system
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human
ELI5: How does an iron lung work?

I was reading up about polio and read that many children ended up in iron lungs to allow them to breath "normally". What exactly does the iron lung do to allow the patient to breath normally?
gpt
Your head is outside an airtight seal in the iron lung, so only the rest of your body is inside (generally, though at least your chest)

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The iron lung alters the air pressure in the chamber.  If the force of the air pressure in the chamber is less than the pressure in the lungs, the lungs seek to expand to correct the difference and will cause the person to inhale with a type of vacuum force, really.  When the pressure in the chamber then alternates to exceed the pressure of the lungs, it pushes down on the lungs with the increased air pressure, and causes the air to flow out of the lungs.

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It was a surprisingly elegant invention considering how much more invasive methods such as breathing tubes are with risks of infection, they aren't ideal for long term use. 

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