A Left-Heart Simulator Reproducing Ventricular Twisting And Valve Dynamics For Circulatory Support Training

Introduction
Mechanical circulatory support and cardiac surgery require accurate understanding of left-heart mechanics under dynamic loading conditions. Devices such as extracorporeal membrane oxygenation (ECMO), off-pump coronary artery bypass grafting (OPCABG), and left ventricular assist device (LVAD), require realistic physiological pressure conditions, realistic valve motions, and reproduced ventricular twisting. However, many simulators lack these features thus limiting the opportunities for procedural training and evaluation of technical skills.

Objective
The work aimed to develop a left-heart simulator capable of reproducing physiological ventricular volume changes, functional aortic valve dynamics and arterial compliance using mechanical actuation.

Methods
A hyperelastic elastomer (polydimethylsiloxane) was reinforced with helically orientated fibres to reproduce physiological left-ventricular wall deformation and twisting during cyclic loading. A mechanically actuated system generated controlled ventricular filling and ejection, producing pulsatile flow with pressures cycling from diastolic to systolic levels (70 to 120 mmHg). Downstream arterial compliance was incorporated to enable realistic pressure development. Hydrodynamic testing quantified ventricular volume change, wall deformation, and twisting behaviour across cardiac cycles.

Results
The left-heart simulator could withstand physiological pressure ranges up to 120 mmHg and demonstrated physiological ventricular twisting (between 6–18°) and functional aortic valve opening. Similarly, ventricular wall motion was observed mimicking ventricular contractions.

Conclusion
The mechanically actuated left-heart simulator provides proof-of-principle for investigating left ventricular haemodynamics and device-heart interactions, supporting procedural training and development in mechanical circulatory support.