The iron lung (example pictured), a type of medical ventilator, was used for the first time at the Boston Children's Hospital to treat an eight-year-old girl paralyzed by polio.

An iron lung is negative pressure ventilator and mechanical respirator which encloses most of the patient's body. The air pressure inside the enclosed space stimulates breathing. The device is used to assist breathing when muscle control is lost. This treatment was historically helpful for polio and botulism, and for counteracting the effects of barbiturates and tubocurarine). The iron lung has become largely obsolete in modern medicine, replaced by more advanced breathing therapies. Polio eradication in most of the world also reduced the need for the iron lung. In 2020, during the COVID-19 pandemic, interest in these devices was revived as a cheap, readily-producible substitute for positive-pressure ventilators which were in short supply.