1. T Stone Robotics Institute and Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, China
2. Department of Automation, Shanghai Jiao Tong University, China
3. Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, Shanghai Jiaotong University, China
4. Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, China
5. Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, Shanghai Jiaotong University, Shanghai, China