title: [Stability and variation of the maximal ventilation and maximal expiratory volume ratios].
abstract: The level of stability of the ratio (alpha coefficient) of maximal ventilation (MBC) over maximal expiratory volume per second (FEV1) was continued statistically for its practical value in estimating the respiratory functional incapacity. Three observations were made: --the mean value of the alpha coefficient=MBC/FEV1 is independent of the sex, age, size or weight in the normal subject; alpha was slightly higher than that found from theoretical values of MBC (CECA) and FEV1 (BALDWIN and COURNAND); --the alpha coefficient varied with the vital capacity (VC) and with FEV1; --there was a particularly simple relation between alpha and VC: alpha decreased from 38 to 30 when VC increased from 1 to 6 litres.
mesh_terms: D000367:Age Factors; D001827:Body Height; D001835:Body Weight; D005540:Forced Expiratory Flow Rates; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008403:Mass Screening; D008448:Maximal Expiratory Flow Rate; D008451:Maximal Voluntary Ventilation; D008962:Models, Theoretical; D012123:Pulmonary Ventilation; D014797:Vital Capacity
vernacular_title: Stabilité et variation du rapport entre ventilation maximale et VEMS