Flow rate and pressure head estimation in a centrifugal blood pump.

Considering a miniaturization of percutaneous cardiopulmonary support (PCPS) system, we have developed a pump system that can estimate flow rate and pressure head in the circuit. A commercially available centrifugal blood pump (C1E3, Kyocera Co., Ltd., Kyoto, Japan) with an exclusive motor driver was used in the experiment. In this system, the motor revolutions per minute and torque were used to derive an estimation equation. Taking into consideration fluid viscosity, the accuracy of the estimation was increased. Bovine blood was used to evaluate the system in vitro. The average maximum difference between the estimated flow rate and the measured flow rate was 0.56 L/min (for 98% accuracy). The average difference between the estimated pressure head and the measured pressure head was 30.7 mm Hg (for 94.2% accuracy). Because of the stability of the estimations, we believe this system has the possibility of use for real-time monitoring and miniaturization of PCPS system.