SNAP Amplitude Calculator

Actual sensory-nerve action potential waveform peak-to-peak and baseline-to-negative/positive sampled amplitudes with explicit independent baseline, not automatic waveform/component detection or a universal nerve norm.

Description

Sensory nerve action-potential amplitude depends on a qualified component and baseline convention.

Sensory nerve action-potential amplitude depends on a qualified component and baseline convention.^[1]

Peak-to-peak and baseline-to-peak measurements describe different amplitude quantities.

When to use SNAP Amplitude Calculator

Use this tool to calculate or review the supplied observations under the stated rules. Establish the assessment or recording protocol, units, instrument version and independently applicable reference or calibration.

How to use SNAP Amplitude Calculator and understand its results

Establish the assessment or recording protocol, units, instrument version and independently applicable reference or calibration.
Enter independentlyMeasuredBaselineCorrectedAmplitudesMv, callerVerifiedBaselineMv, using the field meanings and rules below, then run the tool.
Read result.observedPeakToPeakAmplitudeMv, result.observedBaselineToNegativePeakMv, result.observedBaselineToPositivePeakMv. Use the units and sign conventions below.
Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.

Input field	Meaning	Value type	Requirement
independentlyMeasuredBaselineCorrectedAmplitudesMv	Independently measured baseline corrected amplitudes mv	list of number	Required
callerVerifiedBaselineMv	Caller verified baseline mv	number	Required

Require a nonempty finite amplitude sample list and finite supplied baseline between the sample minimum and maximum inclusive. Return max−min, baseline−min and max−baseline. A single sample is permitted only with baseline equal to that sample; all excursions then equal zero. No time coordinates or component recognition are supplied.

peakToPeakMv=max(samples)−min(samples); negativeExcursionMv=baseline−min(samples); positiveExcursionMv=max(samples)−baseline

Use the matching field units and the exact boundary, ordering and reference rules above.

Output field	Meaning	Value type
result	Structured result; its nested fields below contain the actual calculation or selected reference	object
result.observedPeakToPeakAmplitudeMv	Maximum minus minimum qualified sample amplitude in millivolts	number
result.observedBaselineToNegativePeakMv	Supplied baseline minus minimum sample amplitude, in millivolts	number
result.observedBaselineToPositivePeakMv	Maximum sample amplitude minus supplied baseline, in millivolts	number

json

{
  "input": {
    "independentlyMeasuredBaselineCorrectedAmplitudesMv": [
      0,
      -2,
      3,
      0
    ],
    "callerVerifiedBaselineMv": 0
  },
  "output": {
    "result": {
      "observedPeakToPeakAmplitudeMv": 5,
      "observedBaselineToNegativePeakMv": 2,
      "observedBaselineToPositivePeakMv": 3
    }
  }
}

Limitations and assumptions

Actual acquisition, assessment protocol, instrument version and calibration determine applicability. The tool does not examine a person, classify images, administer a questionnaire or choose diagnostic cutoffs.

Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite. Lists and matrices must be dense, without missing cells. Numeric lists allow at most 10000 entries; ordinary string lists allow at most 128 strings of 128 UTF-16 units each; numeric matrices allow at most 128 rows and 128 columns, subject to narrower requirements above. Extremely large composite outputs are rejected.

Alternative or Complementary methods

For a related step, use M-Wave Amplitude Calculator: An M-wave amplitude uses an independently qualified waveform and baseline convention. For a complementary comparison, use CMAP Amplitude Calculator: Compound muscle action-potential amplitude requires a qualified waveform and baseline.

References

SNAP Amplitude Calculator — tool.io

Similar or alternative tools

M-Wave Amplitude Calculator
An M-wave amplitude uses an independently qualified waveform and baseline convention.
CMAP Amplitude Calculator
Compound muscle action-potential amplitude requires a qualified waveform and baseline.