Circuit diagram of the SOMAH Device. A custom-built apparatus was designed for extra-corporeal reanimation of hearts. The circuit 1 (green) visualizes antegrade coronary perfusion through aorta during initial reperfusion of hearts and circuit 2 (red), for perfusion of hearts through PV in the working state. In circuit 1, the perfusate is pumped from heart chamber to oxygenator-heat-exchanger system and eventually into aorta for coronary perfusion. The return of perfusate to heart chamber through PA completes the circuit. In circuit 2, blood pumped from heart to oxygenator-heat-exchanger system is collected in pre-load bag from where it drained into the PV by gravity. The pressures/flows are adjusted by altering the height of pre-load bag. This circuit is diverted into two components. First component is the part of perfusate that enters coronaries and returns to heart chamber through PA. The second component is formed by the perfusate that continues through aorta into the after-load chamber, from where the perfusate returns to heart chamber by gravity. A CDI monitor was incorporated beyond oxygenator-heat-exchanger system for real-time monitoring of perfusate pH, temperature, pO2, pCO2, K+ and HCO3-. Pressures and flows were recorded at various points in the two circuits and monitored using HMI software specifically written for SOMAH Device.