Table 5.
Electrocardiogram (ECG) metrics for REM sleep behaviour disorder (RBD) detection, which aimed to capture changes in heart rate variability during sleep.
| Channel | Category | Description | Reference |
|---|---|---|---|
| ECG | Time | The mean RR interval standard deviation during all REM epochs (RR_REM_Std), | (Andreotti et al., 2018) |
| ECG | Frequency | The mean RR interval low frequency peak during NREM epochs (LFpeak_NREM), mean RR interval low frequency peak during REM epochs (LFPeak_REM), mean RR interval high frequency peak during NREM epochs (HFpeak_NREM), and the RR interval high frequency peak during REM epochs (HFPeak_REM). | (Andreotti et al., 2018) |
| ECG | Non-linear | The mean sample entropy during REM (SampEn_REM). | (Andreotti et al., 2018) |
| ECG | Heart beat regularity | The mean irregular index (IrrIndex_NREM), the mean irregular index calculated for each REM epoch (IrrIndex_REM), the mean origin count for all NREM epochs (OriginCount_NREM), and mean origin count for all REM epochs (OriginCount_REM) | (Sarkar et al., 2008) |
| ECG | RR index | The mean RR interval ratio between REM and NREM epochs (RR_Index). | This work |
| ECG | LFHF ratio | The mean RR interval low frequency to high frequency ratio between NREM and REM epochs (LFHF_Index). | This work |
| NA | NREM ratio | Ratio of NREM sleep compared to REM sleep (Ratio_NREM). | This work |