The modelling object can be represented as a ring system of compartments: left ventricle (HL), systemic artery (AL), capillaryvenous systemic compartment (systemic vein) (VL), right ventricle (HR), pulmonary artery (AR), capillaryvenous pulmonary compartment (pulmonary vein) (VR). Aortic, tricupsid, pulmonary and mitral valves provide direct blood flow through this ring system.

This scheme is seriously simplified, especially in the representation of vascular system, because it does not detail circulation process in small branches.