Untitled research work

To grasp the conditions of patients and implantable artificial hearts, it is important to monitor the blood flow rate continuously and noninvasively. However, it is difficult to monitor the pump flow rate especially in an implantable axial flow blood pump, because the power consumption of the axial flow blood pump has neither linearity nor uniqueness with respect to the pump flow rate. In this study, we develop a miniaturized mass flow meter that uses centrifugal force for discharged patients with an axial flow blood pump. This mass flow meter measures the centrifugal force corresponding to the mass flow rate in the curved tube, and implements compensation for the static pressure. Because the strain gauges are attached outside of the curved tube, the mass flow meter has no blood contact point, resulting in a compact design. The sensing areas are determined based on the computational fluid dynamic analysis. To evaluate measurement performances, the mass flow meter was compared with the conventional ultrasonic flow meter. As a result, the measurement error ranging from0. 0to5. 0l/min was less than 0. 5l/min. The tracking performance of pulsation flow was approximately equivalent to that of the conventional flow meter.