Sleep apnea syndrome (SAS) causes high-frequency hypopnea or apnea during sleep. Sleep quality deteriorates owing to the decreased sleep depth caused by hypopnea and apnea, which directly impacts sleep, resulting in a lack of substantial sleep relative to the amount of time spent asleep. This can lead to unintentional dozing during the daytime and cause accidents (Findley et al. 1998), and it has received significant social attention. In addition, the effects of hypoxia caused by hypopnea and apnea on body tissues (Ryan et al. 2005), and the strain on the cardiovascular system to recover from hypoxia increases the risk of lifestyle-related diseases, such as hypertension (Lavie et al. 2000), diabetes (Tasali et al. 2008), and even major depression (Sharafkhaneh et al. 2005).