1. National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
2. Imperial College Healthcare NHS Trust, Hammersmith Hospital, Du Cane Road, London, UK
3. Department of Electrical and Electronic Engineering, Imperial College London, South Kensington Campus, London, UK
4. Section of Anaesthetics, Pain Medicine & Intensive Care, Imperial College London, South Kensington Campus, London, UK