1. Medical Research Institute, College of Medicine, Chungbuk National University, Cheongju, Korea
2. Department of Internal Medicine, College of Medicine, Chungbuk National University, Cheongju, Korea
3. Department of Nursing, Woosong College, Daejeon, Korea
4. Department of Biomedical Engineering, College of Medicine, Chungbuk National University, Cheongju, Korea