Mathematical analysis of the effects of geometric parameters and mechanical properties of erythrocytes on the filterability of nonuniform suspensions

Approaches to determination of the shape of erythrocytes distribution in ra tes of their passage through pores (3 mu in diameter) of a membrane filter by processing the data on changes in the flow rates of erythrocyte suspensi ons with time (filtration curves) are discussed. We considered the case whe n the suspension consisted of two subpopulations of erythrocytes differing by a single parameter. Using the model describing the erythrocyte passage t hrough a pore and the model describing filtration of a nonuniform suspensio n, we analyzed how filtration kinetics of such suspensions depends on the r elative contents of the subpopulations and their rheological characteristic s. It was shown that the filtration rate of the major subpopulation, the fi ltration rate of the minor abnormal subpopulation, and their relative conte nts could be determined from analysis of filtration curves. It can be done in the case when the filtration rate of cells of the minor subpopulation is at least by an order of magnitude lower than the filtration rate of cells of the major subpopulation. Thus we can register the presence of a minor su bpopulation in the range of 0.5-1%. If filtration curves are recorded at va rious osmolalities, their analysis makes it possible to determine the surfa ce area, intracellular viscosity, and membrane rigidity of cells of the maj or subpopulation and, in certain cases, these parameters for cells of the m inor subpopulation.