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US4701267A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for removing leukocytes

Assignee: Asahi Kasei Medical Co Ltd
•
Filing: 1985-03-14
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Granted: 1987-10-20
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Expires: 2005-03-14
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Abstract

Abstract A filter unit for removing leukocytes from a leukocyte-containing suspension, comprising a container provided with at least one inlet conduit means and at least one outlet conduit means, the container having a main filter packed therein in the form of a non-woven fabric which comprises fibers of an average diameter of from 0.3 μm to less than 3 μm and which has a bulk density of from 0.01 g/cm 3 to 0.7 g/cm 3 , and which has an average distance between two adjacent fibers defined by the following equation (1) of from 0.5 μm to 7.0 μm: ##EQU1## wherein y is the average distance between two adjacent fibers in micron; x is the average diameter of fibers in microns; ρ is the density of the fibers in g/cm 3 ; D is the bulk density of the filter in g/cm 3 ; and π is a circular constant.

Inventors

  • 👤 Hiroyuki Watanabe
  • 👤 Hiroshi Rikumaru

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 20:12
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; A; A61; A61M; A61M2202/00; A61M2202/04; A61M2202/0413; A61M2202/0439

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 179 words
A method for removing leukocytes from a leukocyte-containing suspension, comprising the steps of: passing a leukocyte-containing suspension through a filter unit which comprises: a container having at least one inlet conduit means and at least one outlet conduit means; and a main filter packed therein in the form of a non-woven fabrics, said fabrics comprising fibers wherein the average daimeter of all of the fibers in said fabrics is from 0.3 μm to less than 3 μm and said fabric having a bulk density of from 0.01 g/cm 3 to 0.7 g/cm 3 , and wherein the average distance between any two of all adjacent fibers throughout said fabric is 0.5 μm to 7.0 μm and is defined by the following equation (1): ##EQU4## wherein y is the average distance between two adjacent fibers in microns; x is the average diameter of fibers in microins; ρ is the density of the fibers in g/cm 3 ; D is the bulk density of the filter in g/cm 3 ; and π is a circular constant; and obtaining a leukocyte-poor liquid.
Claim 2
Independent Claim 179 words
A method for removing leukocytes from a leukocyte-containing suspension, comprising the steps of: passing a leukocyte-containing suspension through a filter unit which comprises: a container having at least one inlet conduit means and at least one outlet conduit means; and a main filter packed therein in the form of a non-woven fabrics, said fabrics comprising fibers wherein the average daimeter of all of the fibers in said fabrics is from 0.3 μm to less than 3 μm and said fabric having a bulk density of from 0.01 g/cm 3 to 0.7 g/cm 3 , and wherein the average distance between any two of all adjacent fibers throughout said fabric is 0.5 μm to 7.0 μm and is defined by the following equation (1): ##EQU4## wherein y is the average distance between two adjacent fibers in microns; x is the average diameter of fibers in microins; ρ is the density of the fibers in g/cm 3 ; D is the bulk density of the filter in g/cm 3 ; and π is a circular constant; and obtaining a leukocyte-poor liquid.
Claim 3
Independent Claim 203 words
A method for removing leukocytes from a leukocyte-containing suspension, comprising the steps of: passsing a leukocyte-containing suspension through a filter unit which comprises: a container having at least one inlet conduit means and at least one outlet conduit means; and a main filter packed therein in the form of a non-woven fabric, said fabric comprising fibers wherein the average diameter of all of the fibers in said fabric is from 0.3 μm to less than 3 μm and said fabric having a bulk density of from 0.01 g/cm 3 to 0.7 g/cm 3 , and wherein the average distance between any two of all adjacent fibers throughout said fabric is 0.5 μm to 7.0 μm and is defined by the following equation (1): ##EQU5## wherein y is the average distance between two adjacent fibers in microns; x is the average diameter of fibers in microns; ρ is the density of the fibers in g/cm 3 ; D is the bulk density of the filter in g/cm 3 ; and π is a circular constant; separating out storage generated microaggregates and adhesive substance with a prefilter inserted in the container between the inlet conduit means and the main filter; and obtaining a leukocyte-poor liquid.
Claim 4
Independent Claim 203 words
A method for removing leukocytes from a leukocyte-containing suspension, comprising the steps of: passsing a leukocyte-containing suspension through a filter unit which comprises: a container having at least one inlet conduit means and at least one outlet conduit means; and a main filter packed therein in the form of a non-woven fabric, said fabric comprising fibers wherein the average diameter of all of the fibers in said fabric is from 0.3 μm to less than 3 μm and said fabric having a bulk density of from 0.01 g/cm 3 to 0.7 g/cm 3 , and wherein the average distance between any two of all adjacent fibers throughout said fabric is 0.5 μm to 7.0 μm and is defined by the following equation (1): ##EQU5## wherein y is the average distance between two adjacent fibers in microns; x is the average diameter of fibers in microns; ρ is the density of the fibers in g/cm 3 ; D is the bulk density of the filter in g/cm 3 ; and π is a circular constant; separating out storage generated microaggregates and adhesive substance with a prefilter inserted in the container between the inlet conduit means and the main filter; and obtaining a leukocyte-poor liquid.

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) 1990-10-19 1991-04-20 1991-10-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-10-19 1995-04-20 1995-10-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-10-19 1999-04-20 1999-10-20 $7700.00 Window Closed / Lapsed

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