pressure than the surrounding atmosphere,
and so air rushes in.
This is called negative pressure breathing,
and it’s also how an iron lung works.ANDEXHALE
The earliest example of the idea of assisted
negative pressure breathing comes from as far
back as 1670. English scientist John Mayvow
built a fairly terrifying model with bellows and
bladders as part of his general obsession with
trying to igure out how respiration worked.
But this was just to demonstrate the idea of
negative pressure breathing.
Actual use of such devices as medical
therapy, didn’t start until the 1830s, and the
irst mass production of a machine we’d
recognise as an iron lung came along in 1928.
Invented - and patented - by US Harvard
professor of industrial hygiene (actual title)
Philip Drinker, it was powered by pumps from
vacuum cleaners and an electric motor.
The idea is straightforward. The iron
lung is an airtight chamber in which
the patient lies, with their head
sticking out one end. An airtight
scary rubber seal goes
around their neck, and
then air is pumped out
of the chamber.
This causes the
patient’s chest to rise, the
lungs to expand, and air
from outside the chamber toPaying the Iron Price
The Iron Lung is a truly terrifying thing. A great chunk of primitive technology that
traps you, but on which you depend totally for survival. The worst part? It works.by ANTHONY FORDHAMWHAT’S YOUR ULTIMATE MEDICAL-
emergency-based, full-on existential-dread-
inspiring, total-body-horror nightmare? All
over body third degree burns, of course, but
right behind that has to be something that robs
you of your ability to breathe for yourself.
Today, tracheotomies and intubation are
pretty scary, but it could be worse. You could
have had polio in the 1950s and ended up in one
of these things: an iron lung.
While there are bunch of pathogens and
poisons that can cause respiratory paralysis, the
most “popular” way to wind up in an iron lung
was via a disease called poliomyelitis.
This is the cause of the infamous polio-
paralysis which left so many kids with limited
mobility. Future US President Franklin D
Roosevelt was also a victim... or at least, that’s
what his doctors thought at the time, though
subsequent research has suggested he probably
had the autoimmune condition Guillian-Barre
Syndrome. But that’s another story.
Anyway, losing the ability to walk thanks to
polio is pretty terrible, but losing control of your
diaphragm is probably worse. Unable to draw
breath, victims would simply suffocate.
Today we mainly use “positive pressure
ventilation”. We intubate the patient, and then
push air into their lungs. After each pump, the
lungs deflate naturally...
...except that’s not actually how human
respiration works. We don’t force air into our
lungs, we force it out, then open up the lungs
again. With less air inside, they are at a lower
The iron lung was refined over the years, to give doctors finer control of air pressure and to make it
more comfortable (or at least, less uncomfortable) for patients. A few people in the US still use them.
Iron lungs saved many children
during polio outbreaks. Most only
had to spend days or a few weeks in
the lung, until the paralysis passed.78 POPULAR SCIENCE