[The present situation and the future prospect of pulmonary function test].
We described 6 points of the present situation and the future prospect of pulmonary function tests. The pulmonary function test using different equipment on the same subject gave different results. The results of the pulmonary function test were affected by the subject's efforts. There were no standard prediction equations. Normal subjects and patients with respiratory disease reached the limit of exercise tolerance when the ratio of tidal volume during exercise to vital capacity (VT/VC ratio) approached 50%. Respiratory rehabilitation was evaluated by pulmonary function tests. The development of equipment allowing measurement by subject's quiet breathing is awaited.