Study on the time relation of airflow and alveolar pressure

　As a preliminary study on the measure—ment of airway resistance the time relationbetween airflow and box-pressure of the body—plethysmograph was investigated by varyingtemperature and humidity．　From the resultsof experiments it was clarified, that thechanges of the box-pressure got behind thatot the airflow at temperatures lower thanthe body-temperature, but at the body-tem-perature the box-pressure changed similarilyand simultaneQusly with the airflow．

　For the purpose of explaining the aboveexperimental data, the time relation amongalveolar pressure, airflow and others weretheoretically considered．　As the results of itthe following conclusion was obtaned；thephase difference between ventilation volumeand change of the thorax volume is given asthe product of airway resistance and lungvolume, and it may be less than O．005 sec innormal respiration．　The phase differencebetween the airflow and box-pressure of theplethysmograph may be less, than the abovephase difference．

　The writer wishes to express his thanks to ProfessorA．Matsumoto for his invaluable advice and forconstant guidance in the course of the work．　Thanksare also due to Mr．　and Mrs．　Shindo and Mr．　Miurafor their assistances in building up the body plethys—mograph．