{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T22:58:04Z","timestamp":1777503484106,"version":"3.51.4"},"reference-count":29,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2017,6,9]],"date-time":"2017-06-09T00:00:00Z","timestamp":1496966400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Drowning is the major cause of death in self-contained underwater breathing apparatus (SCUBA) diving. This study proposes an embedded system with a live and light-weight algorithm which detects the breathing of divers through the analysis of the intermediate pressure (IP) signal of the SCUBA regulator. A system composed mainly of two pressure sensors and a low-power microcontroller was designed and programmed to record the pressure sensors signals and provide alarms in absence of breathing. An algorithm was developed to analyze the signals and identify inhalation events of the diver. A waterproof case was built to accommodate the system and was tested up to a depth of 25 m in a pressure chamber. To validate the system in the real environment, a series of dives with two different types of workload requiring different ranges of breathing frequencies were planned. Eight professional SCUBA divers volunteered to dive with the system to collect their IP data in order to participate to validation trials. The subjects underwent two dives, each of 52 min on average and a maximum depth of 7 m. The algorithm was optimized for the collected dataset and proved a sensitivity of inhalation detection of 97.5% and a total number of 275 false positives (FP) over a total recording time of 13.9 h. The detection algorithm presents a maximum delay of 5.2 s and requires only 800 bytes of random-access memory (RAM). The results were compared against the analysis of video records of the dives by two blinded observers and proved a sensitivity of 97.6% on the data set. The design includes a buzzer to provide audible alarms to accompanying dive buddies which will be triggered in case of degraded health conditions such as near drowning (absence of breathing), hyperventilation (breathing frequency too high) and skip-breathing (breathing frequency too low) measured by the improper breathing frequency. The system also measures the IP at rest before the dive and indicates with flashing light-emitting diodes and audible alarm the regulator malfunctions due to high or low IP that may cause fatal accidents during the dive by preventing natural breathing. It is also planned to relay the alarm signal to underwater and surface rescue authorities by means of acoustic communication.<\/jats:p>","DOI":"10.3390\/s17061349","type":"journal-article","created":{"date-parts":[[2017,6,9]],"date-time":"2017-06-09T10:29:59Z","timestamp":1497004199000},"page":"1349","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Design and Validation of a Breathing Detection System for Scuba Divers"],"prefix":"10.3390","volume":"17","author":[{"given":"Corentin","family":"Altepe","sequence":"first","affiliation":[{"name":"Bogazici Underwater Research Center, Yavuzturk Sk. 32\/1 Altiyol, 34716 Istanbul, Turkey"},{"name":"Information Engineering Department, Marche Polytechnic University, Via Brecce Bianche 12, 60131 Ancona, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S.","family":"Egi","sequence":"additional","affiliation":[{"name":"Computer Engineering Department, Galatasaray University, Ciragan Cad. 36 Ortakoy, 34349 Istanbul, Turkey"},{"name":"DAN Europe Research Division, Contada Padune 11, 64026 Roseto degli Abruzzi, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tamer","family":"Ozyigit","sequence":"additional","affiliation":[{"name":"Computer Engineering Department, Galatasaray University, Ciragan Cad. 36 Ortakoy, 34349 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D.","family":"Sinoplu","sequence":"additional","affiliation":[{"name":"Bogazici Underwater Research Center, Yavuzturk Sk. 32\/1 Altiyol, 34716 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alessandro","family":"Marroni","sequence":"additional","affiliation":[{"name":"DAN Europe Research Division, Contada Padune 11, 64026 Roseto degli Abruzzi, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1436-8864","authenticated-orcid":false,"given":"Paola","family":"Pierleoni","sequence":"additional","affiliation":[{"name":"Information Engineering Department, Marche Polytechnic University, Via Brecce Bianche 12, 60131 Ancona, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,6,9]]},"reference":[{"key":"ref_1","unstructured":"Diving Equipment and Marketing Association (DEMA) (2014). Fast Facts: Recreational Scuba Diving and Snorkeling, DEMA."},{"key":"ref_2","unstructured":"Buzzacott, P. (2016). Annual Diving Report\u2014A Report on 2014 Data on Diving Fatalities, Injuries, and Incidents, Divers Alert Network. Technical Report."},{"key":"ref_3","unstructured":"Trout, B.M., Caruso, J.L., Nelson, C., Denoble, P.J., Nord, D.A., Chimiak, J., Martina, S.D., Nochetto, M., Pollock, N.W., and Lippmann, J. (2015). Annual Diving Report\u2014A Report on 2010\u20132013 Data on Diving Fatalities, Injuries, and Incidents, Divers Alert Network. Technical Report."},{"key":"ref_4","unstructured":"Naval Sea Systems Command (2016). U.S. Navy Diving Manual, Direction of commander, Naval Sea Systems Command. Revision 7."},{"key":"ref_5","unstructured":"Monitoring Sub-Committee of Diving Medical Advisory Committee (1979). In-Water Diver Monitoring, Monitoring Sub-Committee of Diving Medical Advisory Committee. Technical Report."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Kynor, B., and David, A.E.W. (2011). Diver Health Monitoring System, Creare LLC.","DOI":"10.21236\/ADA550401"},{"key":"ref_7","unstructured":"Unnikrishna Menon, K.A., Shibina, J.S., and Menon, V.N. (2014, January 11\u201313). Intelligent system for remote health monitoring of divers using underwater acoustic communication. Proceedings of the Fifth International Conference on Computing, Communications and Networking Technologies (ICCCNT), Hefei, China."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Cibis, T., Groh, B.H., Gatermann, H., Leutheuser, H., and Eskofier, B.M. (2015, January 25\u201329). Wearable real-time ecg monitoring with emergency alert system for scuba diving. Proceedings of the 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Milan, Italy.","DOI":"10.1109\/EMBC.2015.7319777"},{"key":"ref_9","first-page":"50","article-title":"A four-channel ultrasonic telemetry system for obtaining physiological data from ocean divers","volume":"1","author":"Fell","year":"1974","journal-title":"Biotelemetry"},{"key":"ref_10","first-page":"99","article-title":"Acoustic telemetry from human divers","volume":"1","author":"Kanwisher","year":"1974","journal-title":"Undersea Biomed. Res."},{"key":"ref_11","unstructured":"Pieri, M., Cialoni, D., and Marroni, A. (2016). Continuous Real-Time Monitoring and Recording of Glycemia during Scuba Diving: Pilot Study, Undersea & Hyperbaric Medical Society."},{"key":"ref_12","first-page":"11","article-title":"Heart rate responses of scuba divers via ultrasonic telemetry","volume":"2","author":"Gooden","year":"1975","journal-title":"Undersea Biomed. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1134\/S1028334X16020136","article-title":"The possibility of passive acoustic monitoring of a Scuba Diver","volume":"466","author":"Korenbaum","year":"2016","journal-title":"Dokl. Earth Sci."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Sharma, N.S., Yakubovskiy, A.M., and Zimmerman, M.J. (2013, January 12\u201314). SCUBA diver detection and classification in active and passive sonars\u2014A unified approach. Proceedings of the 2013 IEEE International Conference on Technologies for Homeland Security (HST), Waltham, MA, USA.","DOI":"10.1109\/THS.2013.6698998"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Donskoy, D., Imas, L., Yen, T., Sedunov, N., Tsionskiy, M., and Sedunov, A. (2008, January 7\u201310). Turbulence-Induced Acoustic Emission of SCUBA Breathing Apparatus. Proceedings of the 18th International Symposium on Nonlinear Acoustics Nonlinear Acoustics\u2014Fundamentals and Applications, Stockholm, Sweden.","DOI":"10.1063\/1.2956311"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Donskoy, D.M., Sedunov, N.A., Sedunov, A.N., and Tsionskiy, M.A. (2008, January 16). Variability of SCUBA diver\u2019s acoustic emission. Proceedings of the Optics and Photonics in Global Homeland Security IV, Orlando, FL, USA.","DOI":"10.1117\/12.783500"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1016\/j.neunet.2016.03.004","article-title":"Pattern recognition for electroencephalographic signals based on continuous neural networks","volume":"79","author":"Chairez","year":"2016","journal-title":"Neural Netw."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1137","DOI":"10.1007\/s11517-015-1443-z","article-title":"A novel approach for SEMG signal classification with adaptive local binary patterns","volume":"54","author":"Kaya","year":"2016","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.euromechsol.2017.01.007","article-title":"A pattern recognition system based on acoustic signals for fault detection on composite materials","volume":"64","author":"Fontana","year":"2017","journal-title":"Eur. J. Mech. A Solids"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Altepe, C., Egi, S.M., Ozyigit, T., and Pierleoni, P. (2016, January 21). Nerites-Underwater Monitoring System of Diver\u2019s Respiration and Regulator Performance using Intermediate Pressure Signal. Proceedings of the 9th International Joint Conference on Biomedical Engineering Systems and Technologies, Rome, Italy.","DOI":"10.5220\/0005646601190124"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1016\/j.jneumeth.2008.10.010","article-title":"Performance metrics for the accurate characterisation of interictal spike detection algorithms","volume":"177","author":"Casson","year":"2009","journal-title":"J. Neurosci. Methods"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1002\/wcm.654","article-title":"Prospects and problems of wireless communication for underwater sensor networks","volume":"8","author":"Liu","year":"2008","journal-title":"Wirel. Commun. Mob. Comput."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1109\/MCOM.2015.7321970","article-title":"Realizing Underwater Communication through Magnetic Induction","volume":"53","author":"Akyildiz","year":"2015","journal-title":"IEEE Commun. Mag."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1002\/ecj.11617","article-title":"Research and Development on Underwater Visible Light Communication Systems","volume":"98","author":"Uema","year":"2015","journal-title":"Electron. Commun. Jpn."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1109\/MCOM.2009.4752682","article-title":"Underwater acoustic communication channels: Propagation models and statistical characterization","volume":"47","author":"Stojanovic","year":"2009","journal-title":"IEEE Commun. Mag."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.adhoc.2016.02.016","article-title":"SoftWater: Software-defined networking for next-generation underwater communication systems","volume":"46","author":"Akyildiz","year":"2016","journal-title":"Ad Hoc Netw."},{"key":"ref_27","unstructured":"Song, Y., Tong, Z., Cong, B., Yu, X., Kong, M., and Lin, A. (2015, January 25\u201327). A Combined Radio and Underwater Wireless Optical Communication System based on Buoys. Proceedings of the 8th International Conference on Advanced Infocomm Technology, Hangzhou, China."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Laurino, M., Guerriero, L., Allegrini, P., Menicucci, D., Mastorci, F., Magrin, D., Allotta, B., Bedini, R., and Gemignani, A. (2015, January 25\u201329). Psycho-physiological tele-monitoring of human operators in commercial diving: The Life Support System in the SUONO project. Proceedings of the 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Milan, Italy.","DOI":"10.1109\/EMBC.2015.7318333"},{"key":"ref_29","unstructured":"Murat Egi, S., Altepe, C., and Ozyigit, T. (2015). Scuba diving breathing and open-circuit regulator performance monitoring, warning and alarm system. (Application No. 2015\/08200), Turkey Patent."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/6\/1349\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:38:34Z","timestamp":1760207914000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/6\/1349"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,6,9]]},"references-count":29,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2017,6]]}},"alternative-id":["s17061349"],"URL":"https:\/\/doi.org\/10.3390\/s17061349","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,6,9]]}}}