To suppress the progress of the clogging of a separation membrane and to perfectly execute a required blood processing without interruption in the midst of the processing and affecting limit by controlling the flow rate of a blood pump as the function of difference pressure at the separation membrane in a plasma separator.
The flow rate of a blood pump is controlled by monitoring the values of blood taking pressure P1, vein pressure P2 and plasma separator difference pressure and, at the same time, permitting it not to exceed these limit values. Unless the limit of these kinds of pressure is received, the flow rate of the blood pump is increased by a preset initial speed increasing quantity till an integrated flow rate reaches a prescribed value. The integrated flow rate is set to be almost equal to capacitance obtained by adding a blood taking circuit to the plasma separator. When the integrated flow rate of blood reaches the prescribed value, the flow rate increasing rate of the blood pump is changed- over to the normal speed increasing quantity so that the flow rate reaches a target blood flow rate. After that, the operation of the blood pump is controlled so as to keep the target blood flow rate.
TACHIBANA HIROSHI
YOSHIDA KEIICHI
HAMANISHI YASUSHI
TAKAO YOSHIZUMI
NARISADA MASATAKA
YOKOGAWA ELECTRIC CORP