1. Department of Biomedical Engineering, Shenzhen University, Shenzhen 518060, China
2. National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Shenzhen 518060, China
3. Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging, Shenzhen 518060, China
4. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA