Table 2.

Frequency range and selected sensors used in sleep apnea.

Sensor	Measurement	Range	Reference
Accelerator	Wake and sleep periods	0.1 Hz−0.4 Hz	(28)
Acoustic sensor	Respiratory sounds	100–1,400 Hz	(29)
Acoustic sensor	Tracheal sound	100–3,000 Hz	(30)
Acoustic sensor	Sound transmission in respiratory system	150–500 Hz	(31)
Pressure sensor	Pressure	0.06–1.7 Hz	(32)
Captive microphone	Respiratory sound	30–126 Hz	(33)
Captive microphone	Respiratory sound	20–6,000 Hz	(34)
Acceleration sensor	Actigraphy, body position	1–4 Hz	(35)