Lower body negative pressure system for simulation of +Gz-induced physiological strain.

Lower body negative pressure (LBNP) can be considered as an experimental substitute for the +Gz stress. In military aviation, pilots assume a near upright position and are subjected to +Gz stress in this position. An LBNP chamber has been developed in which negative pressure can be applied to the subject in the upright seated position. The chamber is easy to fabricate and can be used to assess the tolerance of subjects likely to be exposed to high levels of +Gz stress.