1. Department of Cardiothoracic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
2. Central Laboratory of Jiangsu Provincial Maternal and Child Health Care Hospital, Maternal and Child Branch of the First Affiliated Hospital of Nanjing Medical University, Nanjing 210036, China
3. Department of Ultrasound, Nanjing Maternity and Child Health Care Hospital, Women’s Hospital of Nanjing Medical University, Nanjing 210004, China
4. Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA