1. School of Electronic Engineering and Computer Science, Queen Mary University of LondonLondonE1 4NSUK
2. Department of InformaticsKings College LondonLondonWC2R 2LSUK
3. Hamlyn Centre for Robotic Surgery, Imperial College LondonLondonSW7 2AZUK
4. School of Electrical Engineering, Yanshan UniversityQinghuangdaoHebei066004People's Republic of China