Tomoyuki Saito1, Naoi Turumachi2, Yasuhisa Okuda2. 1. Department of Anesthesiology, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan - s-tomo@dokkyomed.ac.jp. 2. Department of Anesthesiology, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan.