US5478470A
Expired / Lapsed
US
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Filter material for selectively removing leukocytes
Assignee: Asahi Kasei Medical Co Ltd
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Filing: 1994-12-05
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Granted: 1995-12-26
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Expires: 2014-12-05
Abstract
Abstract Disclosed is a filter material for selectively removing leukocytes from a leukocyte-containing suspension, which comprises a porous element having an average pore diameter of 1 to 25 μm and a total pore volume of 0.40 to 0.95 ml/ml of the porous element, and wherein the sum of respective pore volumes of pores of the porous element which have a pore diameter of 1 to 30 μm is 90% or more, based on said total pore volume. Also disclosed is a filter apparatus for selectively removing leukocyte from a leukocyte-containing suspension which is packed with the above-mentioned filter material. By virtue of the filter material, the filter apparatus not only can remove leukocytes from a leukocyte-containing suspension at a leukocyte removal efficiency as excellent as 10 -4 or less in terms of a leukocyte residual ratio without suffering from a pressure loss increase, but also can be rendered compact.
Inventors
- 👤 Tatsuya Fukuda
- 👤 Takao Nishimura
- 👤 Naokuni Yamawaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:48
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1692; A; A61; A61M; A61M1/00; A61M1/36; A61M1/3621; A61M1/3627; A61M1/3633; B01D39/1607; B01D39/1623; B01D39/1669; B01D39/1676; A61M2202/00; A61M2202/04; A61M2202/0413; A61M2202/0439
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
107 words
A filter material for selectively removing leukocytes from a leukocyte-containing suspension, which comprises a porous element having an average pore diameter of 3 to 20 μm and a total pore volume of 0.40 to 0.95 ml/ml of the porous element, and wherein the sum of respective pore volumes of pores of the porous element which have a pore diameter of 2 to 30 μm is 94% or more, based on said total pore volume, and the sum of respective pore volumes of pores of the porous element which have a pore diameter of more than 30 μm is 2% or less, based on said total pore volume.
Claim 2
Dependent Claim
107 words
A filter material for selectively removing leukocytes from a leukocyte-containing suspension, which comprises a porous element having an average pore diameter of 3 to 20 μm and a total pore volume of 0.40 to 0.95 ml/ml of the porous element, and wherein the sum of respective pore volumes of pores of the porous element which have a pore diameter of 2 to 30 μm is 94% or more, based on said total pore volume, and the sum of respective pore volumes of pores of the porous element which have a pore diameter of more than 30 μm is 2% or less, based on said total pore volume.
Claim 3
Dependent Claim
60 words
The filter material according to claim 1, wherein said porous element has a total pore surface area of 0.50 to 5.70 m 2 /ml, and wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of 1 to 30 μm is 60% or more, based on said total pore surface area.
Claim 4
Dependent Claim
42 words
The filter material according to claim 2, wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of 1 to 10 μm is 50% or more, based on said total pore surface area.
Claim 5
Dependent Claim
47 words
The filter material according to any one of claims 1 to 3, wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of less than 1 μm is 38% or less, based on said total pore surface area.
Claim 6
Dependent Claim
22 words
The filter material according to claim 1, wherein said porous element has a critical wetting surface tension of at least 65 dyn/cm.
Claim 7
Dependent Claim
32 words
The filter material according to claim 1, wherein said porous element has, in a surface portion thereof, a basic functional group at a density of 10 -6 to 3 meq/m 2 .
Claim 8
Dependent Claim
32 words
The filter material according to claim 1, wherein said porous element has, in a surface portion thereof, an acidic functional group at a density of 10 -4 to 5 meq/m 2 .
Claim 9
Dependent Claim
45 words
The filter material according to claim 1, wherein said porous element is a fibrous, porous medium selected from the group consisting of a knit fabric, a woven fabric and a non-woven fabric, each comprising fibers having an average fiber diameter of 0.3 to 3.0 μm.
Claim 10
Dependent Claim
35 words
The filter material according to claim 1, wherein said porous element is a porous article selected from the group consisting of a porous membrane and a spongy structure having a three-dimensional network of continuous pores.
Claim 11
Dependent Claim
32 words
The filter material according to claim 1, wherein said leukocyte-containing suspension is a leukocyte-containing red cell product, and wherein said porous element has an average pore diameter of 5 to 20 μm.
Claim 12
Dependent Claim
60 words
The filter material according to claim 10, wherein said porous element has a total pore surface area of 0.50 to 5.70 m 2 /ml and wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of 2 to 30 μm is 50% or more, based on said total pore surface area.
Claim 13
Dependent Claim
42 words
The filter material according to claim 11, wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of 2 to 10 μm is 35% or more, based on said total pore surface area.
Claim 14
Dependent Claim
76 words
The filter material according to claim 11, wherein the sum of respective pore volumes of pores of said porous element which have a pore diameter of less than 2 μm is 5% or less, based on said total pore volume, and wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of less than 2 μm is less than 40%, based on said total pore surface area.
Claim 15
Dependent Claim
22 words
The filter material according to claim 10, wherein said porous element has a critical wetting surface tension of 65 to 90 dyn/cm.
Claim 16
Dependent Claim
32 words
The filter material according to claim 10, wherein said porous element has, in a surface portion thereof, a basic functional group at a density of 10 -4 to 3 meq/m 2 .
Claim 17
Dependent Claim
32 words
The filter material according to claim 10, wherein said porous element has, in a surface portion thereof, an acidic functional group at a density of 5×10 -2 to 5 meq/m 2 .
Claim 18
Dependent Claim
45 words
The filter material according to claim 10, wherein said porous element is a fibrous, porous medium selected from the group consisting of a knit fabric, a woven fabric and a non-woven fabric, each comprising fibers having an average fiber diameter of 0.3 to 3.0 μm.
Claim 19
Dependent Claim
35 words
The filter material according to claim 10, wherein said porous element is a porous article selected from the group consisting of a porous membrane and a spongy structure having a three-dimensional network of continuous pores.
Claim 20
Dependent Claim
31 words
The filter material according to claim 1, wherein said leukocyte-containing suspension is a leukocyte-containing platelet product, and wherein said porous element has an average pore diameter of 3 to 15 μm.
Claim 21
Dependent Claim
64 words
The filter material according to claim 19, wherein said porous element has a total pore surface area of 0.50 to 5.70 m 2 /ml of the porous element, and wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of 1 to 25 μm is 58% or more, based on said total pore surface area.
Claim 22
Dependent Claim
42 words
The filter material according to claim 20, wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of 1 to 10 μm is 55% or more, based on said total pore surface area.
Claim 23
Dependent Claim
76 words
The filter material according to claim 20, wherein the sum of respective pore volumes of pores of said porous element which have a pore diameter of more than 25 μm is 10% or less, based on said total pore volume, and wherein the sum of respective pore surface areas of pores of said porous element which have a pore diameter of more than 25 μm is 4% or less, based on said total pore surface area.
Claim 24
Dependent Claim
22 words
The filter material according to claim 19, wherein said porous element has a critical wetting surface tension of at least 85 dyn/cm.
Claim 25
Dependent Claim
33 words
The filter material according to claim 19, wherein said porous element has, in a surface portion thereof, a basic functional group at a density of 10 -6 to 10 -1 meq/m 2 .
Claim 26
Dependent Claim
32 words
The filter material according to claim 19, wherein said porous element has, in a surface portion thereof, an acidic functional group at a density of 10 -4 to 1 meq/m 2 .
Claim 27
Dependent Claim
45 words
The filter material according to claim 19, wherein said porous element is a fibrous, porous medium selected from the group consisting of a knit fabric, a woven fabric and a non-woven fabric, each comprising fibers having an average fiber diameter of 0.3 to 3.0 μm.
Claim 28
Dependent Claim
35 words
The filter material according to claim 19, wherein said porous element is a porous article selected from the group consisting of a porous membrane and a spongy structure having a three-dimensional network of continuous pores.
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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) | 1998-12-25 | 1999-06-26 | 1999-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-25 | 2003-06-26 | 2003-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-25 | 2007-06-26 | 2007-12-26 | $7700.00 | Window Closed / Lapsed |