Description
Descriptive bench pressure-decay rate and initial-pressure-normalized volume loss proxy, not a compressible leak-orifice model or safety test.
A bench or research calculation starts from supplied measurements, reference values, and unit conventions. A transformed value, timing difference, or support fraction describes that model; its clinical meaning depends on measurement validity and a separate professional assessment.
Descriptive bench pressure-decay rate and initial-pressure-normalized volume loss proxy, not a compressible leak-orifice model or safety test.
When to use this tool
Use it for pulmonary device leak decay term when the required inputs and conventions are already available.
How to use the tool and how it works
- Enter initialGaugePressure, finalGaugePressure, duration, testVolume. Use the stated units and boundary conventions.
- Run the calculation. Correct any input error before interpreting a result.
- Read decayRate, exponentialTimeConstant, linearEquivalentLeak. Inspect any known, defined, inclusion, or boundary flags before interpreting numeric values.
Require initialGaugePressure>finalGaugePressure>0, nonnegative testVolume, and positive duration. Return decayRate=-ln(final/initial)/duration, its reciprocal time constant, and linearEquivalentLeak=testVolume*(initial-final)/(initial*duration).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| initialGaugePressure | Initial Gauge Pressure | Required. Finite number. |
| finalGaugePressure | Final Gauge Pressure | Required. Finite number; strictly above 0. |
| duration | Duration | Required. Finite number; strictly above 0. |
| testVolume | Test Volume | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| decayRate | Decay Rate | Required. Finite number. |
| exponentialTimeConstant | Exponential Time Constant | Required. Finite number. |
| linearEquivalentLeak | Linear Equivalent Leak | Required. Finite number. |
{
"input": {
"initialGaugePressure": 100,
"finalGaugePressure": 50,
"duration": 10,
"testVolume": 2
},
"output": {
"decayRate": 0.06931471805599453,
"exponentialTimeConstant": 14.426950408889635,
"linearEquivalentLeak": 0.1
}
}Limitations and assumptions
- The exponential and linear-equivalent terms use the supplied gauge-pressure model. They do not certify leak tightness, infer ambient pressure effects, or establish clinical device safety.
- The field tables describe structural bounds; the mechanics also state cross-field requirements. Malformed input shapes, disallowed keys, and invalid domains cause input errors. Results must remain finite and within the declared output contract. A successful false flag or zero placeholder is distinct from an error.
- Numeric arithmetic uses binary floating point. Exact comparisons have no hidden tolerance or decimal rounding; negative zero is exported as zero. Decimal-text integer operations retain the exactness specifically stated above.
Alternative or Complementary methods
For pulmonary device leak decay term, check the source records and the supplied rule before comparing the result with another method. Use an appropriately validated measurement or analysis method for clinical interpretation.
References
Similar or alternative tools
- Pulmonary Sample Gaslag Volume Factor
Ideal plug-flow sample-line residence plus an explicitly supplied analyzer delay, excluding dispersion or device operating recommendations.
- Breath Reference Zero Gap
Calculate breath reference zero gap from explicit caller-supplied inputs.