Cyborgs of the past: The history of the iron lung
We live in a world of bionic limbs that are becoming increasingly futuristic and reminiscent of Iron Man, both in aesthetic and function. But these are almost exclusively external. They replace lost limbs, not organs inside our bodies. For this reason, the iron lung sounds like something straight out of a science fiction film, or like it belongs to The Justice League’s Cyborg. It is very far from futuristic however. In fact, it is a relic from the past, an archaic piece of machinery that was primarily used to treat those whose respiratory systems had become damaged due to polio.
Polio is a disease that ravaged the population of developed and third world countries alike at the start of the 1900s. Poliomyelitis is a virus that the body naturally produces antibodies against. For this reason many who contract the virus will never show symptoms and never know that they have it, as the body fights it off before it becomes a problem. However for an unlucky few the virus would reach their blood stream and would then attack the central nervous system. These people often experienced levels of paralysis, mostly in their legs. This was usually temporary, and with intensive physical therapy patients could regain some if not all of the strength and function of the affected limbs. However, for some the paralysis weakened the muscles of their respiratory system, making breathing difficult if not impossible.
Before modern respirators this was the most common cause of death affiliated with polio. Necessity being the mother of invention, the polio crisis prompted scientists to start putting effort into figuring out how to aide and restore respiration. In 1927 Philip Drinker and Louis Agassiz Shaw from Harvard University devised a version of a tank respirator that could maintain artificial respiration until the person had regained the strength to breathe independently again.
Drinker and Shaw’s iron lung worked on the premise of negative pressure. The device was an air tight chamber with a sliding bed that the patient would lie on. Their head would stick out of the top with a collar around their neck, making sure that the tank was air tight. The device ran on a 1 1/2 horse power motor that was attached to a lever. The lever would operate the leather bellows at the base of the tank which would suck air out of it, creating negative pressure and forcing the diaphragm of the patient to expand and draw breath into the lungs. In the event of a power cut or if the generator failed, then it could be operated manually by the lever. Nurses were trained in operating the lever and would rotate every few minutes to ensure that neither exhausted themselves.
The length of time that patients used the iron lung for varied from person to person. Some would only be in it for a few days whilst their respiratory systems regained strength, others would be in them for weeks or even months. For an unlucky few they would find themselves dependent on the iron lung in some capacity for the rest of their lives. Since the first patient was successfully treated in an iron lung in 1928 it became the standard practice of care for patient’s whose respiratory systems had become compromised. It would remain so until the 1960s when the positive pressure respirators were invented.
Despite this antiquated piece of machinery having become largely redundant, there are a few people who are still reliant on them. By 2013 there was only one person in the UK who was still reliant on an iron lung for respiration support, and there were 3 in the US as of 2017. Though they seem like archaic pieces of technology, for a long time they were all that stood between someone with a compromised respiratory system and death. They helped inspire the designs for the modern respirator and saved a generation of children from the polio virus that had threatened to devastate lives across the world.