Influence of changed gas media on acoustic parameters of human forced exhalation].

In previous study it was shown that duration of tracheal forced expiratory noises is promising to reveal negative changes of lung function after dive. The objective is a study of parameters of tracheal forced expiratory noises in changed gas media. The first experiment involved 25 volunteers (22-60 years), performed forced exhalation under normal pressure with air, oxygen-helium and oxygen-krypton mixtures. The second experiment in the chamber involved 6 volunteers (25-46 years), which performed forced exhalation with air under normal pressure (0.1 MPa), and under elevated pressure 0.263 MPa with air and oxygen-helium mixture. In the first experiment the direct linear dependence on gas density was found for forced expiratory noises common duration in the band of 200-2000 Hz and for its durations in narrow 200-Hz bands, excluding high frequency range 1400-2000 Hz. In the second experiment a significant reversed dependence of high frequency durations and spectral energies in 200-Hz bands (1600-2000 Hz) on adiabatic gas compressibility. Individual dynamics of common duration of tracheal forced expiratory noises under model dive of 16.3 m (0.263 MPa) is more then the diagnostic threshold of this parameter for lung function decrease, previously obtained for divers under normal pressure.

Citation

A I D'iachenko, V I Korenbaum, Iu A Shulagin, A A Osipova, A N Mikhaĭlovskaia, Iu A Popova, E V Kir'ianova, A E Kostiv, E S Mokerova, S N Shin, I A Pochekutova. Influence of changed gas media on acoustic parameters of human forced exhalation]. Fiziologiia cheloveka. 2012 Jan-Feb;38(1):92-8

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PMID: 22567842

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