[Report of a trial of polyfrequent oscillo-resistometry with the custo vit equipment].

With the aim of determining the significance of the principle of the multi-frequency forced oscillation technique employed by the custo vit to determine the airway resistance, measurements were performed on a number of test subjects, employing a unit available with three different software modifications. A comparison with the resistance values obtained with other equipment (whole-body plethysmograph, Siregnost FD5), revealed the diagnostic usefulness of the technique of frequency-dependent resistance. It was also confirmed that the phase angles, also obtainable with the custo vit, play a considerable role in the significant differentiation of the degree of obstruction. The differences in comparison with other methods are critically examined, and proposals made for a further improvement of the forced oscillation technique employed by the custo vit.