Abstract: A porous polypropylene hollow fiber membrane constructed and arranged for artificial lung use and an artificial lung. The membrane includes a solid phase in an inner surface region thereof formed with particles of polypropylene closely fused and joined to give rise to a continuous phase while partially exposed through the surface thereof, a solid phase in an interior and an outer surface region thereof formed with particles of polypropylene interconnected in the direction of axis of the fiber to give rise to a multiplicity of lumps of polyproplylene and an interstice between the phases having continuous pores interconnected in the form of a three-dimensional network.

Abstract: A porous polypropylene hollow fiber membrane is disclosed which is characterized by the fact that the solid phase in the inner surface region thereof is formed with particles of polypropylene closely fused and joined to give rise to a continuous phase while partially exposed through the surface thereof, the solid phase in the interior and the outer surface region thereof is formed with particles of polypropylene interconnected in the direction of axis of fiber to give rise to a multiplicity of lumps of polypropylene, and the interstices between these solid phases has continuous pores interconnected in the form of a three-dimensional network. When this porous polypropylene hollow fiber membrane is used in an artificial lung, without reference to the choice between the type adapted to pass blood inside the hollow fiber membrane, it exhibits a high gas-exchange capacity without infliction of injury upon blood cells, aggravation of pressure loss, or leakage of blood plasma.

Abstract: A sheetlike permeable membrane is characterized by being provided on at least one surface thereof with a plurality of minute protuberances. When a plurality of such sheetlike permeable membranes are incorporated as superposed in a modular structure, the minute projections on the surfaces of these permeable membranes form a stable and proper body fluid flow path between the adjacent permeable membranes and permit dimensional reduction of the modular structure and impart improved performance thereto. Thus, the permeable membranes are suitable for use in such body fluid filtration apparatus as blood plasma separation apparatus.