Hardware support of volumetric calibration of impedance pneumogram

Failure to determine volumetric lung ventilation parameters is a limitation of impedance pneumography. The purpose of the study is to develop hardware and software for volumetric calibration of an impedance pneumograph and to assess the errors of methods in the measurement of breathing volume in healthy individuals and in patients with bronchial asthma (BA). A personal computer-based Respicard 1.2 hardware complex is described. The improved calibrating algorithm that ensures a 1.5-fold decrease in errors. The calibration coefficient was 1.41 +/- 0.13 l/ohm in healthy individuals and 1.13 +/- 0.07 l/ohm in patients with bronchial asthma. The relative errors of breathing volume measurement was 6.1 +/- 0.6 and 12.0 +/- 1.0%, respectively (p < 0.01). It has been concluded that it is expedient to use the developed hardware complex for monitoring the respiratory pattern.