Synchronous PIV measurements of a self-powered blood turbine and pump couple for right ventricle support

Abstract

A blood turbine-pump system (iATVA) was proposed as a self-driven, motorless mechanical right-heart assist device. In this study, the iATVA system is investigated with particular emphasis on the blood turbine flow dynamics. A time-resolved 2D particle image velocimetry (PIV) set-up allowed simultaneous recordings from both the turbine and pump impellers. Results showed that magnetically coupled impellers operated synchronously. As the turbine flow rate increased from 1.6 to 2.4 LPM, the rotational speed and relative inlet flow angle increased from 630 to 900 rpm, and 38 to 55% respectively. At the trailing edges, backflow region spanned 3/5 of the total passage outlet flow, and an extra leakage flow was observed at the leading edge. For this initial turbine design, ~75% of the turbine blade passage was not contributing to the impulse operation mode. The maximum non-wall shear rate was ~2288 s-1 near to the inlet exit, which is significantly lower than the commercial blood pumps, encouraging further research and blood experiments of this novel concept. Experimental results will improve the hydrodynamic design of the turbine impeller and volute regions and will be useful in computational fluid dynamics validation studies.