1. Department of Anesthesiology, The First Hospital of China Medical University, Shenyang, China
2. Department of Ultrasound, Xiaoshan Traditional Chinese Medical Hospital, Zhouhang, China
3. Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, China
4. Department of Laboratory Medicine of Shengjing Hospital of China Medical University, Shenyang, China