Influence of Heart Rate on Dynamic Characteristics and Hemolytic Potential: A Study Using In-Vitro and Numerical Methods

Objective: This study investigates the influence of heart rate (HR) on the pump at the coupled working state with the cardiovascular system. Methods: A combined approach integrating in-vitro and numerical methods is employed to predict cycle-average hemolytic potential (denoted as ${\bm{H}}{{{\bm{I}}}_{{\bm{ave}}}}$). The pump dynamic characteristics under varying HR conditions are investigated in the in-vitro experiments. The hemolytic potential at different operation points (represented by ${\bm{HI}}$) are predicted numerically. Results: HR variations affect the shape of the pump dynamic characteristic loop and the cycle-average hemolytic potential. Specifically, in all three series studied, ${\bm{H}}{{{\bm{I}}}_{{\bm{ave}}}}$ demonstrated an increase from 60 to 80 bpm and a decrease from 100 to 120 bpm. Conclusion: Higher HR correlates with heightened hysteresis effects within turbomachinery, thereby impacting the dynamic characteristics' profile. Significance: This study unveils the physical mechanisms underlying the influence of HR on pump dynamic characteristics and provides crucial insights for estimating potential adverse effects associated with left ventricular assist device (LVAD) implantation under diverse HR conditions, which helps prompt pump adjustments in clinical applications and the development of coupled working models.