1. a School of Health and Related Research , University of Sheffield , Sheffield, UK
2. b Bath Institute for Medical Engineering (BIME) , University of Bath , Bath, UK
3. c Pain Management Unit , University of Bath , Bath, UK
4. d Centre for Health and Social Care Research , Sheffield Hallam University , Sheffield, UK
5. e Faculty of Health and Wellbeing , Sheffield Hallam University , Sheffield, UK
6. f Research and Innovation , University of Ulster , Coleraine, Co., Londonderry, UK
7. g West Midlands Rehabilitation Centre , Birmingham, UK
8. h Computer and Electronic Systems , University of Essex , Colchester, UK