Cryostasis
Cryostasis is the procedure in which a human is "preserved" for a very long period of time. Essentially, a human is frozen, while keeping vital functions of the body supplemented as needed.
Cryostasis is used typically for long-term preservation of an organic life-form. Cryostasis was used early in the 2400s to preserve many terminally ill patients in hopes that one day there will be a cure. Unfortunately for many of them, cures were not found for many of the diseases they sought to escape from, and once the cyborg technology became a viable option instead of endless cryostasis, many of the humans in cryostasis at the time were converted into the first-run of cyborgs once the companies that originally kept the humans in cryostasis were bought out.
Humans that were in cryostasis before the first UY and turned into cyborgs are known as Cryocyborgs. Since the first UY, cryostasis has not been a popular venue of life preservation, as cyborgs became much more cost-effective and met the goal of what cryostasis had been generally used for. Cryocyborgs are known as the oldest group of cyborgs.
Since the first UY, cryostasis is only mainly used for preservation of specimens, or for temporary cryostasis in long-term conventional space travel before astral gates and dimensional travel were put into use. Temporary cryostasis is known as cryosleep, and is vital for many humans during space travel, but not all, depending on whether they are a cyborg or some other modified human.