Peter F Hamilton's "Fallen Dragon" had a sub-plot along these lines. Some soldiers wore exo-suits-of-muscle that had access to valves embedded in the femoral an

Peter F Hamilton's "Fallen Dragon" had a sub-plot along these lines. Some soldiers wore exo-suits-of-muscle that had access to valves embedded in the femoral and carotid arteries. The human inside was breathing for both themselves and the suit while hooked up. The suits could be disconnected and hooked up to a external rack that did circulation and respiration when not in use.