By Richard Sandomir

New York Times News Service

Andrew Dibner, a psychologist who launched a new segment in the health care industry when he invented a medical alert system that let elderly and disabled people call for help when they cannot reach a telephone or knock on a neighbor’s door, died on Saturday in a memory care facility in Peoria, Arizona. He was 93.

Dr. Robin Dibner, his daughter, said the cause was complications of Alzheimer’s disease.

Dibner was a psychology professor at Boston University with a special interest in the problems of old age in 1972 when one day, while shaving, he pondered what happens when a frail person, living alone, falls and cannot move.

“How does someone who can’t call for help call for help?” he recalled wondering.

He and his wife, Susan Schmidt Dibner, a sociologist, answered the question in 1974 by starting Lifeline Systems, widely recognized as the first company to sell personal emergency response systems in the United States.