COMPUTATION OF TIME-CONSTANT HISTOGRAMS FROM THE FORCED EXPIRED VOLUME-TIME CURVES / 第二军医大学学报

An efficient BASIC program was established on Apple-Ⅱ microcomputer with the CHESTAC-3EF pulmonary function testing system to calculate the time-constant histogram from the spirogram.By a set of analogue studies, we confirmed that the recovered time-constant histogrgram was within one compartment of the assumed one and that the root of mean square values of the residuals between the experimental and model volume-time curves was 0.02. In four adult healthy subjects, the mean value of time-constant histograms (TCx ) had the variation coefficient (6.6%). The results show that our method is reliable and reproducible, and it can be used for clinical investigation.