Diagram of the first artificial respirator invented by Philip Drinker and Louis Agassiz Shaw at the Harvard School of Public Health. The 'iron lung' as it was nicknamed, was a huge metal box attached to bellows in which the patient was encased. The ongoing suction from the bellows kept the patient breathing. It was used for patients affected by paralysis caused by polio as many patients were unable to breathe on their own. After the early 1950s, following the introduction of the polio vaccine, use of the iron lung declined, and today it is generally obsolete.