title: [Fatigue and performance of divers during a simulated, non-saturated oxygen-helium dive to 180 meters].
abstract: A non-saturated mixed-gas dive to 180 meters depth was carried out at JAMSTEC, using diving simulator (hyperbaric chamber) facilities. Compression started at 10:00 h with helium and oxygen and was carried out at a rate of 12 m/min. Decompression started at 11:15 h using the Comex Helox 180 Diving Manual. Decompression to 1 ATA required 49.2 h. A survey of subjective symptoms, sleep feelings and ball-bearing tests were performed. All night electrophysiological recording of subjects' sleep was performed and polygraphic analysis of nocturnal sleep was done with visual scoring. The results were as follows: Arriving at 180 meters, the complaint rate was 39.2% and fatigue was greater. The type of fatigue that was based on the composition + ratio of symptoms was that of mental fatigue. During the decompression it was recovery. The performance in the ball-bearing test decreased about 20% at a depth of 180 meters because of tremors and disturbance of attention as well as other factors showing symptoms of high-pressure nervous syndrome. The sleep feelings were different in experienced persons and non-experienced persons. The non-experienced persons had markedly decreased REM stages and slept badly all night. Based on these results, fatigue and the performance of divers were discussed.
authors.affiliation: Japan Marine Science and Technology Center, Yokosuka.
authors.forename: M
authors.initials: M
authors.lastname: Mohri
mesh_terms: D000328:Adult; D004242:Diving / Q000009:adverse effects*; D005221:Fatigue / Q000209:etiology*; D006801:Humans; D008297:Male; D009784:Occupational Diseases / Q000523:psychology*; D012893:Sleep Wake Disorders / Q000209:etiology*; D013647:Task Performance and Analysis