Introducing the leakoff coefficient related with time, a new calculating model with multi parameters based on the dynamic fluid leakoff experiment is established.

Clearance, ultrafiltration coefficient and zeta potential were obtained on a new F80B dialyzer, after exposure to plasma in a 3 h in vitro dialysis session, and after cleaning with bleach and peracet.

The internal model controller is designed by Pole-zero Cancellation,and its filter coefficients meet the demands of robustness in uncertain conditions,and PID parameters can be fixed with PID principle approaching IMC.

On the basis of unit bed element and cylindrical cell model, an initial filtration coefficient expression of direct filtration with upward flow fibrous bundle media was presented.

The method of test to determine the filtration coefficient of a filtration bed is rather complicated.

The filtration coefficient (λ_0) is introduced and a mathematical model for the leukocyte filtration process, which relates filtration efficiency, capacity and leukocyte concentration, filter thickness and filter area, is established according to the mass balance for particles in a filter and the particle concentration decrease per unit of filter length.