Open loop network with: atrial reservoir (preload), right ventricle and pulmonary arterial tree devoded in three branches.  The behavior of the native ventricle is implemented as reported in "Numerical Hart Model (1)". RAP is the right atrial pressure and RVP is the right ventricular pressure. TV (PV) is the tricuspid (pulmonary) valve. The main pulmonary artery is modelled with RLC elements (R_pam, L_pam and C_pam), the behavior of the small pulmonary artery is reproduced with R_pas, L_pas and C_pas, the pulmonary arteriole and capillary circulation is implemented using R_pac, L_pac and C_pac. R_ap is the variable pulmonary peripheral resistance. Qri is the (Qro) input (output) right ventricular flow. TV and PV are modelled using resistances and diodes when the valve regurgitation is not simulated.TV is implemented with the resistance (Rri) and the inverese resistance (Rinv) when the valve regurgitation is simulated.