Document p2Z7v1rYm3gqmvR4jRVzOk8rk

air flow measurements on human subjects with and with out RESPIRATORY RESISTANCE AT SEVERAL WORK RATES LESLIE SILVERMAN, ScD.flndust. Hyg.) GEORGE LEE THEODORE PLOTKIN, A.B. LEONORE AMORY SAWYERS, A.B. ANO ANNE R. YANCEY, A.B. BOSTON THIS INVESTIGATION was made during the recent war in order to deter mine air flow characteristics of human subjects. Such information is of value in the design of protective respiratory equipment such as gas masks, dust masks and oxygen supply equipment for aviators. It was desired to have these data for several sedentary subjects and for subjects working at several work rates. The effect of inspiratory and expiratory resistance comparable to gas and oxygen masks on the shape of the air flow curve is also essential information for equipment design or ratings. The development of inspiratory and expiratory air flow curves under these conditions makes it possible to design cams for pumps which can simulate various breathing conditions. HISTORICAL REVIEW Expiratory Measurements.--The only data on air flow measurements during expiration are those reported by Bretschger.*1 Other investigators 2 have described methods but present very little information. Most of these measurements were This article is based on work performed for the Office of Scientific Research and Develop ment under contract OEMsr 306. From the Departments of Industrial Hygiene and Physiology, Harvard School of. Public Health, Boston, and the Nutrition Laboratory of the Carnegie Institution of Washington, D. C. 1. Bretschger, H. J.: Die Geschwindigkeitskurve der menschlichen Atemluft (Pneumotachogram). (The Curve-of Velocity of Human Respiratory Air [Pneumotachogram]), Arch. ges. Physiol. 210:134-148, 1925. 2. Hadorn, W.: Ein neues-Pjieumometer zur Bestimmung des Exspirationsstosses (maxi male Ausatmungsstromstarke) (New Pneumometer for Determination of Forced Expiration; Maximum Strength of Expiratory Flow), Schweiz, med. Wchnschr. 72:946-950, 1942. Hamada, T.: Pneumotachographische Studien: fiber den Einfluss der korperlichen Anstrengung auf. das Pneumotachogram (Pneumotachographical Studies^ Effects of Exercise on Pneumotacho gram), Acta scholae med. Univ. imp. Kioto 10:58-64, 1933. Steup, A.: Eine Anordnung zur Messung des Spitzenwertes der Stromgeschwindigkeit der Ausatmungsluft (Apparatus for Measuring Maximum Value of Flow Velocity of Expired Air), Ztschr. ges. exper. Med. 104:576-595, 1938. 461 H ' i