Hollow fiber plasmapheresis module

Apparatus including:

• A. an improved microfiltration module for separating whole blood into a cellular-enriched fraction and a plasma-enriched fraction, the module comprising in combination a bundle consisting of a plurality of blood wettable porous membrane hollow fibers all of which are in parallel bundle alignment and have pores of substantially uniform diameter and capable of passing plasma but not cellular components, each of the fibers having a pore diameter within the range 0.1 to 1.0 .mu.m and a lumen diameter (D) no greater than 0.050 cm, the fibers being of substantially equal lengths and terminating in first open ends and second open ends;
• a liquid tight housing to contain the fibers;
• liquid tight sealing means cooperating with the housing and the first open ends of the fibers;
• liquid tight sealing means cooperating with the housing and the second open ends of the fibers, the two sealing means dividing the housing into two end chambers and one central chamber, the end chambers being in liquid transfer relationship with each other through the hollow fibers;
• blood inlet means for introducing whole blood into one chamber;
• blood outlet means for removing a cellular-enriched blood fraction from the other end chamber;
• and plasma outlet means for removing a plasma-enriched blood fraction from the central chamber, the improvement characterized in that the effective length (L), that is, the portion of each fiber, between the ends, through which plasma passes, to lumen diameter (D) ratio (L/D) is not greater than 16,400 cm.sup.-1 D (L and D being in centimeters);
• and
• B. means, operably associated with the microfiltration module, for conducting blood through the fibers in reciprocatory pulsatile flow.