1. Division of Superconducting Magnet Science and Technology, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
2. School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3. School of Information Technology and Electrical Engineering, The University of Queensland, Queensland QLD 4072, Australia
4. Guangdong Provincial Key Laboratory of Medical Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China