The decay of thoracic gas volume during forced expiration

The MEFV curve has been analysed for the mechanical time constant distribution through the lungs, and it has been transformed into the forced decay of the thoracic gas volume (FVtD). The best regression formula to express the FVtD was the exponential in respect to the linear one, and this difference was statistically significant only in asthmatic patients. It seems likely that the FVtD will prove to be useful for detecting, already in the simple routine functional investigation, the airways obstruction due to asthma as interlobular inhomogeneity of ventilation.