Hsien-Yi Chiu1, Tsen-Fang Tsai2. 1. Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan; Department of Dermatology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan; Department of Dermatology, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan. 2. Department of Dermatology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: tftsai@yahoo.com.