1. Department of Sleep Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University; 1-2-3 Kasumi, Minami-ku , Hiroshima , Japan
2. Department of Perioperative and Critical Care Management, Graduate School of Biomedical and Health Sciences, Hiroshima University; 1-2-3 Kasumi , Minami-ku, Hiroshima , Japan
3. Graduate School of Humanities and Social Sciences, Hiroshima University; 1-7-1 Kagamiyama , Higashi-Hiroshima , Japan