Lumped parameter model for the dynamics of the pulmonary circulation

The pulmonary circulation is a low pressure system such that respiration has an important effect on pulmonary hemodynamics and has to be taken into account when predicting its behavior. Most models of circulatory dynamics rely on phasor methods which provide useful parameters such as characteristic impedance, compliance, etc., however, these models can only describe the pulmonary circulation during specific phases of the respiratory cycle. In this study the authors model the entire canine pulmonary circulation, including respiratory effects, with an hydraulic analog under open chest conditions. The lumped parameter model consists of a single compartment. The airway pressure and the right ventricle are considered as two independent power sources and the dynamics of the pulmonary valve are also included.