Measurement of airway resistance with a volume displacement body plethysmograph

Airway resistance was measured with a volume displacement body plethysmograph in 40 normal subjects breathing at their spontaneous breathing rate. The measurements are based on a method designed by DuBois et al. which was modified in order to extend its applicability. The subjects were rebreathing from a bag containing gas at approximately BTPS conditions. Possible errors in conditioning the gas in the bag were corrected mathematically. The values of airway resistance obtained (1.26 ± .39 cm H2O/liter-1 sec) agree with those published by DuBois et al. and other authors using his technique. The measurements were found to correlate with results obtained on the same subjects with related techniques. The paper also includes measurements of lung tissue viscous resistance and inertance of the gas in the airways. respiratory mechanics; mechanics of breathing; airway inertance; lung tissue viscance Submitted on November 22, 1963