The Iron Lung Saved an 8-Year-Old in Under a Minute and Defined Polio Care

On October 12, 1928, an eight-year-old girl with paralytic polio lay near death at Boston Children's Hospital. Her diaphragm and intercostal muscles had stopped functioning. The Harvard industrial hygienist Philip Drinker had been working for a year on a pressure chamber meant for victims of coal-gas asphyxiation, and convinced the staff to wheel his prototype into her room. They sealed her body inside it from the neck down. A motor pulled the air pressure inside the chamber down a few centimeters of water, and her chest expanded into the vacuum. They cycled it. Within a minute she was breathing. She was speaking by the next morning.

Drinker had built the device with another Harvard hygienist, Louis Agassiz Shaw Jr., the year before. The principle was simple. Normal breathing pulls the diaphragm down, lowering the pressure inside the lungs and drawing air in through the mouth. If you instead reduce the pressure around the body in a sealed metal cylinder, the chest expands the same way and air rushes in through the open trachea. A patient with no functioning respiratory muscles could be kept breathing for weeks, months, or in some cases the rest of their life.

Polio epidemics through the 1930s, 1940s, and 1950s made wards full of iron lungs a standard sight. By 1959 about 1,200 Americans depended on them daily. The 1952 Copenhagen polio epidemic accelerated a shift to positive-pressure ventilation through tracheostomy, which dropped fatality among bulbar polio cases from around 80 percent to about 11 percent. Modern ventilators that puff air into the lungs descend from that change.

Paul Alexander, paralysed by polio in 1952, lived inside an iron lung for 72 years. He earned a law degree, wrote a memoir, and died in March 2024 — the last daily user of the device.