Patient-Specific Soft Robotic Cardiac Simulator for Advanced Surgical Training

Background: Cardiac simulators for surgical training have proven instrumental in honing surgeons' expertise, allowing them to perform surgical treatments in a safe, realistic, and controlled environment. Therefore, developing hemodynamically and anatomically realistic training platforms is essential for clinicians to devise tailored solutions for patients, enhance accuracy and efficacy, and minimize surgical risks. In this work, we developed a patient-specific beating heart simulator integrated into a mock circulatory system and actuated through soft robotic technology. Specifically, the use of soft robotic actuators enabled us to obtain an active ventricular contraction, producing physiological hemodynamics without using an external pulsatile pump. Methods: A patient-specific right ventricle model was developed employing silicone injection molding technique. Starting from CT images of a patient, design solutions were implemented with CAD software, and silicone injection molds were 3D printed in PLA. A heat-soluble core in prosthetic animal gelatine was used to reproduce the internal heart cavity. Soft pneumatic artificial muscles (PAMs) that contract when pressurized with air were used to achieve active contraction of the ventricular model. Specifically, PneuNets and McKibben soft robots were developed and characterized in terms of contraction, force development, and operating pressure. A design study was conducted to incorporate them into the ventricle model, aiming to obtain circumferential and longitudinal contraction. Furthermore, the heart model was integrated into a dedicated cardiovascular mock-loop with mechanical support valves to reproduce the cardiac phases by analyzing the fluid dynamic parameters of interest. Results: The patient-specific right ventricle model, obtained through silicone injection molding, accurately replicated heart anatomy. Using soft robotic actuators enabled active ventricular contraction, overcoming limitations of the paradoxical movement typical of passive heart simulators and preventing unnatural heart contractions. The incorporation of a cardiovascular mock-loop with mechanical support valves allowed for the faithful reproduction of cardiac phases, resulting in a realistic simulation of fluid dynamic parameters. Conclusion: The developed cardiac simulator, using soft robotic technology and a dedicated cardiovascular mock-loop, is a valuable training tool for surgeons and exhibits potential uses in medical device testing and research. The ability to accurately replicate physiological conditions and fluid dynamics positions the simulator as a versatile tool to advance surgical training methodologies and cardiovascular research efforts.