Thomas David Preston was a consultant in computer medicine at Westminster Hospital, London. He studied medicine at Cambridge University and qualified BChir in 1961. After initial house jobs in obstetrics and gynaecology at St Thomas’s Hospital in London he became a house surgeon at the Hammersmith Hospital followed by posts as a surgical registrar at Sutton General Hospital and senior registrar in clinical measurement at the Westminster Hospital. A member of the BMA, he was the author of various papers on clinical measurement and the application of computers to patient care. He died on 13 October 2012.