Automatic Correction for the Effects of Changing Gas Viscosity in Pneumotachographic Measurements
Pneumotachography is still one of the most exact methods of measuring respiratory flow rate and volume. Changes in the measured pressure difference of the pneumotachograph are due to changes in gas flow as well as gas viscosity. Therefore, for exact flow measurements, the calibration of the pneumotachograph must be perfored under the same conditions (i.e. same gas mixture and same gas temperature) as during the measurement. In the present paper, a method for automatic continuous calibration of the pneumotachograph during measurements with changing gas composition is described and tested for reproducibility and accuracy.
KeywordsCalibration System Automatic Correction Volume Reading Multiple Breath Exact Flow
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