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A C++ implementation of the Bühlmann ZH-L16C decompression algorithm for simulating tissue gas loading/offloading and calculating decompression obligations. It tracks nitrogen and helium gas partial pressures in 16 tissue compartments during diving operations and calculates safe ascent profiles.

Features:

• Gas uptake/elimination modeling using Haldane and Schreiner equations
• Trimix gas mixture support (O₂/N₂/He)
• M-value ceiling calculations
• Gradient Factors
• Ascent rate-controlled decompression planning

Calculates underlying inert gas pressure in lungs:

Inert gas exchange in haldanian models is assumed to be perfusion limited and can be described by the following ODE:

Saturates tissues with inert gases at the MOD for a predefined bottom time duration. Solves the above ODE for constant$P_{alv}$:

Gradual gas offloading from tissue compartments:

The model is based on the Dalton's Law in combination with Partial Pressuresconstraint optimisation on the pressure limits recommended in theUS Navy Diving Manual (Revision 7, 2020):

• PP02 (21,278 Pa - 141,855 Pa) - to eliminate O2 toxicity under high ambient pressure.
• PPN2 (0 Pa - 354,638 Pa) - to amortise N2 narcotic effect under high ambient pressure.

WARNING:Underlying model assumes no hazardous properties of Helium under high ambient pressures:

• PPHe (0 Pa, ∞ Pa)

./mixture --min=1 --max=10 --interval=0.5 --pressure-unit=ata

• Bühlmann, A.A. (1983). Decompression-Decompression Sickness. Springer-Verlag

• DeeperBlue ZH-L16 Explained

• Dive Friends Bühlmann Implementation

WARNING: USE OF THIS LIBRARY FOR UNDERWATER DIVING MAY CAUSE HEALTH PROBLEMS OR DEATH

The use of this library for underwater diving is strictly prohibited. The calculations and algorithms used in this library are not intended for use in life-critical applications, including underwater diving.

underwater diving is a high-risk activity that can result in serious health problems or death. The use of this library for underwater diving may increase the risk of:

• Decompression sickness (DCS)
• Nitrogen narcosis
• Oxygen toxicity
• Carbon dioxide poisoning
• Other diving-related injuries or illnesses

This library is not designed to provide a safe or reliable means of calculating dive plans or managing gas mixtures for underwater diving. The calculations and algorithms used in this library are based on simplified models and assumptions that may not accurately reflect the complexities of real-world diving scenarios.

The authors and maintainers of this library disclaim any warranty or liability for damages or injuries resulting from the use of this library for underwater diving. By using this library, you release and hold harmless the authors and maintainers of this library from any claims or liabilities arising from the use of this library.