Evaluation of different decompression schedules by an agarose gel bubble technique

It is well known that diving decompression schedules vary according to country and that Navy schedules are often different from civilian ones. Furthermore, it is difficult to compare them effectively, because the bends incidence for each schedule is rarely known accurately. We have evaluated various decompression schedules by an agarose gel bubble technique in which the appearance of bubbles in a dry chamber at a controlled temperature was used, and we report this as a useful method of evaluating decompression tables. It is generally accepted that decompression sickness symptoms are due to bubble formation and the body's subsequent physiological reaction. Individual differences and physical conditions are also influential factors. However, bubble formation appears to be the most important factor in initiating symptoms. As the number of bubbles is influenced by the physical decompression ratio, it can be estimated which decompression schedule is more likely to minimize the number of bubbles. Nine decompression schedules were studied in this experiment: U.S. Navy Table, French Navy Table, Japanese Standard Decompression Schedule Numbers 1 and 2, Royal Naval Physiological Laboratory Table, French Ministry of Labor Table, Model 1 Table by Mano et al., Washington State Table, and Blackpool Table.