US 5,665,233 AGranted

Filter apparatus for selectively removing leukocytes

AssigneeAsahi Medical Co., Ltd.

InventorsTatsuya Fukuda, Takao Nishimura, Naokuni Yamawaki

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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 .mu.m 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 .mu.m 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.sup.-4 or less in terms of a leukocyte residual ratio without suffering from a pressure loss increase, but also can be rendered compact.

A filter apparatus for selectively removing leukocytes from a leukocyte-containing suspension, which comprises a container having an inlet for a leukocyte-containing suspension and an outlet for a filtrate, and a porous structure packed in said container, said porous structure comprising a main porous element having an average pore diameter of 1 to 25 .mu.m and a total pore volume of 0.40 to 0.95 ml/ml of the main porous element, wherein the sum of respective pore volumes of pores of said main porous element which have a pore diameter of 1 to 30 .mu.m is 90% or more, based on said total pore volume, and at least one preliminary porous element disposed upstream of said main porous element with respect to a flow direction in which a leukocyte-containing suspension to be treated for removal of leukocytes is adapted to be flowed, said preliminary porous element having an average pore diameter which is larger than the average pore diameter of said main porous element so that said porous structure has an average pore diameter of 1 to 300 .mu.m,

said porous structure having an average pore diameter gradient such that the average pore diameter is substantially continuously or stepwise decreased in said flow direction from an upstream end portion to a downstream end portion of the porous structure, wherein said upstream end portion and said downstream end portion each have a thickness of 0.5 mm or less, as measured in a thicknesswise direction from the upstream end surface and from the downstream end surface of said porous structure, respectively, and wherein said upstream end portion of said porous structure has an average pore diameter of 10 to 300 .mu.m and said downstream end portion of said porous structure has an average pore diameter of 1 to 25 .mu.m, with the proviso that the average pore diameter of the upstream end portion of said porous structure is 2 to 100 times that of the downstream end portion of said porous structure,
wherein said preliminary porous element is capable of capturing at least 60% of all leukocytes contained in said leukocyte-containing suspension.

Facts

Application

08/531,700Filed 21 Sep 1995 · division

Priority

JP 3-23370222 Aug 1991

Granted

9 Sep 1997

Term ends

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Classification7 codes

B01D 39/1692
Of organic material, e.g. synthetic fibres: other shaped material, e.g. perforated or porous sheets
A61M 1/3633
Degassing devices; Buffer reservoirs; Drip chambers; Blood filters: blood component filters, e.g. leukocyte filters
B01D 39/1623
The material being fibrous: of synthetic origin
B01D 39/1676
Cellular material: of synthetic origin

Abstract

Claims10