Table 1.

Summary of wearable devices to monitor sleep stages

Type	Product	Signals
Headband	Dreem Headband	EEG (O1, O2, Fpz, F1, F8), Acc., PPG, SpO2
	Sleep Shepherd	EEG
	Muse Series	EEG, Acc., PPG, SpO2
In-ear	Nightbuds	EEG, Acc.
Watch	Halo Band	PPG, Acc.
	Fibit Series
	Apple Watch Series
	Galaxy Watch Series
	Biostrap
	Actiwatch Series	Acc., Light Illuminance
	Whoop 4.0	Skin Temp., Acc., PPG, SpO2
Ring	Oura	PPG, Acc., Skin Temp.
	Sleepon	PPG, SpO2
Etc.	WatchPAT 300	PAT, PPG, SpO2, Acc., Body Position, Sound (snoring), Resp. (chest movement)

EEG electroencephalogram, Acc. Accelerometry signals, PPG photoplethysmogram, Skin Temp. Skin temperature, PAT peripheral arterial tone, Resp. Respiration