1. Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei 100, Taiwan
2. Division of Gastroenterology, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 116, Taiwan
3. Department of General Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
4. Department of Electrical Engineering, College of Electrical and Communication Engineering, Yuan Ze University, Taoyuan 320, Taiwan
5. Department of Otolaryngology, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan
6. Department of Biomedical Engineering, National Taiwan University Hospital, Taipei 100, Taiwan