A model of the pulmonary arterial bed in adults and infants.

A microcomputer model based on an equivalent model of the systemic arterial circulation was used to simulate the pulmonary arterial circulation. The elements chosen to represent the physical properties of the pulmonary arterial bed were determined from the characteristic impedances and tme delays in the system. A terminal resistance that provided a reflection coefficient of 0.56 at a heart rate of 75 min-1 was chosen. The model simulated normal values for pressure and blood velocity in the main pulmonary artery and pulmonary capillary bed of adults and newborn infants. The results indicate that the relatively simple physical principles used to explain systemic hemodynamics are equally applicable to the pulmonary arterial circulation.