抄録
In this paper are reviewed several different methods for detecting partial obstruction of peripheral airways appearing in the early stage of obstructive lung disease. The first method is based on the detection of abnormality in gas exchange efficiency by means of the analysis of arterial blood and expired gas. The methods involved in the second group are based on uneven distribution of mechanical time constants in the lungs ; one of which is related to the frequency-dependency of pulmonary resistance and compliance ; another, to the Pendelluft appearing at the airflow interruption ; another, to the phase difference between the alveolar pressure and airflow ; and still another, to the pattern analysis of the flow-volume curve. Two methods involved in the third group are based on uneven distribution of gas components in the lungs ; one deals with the classical N2-clearance curve of Fowlers, and the other, with the measurement of “closing volume” which has recently been developed. Theoretical ground and applicability of these methods have been discussed on the basis of the clinical data.
