What Is an Iron Lung?
An iron lung is a large, airtight metal chamber that helps a paralyzed person breathe by mechanically changing the air pressure around their chest, rather than pushing air directly into their lungs. The patient lies inside with only their head outside the machine. For decades, it was the only thing standing between severe polio paralysis and death — and remarkably, the technology’s real-world use didn’t fully end until 2026, nearly a century after it was invented. Here’s how it works, where it came from, and the story of the very last people who depended on one.
Picture a giant metal tube, roughly the size of a small car, with only a person’s head sticking out one end. That image sounds like science fiction, but for decades it was the difference between life and death for thousands of people paralyzed by polio.
What the Iron Lung Actually Is
An iron lung is a large, airtight metal chamber built to help someone breathe when their own chest muscles can’t do the job. The patient lies flat inside the tank with just their head poking out through a sealed opening, while the rest of their body stays enclosed. A motor-driven system inside the machine constantly changes the air pressure around the patient’s chest.
How Negative Pressure Ventilation Works
Here’s the clever part: instead of pushing air directly into the lungs the way a modern ventilator does, the iron lung works by changing the pressure surrounding the whole body. When the machine lowers the pressure inside the chamber, the chest expands and pulls air into the lungs naturally, the same way breathing works outside the machine. When the pressure rises again, the chest gets pushed back in and air flows back out. Doctors call this negative pressure ventilation, since it recreates breathing from the outside in, rather than forcing air in directly.
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Where the Iron Lung Idea Came From
The core concept wasn’t entirely new when the iron lung became famous. British physician John Dalziel described an early negative-pressure breathing box in 1832. Decades later, Dr. Woillez of Paris built a hand-operated, bellows-driven device called the “Spirophore” in 1876, and in 1918, Dr. Stueart of South Africa built a clay-sealed wooden box specifically to treat polio patients.
The version that changed medicine forever came out of Harvard in the late 1920s. Philip Drinker and Louis Agassiz Shaw, both researchers focused on industrial hygiene, built a working metal chamber and successfully used it on a patient for the first time in 1928. You can hear the full story of how the iron lung was invented from the American Chemical Society’s podcast on the topic. Their early machine ran on an electric motor hooked up to two ordinary vacuum cleaner pumps. A few years later, engineer John Haven Emerson refined the design into a lighter, more reliable version that became the standard model used in hospitals for decades.
| Year | Milestone |
|---|---|
| 1832 | John Dalziel (Scotland) describes the first negative-pressure breathing device |
| 1876 | Dr. Woillez (Paris) builds the hand-operated “Spirophore” |
| 1918 | Dr. Stueart (South Africa) builds a clay-sealed wooden box for polio patients |
| 1928 | Philip Drinker & Louis Agassiz Shaw (Harvard) build the first modern iron lung |
| 1931 | John Haven Emerson releases a lighter, cheaper, more reliable design |
| 1955 | Jonas Salk’s polio vaccine begins mass rollout in the U.S. |
| March 2024 | Paul Alexander, who used an iron lung for 72 years, dies at 78 |
| June 2026 | Martha Lillard, the last known American iron lung user, dies at 78 |
Why Polio Made the Iron Lung Necessary
Polio is a viral illness that can attack the nervous system, and in its most severe form, it can paralyze the muscles that control breathing. Before vaccines existed, polio outbreaks tore through communities every year, and doctors had almost no way to treat the disease itself. When paralysis reached the chest and diaphragm, a patient would slowly suffocate, since their body could no longer expand and contract on its own.
The iron lung changed that outcome completely. By taking over the mechanical work of breathing, it kept people alive long enough for their bodies to recover, which happened in many polio cases once the acute phase of the infection passed. For patients whose paralysis never fully went away, the machine became a long-term lifeline rather than a temporary bridge.
During the worst polio years in the mid-20th century, hospital wards lined with iron lungs became a common and unforgettable sight, especially in children’s hospitals. Some units housed dozens of patients side by side, each encased in their own tank, with nurses and family members able to see and speak with them only through small windows built into the sides of the machine.
What Life Inside an Iron Lung Was Actually Like
Living inside an iron lung wasn’t just physically demanding, it reshaped daily life entirely. Patients were essentially sealed away from normal physical contact with the world, able to interact with visitors mostly through their voice and whatever they could see through the machine’s small portholes. Simple things most people take for granted, like sitting up for a cup of tea, required careful monitoring, since even short breaks from the machine could leave a patient short of oxygen within minutes.
“That’s what keeps me healthy. That’s what heals me.”
— Martha Lillard, describing her iron lung, in a 2012 NBC News interview
Beyond breathing, severe polio sometimes affected the muscles needed for eating, swallowing, and speaking, so some patients had to relearn these basic skills after the worst of the illness passed. Despite all of this, plenty of iron lung patients went on to build full lives — some, like Lillard and Paul Alexander, even taught themselves glossopharyngeal breathing, a technique of gulping air using throat and mouth muscles that let them spend limited stretches of time outside the machine.
The Decline of the Iron Lung
Everything changed with the arrival of the polio vaccines developed by Jonas Salk and Albert Sabin in the 1950s and 1960s. As vaccination spread and new polio cases plummeted, the need for iron lungs dropped along with them. At the same time, medicine was moving toward positive pressure ventilation, the technique used in virtually all modern ventilators, where air gets pushed directly into the lungs through a tube inserted into the airway. This approach was more precise, easier to manage at a patient’s bedside, and far more practical for hospitals treating a wide range of breathing problems, not just polio.
By the later decades of the 20th century, iron lungs had mostly disappeared from active use, replaced by compact, bedside ventilators that could do the same job with a fraction of the size and complexity.
The Last People Who Ever Needed an Iron Lung
Here’s a detail that rarely gets much attention outside of specialized reporting: iron lungs didn’t fully vanish until remarkably recently — and as of this writing, that chapter has just closed for good.
Paul Alexander, a Texas man who contracted polio in 1952 at age six, spent nearly 72 years depending on his iron lung — taught himself glossopharyngeal breathing, earned a law degree, became a practicing attorney, and built a large TikTok following late in life before he died in March 2024 at age 78.
That left Martha Lillard of Oklahoma, who contracted polio in 1953 at age five, as the last known American still relying on an iron lung. Lillard slept in hers nightly for over 70 years. She died on June 26, 2026, at age 78, from complications linked to post-polio syndrome and long COVID — bringing to a close the practical, real-world use of a technology invented nearly a century earlier, in 1928.
Why the Iron Lung Still Matters
Even though nobody depends on an iron lung today, its legacy runs through nearly every ventilator used in hospitals right now. It was the first machine that let people survive on mechanical support for breathing over the long term, proving that technology could take over a basic bodily function indefinitely. That single idea reshaped critical care medicine and paved the way for the ICU ventilators, anesthesia breathing systems, and home respiratory devices used across the world today.
The iron lung was bulky, loud, and far from comfortable, but for thousands of families during the polio era, it was the machine standing between their loved one and death. That’s a legacy worth remembering, even in an age where a virus like polio has been pushed to the edge of eradication in most of the world.
Frequently Asked Questions
Does anyone still use an iron lung today?
No. As of June 2026, with the death of Martha Lillard, there is no longer a known iron lung user in the United States. She was the last of the two final known users, after Paul Alexander died in March 2024.
Why don’t hospitals use iron lungs anymore?
Modern positive-pressure ventilators push air directly into the lungs through a tube, making them smaller, more precise, and usable for a much wider range of breathing problems than the bulky, single-purpose iron lung.
How is an iron lung different from a modern ventilator?
An iron lung uses negative pressure — changing the air pressure around the whole body to make the chest expand and contract. A modern ventilator uses positive pressure, pushing air directly into the lungs through a tube in the airway.
This article is for historical and educational purposes and is not medical advice.
