Clinical evaluation of the ETOS pneumotachograph

The present study aimed at testing clinically the computerized pneumotachograph ETOS, a joint Bulgarian-Russian manufacture. It was evaluated by comparing its performance with that of a similar pneumotachographic system made by JAEGER, Germany. 20 patients with chronic obstructive pulmonary disease and 21 healthy subjects were enrolled in the study. Each of the pneumotachographs was used first to generate separately enveloped maximal expiratory flow-volume curves. Then, with the machines in series, they were used for the analyses of single forced expirations. The results for linearity, systematic and random errors showed the ETOS pneumotachograph to be reliable for the values of the major forced expiration parameters--FVC, FEV1.0, PEF and MEF50%.