Sedimentation theory and practical considerations for the design of centrifugal blood cell processes.

This is the first of a five-part series discussing the basic conceptualization and evaluation of techniques for centrifugal separation of blood cells. In this paper, the basic concepts of sedimentation theory will be discussed. The next two papers will discuss the effects of plasma recycle and stagewise separations, respectively, as applied to continuous-flow and semicontinuous-flow processing systems. The subsequent paper will underline the differences between the theoretical approach and our experimental efforts, and the final paper will consider potential future process configurations and areas of expected improvement. A series of calculations is presented for the prediction of sedimentation velocities for red and white cells. The equations are simplified to investigate the regions of high red cell concentration, and are not valid for regions of concentrated platelets or white cells. The intent is to present a sample calculational design approach.