Authors:
Marcel Młyńczak
1
and
Gerard Cybulski
1
;
2
Affiliations:
1
Warsaw University of Technology, Poland
;
2
Mossakowski Medical Research Centre, Polish Academy of Sciences, Poland
Keyword(s):
Ambulatory Monitoring, Impedance Pneumography, Cardiorespiratory Activity, Decomposition.
Abstract:
Impedance pneumography (IP) measures changes of thoracic electrical impedance connected with change of
the air volume in the lungs. The electrode configuration used in IP applications causes that electrical heart
activity is visible in the IP signals. The aim of this paper is to assess the opportunity to decompose both respiratory
and cardiac components and its quality using various methods. Ten students performed static breathing
sequences, intended both for calibration and testing. Our prototype, Pneumonitor 2, and the reference pneumotachometer,
were used. The accuracy of calculating tidal volume and heart rate, the calibration procedure
and the time of analysis, were considered. Mean 86.5% accuracy of tidal volume calculating and only 2.7%
error of heart rate estimation were obtained using moving average smoothing filters, for simple short recording
of free breathing calibration procedure, in three body positions. More sophisticated adaptive filtering also
provided good accuracy,
however the processing time was 100-times higher, compared to simple methods.
It seems impedance pneumography, without ECG, could be enough for measuring basic cardiorespiratory
activity, particularly during ambulatory recordings, in which the least disturbing equipment is desirable.
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