Prevention of the pathophysiologic effects of acceleration in humans: fundamentals and historic perspectives

The deleterious effects of high-G environments and their relevance to the development of anti-G suits are examined. The history of efforts to protect fighter pilots against these effects is recounted. The discussion covers the discovery of cerebral anoxic reserve time, the limited power and consequent restricted sustained G capabilities of propeller-driven fighter planes, the use of M-1-type positive respiratory pressure muscular straining maneuvers, the development of more effective G suits after World War II, the pathophysiologic limitations of protection against G/sub z/ acceleration by external garments, the development of a premonitory G-LOC (loss of consciousness) warning system based on real-time monitoring of arterial opacity pulses within the ear, development of a horizontal prone position couch with a fiber-optic, video-assisted omnidirectional pilot surveillance system, physiological and anatomical considerations, and practical aspects (bodily comfort, field of view, etc.) of a prone cockpit position for fighter pilots.<>