The iron lung, a medical device from the early 20th century, was designed to artificially ventilate people with lung disease when the muscles, including the diaphragm, were paralyzed by the polio virus. The invention by the American engineer Philip Drinker around 1920 was one of the first of its kind to enable mechanical ventilation.
This is how the iron lung works
Patients were placed inside the cylinder-shaped device with their heads remaining outside. The iron lung enclosed the neck in an airtight manner and created a negative pressure that promoted inhalation, and by changing to positive pressure, exhalation could take place. This alternation between negative and positive pressure imitated the natural breathing movements and thus enabled the patients to survive.
Paul Alexander lived in an iron lung for over 70 years
Paul Alexander, a Texan, contracted polio in 1952 and lived in an iron lung ever since. Despite the challenge of his physical impairment, Alexander graduated from Dallas High School and continued his education at the university. He made it to law school at the University of Texas at Austin, where he successfully completed his studies. After over 70 years of use, Paul Alexander died of COVID-19 in 2024.
These modern alternatives exist today
With the introduction of endotracheal intubation and other ventilators that use positive pressure, the iron lung has almost disappeared. Today, respiratory pacemakers are used to stimulate the diaphragm directly, and ECMO is used in cases of severe pulmonary dysfunction. Cuirass ventilation represents a further development of negative pressure ventilation.