A Physiological Controller for Turbodynamic Ventricular Assist Devices Based on a Measurement of the Left Ventricular Volume

Abstract

The current article presents a novel physiological control algorithm for ventricular assist devices (VADs), which is inspired by the preload recruitable stroke work. This controller adapts the hydraulic power output of the VAD to the end-diastolic volume of the left ventricle. We tested this controller on a hybrid mock circulation where the left ventricular volume (LVV) is known, i.e., the problem of measuring the LVV is not addressed in the current article. Experiments were conducted to compare the response of the controller with the physiological and with the pathological circulation, with and without VAD support. A sensitivity analysis was performed to analyze the influence of the controller parameters and the influence of the quality of the LVV signal on the performance of the control algorithm. The results show that the controller induces a response similar to the physiological circulation and effectively prevents over- and underpumping, i.e., ventricular suction and backflow from the aorta to the left ventricle, respectively. The same results are obtained in the case of a disturbed LVV signal. The results presented in the current article motivate the development of a robust, long-term stable sensor to measure the LVV.

A Physiological Controller for Turbodynamic Ventricular Assist Devices Based on Left Ventricular Systolic Pressure

“…Figure depicts the prescribed variations of cardiovascular parameters for our experiments. The parameters for after‐ and preload variations correspond to the variations presented in , with a wider range of parameters. We additionally conducted experiments with a varying contractility.…”

“…Many controllers are based on pump intrinsic signals, like the motor current, the pump speed, or the heart rate (HR), which can be calculated from the motor current waveform . Other physiological controllers based on either measured or estimated flow , atrial pressure , pump pressure head , end‐diastolic volume (EDV) , or end‐diastolic pressure (EDP) have been developed, evaluated, and published.…”

Standardized Comparison of Selected Physiological Controllers for Rotary Blood Pumps: In Vitro Study

“…Particularly, two of the implemented controllers (described below) were selected due to their outperformance over another five controllers and the CS operation presented in the comparison study of Pauls et al . The other four controllers were selected due to their clear outperformance over the CS operation that they presented when published , while they offered a reasonable concept variability. For the case of controllers presented in , they have been previously developed in our group and, therefore, we have a deep insight of both, while they have been successfully evaluated in vivo .…”

“…The other four controllers were selected due to their clear outperformance over the CS operation that they presented when published , while they offered a reasonable concept variability. For the case of controllers presented in , they have been previously developed in our group and, therefore, we have a deep insight of both, while they have been successfully evaluated in vivo . Each principle is described below.…”

“…The preload responsive speed (PRS) controller is based on the measurement of the end‐diastolic volume (EDV) to calculate the desired hydraulic power output of the LVAD and to control the speed . This controller constitutes a P controller.…”