Table 2
Description of parameters calculated by frequency domain analysis. Parameters were calculated for heart rate and systolic and diastolic blood pressure.
| | Method | Parameter | Description |
| | Frequency domain | ULF | Power (=variability) in “ultra low frequency” range (0–0.0033 Hz) | | VLF | Power (=variability) in “very low frequency” range (0.0033–0.04 Hz) | | LF | Power (=variability) in “low frequency” range (0.04–0.15 Hz) | | HF | Power (=variability) in “high frequency” range (0.15–0.4 Hz) | | XHF | Extended high frequency band from 0.15 to 0.6 Hz | | XF | Frequency band from 0.12 to 0.18 Hz | | P | Total power density spectra (variance of all NN intervals ≤0.4 Hz) | | LF/HF | Ratio of LF and HF | | LF/P | Ratio of LF and P | | HF/P | Ratio of HF and P | | XHF/PX | Ratio of XHF and the extended total power
(variance of all NN intervals ≤0.6 Hz) | | VLF/P | Ratio of VLF and P | | ULF/P | Ratio of ULF and P | | (ULF + VLF + LF)/P | Ratio of (ULF + VLF + LF) and P | | (ULF + VLF)/P | Ratio of (ULF + VLF) and P | | UVLF | Sum of ULF, VLF, and LF (≤0.15 Hz) | | LFN | Normalized low frequency | | HFN | Normalized high frequency |
|
|
