A fluid transfusing device and method of control therefor includes a plurality of pump driving portions and a microprocessor. Each pump driving portion is for driving a pump, and the microprocessor controls the pump driving portions. The microprocessor executes a fluid transfusing device control program, and interrupts the fluid transfusing device control program upon receiving a pump interrupt. The microprocessor then executes a pump driving interrupt module. When the microprocessor executes the pump driving module, the microprocessor generates a pump driving pulse to control a pump driving portion associated with the pump corresponding to the pump interrupt, determines receipt of another pump interrupt corresponding to a another pump, and generates a pump driving pulse to control a pump driving portion associated with the another pump corresponding to the another pump interrupt. Determining the receipt of another pump interrupt and generating another pump drive pulse without exiting the pump driving interrupt module, prevents undue delay in processing the another pump interrupt. Consequently, the pump drive portions, which are motors, do not disengage or stop due to delay in receiving pump drive pulses.