A method for measuring airway resistance in man

　The pulmonary airway resistance wasmeasured by a newly modified method ofthe body plethysmograph．　The principle whichunderlies this method is to compare thepulmonary resistance with a known artificialresistance inserted between pneumotachographand mouth-piece．　Through this lnethod thethoracic gas volume could also be obtainedbesides resistance by calibrating airflow andbox-pressure．

　There were observed a correlation betweenpulmonary resistance and lung volume：Theformer decreased linearly as the lung volumeincreased．The resistances and lung volumeswere measured at 27°and 37℃　of the box—temperatures；the　higher　resistances　andsrnaller lqng volumes were obtained at 27℃than at 37℃．

　The author wishes to express his thanks to Dr．Ishitani, Mrs．　Koyama and Kabashima for theircordial assistances in the course of the measurements．