1. Department of horacic and Cardiovascular Surgery, Pusan National University Hospital, Biomedical Research Institute, Pusan National University School of Medicine, Busan, Korea
2. Department of Neurology, Pusan National University Hospital, Biomedical Research Institute, Pusan National University School of Medicine, Busan, Korea
3. Department of Anesthesiology and Pain Medicine, Pusan National University Hospital, Biomedical Research Institute, Pusan National University School of Medicine, Busan, Korea