1. London Spinal Cord Injury CentreRoyal National Orthopaedic HospitalStanmoreUK
2. Division of Surgery and Interventional ScienceUniversity College LondonLondonUK
3. Department of Medical Physics BioengineeringUniversity College LondonLondonUK
4. Nephro‐Urology Clinical Trials Ltd.Queen Anne Street Medical CentreLondonUK