1. Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, Taiwan, ROC;
2. Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Tao-Yuan, Taiwan, ROC;
3. Department of Neurosurgery, Asia University Hospital, Taichung, Taiwan, ROC;
4. Division of Neurosurgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan, ROC;
5. Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC