June Middleton of Melbourne, Victoria, Australia, relied on an iron lung to keep her alive from contracting polio in April 1949 until her death in October 2009.
Ms June Middleton (b. 4 May 1926) spends approximately 16 hours each day on the negative pressure respirator and did so for over 60 years.
She died on 30 October 2009 aged 83 having spent just over 60 years in the iron lung. Ref http://www.dailymail.co.uk/news/worldnews/article-1224291/Polio-survivor-spent-60-years-iron-lung-dies-aged-83.html
Comments below may relate to previous holders of this record.