A Mechatronic Bio-Mimicking Simulator Platform for Cardio-Pulmonary Resuscitation

Current automated cardio-pulmonary resuscitation (CPR) machines have not shown significant advancements compared to manual CPR. Furthermore, their effectiveness in different combinations remains unexplored, except in limited theoretical and electrical models. To bridge this gap and potentially discover better CPR techniques, a mechatronic bio-mimicking simulator has been developed herein. This simulator incorporates a fluid-filled circulatory circuit with multiple chambers representing the heart, lungs, splanchnic organs, and lower limbs. A conduit connected to the cardiac chamber includes fluidic sensors for monitoring cardiac output (COP). The platform is housed within a programmable electro-pneumatic actuation system capable of executing various combinations of traditional and innovative thoracic and abdominal compression sequences, adjusting for force, speed, and timing. Three actuator configurations mimicking the actions of commercially available LUCAS, Autopulse, and Lifestick devices produced mean aortic pressure of 27.64 $\pm$ 28.23, 18.32 $\pm$ 19.38, and 15.96 $\pm$ 21.24 mmHg, respectively, with corresponding flow rates of 6.02 $\pm$ 2.65, 5.16 $\pm$ 1.69, and 4.20 $\pm$ 2.22 L/min. However, a novel configuration involving sustained abdominal compression followed by thoracic compression and subsequent collective release yielded significantly higher mean pressures of 44.46 $\pm$ 40.81 mmHg ($>$60% higher than LUCAS) with flow rates of 5.09 $\pm$ 1.72 L/min. Hence, the mechatronic bio-mimicking simulator offers a versatile platform for evaluating a wide range of conventional and innovative CPR techniques. This facilitates the identification of methods that generate the highest COP, warranting further exploration in animal and human studies. Drawing from these results, the authors suggest a venous-backflow hypothesis to explain CPR hemodynamics and explore its potential implications for interventions.