1. Cardiovascular Research Centre; Royal Brompton Hospital; London SW3 6NP UK
2. National Heart and Lung Institute; Imperial College London; London SW7 2AZ UK
3. School of Data Science; Fudan University; Shanghai 201203 China
4. Department of Biomedical Engineering; Shanghai Jiao Tong University; Shanghai 200240 China
5. School of Computer Science; University of Lincoln; Lincoln LN6 7TS UK
6. Department of Computer Science; City University London; London EC1V 0HB UK