Physiological Measurements and Tests of Lung Function

In recent years, many new tests have been developed to assess pulmonary function in man. Here are presented the general principles, methodology, and clinical significance of the major lung function tests used in the diagnosis of obstructive and restrictive lung diseases. Obstructive diseases of the lung 

Four primary lung volumes and capacities are usually measured (Fig. 9). Each capacity includes two or more of the primary volumes. The lung volumes and capacities are defined as follows. 

Tidal volume (TV) The volume of gas inhaled or exhaled with each normal breath. 

Inspiratory reserve volume (IRV) The maximum amount of gas that can be forcefully inspired from the end-inspiratory position in tidal volume. 

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