Born in the UK, Dr David Humphrey trained as doctor at UCH London. He worked for four years in a remote hospital in Zululand before taking up a post in Anaesthesia at Durban’s University Hospital. Being interested in low-flow anaesthesia, he transferred into a senior lecturer research post in Anaesthesia and Physiology. He designed the Humphrey ADE-circle which proved to be a highly efficient multi-purpose anaesthetic breathing system for adults and children. A vet bought one. After his paper at BSAVA-2000, it became a popular very low-flow system in veterinary practice. With updates, it’s 100% efficient in all modes of use requiring only 300-500 ml/kg/min.