Polysomnography:
A state-of-the-art polysomnography (PSG) system Nox A1, from Nox Medical. The PSG measures brain waves, eye movements, body position, chest and abdominal movement, limb movement, breathing pattern, sweating, noise, heart rate and blood oxygen level. The system is portable and research subjects can easily drive home after the attachment of the equipment, as needed [Dae Wui Yoon et al., 2019; PunjabiNM et al., 2018]. Nox Medical is a world leading company in the field of measuring biomedical signals during sleep. Their equipment is used worldwide.