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Detecting respiratory noises of diver equipped with rebreather in water

2016; Acoustical Society of America; Linguagem: Inglês

10.1121/2.0000171

1939-800X

Sergey Gorovoy, В. И. Коренбаум, A.M. Borodin, Alexandr Tagiltcev, А. Е. Костив, Anton Shiryaev, И. А. Почекутова,

Marine animal studies overview

The aim is an analysis of respiratory noises of diver equipped with a closed circuit breathing apparatus (rebreather). The noises were recorded in the shallow-water bay near the suit of the diver equipped with F.R.O.G.S. (Full Range Oxygen Gas System, http://www.aqualung.com) rebreather and at the distance of 3 m (in rest) by bottom located omnidirectional hydrophones. Energy receivers were used for detecting the noise signals in frequency bands of 30-300 Hz. Both hydrophone responses contained evident quasi-periodic components induced by amplitude modulation of wideband respiratory noises with the rate of breathing maneuvers. The breathing rate estimated by means of spectral transform of the envelope was about 0.3 Hz for inspirations and 0.6 Hz for the whole respiratory cycle. The quasi-periodic components with closely located frequencies were also found when the diver moved on fins around the hydrophones. The breathing rate index represents human individual physiologic status. Thus the procedure is pertinent for distant monitoring the breathing rate of submerged divers equipped with F.R.O.G.S. rebreathers as well as with scuba apparatus.