Separation of plasma from whole blood by membrane filtration in oscillatory flows.

This paper describes the performance of a microfiltration plasmapheresis unit operating with reversing oscillatory flows. The device consists of a flat channel duct between cellulose nitrate membranes and was used to extract plasma from anticoagulated fresh whole bovine blood. Measurements were made of plasma flux, haematocrit concentration, haemolysis and protein sieving coefficients. The effects on plasma flux are reported for alterations in the stroke and frequency of flow pulsations, transmembrane pressure, membrane properties and blood throughput. It was found that the imposition of oscillatory flows enhanced the plasma extraction rate by a factor of 3, producing about 0.9 litre/min/m2 membrane.