Measurement of ventilation using digitally filtered transthoracic impedance

Autor: L. H. Hamilton, P. E. Newton, Hubert V. Forster
Rok vydání: 1983
Předmět:
Zdroj: Journal of Applied Physiology. 54:1161-1166
ISSN: 1522-1601
8750-7587
DOI: 10.1152/jappl.1983.54.4.1161
Popis: A seven-stage low-pass digital filter was used to remove the cardiac artifact and motion interference from a respiratory transthoracic impedance signal in human subjects. After removal of these artifacts, the mean difference from a conventional gasometer technique fell from 5% to 1.6%. When the impedance technique was used to measure ventilation during air breathing, the addition of a breathing valve with a mouthpiece and noseclip induced the following changes in ventilatory parameters: 7% drop in frequency, 24% increase in tidal volume, 49% increase in inspiratory time, 56% increase in expiratory time, 10% decrease in inspiratory flow rate, and 4% decrease in ratio of respiratory time to total breath duration. These alterations were not significant at elevated inspired CO2 levels. The digitally filtered transthoracic impedance technique provides an accurate technique for measuring ventilatory parameters without the perturbations induced by using a conventional breathing valve technique even when cardiac and motion artifacts were prominent.
Databáze: OpenAIRE