Activation of a Soft Robotic Left Ventricular Phantom Embedded in a Closed-Loop Cardiovascular Simulator: A...

Cardiovascular simulators are used in the preclinical testing phase of medical devices. Their reliability increases the more they resemble clinically relevant scenarios. In this study, a physiologically actuated soft robotic left ventricle (SRLV) embedded in a hybrid (in silico- in vitro) simulator of the cardiovascular system is presented, along with its experimental and computational analysis.

A SRLV phantom, developed from a patient's CT scan using polyvinyl alcohol (PVA), is embedded in a hybrid cardiovascular simulator. We present an activation method in which the hydraulic pressure external ( $P_e\left(t\right)$ ) to the SRLV is continuously adapted to regulate the left ventricular volume ( $V_i\left(t\right)$ ), considering the geometry and material behavior of the SRLV and the left ventricular pressure ( $P_i\left(t\right)$ ). This activation method is verified using a finite element (FE) model of the SRLV and validated in the hybrid simulator. Different hemodynamic profiles are presented to test the flexibility of the method.

Both the FE model and hybrid simulator could represent the desired in silico data ( $P_i\left(t\right)$ , $V_i\left(t\right)$ ) with the implemented activation method, with deviations below 8.09% in the FE model and mainly < 10% errors in the hybrid simulator. Only two measurements out of 32 exceeded the 10% threshold due to simulator setup limitations.

The activation method effectively allows to represent various pressure-volume loops, as verified numerically, and validated experimentally in the hybrid simulator. This work presents a high-fidelity platform designed to simulate cardiovascular conditions, offering a robust foundation for future testing of cardiovascular medical devices under physiological conditions.