As the conventional sieving coefficient of a menbrane is calculated by using the average concentrations of blood and filtrate in the hemofiltration system, it is not correct in a strict sense. The sieving coefficient used everywhere must be corrected to introduce a new one, which is defined as a concentration ratio of blood and filtrate anywhere in the filtration.
The biomedical transport was considered with respect to dialyzer and filtrator with highly permeable membranes. The change of theoretical clearance in HD, HF, HDF under a given set of operating conditions was investigated by the idea of biomedical transport including the behavior of solutes binding with protein and erythrocytes.
The solute transport analysis combined with pool model in human body was compared with in vitro and in vivo data in hemofiltration, and it has become apparent that the good agreement was
