A possibility to use respiratory noises for detecting diver and monitoring his physiologic status

• Published in: The Journal of the Acoustical Society of America 2014-04, Vol.135 (4_Supplement), p.2303-2303
• Main Authors: Gorovoy, Sergei, Korenbaum, Vladimir, Tagiltcev, Aleksandr, Kostiv, Anatoly, Borodin, Aleksey, Pochekutova, Irina, Vasilistov, Aleksey, Krupenkov, Aleksandr, Vlasov, Denis, Shiryaev, Anton
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4877584

The objective is acoustic detection of submerged diver and monitoring his physiologic condition. A possibility to use diver's own respiratory noises for this aim is analyzed. Respiratory noises were recorded above trachea of submerged scuba diver and in the water layer of shallow-water bay. Both signals contain quasi-periodic components induced by amplitude modulation of wideband respiratory noises with the rate of breathing maneuvers. These components are detected in water layer by means of energy processing of single hydrophone response (in a frequency band of 200–500 Hz) at the distances up to 50 m. The breathing rate is estimated by means of spectral transform of the signal envelope. It is well known that this index represents human individual physiologic status. Thus, it is pertinent for submerged diver's condition monitoring. The quasi-periodic components if detected may be used to estimate time delays in responses of several hydrophones, for example, by means of the signal envelopes correlation processing. These time delays are pertinent to find diver's location by triangulation technique.