Simulation of gas uptake as an aid to developing a scheme for noninvasively estimating cardiopulmonary parameters

The established methods of measuring cardiac output are invasive and involve a degree of risk to the subject. The authors describe research aimed at developing a convenient, reliable, noninvasive method of estimating pulmonary blood flow and the gas and tissue volumes of the lung. They estimate the parameters of a model describing gas uptake and distribution using measurements of inspired and expired gas volume. In order to compare the effectiveness of candidate parameter estimation techniques it is essential to have available a comprehensive and flexible simulation of the uptake and distribution of inert gases. The authors describe the development of such a simulation and present examples to illustrate its use.<>