Comparison of Hemodynamic Circulation in Pulsatile and Nonpulsatile Extracorporeal Membrane Oxygenation Systems Using an In-Vitro Heart Model

This study conducts an in-vitro experiment using a mock circulation system that mimics human circulation to assess the veno-arterial extracorporeal membrane oxygenation (ECMO) system. This study aims to compare the hemodynamic effects of centrifugal and pulsatile ECMO systems on the body using an in-vitro cardiogenic shock model. The heart model used in this study involves a contracting blood sac with inlet and outlet valves, capable of maintaining arterial pressure between 80 and 120 mm Hg while delivering a blood flow of 1.8-2 L/min, effectively replicating a cardiogenic shock model. The contraction force in the heart model was generated using a pneumatic cylinder and gradually decreased to simulate reduced cardiac function. The initial blood flow rates of both ECMO systems were maintained at 2 L/min under identical conditions for a fair comparison. Upon reducing the stroke volume of the heart to 35 ml, the ECMO system with counter-pulsation control increased the cardiac output by 10.7% and systemic circulation by 3.8% compared with the conventional ECMO system. This study demonstrates the hemodynamic benefits provided by the sustained counter-pulsation in an in-vitro weakened heart model. Pulsatile flow ECMO systems may serve as an alternative to address the limitations of continuous flow ECMO systems.