Blood fractionating process and apparatus for carrying out same

Claim 2

hemolysis.Iaddend.. 6. A process as defined in claim 5 wherein said filtration membrane has a pore size from about 0.4 to about 0.7 micron in

Claim 3

diameter. 7. A process as defined in claim 6 wherein the pressure

Claim 4

differential is from 2 to 5 p.s.i. 8. In a process for removing whole blood from a blood donor and returning the blood constituents to the donor while keeping the plasma for medical use, the improvement consisting of (1) transferring said whole blood from said donor into contact with the upstream side of filtration membrane having a pore size from about 0.1 to about 0.8 micron in diameter, (2) conducting said whole blood across the surface of the membrane in a path which is substantially parallel to the upstream side of said membrane and has a maximum depth of 20 mils measured vertically from the face of the membrane, (3) applying sufficient pressure to said whole blood to provide a pressure differential of 1 to 15 p.s.i. between upstream and downstream sides of said membrane and to provide a flow velocity across the face of the membrane from 2 to 50 feet per minute, and (4) recovering the retained blood components from the upstream side of the membrane and transferring them back to the blood donor.Iadd., said plasma being removed from the downstream side of said membrane and being substantially free of evidence of hemolysis.Iaddend..