The "Steve Jobs" biography by Walter Isaacson specifically mentioned that Steve spent a good portion of his time in the hospital designing superior interfaces for the medical devices that surrounded him.
Maybe I'm wrong but it wasn't so much designing as it was complaining about the design of various devices around him. I remember something about a face mask and the pulse reader on his finger. I'm not sure though. It came off as he was being a bit difficult rather than offering up design suggestions.