Tetanus Fusion Frequency
Screen measured force ripple across stimulation frequencies against a supplied fusion criterion; zero qualifying frequency explicitly means no observed qualifying point.
Description
Force ripple measures how far a trough falls below a stimulation peak.
Force ripple measures how far a trough falls below a stimulation peak. A caller-defined maximum ripple can screen sampled frequencies for apparent fusion.
The tool returns rippleFractions (ripple fractions); firstQualifyingFrequencyHz (first qualifying frequency hz); observedFusion (observed fusion). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use Tetanus Fusion Frequency
Use Tetanus Fusion Frequency when you already have stimulationFrequenciesHz, peakForces, troughForces, maximumRippleFraction and want rippleFractions, firstQualifyingFrequencyHz, observedFusion. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use Tetanus Fusion Frequency and understand its results
- Enter stimulationFrequenciesHz, peakForces, troughForces, maximumRippleFraction using the field table below. Match the units, ordering and data boundaries described in the calculation.
- Run the tool after checking the stated bounds and matching paired observations or categories. A malformed request gives a tool error rather than a usable measurement.
- Read rippleFractions, firstQualifyingFrequencyHz, observedFusion. Use the calculation and interpretation below to distinguish amounts, ratios, signs and decision flags where applicable.
- Review the supplied parameters and assumptions before using the result in a report or comparing it with another observation.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| stimulationFrequenciesHz | Stimulation frequencies hz | list of number | Required |
| peakForces | Peak forces | list of number | Required |
| troughForces | Trough forces | list of number | Required |
| maximumRippleFraction | Maximum ripple fraction | number | Required |
Require increasing positive frequencies, positive peaks and troughs between zero and the matching peak. Return the first qualifying sampled frequency or zero with observedFusion=false.
ripple = (peak−trough)/peak; qualify = ripple ≤ maximumRipple The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"stimulationFrequenciesHz": [
10,
20,
40
],
"peakForces": [
10,
10,
10
],
"troughForces": [
2,
6,
9
],
"maximumRippleFraction": 0.15
},
"output": {
"rippleFractions": [
0.8,
0.4,
0.1
],
"firstQualifyingFrequencyHz": 40,
"observedFusion": true
}
}Limitations and assumptions
The zero sentinel is not a measured frequency. No interpolation or physiological fusion criterion is selected internally.
Numerical inputs must be finite. The tool checks its declared input shape and calculation constraints; those checks do not verify the quality, calibration or representativeness of the supplied observations.
Alternative or Complementary methods
Twitch Interpolation Voluntary Activation: Calculate paired trial voluntary activation as 100·(1−superimposed/rest potentiated twitch); negative estimates are preserved to expose model/protocol incompatibility, not clipped. Twitch Force: Measure sampled twitch peak and net impulse after baseline subtraction across explicit disjoint windows; force must already be calibrated.
Methodological background: Twitch interpolation in human muscles: mechanisms and implications for measurement of voluntary activation.1
References
-
Twitch interpolation in human muscles: mechanisms and implications for measurement of voluntary activation — Herbert and Gandevia; Journal of Neurophysiology
Similar or alternative tools
- Twitch Interpolation Voluntary Activation
Calculate paired trial voluntary activation as 100·(1−superimposed/rest potentiated twitch); negative estimates are preserved to expose model/protocol incompatibility, not clipped.
- Twitch Force
Measure sampled twitch peak and net impulse after baseline subtraction across explicit disjoint windows; force must already be calibrated.