aGuangdong Key Laboratory of Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen, China

bSchool of Biomedical Engineering

cFaculty of Medicine

dPacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia, Canada

Correspondence to Yuheng Wang, School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada. Tel: +1 778 681 5549; e-mail: [email protected]