Is it ensure, insure, or assure?
life-support system n.
Equipment that creates a viable environment under conditions otherwise incompatible with life.
Medical equipment that augments or substitutes for an essential bodily function, such as respiration or excretion, enabling a patient who otherwise might not survive to live.
any mechanical device that enables a person to live and usually work in an environment such as outer space or underwater in which he could not otherwise function or survive for any appreciable amount of time. Life-support systems provide all or some of the elements essential for maintaining physical well being, as for example oxygen, nutrients, water, disposal of body wastes, and control of temperature and pressure. The danger of contaminants and psychological factors must also be considered. Life-support systems are designed not only to enable survival in inhospitable environments but also to obviate the extreme difficulty people sometimes have in working under such conditions; thus life-support systems promote comfort, efficiency, and safety as well.