Variations in the Vital-Capacity Measurement in Patients with Bronchial Asthma and Pulmonary Emphysema

ACCORDING to Myers1 the earliest attempt to determine the inspiratory lung volume is attributed to Borelli, whose investigations were published in 1679. Subsequent investigators showed the vital capacity to be approximately 200 to 250 cubic inches.2 , 3 Hutchinson4 made a detailed study of the vital capacity of 3000 people and noted that it was influenced by such factors as age, disease, weight and height. Further studies confirmed these correlations, particularly that with surface area.5 , 6 The influence of these factors is shown in various tables of normal vital-capacity measurements.1 It is also well recognized that motivation, training and fatigue influence the accuracy . . .