CPP Curiosities: The Iron Lung

Logo for CPP Curiosities

Greetings, patient historico-medico aficionados. After a brief hiatus, your monthly dose of the medically weird is back again. In keeping with our transition from CEPI to the Center for Education, CEPI Curiosities is also receiving a new moniker: CPP (as in College of Physicians of Philadelphia) Curiosities. Make no mistake, however, despite the new name we are sticking to our tried-and-true formula of medical history stories to surprise you or at the very least make you look at the world of medicine just a bit differently.

This time around we are tackling the strange and fascinating history of the negative pressure ventilator, more commonly known as the “iron lung.”

Emerson Iron Lung at the Mütter Museum

Emerson Iron Lung at the Mütter Museum

“Iron Lung” is a colloquial term for a variety of artificial respiration machines that encapsulate all or part of a patient’s body. They help a person breathe through a method called negative pressure ventilation where the air pressure surrounding the patient’s body is reduced, forcing their lungs to expand and take in air; the pressure around the patient is then increased, causing them to exhale. For a time, iron lungs were a common treatment during the twentieth century for conditions where a patient could not sufficiently breathe unassisted.

However, they are most commonly associated with one particular disease: polio. Also known as infantile paralysis or poliomyelitis, polio is caused by the poliovirus, a contagious virus most commonly spread through infected feces that comes into contact with a patient’s mouth. The majority of people exposed to the poliovirus exhibit no symptoms; according to the Centers for Disease Control and Prevention, one in four people infected with the poliovirus will have relatively mild symptoms, including sore throat, nausea, fatigue, headaches, and stomach pain, and these symptoms generally go away after a few days (this is known as “abortive polio”). However, a small percentage of people exposed to the poliovirus develop temporary or permanent neurological symptoms, ranging from light sensitivity and stiffness to muscle spasms to partial or total paralysis.

Image of a patient's legs with chronic anterior poliomyelitis, Source: Historical Medical Library of the College of Physicians of Philadelphia

Image of a patient’s legs with chronic anterior poliomyelitis, Source: Historical Medical Library of the College of Physicians of Philadelphia

According to our sister page, History of Vaccines, the earliest reported polio outbreak in the United States took place in 1894. The nation’s most severe outbreak occurred in the 1930s-1950s. The development of polio vaccines and public health initiatives to inoculate the public significantly reduced the number of polio cases. Thanks to vaccines, polio has been largely eradicated in the developed world (it was eliminated in the US in 1979). However, periodic outbreaks occur in areas with limited or inadequate medical resources. Between 2013 and 2015, a polio epidemic spread through Syria and into neighboring Iraq followed by a second outbreak in Syria in June 2017 as well as another in the Congo around the same time.

Conceptually, negative pressure ventilation dates back to the late 1700s, and the earliest negative pressure devices emerged in the mid 1800s. In 1864, Alfred F. Jones of Lexington, KY, filed the first patent for a negative pressure respirator. His device, which he dubbed a “Restorator,” required the patient to sit upright in a small chamber with only their head exposed, covered in a specialized hood to maintain an air seal. Air circulated through the chamber through a hand pump. However, it’s unclear if Jones ever developed a model for mass production. In 1876, a French physician named Eugene Woillez developed what is considered the first functional negative pressure ventilator. Woillez’s “Spirophone” allowed for a patient to lie flat on their back, encasing them up to their neck in a sealed enclosure. Air was pumped into the Spirophone through the use of hand-operated bellows.

Image of Alfred Jones' "Restorator" from his patent application US Patent No: US44198

Image of Alfred Jones’ “Restorator” from his patent application US Patent No: US44198

However, the negative pressure ventilator did not receive wide usage or exposure until the early 20th century. In 1928, a pair of Harvard University professors–Drs. Philip Drinker and Louis Agassiz Shaw–developed an automated negative pressure ventilator. Similar to the Spirophone, a patient lay flat on a movable table with all but their head and neck encased within the device. The Drinker respirator generated negative pressure via a motor that pumped a bellows (this silent film demonstrates it in action). They initially tested the device by conducting preliminary experiments on a cat before moving into to human testing on an eight-year-old girl with respiratory paralysis from polio. According to Drinker’s later accounts the girl’s breathing significantly improved after being encased in the Drinker respirator for a short period of time, and their “iron lung” quickly gained wide circulation as a treatment for polio-induced respiratory failure (Louis A. Shaw, “Cutaneous Respiration of the Cat,” American Journal of Physiology. 85 (1928): 158-167; Philip Drinker and Charles F. McKhann, III. The Use of a New Apparatus for the Prolonged Administration of Artificial Respiration: I. A Fatal Case of Poliomyelitis. JAMA. 92.20 (1929): 1658-166). In 1931, a Boston machinist named John Haven Emerson devised improvements for the Drinker and Shaw design; reportedly, Emerson approached Drinker with his ideas but found a tepid response, prompting him to design and sell it on his own. The Emerson Iron Lung proved lighter, more efficient, and significantly cheaper to produce than the Drinker model and became a staple in polio treatment wards across the country (Drinker also unsuccessfully attempted to sue Emerson for patent infringement). The College of Physicians has an Emerson Iron Lung among its vast collection; however, it is not currently on display.

During the polio outbreaks of the 1930s-1950s, if paralysis impeded a person’s ability to breathe (respiratory paralysis), they would be placed into an iron lung until such time as they could breathe on their own, usually after 1-2 weeks of treatment. However, in cases of extreme paralysis, patients may periodically be encased in one over the course of months or years. For those curious about what it is like to be in an iron lung, in 2010, the Journal of the Royal Society of Medicine published an account from Marshall Barr, a patient who regularly used an iron lung for fifteen years.

Robert Hicks, Mütter Museum Director Robert Hicks in an iron lung for an episode of the YouTube series Grey Matter

Robert Hicks, Mütter Museum Director Robert Hicks in an iron lung for an episode of the YouTube series Grey Matter

With the rise in positive pressure ventilation devices (the kind used in modern ventilators), negative pressure respirators like the iron lung generally fell out of favor. However, there are reportedly a small handful of patients who still utilize an iron lung to help them breathe.

Until next time, catch you on the strange side!

The Karabots Junior Fellows Test The Pox Hunter

Much of the curriculum of the current cohort of the Karabots Junior Fellows Program has revolved around games, from using games to teach our fellows about STEM concepts such as the spread of disease, crime scene investigation, and the Scientific Method to our Fellows designing their own forensic science-themed games. Recently, our Fellows got the chance to flex their game development muscles by acting as play testers for a computer game about vaccines.

The Karabots Junior Fellows test The Pox Hunter, a game about vaccination

The Fellows met with John Theibault who is part of a development team designing a game centered around public health and vaccination. The Pox Hunter puts players in the role of a physician in early 1800s Philadelphia whose goal is to convince people in the city to receive smallpox vaccinations in order to curtail a potentially deadly outbreak. The player pleads their case using different conversation tactics, such as empathy, reason, and intimidation, to convince a variety of characters representing different racial and socioeconomic groups throughout the city. Working individually or in pairs, the Fellows played through the game and offered their feedback. Drawing upon their experience developing and playtesting their own game prototypes, the Fellows shared what they felt were the game’s strengths and weaknesses and offered recommendations for what they would like to see in the final completed version.

The Karabots Junior Fellows navigate The Pox Hunter, a vaccination theme game currently in development

While The Pox Hunter is still in development, if you are interested in using games to learn more about vaccines, feel free to check out Illsville: Fight the Disease, an interactive activity that explores the evolution of vaccination developed by The College of Physicians of Philadelphia.