Man In The Machine: A few early examples (some of which are even still around), but in the more modern day – and with the caveats mentioned under Cyborg – it’s virtually always easier, and more comfortable, just to go full infomorph (i.e., Brain Uploading) than try to keep the meat around just ’cause.
This is a companion discussion topic for the original entry at https://eldraeverse.com/2015/01/13/trope-a-day-man-in-the-machine