1. Department of Electronic Engineering and the Shun Hing Institute of Advanced Engineering, The Chinese University of Hong Kong (CUHK), Hong Kong, Hong Kong
2. Department of Medical Physics and Biomedical Engineering, Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, U.K.
3. Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore