Effects of Pulsatile Flow and Backwashing on Plasma Flow Rate in an Implantable Plasmapheresis. I. Theory and Principle

Abstract

The first stage of blood filtration in kidneys involves separation of solids (blood cells and proteins) from liquid blood part (plasma). In an attempt to design and fabricate an implantable artificial kidney, this stage is considered fundamental and as such is given both in depth theoretical and experimental consideration. This report outlines the theory of backwashing to determine permeate flux dependence on time during cross-flow filtration in the case of blood cell separation. The presented method reduces, and we hope for elimination of, filter membrane fouling. The method proposed in this research will use the internal energy of the body (blood pressure pulsation) to provide enough movement for a diaphragm pump to provide a backwash flow as a phase of the filtration cycle. We investigated the effect of operational parameters such as cross-flow velocity, Womersley number, pressure difference, and filtration time on permeate flow rate.