1. Chinese Academy of Sciences, Key Laboratory of Molecular Imaging of Chinese Academy of Sciences, Institute of Automation, No.95 Zhongguancun East Road, Haidian District, Beijing 100190, China
2. Beijing Jiaotong University, School of Computer and Information Technology, Department of Biomedical Engineering, No.3 Shangyuancun, Haidian District, Beijing 100044, China