Pulmonary microvascular exchange: an analog computer simulation.

An analog computer simulation of human pulmonary microvascular exchange was programmed and tested. This model of blood-to-lymph transport is based on a compartmental analysis of the lungs and has the capacity to describe fluid volumes, plasma protein content, flows and pressures for both normal and perturbed conditions. Normal conditions were predicted and shown to be in agreement with the literature. The trends in the response of the lungs to changes in microvascular pressure is shown also to agree with the literature both for steady state and transient predictions. The results of a sensitivity analysis, which demonstrates the response of the lungs to a variety of perturbations, is also reported. The simulation predicts reasonable results for normal, transient, and perturbed conditions in human lungs.