 Susan C. Molthop
- 👤 Milo Eldridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:50
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0095; B01D63/00; B01D63/02; B01D63/021; B01D65/00; B01D65/02; B01D65/022; B01D2321/00; B01D2321/02; B01D2321/16; B01D2321/168; B01D2321/18; B01D2321/185
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
123 words
A method of preparing a dialyzer unit that has a plurality of coextensively oriented, hollow, fluid conducting, porous, ultrafiltrating lumens, the method including: washing interior surfaces of the lumens with a selected mixture of acid and water so as to remove impurities therefrom as well as to substantially enlarge and expand the physical dimensions of the porous structure of each lumen; flushing the acid mix from the interior surfaces using a selected organic polyol solution while simultaneously providing for absorption of substantial quantities thereof by each lumen so as to retain the expanded physical dimensions thereof; removing the flushing solution leaving only the absorbed polyol in the lumens; and sterilizing the polyol filled lumens without any substantial reduction in the ultrafiltrating characteristics thereof.
Claim 2
Independent Claim
123 words
A method of preparing a dialyzer unit that has a plurality of coextensively oriented, hollow, fluid conducting, porous, ultrafiltrating lumens, the method including: washing interior surfaces of the lumens with a selected mixture of acid and water so as to remove impurities therefrom as well as to substantially enlarge and expand the physical dimensions of the porous structure of each lumen; flushing the acid mix from the interior surfaces using a selected organic polyol solution while simultaneously providing for absorption of substantial quantities thereof by each lumen so as to retain the expanded physical dimensions thereof; removing the flushing solution leaving only the absorbed polyol in the lumens; and sterilizing the polyol filled lumens without any substantial reduction in the ultrafiltrating characteristics thereof.
Claim 3
Dependent Claim
14 words
The method in accordance with claim 1 in which said organic polyol is glycerin.
Claim 4
Dependent Claim
18 words
The method in accordance with claim 2 wherein: the flushed lumens absorb approximately 30% by weight of glycerin.
Claim 5
Dependent Claim
21 words
The method in accordance with claim 3 wherein the glycerin flush solution includes glycerin in a range of 25%-50% by volume.
Claim 6
Dependent Claim
22 words
The method in accordance with claim 4 wherein the glycerin corresponds to at least 25% by volume of the glycerin flush solution.
Claim 7
Dependent Claim
16 words
The method in accordance with claim 4 wherein the solution preferably contains 50% glycerin by volume.
Claim 8
Dependent Claim
17 words
The method in accordance with claim 4 wherein the glycerin flush solution includes a selected nonreactive solvent.
Claim 9
Dependent Claim
15 words
The method in accordance with claim 7 wherein the solvent corresponds to a selected alcohol.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |