Prof Oswald was born in London on August 4, 1929, and attended primary school there before moving with his family to Belper, Derbyshire, during the Second World War after his father got a job with Rolls-Royce.
He began his studies at Cambridge University’s Caius College and then moved to Bristol University. National service with the RAF for two years broke up his studies but, upon completion, he carried on studying at Oxford, before going back to Cambridge for his MD in 1959.
He moved to Edinburgh to become a lecturer in the department of psychological medicine, and he stayed in the city during his 30-year career.
Throughout his career, Prof Oswald theorised that sleep helps to “recharge the body” and he found that “orthodox non-dreaming sleep” helps to renew brain tissues.
Between 1965 and 1967, he also helped establish a department of psychiatry at the University of Western Australia in Perth during a two-year leave from Edinburgh University.
Despite publishing books, including Sleep in 1966 and How to Get a Better Night’s Sleep, which he co-wrote with his second wife, Dr Kirstine Adam, he remained out of the media spotlight until the early 1990s.
His research had a major influence on the development of sleeping pills, although Prof Oswald’s work also saw the drug triazolam – better known as halcion – banned by the British Department of Health.
His research that found the drug could cause adverse mental disturbances during the daytime was reported on the BBC’s Panorama, pushing his name into the national media after his retirement.
The manufacturer of the drug, Upjohn, based in the United States, sued Prof Oswald whilst he counter-sued the company. Both sides won damages for different reasons.
In his retirement, he was also a key expert witness for trials that involved sleepwalking. The most famous was the 2000 trial of Allan Kellman, a music teacher at Perth High. Prof Oswald was able to prove that Mr Kellman had been sleepwalking at the time of an indecent sexual assault of a male colleague and he was acquitted.
Dr Chris Idzikowski, one of Prof Oswald’s former students, spoke highly of the work he undertook during his career. He said: “Emeritus Prof Ian Oswald was one of the founding fathers of sleep research in the UK and he laid the foundations upon which sleep medicine began.”
He passed away at his home in Innerleithen. His first wife, Joan, predeceased him. He is survived by Kirstine and four children from his first marriage – Andrew, Sally, Malcolm and Jim – along with seven grandchildren.