life-support system

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Equipment that creates a viable environment under conditions otherwise incompatible with life.
• noun Medical equipment that augments or substitutes for an essential bodily function, such as respiration, enabling a patient who otherwise might not survive to live.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun equipment that makes life possible in otherwise deadly environmental conditions
• noun medical equipment that assists or replaces important bodily functions and so enables a patient to live who otherwise might not survive