Iso-risk air no decompression limits after scoring marginal decompression sickness cases as non-events

Area of Science:

• Physiology
• Biophysics
• Aerospace Medicine

Background:

• Decompression sickness (DCS) arises from pressure changes during diving, aviation, or spaceflight.
• DCS symptoms range from joint pain to severe dysfunction and death.
• Probabilistic models predict DCS by analyzing gas dynamics in tissue compartments.

Purpose of the Study:

• To evaluate the impact of coding marginal DCS events as non-events on probabilistic model performance.
• To assess how adjusting marginal DCS event weighting affects air diving no-stop limits.

Main Methods:

• Calibration of probabilistic DCS models using historical exposure data.
• Comparison of model performance with different weightings for marginal DCS cases.
• Analysis of changes in no-stop limits derived from adjusted models.

Main Results:

• Models calibrated with marginal DCS events coded as non-events showed improved performance.
• Derating marginal DCS events impacts model-prescribed air diving no-stop limits.

Conclusions:

• Coding marginal DCS events as non-events enhances the accuracy of probabilistic DCS prediction models.
• Adjusting the treatment of marginal DCS cases is crucial for refining safety guidelines in hyperbaric environments.