getNormSpectralUnits function

Normalized Spectral Units

Normalized Spectral Units

Calculates the spectrogram bands in normalized units

getNormSpectralUnits(
  HRVData,
  indexFreqAnalysis = length(HRVData$FreqAnalysis),
  VLFnormalization = T
)

Arguments

  • HRVData: Data structure that stores the beats register and information related to it
  • indexFreqAnalysis: Reference to the data structure that contains the spectrogram analysis
  • VLFnormalization: Logical value. If TRUE (default), the function normalizes LF and HF power series by its sum. If FALSE, the function computes VLF, LF and HF power series by its sum.

Returns

The getNormSpectralUnits returns a list storing the resulting normalized power-band series. Note that this list is not stored in the HRVData structure.

Details

The default behaviour of this function computes the normalized power time series in the LF and HF bands following the Task Force recommendations:

normalized_LF=LF_power/(total_power−VLF_power−ULF_power)normalizedLF=LFpower/(totalpower−VLFpower−ULFpower) normalized\_LF = LF\_power / (total\_power - VLF\_power - ULF\_power)normalized_LF = LF_power / (total_power - VLF_power - ULF_power) normalized_HF=HF_power/(total_power−VLF_power−ULF_power)normalizedHF=HFpower/(totalpower−VLFpower−ULF−power) normalized\_HF = HF\_power / (total\_power - VLF\_power -ULF\_power)normalized_HF = HF_power / (total_power - VLF_power -ULF-power)

If VLFnormalization is set to FALSE, the functions computes:

normalized_VLF=VLF_power/(total_power−ULF_power)normalizedVLF=VLFpower/(totalpower−ULFpower) normalized\_VLF = VLF\_power / (total\_power - ULF\_power)normalized_VLF = VLF_power / (total_power - ULF_power) normalized_LF=LF_power/(total_power−ULF_power)normalizedLF=LFpower/(totalpower−ULFpower) normalized\_LF = LF\_power / (total\_power - ULF\_power)normalized_LF = LF_power / (total_power - ULF_power) normalized_HF=HF_power/(total_power−ULF_power)normalizedHF=HFpower/(totalpower−ULFpower) normalized\_HF = HF\_power / (total\_power - ULF\_power)normalized_HF = HF_power / (total_power - ULF_power)

The resulting time series are returned in a list. Note that before using this function, the spectrogram should be computed with the CalculatePowerBand

function.

Examples

## Not run:

# load some data...
data(HRVProcessedData)
hd = HRVProcessedData
# Perform some spectral analysis and normalize the results
hd = CreateFreqAnalysis(hd)
hd = CalculatePowerBand(hd,indexFreqAnalysis = 1,shift=30,size=60)
normUnits = getNormSpectralUnits(hd)
# plot the normalized time series
par(mfrow=c(2,1))
plot(normUnits$Time, normUnits$LF, xlab="Time", ylab="normalized LF",
     main="normalized LF",type="l")
plot(normUnits$Time, normUnits$HF, xlab="Time", ylab="normalized HF",
     main="normalized HF",type="l")
par(mfrow=c(1,1))
## End(Not run)

References

Camm, A. J., et al. "Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology." Circulation 93.5 (1996): 1043-1065.

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