The Iron Lung: Medicine's Strangest Life-Saving Machine

Elle
Aug 19
8 min read

Imagine being completely paralyzed. You can't move your arms, your legs, or even your chest. But your brain still works. You can see, hear, think, and feel everything. And now you're lying inside a giant metal tube, with only your head sticking out, while a machine breathes for you.

That's what it was like to be trapped in an iron lung.

For most of the 20th century, the iron lung was one of the most terrifying and life-saving machines ever invented. It looked like a coffin made of metal. It sounded like a vacuum cleaner mixed with a dying robot. And it kept thousands of people alive during one of the worst disease epidemics in American history.

The iron lung is basically a time capsule of medical innovation. It's weird, it's horrifying, and it's absolutely fascinating. And the story of how it was invented and used tells us a lot about human ingenuity, disease, and what happens when we refuse to give up on saving people's lives.

The Disease That Changed Everything

Before we talk about the iron lung, we need to talk about polio. If you haven't heard of it, that's actually a good thing. It means the vaccine worked.

Polio, short for poliomyelitis, is a viral disease that can paralyze you. Most people who catch polio have mild symptoms or no symptoms at all. But some people get hit hard. The virus attacks nerve cells in the spinal cord, destroying the neurons that control your muscles. When the virus damages these neurons, the muscles they control stop working. Permanently.

For most people with severe polio, the paralysis starts in the legs and works its way up. Your legs go numb. Then your arms. Then your torso. And if the virus reaches your diaphragm, the muscle that controls your breathing, you lose the ability to breathe.

You can think. You can see. You can hear. You can feel. But you can't breathe on your own.

In the early 20th century, polio was one of the most feared diseases in the world. It killed thousands of people and paralyzed hundreds of thousands more. In industrialized countries, it became basically the plague of the modern era. Parents were terrified to let their kids play outside in summer because that's when polio season hit.

In 1916, there was a massive polio outbreak in New York City. Over 9,000 people got the disease. Nearly 2,400 people died. The city was basically in panic mode. Hospitals were overwhelmed. There was no cure. There was no vaccine (yet). And if the virus got your diaphragm, you were done for.

Then, in 1928, two Harvard engineers had an idea.

The Box That Breathes

Philip Drinker and Louis Agassiz Shaw invented the first iron lung in 1927 at Harvard University, and it was implemented with patients in 1929. The first iron lung was used at Boston Children's Hospital to save the life of an eight-year-old girl with polio in 1928.

The machine they invented was simple in concept but ingenious in execution. The machine consisted of an airtight chamber that enclosed the body, with bellows attached at the foot end. Patients lie inside with just their heads resting outside, with a seal around the patient's neck creating a vacuum. Bellows at the base of the device function like a human diaphragm, creating negative pressure to fill the user's lungs with air and positive pressure to allow exhalation.

Here's how it actually worked: The iron lungs used negative pressure ventilation to compress and depress the chest, simulating respiration. Think of it like this: when you breathe normally, your diaphragm contracts and pulls down, creating negative pressure in your lungs. Air rushes in to fill that negative space. Your lungs expand.

The iron lung does the same thing. The bellows create a vacuum inside the metal chamber. The pressure difference pulls air into the patient's lungs. Then the bellows release and push out, creating positive pressure that forces air out. Breathe in. Breathe out. Breathe in. Breathe out. All without the patient having to do anything except exist.

It was incredibly simple. It was also absolutely genius.

The Coffin-Like Chamber Becomes an Icon

By 1939, around 1,000 iron lungs were in use in the USA. But that was just the beginning.

When the polio epidemics really hit in the 1940s and 1950s, everything changed. During the polio outbreaks of the 1940s and 1950s, iron lungs filled hospital wards, assisting patients with paralyzed diaphragms in their recovery.

Hospital wards full of iron lungs became a defining image of the era. Imagine walking into a hospital ward during a polio epidemic: rows and rows of giant metal tubes with human heads sticking out. The constant whoosh-whoosh sound of the bellows. The eerie mechanical rhythm of hundreds of machines all breathing in sync.

The wards were filled with the thrum of the motors and the whoosh of the bellows that accompanied the operation of iron lungs.

For patients inside, it was claustrophobic and terrifying. You couldn't move. You couldn't leave. You were essentially imprisoned in a metal box. But you were alive. And if not for the iron lung, you wouldn't be.

In 1931, John Haven Emerson designed and invented the Emerson Respirator, an improvement over the Drinker model developed in 1928. The Emerson model became the more popular version, and many of the iron lungs in hospitals were Emerson machines.

Life Inside the Machine

Living in an iron lung was surreal. You were trapped, but you weren't dying. You could talk (sort of). Hospitals added mirrors inside the machines so patients could see what was happening around them. Some iron lungs had windows so visitors could see the patients' faces.

Patients had to spend hours inside the machine every day. Some spent entire years, or even decades, inside. Their whole life became the metal tube and the bellows' rhythm.

Some patients needed the machine 24 hours a day. Others could breathe on their own for short periods and only needed the machine at night or when they got tired. But for those with severe paralysis of the diaphragm, the iron lung was their lungs. Without it, they would die within minutes.

Imagine that. Imagine knowing that if the electricity goes out, you die. If the machine breaks, you die. If there's a problem and no one notices, you die.

The psychological impact must have been intense. Some patients adapted. Some struggled. Many did both. But they survived. They lived. They existed in these machines, sometimes for decades.

The Gradual Fade

The iron lung's dominance didn't last forever. As polio vaccination programs rolled out in the 1950s and 1960s, fewer people got polio. The vaccine was like a miracle cure for the disease. Within a generation, polio went from one of the most feared diseases to something that barely anyone had heard of.

At the same time, technology improved. New ventilators were developed that were smaller, more portable, and less claustrophobic. Methods of care were transformed when mechanical ventilation evolved as standard practice for the treatment of patients with acute respiratory failure in the first ICUs in the 1960s.

The iron lung became obsolete. Hospital wards full of whooshing metal tubes were replaced by modern ICUs with sleeker machines. The iconic image of the polio era faded.

The Last Survivors

But the iron lung didn't completely disappear. Some people who got polio decades ago are still alive. And some of them still use iron lungs.

Martha Lillard had just turned 5 years old when polio incapacitated her. She still uses a form of the ventilator that saved her life as a child. There are a handful of people like Martha, living with the legacy of polio epidemics from 70 or 80 years ago. They're the last survivors of the iron lung era.

These people face challenges. The machines are old. Replacement parts are hard to find. Hospitals aren't familiar with iron lungs anymore because they don't see them. But these survivors keep using them because the machines still work, and they're what these patients' bodies have adapted to.

It's like being stuck in a time capsule. These people are living reminders of a disease that almost destroyed a generation, and a technology that saved lives when nothing else could.

Why This Matters

The iron lung story tells us something important about medical innovation. Sometimes the best solution isn't flashy or high-tech. Sometimes it's just a metal box with some bellows that does one job and does it really, really well.

The iron lung didn't cure polio. But it gave patients time. It gave them life. It turned a death sentence into a chronic condition. It bought time for researchers to develop a vaccine. And in the decades after the vaccine was developed, it became a less-used but still-vital piece of medical equipment for people with other respiratory conditions.

The iron lung also reminds us about the importance of fighting diseases with vaccines and public health measures. Once polio vaccination became widespread, the iron lung became almost unnecessary. The best medical intervention isn't always the most advanced piece of equipment. Sometimes it's preventing the disease from happening in the first place.

And the iron lung is a reminder of human determination. Engineers saw a problem and invented a solution. Doctors used that solution to save lives. Patients survived inside these machines, day after day, month after month, year after year, never giving up.

It's one of the most bizarre and beautiful pieces of medical history.

The Sound That Meant You Were Alive

If you ever listen to old recordings of iron lung wards, the first thing you notice is the sound. Whoosh. Whoosh. Whoosh. Over and over and over. That sound meant someone was alive. That sound meant a virus hadn't won. That sound meant medical innovation had found a way to keep people breathing when their bodies had betrayed them.

The iron lung isn't a sophisticated piece of equipment. It's not elegant or small or beautiful. It's bulky and mechanical and a little bit creepy-looking, but it worked. And for countless people in the 20th century, it meant the difference between life and death. Sometimes the most important inventions are the ones that do the simplest jobs in the most effective way. And sometimes the most powerful sound in the world is just a machine, breathing for someone who can't breathe for themselves.

Sources

Wikipedia - "Iron lung" - Development and use during polio outbreaks of 1940s and 1950s
Science Museum UK - "The Iron Lung" - First use at Boston Children's Hospital in 1928 and statistics on iron lung use
Britannica - "Iron lung" - Philip Drinker and Louis Shaw invention in 1927, implementation in 1929
CDC Museum - "Polio and The Epidemic Intelligence Service" - How iron lungs work and their use in treating polio
NPR - "Decades after polio, Martha is among the last to still rely on an iron lung to breathe" - How the iron lung functions with negative pressure ventilation and information on modern-day iron lung users
PubMed/PMC - "A practical mechanical respirator, 1929: the iron lung" - The Drinker respirator's use in treating respiratory paralysis
Ohio State University Health Sciences Library - "Emerson Respirator or Iron Lung" - John Haven Emerson's improvements to the design in 1931
Rare Historical Photos - "Iron Lungs for Polio Victims: Photos from the 1930s-1950s" - Negative pressure ventilation and polio's impact in the early 20th century
Barlow Respiratory Hospital - "From Iron Lungs to Modern Ventilators" - Treatment through the 1950s and transition to modern ventilation in the 1960s
Mayo Clinic - "History of polio: Outbreaks and vaccine timeline" - Iron lungs in isolation wards and their life-saving function
Vanderbilt University Medical Center - "Polio patients, iron lung respirators" - Description of iron lung wards during polio epidemics
MedicineNet - "How Long Can You Live in an Iron Lung?" - External negative pressure ventilation (ENPV) and how iron lungs mimic diaphragm function