Electronic circuit simulating the one-atrium one-ventricle heart and the artificial systemic circuit. Subcircuits (for explanation see Figure 1(b)) are indicated by dashed-lined and shaded boxes. The mode of simulation is determined by 3 switches: S1 and S2 operated by the “space” key, and S3 operated by the “A” key. Various variables can be recorded and measured at points as indicated: pressures (e.g., atrial, ventricular, and “aortic”); flows (e.g., mitral, aortic, and cardiac output); volumes (e.g., ventricular). The “systemic” circuit is made up by a chain of resistor/capacitor segments. The direction of flow (current) is indicated by arrows.
