Ever since the 1940s, when she was a girl in a small Southern town, Martha Mason dreamed of being a writer. But it was not till nearly half a century later, with the aid of a voice-activated computer, that she could begin setting a memoir down on paper.

Published in 2003, Ms. Mason’s memoir, “Breath,” is not well known outside the Southeast, or perhaps even outside North Carolina, where she was born, grew up and died. It was published by a small regional house, Down Home Press, and was not widely reviewed. But the truly significant thing is that the book was written at all.

Ms. Mason died on Monday at her home in Lattimore, N.C. She was 71 and had lived for more than 60 years in an iron lung.

Her death was confirmed by a friend, Mary Dalton, who said Ms. Mason had died in her sleep.

Paralyzed from the neck down as a result of childhood polio, Ms. Mason was one of the last handful of Americans, perhaps 30 people, who live full time in iron lungs. There is no documented case of any American’s having done so for quite as long as she, David W. Rose, the archivist of the March of Dimes Foundation, said on Friday.