Abstract
Human mental performance was studied in eleven simulated dives. Results showed that in oxyhelium mental abilities were impaired by about 15 % at 300 msw. Impairments were greater with greater depths, and performance at 540 msw was impaired by as much as 80% in some cases. These results could not be explained by sleep loss or mood changes, the time of day or by long periods spent in a cramped environment. One dive to 660 msw investigated claims that TRIMIX (helium, oxygen and nitrogen) may prove beneficial. However in this dive performance was worse than that found in oxyhelium at equivalent depths. One other ‘control’ dive involved a maximum depth of 61 msw in oxynitrogen, where the partial pressures of these gases were identical to those in the deep TRIMIX dive. Results suggested that the results with TRIMIX were not due to the partial pressure of nitrogen, but to an interaction between the gas mixture and overall pressure. Performance impairments at 55-60 msw in oxynitrogen are of the same order as those found at 300 msw in oxyhelium. These results have important implications for maximising the safety of human divers in an extremely hazardous environment.
Original language | English |
---|---|
Title of host publication | Progress in Underwater Science |
Editors | J.W.P. Leach |
Place of Publication | Margate, Kent |
Publisher | The Underwater Association |
Pages | 137-158 |
Volume | 12 |
Publication status | Published - 1987 |