1. Department of Anatomy and Cell Biology, Wakayama Medical University, Wakayama, Japan
2. Department of Otorhinolaryngology-Head and Neck Surgery, Wakayama Medical University, Wakayama, Japan
3. Department of Emergency and Intensive Care Medicine, Wakayama Medical University, Wakayama, Japan
4. Clinical Study Support Center, Wakayama Medical University Hospital, Wakayama, Japan
5. Department of Nursing, Wakayama Medical University Hospital, Wakayama, Japan.