N₂ exchanges in hyperbaric environments: toward a model based on physiological gas transport (O₂ and CO₂)

Area of Science:

• Physiological modeling
• Diving medicine
• Inert gas exchange

Background:

• Decompression sickness risks persist despite following standard procedures.
• Individual physiological variations significantly impact gas bubble formation during dives.
• Current decompression protocols lack personalization, necessitating improved approaches.

Purpose of the Study:

• To develop a foundational framework for a novel inert gas exchange model.
• To create a physiological model for oxygen delivery, adaptable to nitrogen.
• To enable personalized decompression strategies in SCUBA diving.

Main Methods:

• A physiological model for oxygen (O2) delivery was constructed and adapted for nitrogen (N2).
• Model validation involved transposing the N2 model to carbon dioxide (CO2) and comparing with physiological data.
• The O2 model was validated under normobaric and hyperbaric conditions against reference Po2 values.

Main Results:

• The O2 model accurately replicated reference physiological Po2 under various conditions (Spearman correlation, P < 0.001).
• The transposed CO2 model showed strong agreement with physiological reference values (Spearman correlation, P < 0.01), confirming model plausibility.
• While N2 model simulation is possible, direct validation is pending due to lack of reference data.

Conclusions:

• The validated CO2 model, derived from the N2 model, demonstrates the plausibility of the physiological inert gas exchange framework.
• This model allows integration of diverse physiological and morphological parameters for personalized N2 saturation/desaturation.
• It paves the way for individualized decompression procedures in SCUBA diving, enhancing safety.