Fig. 1From: Threshold of the upper airway cross-section for hypopnea onset during sleep and its identification under waking conditionFour different types of changes in the cross-sectional area of the upper airway (CSA-UA) in OSA patients. The number of the patients in the four groups were 6, 4, 8, and 2 (30, 20, 40, and 10% of the total participants), respectivelyBack to article page