title: [Influence of changed gas media on acoustic parameters of human forced exhalation].
abstract: 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.
authors.forename: A I
authors.initials: AI
authors.lastname: D'iachenko
authors.forename: V I
authors.initials: VI
authors.lastname: Korenbaum
authors.forename: Iu A
authors.initials: IuA
authors.lastname: Shulagin
authors.forename: A A
authors.initials: AA
authors.lastname: Osipova
authors.forename: A N
authors.initials: AN
authors.lastname: Mikhaĭlovskaia
authors.forename: Iu A
authors.initials: IuA
authors.lastname: Popova
authors.forename: E V
authors.initials: EV
authors.lastname: Kir'ianova
authors.forename: A E
authors.initials: AE
authors.lastname: Kostiv
authors.forename: E S
authors.initials: ES
authors.lastname: Mokerova
authors.forename: S N
authors.initials: SN
authors.lastname: Shin
authors.forename: I A
authors.initials: IA
authors.lastname: Pochekutova
mesh_terms: D000162:Acoustics; D000328:Adult; D000388:Air; D004242:Diving / Q000502:physiology*; D045853:Exhalation / Q000502:physiology*; D006371:Helium; D006801:Humans; D007726:Krypton; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010100:Oxygen; D011312:Pressure; D012119:Respiration
chemical_list: D006371:Helium; D007726:Krypton; D010100:Oxygen