Pioneering sleep researcher;

Born: August 4, 1929; Died: April 25, 2012.

PROFESSOR Ian Oswald, who has died aged 82, was Emeritus Professor of Psychiatry at Edinburgh University, best-known as "the founding father" of sleep research in the UK.

He spent most of his career studying the impact of sleep, to what extent it is "restorative" to mind and body, its effect on memory and on protein synthesis, and why some sleepwalkers can turn violent. He was the author of many books and articles in scientific journals, many written jointly with his wife and fellow sleep researcher Dr Kirstine Adam. His 1966 book Sleep, published widely by Penguin, became something of a bible among future sleep researchers in the UK and beyond. How to Get a Better Night's Sleep, written with Kirstine, also became a big seller in 1983. Over the years, his research also had a major influence on the development of sleeping pills.

Ironically, it was a dispute over sleeping pills that pushed Prof Oswald's name into newspapers around the UK and beyond in the early 1990s, immediately after his retirement. Based on his research, he claimed that the sleeping pill Triazolam (also known as Halcion) could cause adverse mental disturbance during the day. The influential BBC news programme Panorama broadcast a documentary on his findings and the British Department of Health felt his research was strong enough to ban the drug. In 1992 its manufacturer, Upjohn of the US, sued Prof Oswald for libel and he countersued. The outcome was something of a face-saving one, each party being awarded damages for different reasons, each claiming victory and with the BBC stumping up a large sum to Upjohn as well.

Also during his retirement, Prof Oswald's name regularly popped up in the newspapers after he was called in as an expert witness during cases involving sleep disturbances or sleepwalking. In 2000 a 35-year-old Perth High School music teacher, Allan Kellman, was acquitted of an indecent sex assault on a male colleague after Prof Oswald gave evidence on Mr Kellman's claim that he had been sleepwalking at the time of the assault. The professor testified that Mr Kellman must have suffered trauma while serving as a Territorial Army orderly during the 1990 Gulf War. Since he had been somnambulating, or sleepwalking, at the time of the assault, he could not be held responsible for his actions, Prof Oswald told the court.

One of his best-known theories was a sophisticated variation of the generally accepted fact that sleeping "recharges the body's batteries". Using electrodes to monitor the brains of sleepers, he found that "orthodox, non-dreaming sleep" helps renew body tissues, while what is known as "paradoxical sleep" helps renew brain tissues. Babies probably sleep so much because they are building up both brain and body tissue, while old people sleep less because they have smaller amounts of tissue to renew.

Ian Oswald was born in London in 1929, a few weeks before the Wall Street Crash, and went to primary school there. During the Second World War he moved with his family to the market village of Belper, near Derby, where his father John, an aeronautical engineer, had got a job at the Rolls-Royce factory.

He studied first at Cambridge University (Caius College) and later Bristol, with a break for two years national service in the RAF, then Oxford and back to Cambridge for his MD in 1959 before moving to Edinburgh as a lecturer in the department of psychological medicine. He would remain in Edinburgh throughout his 30-year career, and thereafter as Emeritus Professor of Psychiatry, often commuting from Innerleithen. In 1965-67, on leave from Edinburgh, he established a department of psychiatry in the University of Western Australia in the Perth suburb of Crawley.

In 2007 Prof Oswald saw one of his experiments listed in a book titled Elephants on LSD: the Ten Silliest Experiments of All Time by Alex Boese. According to Boese, Prof Oswald, at the time a researcher at Edinburgh University, sought to prove that some people can sleep through anything. He taped the eyes of three volunteers before exposing them to flashing lights, minor electric shocks and loud music. All three dozed off within 12 minutes, possibly soothed by the monotony of the combination of light, pain and noise.

One of Prof Oswald's former students is Dr Chris Idzikowski, now the director of the Edinburgh Sleep Centre, which provides diagnosis and treatment for people with sleep or related disorders. "He was hugely important," Dr Idzikowski said. "Fiery, evidence-based, clear and incisive, a razor-sharp intellect, a horticulturalist and a connoisseur of fine wines."

Among his many titles, Prof Oswald was a Foundation Fellow of the Royal College of Psychiatrists (FCRPsych). He died at home in Innerleithen and was buried not far away in a private woodland ceremony in the Scottish Borders. His first wife Joan (née Thomsett) predeceased him. He is survived by his second wife Kirstine, his four children from the first marriage, Andrew (Professor of Economics at the University of Warwick), Sally, Malcolm and Jim, and seven grandchildren.