SYSTEM FOR FILTERING MEDICAL AND BIOLOGICAL FLUIDS

摘要

A method and apparatus for filtering suspensions of medical and biological fluids, one aspect of which is separating a suspension comprising at least two types of particles which are differently sized or shaped and in which the first type of particle may be deformable at a relatively lower force and/or faster rate than the second type of particle. A filter member is provided having substantially precisely dimensioned pore sizes, with the pores being dimensioned to allow passage of the first type of suspended particle without distortion or only minimal distortion and passage of the second type of particle only with substantial distortion. Because the filter membrane has precisely dimensioned pores, with spacing between the pores being maintained despite the smaller interval between the pores, the porosity of the membrane may be much greater than nominal pore size membranes, allowing faster filtration rates and/or smaller membranes for a given filtration rate, while reducing the exposure time of the cells within the shear environment, and consequently reducing particle damage. Various methods for preventing clogging of the membrane are also disclosed.