[Technical and experimental study of two electronic spirometers (author's transl)].

Two electronic spirometers which use standard pneumotachographs were evaluated for their static and dynamic response, and clinically compared in 20 subjects to a reference flow channel. In the Pneumoscreen the data are digitalized and stored, permitting to play back the flow-volume curves at low or high speed. The instrument provides a direct read-out of forced vital capacity and of five indexes of forced expiration. It was found perfectly adequate with respect to linearity and frequency response. However, due to some systematic error in digital processing, maximum flow at low lung volumes appeared substantially over-estimated. Besides forced vital capacity and a number of indexes of forced expiration, the Medistor type M 010 may be used to measure ventilation, tidal volume, frequency and maximum breathing capacity. The data are processed by an analog computer. The transducer was found poorly linear with inadequate frequency response. However, no systematic bias in the measurements was found, except for peak flow and maximum breathing capacity.