1. Department of Neurosurgery, Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul 07985, Republic of Korea
2. Informatization Department, Seoul Hospital, College of Medicine, Ewha Womans University, Seoul 07804, Republic of Korea
3. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul 07985, Republic of Korea
4. Department of Neurosurgery, Seoul Hospital, College of Medicine, Ewha Womans University, Seoul 07804, Republic of Korea