Description
Return fractional area change and supplied-uncertainty bounds.
Cardiac measurement formulas depend on geometry, units, calibration and reference origins. A Doppler projection correction, echo disc-volume contribution or waveform integral evaluates supplied quantities without validating image acquisition, signal quality or physiological interpretation.
Return fractional area change and supplied-uncertainty bounds.
When to use this tool
Use Cardiac Research Fractional Area Change when checking one supplied cardiac measurement, geometry or calibration term.
How to use the tool and how it works
- Enter maximumArea, minimumArea, maximumUncertainty, minimumUncertainty. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read fractionalAreaChange, conservativeLower, conservativeUpper. Use the output convention below.
Return fractional area change and supplied-uncertainty bounds. Require maxArea > 0, minArea within max, maxUncertainty < max and nonnegative uncertainties; nominal = 1-min/max, lower = 1-(min+uMin)/(max-uMax), upper = 1-max(0,min-uMin)/(max+uMax).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| maximumArea | Maximum Area | Required. Finite number; strictly above 0. |
| minimumArea | Minimum Area | Required. Finite number; minimum 0. |
| maximumUncertainty | Maximum Uncertainty | Required. Finite number; minimum 0. |
| minimumUncertainty | Minimum Uncertainty | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| fractionalAreaChange | Fractional Area Change | Required. Finite number. |
| conservativeLower | Lower fractional-area-change envelope; can be negative under the supplied area bounds. | Required. Finite number. |
| conservativeUpper | Conservative Upper | Required. Finite number. |
{
"input": {
"maximumArea": 20,
"minimumArea": 10,
"maximumUncertainty": 1,
"minimumUncertainty": 1
},
"output": {
"fractionalAreaChange": 0.5,
"conservativeLower": 0.42105263157894735,
"conservativeUpper": 0.5714285714285714
}
}Limitations and assumptions
- The lower bound can be negative; these are deterministic supplied area envelopes, not confidence intervals or clinical thresholds.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use validated acquisition and calibration, a complete appropriate measurement method and qualified clinical interpretation; assess measurement uncertainty and model assumptions separately.
References
Similar or alternative tools
- Cardiac Research Stroke Volume Balance
Return total and loss-adjusted forward stroke-volume terms.
- Echo Reference Axis Gap
Compare two echo-axis endpoints against a shared origin.