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Model

OpenDeco linear-tolerance dissolved gas compartment model, 1.0.0

This record describes OpenDeco linear-tolerance dissolved gas compartment model, version 1.0.0, implemented as opendeco-reference-models 1.0.0, in-process Python adapter 1.0.0 using configuration linear_tolerance_compartment_synthetic_v1 1.0.0. Any reported result applies to this exact implementation and configuration.

CautionEvery empirical value this model uses is synthetic

They were chosen, and they were not measured, fitted or transcribed. No output of this model on those parameters describes any real exposure.

Identity

A family name does not identify the coefficients, the algorithm version, the ascent constraints, the gas handling or the software behaviour behind a number. OpenDeco records those layers separately, and a benchmark result attaches to the bottom of the stack, never to the name at the top.

Family
OpenDeco linear-tolerance dissolved gas compartment model
Version
1.0.0
Implementation
opendeco-reference-models 1.0.0, in-process Python adapter 1.0.0
Configuration
linear_tolerance_compartment_synthetic_v1 1.0.0
Aliases
Does not exist for this sourceThe adapter declares no alternative name.
First publication
Does not exist for this sourceNo public record is available for this field.
Ownership
OpenDeco
Openness
Open source implementation
Model class basis
Assigned from the adapter's declared family name. No model family record exists in the registry yet.

Source and lineage

It wraps no external implementation, transcribes no published parameter table, and is named for the shape of its tolerance rule instead of any published model family.

No BIG292 lineage assessment has been recorded for this model version. The flag no known BIG292 training would say that somebody looked and found nothing, and it requires a named evidence basis that this record does not have.

BIG292 lineage flag
Unknown
Lineage evidence basis
Not yet obtainedNo search for a BIG292 development relationship has been run and recorded for this model version.
Derived from
Does not exist for this sourceThe model version derives from no parent model version, so no lineage flag is inherited.
Performance class
Unknown lineage

Implementation

OpenDeco can inspect and version the implementation used for this record.

This adapter claims agreement only to its declared tolerance, and the numerical method is a closed-form solution of the linear first-order uptake equation per segment, an affine tolerance rule inverted in closed form for the ascent ceiling, and a fixed-step scan followed by bisection for the no-decompression limit.

Implementation type
Open source
Adapter pattern
In-process Python
Adapter version
1.0.0
Trust classification
OpenDeco authored
Determinism
Deterministic within a declared tolerance
Declared relative tolerance
1e-9
Declared absolute tolerance
0.0012Pa
Minimum ambient pressure
20,000Pa
Maximum ambient pressure
1,200,000Pa
Schedule generation
Not supported
Native probability output
Does not exist for this sourceThe adapter produces no probability, so no risk metric may be computed from it.
Licence
Apache-2.0
  • profile_replay
  • ndl_generation
  • ceiling
  • tissue_state
  • repetitive_state
  • gas_switching
  • altitude
  • helium
Verification evidence recorded against this implementation under the verification protocol.
EvidenceKindWhat it checks
linear_tolerance_closed_form_v1unit_test_suiteThe per-segment uptake solution agrees with an independently written closed-form expression, and the inverted ceiling agrees with the forward tolerance rule.
linear_tolerance_properties_v1property_test_suitethe verification protocol invariants hold under generated inputs, including monotonic loading, no crossing of the inspired partial pressure, and segment splitting reproducing the undivided segment.
linear_tolerance_state_round_trip_v1state_round_trip_testSerialised state round-trips to an identical tissue state.
linear_tolerance_invalid_input_v1invalid_input_testMalformed profiles, out-of-range gas fractions and pressures outside the declared range raise typed adapter errors instead of returning a value.

Configuration

The parameter set carries four compartments, each with a nitrogen half-time, a nitrogen tolerance intercept and slope, and the matching helium coefficients. The tolerance rule is affine in absolute ambient pressure: the tolerated inert tension is an intercept plus a slope times ambient pressure, modified by a gradient factor. It is not an M-value and it carries no equivalence claim to any published M-value formulation.

The document declares provenance class synthetic and carries the label SYNTHETIC. Validation refuses a synthetic document that claims a source, and it refuses a document claiming a published source that names none.

Parameter set
linear_tolerance_compartment_synthetic_v1
Parameter set version
1.0.0
Provenance class
Synthetic
Compartments
4
Tracks helium
Yes
Gradient factor rule
Interpolated linearly in absolute ambient pressure between the first-stop reference pressure and the surfacing pressure
Published source
Does not exist for this sourceNo value in this parameter set is taken from, derived from or checked against any published source.

Known calibration data

No dataset was used to develop, calibrate or tune this model version, because no dataset was used at all.

The repository records three open parameter gaps for this model. Each names the kind of source that must supply a real value and what that source has to state beyond the numbers. None names a work, an author, an identifier or a year, because inventing a citation is worse than recording an open gap.

Parameter groups that still need a real source, and what that source has to be.
Parameter groupRequired source kindParameter keys
compartment_halftimesPeer-reviewed primary publicationnitrogen_halftime_s, helium_halftime_s
tolerance_coefficientsPeer-reviewed primary publicationnitrogen_tolerance_intercept_pa, nitrogen_tolerance_slope_ratio, helium_tolerance_intercept_pa, helium_tolerance_slope_ratio
gradient_factor_defaultsManufacturer technical documentationgradient_factor_low_ratio, gradient_factor_high_ratio

Benchmark results

Not applicable at this stage

No released benchmark result is attached to this model record.

Sensitivity

Not applicable at this stage

No sensitivity analysis is attached to this model record.

Failure regions

Not applicable at this stage

No failure-region analysis is attached to this model record.

Limitations

  • Every empirical value comes from a parameter set file, and the parameter sets shipped here are synthetic. No output on them describes any real exposure, and the verification level speaks to arithmetic, never to physiological validity.
  • The adapter is not a published decompression model and reproduces none. Its name describes the shape of its tolerance rule.
  • The tolerance rule is affine in absolute ambient pressure. It is not an M-value.
  • The gradient factor interpolation rule is an implementation choice of this adapter and reproduces no published gradient factor algorithm.
  • In a compartment carrying both inert gases the tolerance coefficients are weighted by each gas's share of total inert tension. That combination rule is an implementation choice.
  • The no-decompression limit assumes instantaneous direct ascent to the surfacing pressure and accounts for no ascent time.
  • The no-decompression limit is located by a fixed-step scan and a fixed number of bisection refinements, so a tolerance excursion lying entirely between two scan points goes undetected.
  • Oxygen exposure, bubble dynamics, workload, temperature and subject covariates are not modelled and are ignored if supplied.
  • Alveolar water vapour pressure is a required parameter with no default, because published conventions differ and this adapter asserts none of them.

Reproducibility

The configuration digest below identifies the exact parameter values a run used, and a different digest means a different model.

They pin adapter behaviour between commits and they are not cited here as a result.

Licence
Apache-2.0
Release identifier
Not applicable at this stageNo OpenDeco release includes this implementation yet.

Verification level

Level
V1 Sanity checked
What the level means
Basic known profiles and invariants pass.
Evidence records
4

Development-data lineage

Flag
Unknown
Performance class
Unknown lineage

Content addressing

Parameter set digest, SHA-256
5153a6918ff9aed49177b356a9257a6516f4edaa9b6d24a5a65409337ed5e075The canonical serialisation of the parameter set document under the content-addressing contract, excluding the recorded hash field.

Elsewhere