Robert Andrew Hingson, a pioneer in the field of public health who made important contributions to anesthesia for safer, easier childbirth and to mass immunizations with the ''jet'' injection, died on Wednesday at the Veterans Affairs Medical Center in Lake City, Fla.

He was 83 and lived in Ocilla, Ga.

The cause was complications of polymyositis, an inflammation of voluntary muscles akin to Lou Gehrig's disease, said the Brother's Brother Foundation of Pittsburgh.

Dr. Hingson created the foundation in 1958 to expand basic health care and had served as the president of the volunteer, interfaith organization. Under his leadership, its mission broadened to include other types of aid. In the last four decades, the foundation has distributed $560 million worth of things like medical supplies, textbooks, seeds and food to 40 million people on five continents.

But Dr. Hingson's fame was assured well before this relief work. His invention of continuous caudal -- posterior -- anesthesia and perfection of lumbar epidural anesthesia to prevent pain in childbirth earned him worldwide recognition.