Toward a metrological model of maximal expiration

The purpose of this investigation is to derive a metrological model of maximal expiration characterized by a small amount of independent parameters that can be estimated from experimental data. Elaboration of the model was based on a forward-inverse method. The carried out regression analysis showed good approximation of airway properties by exponential functions with correlation coefficients lower then -0.95. The cross-sectional areas, airway lengths and compliances were replaced by the exponential functions with two parameters. The complex and simplified models for maximal expiration were implemented on a PC and compared. The sensitivity index expressing the effect of parameter reduction was 0.64%. The study showed possibility to reduce the parameters number of the maximal expiration model at least to 18