Liam Ó Sé, who has died aged 88, served for a time as county medical officer for Mayo before returning to Dublin as director of community care with the Eastern Health Board. Although he specialised in public health medicine and epidemiology, it is probably for his work on behalf of the Irish language that he will be best remembered. He developed a special interest in linguistics and combined this with his professional training and practice in his life's work, Crannóga: An Epidemiological Approach to the Gaeltacht (2000).
In the book he recalled an episode when he was a junior doctor at the County Hospital, Ennis, in the late 1940s. In the space of a few days he admitted five or six native Irish speakers whereas normally one or two would be admitted in a week.
He had them placed in adjoining beds – as they were all male this did not present a problem. The outcome exceeded his expectations.
"With the sound of fluent and racy north Munster Irish echoing around the ward", other native speakers whose Irish had grown rusty joined in and soon their Irish was on a par with that of the others. The mini-revival he witnessed prompted him later to turn his attention to the bigger picture.
His proposals to revive Irish included the acceptance of bilingualism, as well as the formation of new, self-sufficient Gaeltacht communities. He encouraged parents to develop Gaeilge ón gcliabhán in their children.
Born in Dublin in 1921, he was the son of William O'Shea and his wife Anne Marie (née Kett). After the untimely death of his father in 1923 the family moved back to Kilrush, Co Clare, where he grew up.
Educated at St Flannan's College, Ennis, he studied medicine at UCD. After working in a number of hospitals he specialised in public health medicine.
Predeceased by his wife Maura and brother Joe, he is survived by his daughters Dervilla and Emer and sons Declan, Colm and Cormac.