Performance Effects Of Increased Ambient Pressure. 1. Helium-Oxygen Saturation And Excursion Dive To A Simulated Depth Of 900 Feet.

Abstract

Two experienced commercial divers were administered an addition, a letter-cancellation and a form perception test before, at selected intervals, during, and after a simulated helium-oxygen dive to a saturation depth of 600 feet with excursions to 800 and 900 feet (total dive time 143 hours). Apart from vague joint and muscle sensations reported by means of a subjective checklist, the slow descent to 600 feet was uneventful. Slightly porrer performance in addition letter-cancellation and form perception was seen at 800 feet as were symptoms resembling the so-called helium tremors. No remarkable changes in the test profiles were observed during the implementation of a conservative (15 minute/foot) decompression schedule, though obscure knee pains in one diver persisted to the 'surface' but with no untoward sequelae. Suggestions for improving experimentation aimed at an assessment of the performance effects of hyperbaric conditions are provided. (Author)