The idea of putting a decaying radioactive isotope inside your chest might make you a little uneasy — and rightly so. But, in 1967, the National Heart Institute and the Atomic Energy Agency set out to make it happen in the form of an plutonium-238-powered atomic heart. Think Tony Stark with nuclear waste in his chest.
The program, operating on US government funds, actually went on for about a decade and was spurred by contractors who took great pains to frame this atomic solution as the only solution. In The Atlantic's story, Shelley McKellar explains their reasoning:
The ideal implantable device meant no external lines or connections from the patient to outside power sources and a ten-year reliability span. By comparison, conventional batteries required recharging multiple times each day from an external source and would need to be explanted from patients every two years.
So, essentially, the Atomic Energy Comission saw a problem they could (theoretically) fix and jumped on the opportunity to try. Of course, this created a whole new hurdle to overcome: how can you possibly embed radioactive content safely in the body. The Atlantic notes:
The NHI and AEC battled over the proper way of conducting the research: the NHI created a non-atomic intermediary device that they implanted into animals, while the AEC promoted an all-at-once design strategy. But both agencies saw the problems as fundamentally soluble.
So even though the NHI's attempt at keeping radioactive material out of the actual body with an "intermediary device" seems slightly more viable, their combined dreams never came to fruition. Even 50 years later, we still haven't been to find an "ideal implantable device". And with all our technological advances and knowledge, it's fascinating to think that, try as we might, we may never be able to perfectly conquer the incredible complexity of the human body. [The Atlantic]