DEVELOPMENT OF AN AUTOFLOW CRUISE CONTROL-SYSTEM FOR A CENTRIFUGAL PUMP

To improve the ease of driving a centrifugal pump that is afterload de pendent, we have developed an automatic flow control system for the Te rumo Capiox centrifugal pump system. This system consists of an autofl ow cruise control system with a safety cutoff. The Capiox Pump Console 3000 was controlled by a personal computer through a serial communica tion line. In the usual manual mode, the motor speed knob works as a p ump speed control, and in the autoflow mode, the same knob works as a blood flow rate control. After selecting and obtaining the desired flo w rate, the mode was changed from manual to autoflow mode, In the auto flow mode, the computer compares the desired flow rate with the actual flow measured by an ultrasonic Doppler flowmeter and adjusts the moto r rotational speed accordingly. During both in vivo and in vitro testi ng, this autoflow mode was able to return the changed flow that was di srupted by either clamping and declamping of the tubing or by the bolu s injection of a vasomotor drug to the selected flow rate within 10 s without any significant fluctuation, In conclusion, the newly develope d computer controlled autoflow system was able to produce a reliable a nd effective flow regulation for a centrifugal pump.