SPECIAL COMMUNICATIONS A simplified method for determination of residual lung volumes

WILMORE, JACK H. A simpl$ed method for determination of residual lung volumes. J. Appl. Physiol. 27(l): 96-100. 1969.-An attempt has been made to develop a method for obtaining an indirect estimate of residual lung volume which is valid and reproducible and which minimizes the time needed for duplicate determinations on a single subject. The proposed method is basically a modifica-tion of the closed-circuit oxygen-dilution method reported by Lundsgaard and Van Slyke in 19 18. It was compared with the open-circuit method on a sample of 20 normal and healthy sub-jects with a resulting intercorrelation of r = 0.958 and a mean difference of only 26 ml. The reproducibility of this method was established on a sample of 195 males with a test-retest correlation of 0.993 and a standard error of measurement of 28 ml, and on a sample of 102 females with a correlation of 0.987 and a standard error of measurement of 30 ml. The proposed method, in additio