A Dynamical Model for Pulsatile Flow Estimation in a Left Ventricular Assist Device

Abstract

Keywords:Implantable rotary blood pumps (iRBPs), noninvasive pulsatile flow estimation, left ventricular assist device (LVAD). Abstract:In this paper, we propose a dynamical model for pulsatile flow estimation of an iRBP. Noninvasive measurements of the motor power (V I) and pump impeller rotational speed (ω) were acquired from the pump controller and used together with blood hematocrit (HCT ) values as inputs to the model. A circulatory mock loop was operated with different aqueous glycerol solutions, mimicking different values of viscosities equivalent to the range of 20 -50% of human blood HCT , to generate pulsatile flow data. Linear regression between estimated pulsatile flow (Q est ) and measured flow (Q meas ) obtained from the mock loop resulted in a highly significant correlation (R 2 = 0.957) and mean absolute error of e = 0.364 L/min. Also, R 2 = 0.902 and e = 0.317 L/min were obtained when our model was validated using six sets of ex vivo porcine data. Furthermore, in steady state, the solution of the presented model can be described by a previously designed and verified static model.