Uh, you would mostly have to be completely ignorant of the more dystopic elements of nanotech rapid repair... https://www.youtube.com/watch?v=5QHKCYgrBiE
But to have seen at least a few episodes of Stargate where the use the sarcophagus to heal people.
Both area "idealized" to varying degrees. If we look at how nature does these things with lysomes, T-cells, macrophages, boils, cysts, rapid sloughing of skin.. It gets decidedly un-pretty. :D
My own biology is a bit atypical, but not exactly unique as I've found other people with similar issues. Had some heart and lung problems for 8-12 months, finally went on a long road trip down south as I thought I was gonna buy it. Into part of my motel stay, camping, fishing, goofing around I noticed a growth poking at me under on peck/boob whatever you wanna call it. Looks like a kind of welt you get from a bullet wound, but this one was erupting outwards like a very large whitehead.
It gets big enough that eventually, I get a scalpel, and lightly slice the top, try to drain it, and there's a BIT more than just the stuff at the top. Maybe a cubic inch of some mix of blood, pus, with the majority of it looking like metal shavings. Drain that while almost passing out, antibiotic goop it, bandage it, and drain it a few more times until its gone.
Good news is, my heart and lungs were 1000% better. Not sure what happened, but, other similar things happened. Various minor injuries, they quickly heal, and then the skin nearby looks like hundreds of exit pinpricks opened up, then healed.
While this sounds horrible, whatever my body is doing, seems to get the job done, and FAST. Now if this method could be transferred into other people, and sped up, improved. I honestly DO NOT think the craziest fucking QAnon would volunteer for it.
Doctors I've asked said this isn't unheard of, in housecats, big cats, various other animals. But unless you have bubonic plague, or nasty parasites like bot flies, not so much in people, in modern times at least. Or possibly, you have something lodged under your skin like a bullet fragment, or a similar deep puncture injury.
Anyway, the body is capable of amazing and horrible things. Supercharging it CAN be done. In theory you could attach something like an engineering parasite or accessory organ. Remember, ALL OF YOU once had an accessory organ far bigger than you called a Placenta.. And this could filter out your blood, provide nutrients, revive the skin, organs, acted as an immune system, toxin screen, hormonal balancing, take on dangerous wastes into itself, and what could not be excreted would die with the organ once its purpose was through.
Would someone want to be inside such a sack for 2-3 months like someone in Invasion of the Body Snatchers? Anyone? Anyone? :D Because that's EXACTLY what a medbed would be. Tie it into your blood, lymph, interstitial fluids, digestive system, skin, nervous system. Your lungs and digestive system would be filled with something like placental fluid, and your sensor system would be in the mother of all, not quite sensory deprivation tank, but tied to whatever your host organism was. Machine, quasi animal, some poor engineered creature(hopefully not fully sentient).
Is it possible to engineer such a thing that works? Sure, we've had the biological proof of it since forever. Since someone held a candle up to a living birds egg, fish egg, etc. And we've been creeping up on it with various life support schemes over the decades. But even the most green OBGYN nurse has seen enough things in school to know, even something biology has had working for half a billion years, can and does go VERY wrong from time to time.
Various farmers who've birthed an assortment of animals routinely see it go wrong. Say like a desiccated fetus, the placenta is engorged with blood and fluid. Somehow the fluid balance went to hell, some key genetic fragment failed, and you have a stillbirth. For something that's already been alive for a while, and hooked up to an engineered accessory organ, with LESS than a million years of trial runs.. Well, how desperately DO you want that fountain of youth. lol!