1. Department of Anesthesia, Chi Mei Medical Center, Tainan 70722, R.O.C.
2. Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan 70101, R.O.C.
3. Department of Anesthesia, China Medical University, Taichung 40406, R.O.C.
4. Department of Anatomy, School of Medicine, Kaohsiung Medical University, Kaohsiung 80807, R.O.C.