1. Department of Otolaryngology-Head and Neck Surgery, Nara Medical University, 840 Shijo-cho, Kashihara 634-8522, Nara, Japan
2. MBT (Medicine-Based Town) Institute, Nara Medical University, 840 Shijo-cho, Kashihara 634-8522, Nara, Japan
3. Graduate School of Engineering Science, Osaka University, D436, 1–3 Machikaneyama, Toyonaka 560-8531, Osaka, Japan