Development, Evaluation, and Validation of a Realistic Simulator for the Human Left Ventricle

Introduction

Mock circulation systems are widely used for preclinical testing of cardiovascular implants. Existing setups are driven by sophisticated hardware and complex control algorithms, which increase costs, whereas animal models raise ethical concerns. Computational simulations can address some limitations but may be oversimplified or computationally expensive. We present a low-cost and realistic left ventricular (LV) simulator designed for the efficient evaluation of physiological scenarios to overcome the challenges mentioned above.

Methods

Interpretive Structural Modelling (ISM) was utilised to compare three different beating LV simulator design approaches (pneumatic artificial muscle, flexible band, and artificial muscle actuation) and analyse the interaction of factors and their effects on the performance of the LV simulator. ISM guided the selection of pneumatic artificial muscles and latex rubber as the optimal actuation method and material for replicating LV motion. Finite element simulations were employed to evaluate an LV model, similar in size to the native LV, made of latex rubber and driven by pneumatic artificial muscles. A prototype of the LV model was also built to validate the numerical simulations.

Results

Numerical simulations predicted an apex twist of 17 degrees and long-axis shortening of 11 mm. Experiments at 50, 60, and 70 bpm demonstrated the simulator’s ability to generate flow rates up to 2.27 L/min. Mechanical performance matched with the native LV behaviour and numerical results, with apex twisting between 18 degrees and 21 degrees, and an apex shortening ranging from 5 mm to 11 mm.

Conclusion

Twist angles and long-axis shortening show that it is capable of functioning like a native left ventricle. The simulator’s geometry, including basal diameter and long-axis length, matches native human LV anatomy. Therefore, the developed LV simulator combines anatomical fidelity and cardio-mechanical performance in a relatively simple and cost-effective configuration, making it a promising tool as a test setup.