The Iron Lung
The iron lung, also known as a negative pressure ventilator or pulmotor, is a mechanical respirator which enables a person to breathe on his or her own in a normal manner when muscle control is lost.
The metal tank encloses all of the body except the head and forces the lungs to inhale and exhale through regulated changes in air pressure.
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The movement of a diaphragm at one end of the tank alternately increases and decreases the pressure inside the tank to above or below the atmospheric pressure outside of the tank. As the pressure increases in the tank, air is forced out of the patient’s lungs through the mouth, and as pressure decreases in the tank, air is drawn into the patient’s lungs. (9)
Philip Drinker created the first iron lung after designing artificial respiration methods for use after surgery. He conducted experiments with Louis Shaw and his brother Cecil.
For their first experiment, they placed a cat inside an airtight box with its head protruding from an airtight collar, and they measured the changes in volume in order to determine normal breathing patterns. (1)
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John Emerson, an engineer of medical equipment, made significant improvements to the iron lung built by Dr. Philip Drinker in 1928.
Emerson constructed and successfully tested his first model in 1931. It was quieter, lighter and less expensive than Dr. Drinker’s device, and by the 1940s, during polio epidemics, it was widely used in hospital wards.
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The invention of the iron lung in 1928 gave hope to victims of poliomyelitis, also known as infantile paralysis. The disease caused the destruction of nerve cells and the crippling of muscles and limbs. The iron lung was used in treating anterior polio, which involved the paralysis of respiratory muscles and caused respiratory distress and possible death within a few hours. (2)
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The concept of an intensive care unit, which is commonly found in modern hospitals, was created out of the polio epidemic. Large numbers of polio patients were attached to iron lung ventilators and needed to be monitored by staff members. These patients were clustered together so that nurses could attend to all of them at once. (4)
Some physicians and doctors believed that patients would become chronically dependent on the iron lung respirator, but it was eventually shown that only a small percentage of patients became dependent on the machine. (3)
Footnotes
1. "New Medical Machinery." In 1920-1929, edited by Judith S. Baughman, Victor Bondi, Richard Layman, Tandy McConnell, and Vincent Tompkins. Vol. 3 of American Decades. Detroit, MI: Gale, 2001. http://link.galegroup.com/apps/doc/CX3468300949/UHIC.
2. Ibid.
3. Ibid.
4. Halstead S. Lauro "Post-Polio Syndrome." Scientific American278, no. 4 (1998): 42-47. http://www.jstor.org/stable/26057741.
5. "New Medical Machinery"
6. "Yale-New Haven Hospital and the Hospital of Saint Raphael, 1960s to the Present." New Haven's Hospitals. Last modified May 2000. Accessed May 3, 2019. http://doc1.med.yale.edu/news/exhibits/hospitals/1960s.html.
7. "Polio and Iron Lungs in the 1950s | American Masters -- Tanaquil Le Clercq: Afternoon of a Faun." Video file. Youtube. Posted by PBS, June 4, 2014. Accessed May 16, 2019. https://www.youtube.com/watch?v=VKBf3M-KJ4s.
8. "Iron Lung." Cottingham Road Club. Last modified April 26, 2017. Accessed May 17, 2019. https://cottinghamroadclub.co.uk/2017/04/27/ladies-underwear-motionless-dog-iron-lung/iron-lung/.
9. "Iron Lung." The Wood Library-Museum. Accessed May 17, 2019. https://www.woodlibrarymuseum.org/museum/item/918/iron-lung.
10. Ibid.
11. "John 'Jack' Haven Emerson." Polioplace. Accessed May 17, 2019. https://www.polioplace.org/people/john-h-emerson.