AEROSPACE MEDICINE

specialized branch of medical science concerned with those medical problems encountered in human flight in the atmosphere (aviation medicine) and beyond the atmosphere (space medicine). The ultimate aim of this specialty is to promote the safety and effectiveness of humans while they are exposed to the stresses of aerospace flight, such as extreme temperatures, low atmospheric pressure, radiation, noise, vibrations, oxygen deprivation, and the strong forces of acceleration and deceleration. Other hazards of space flight include weightlessness, motion sickness, pilot fatigue, discomfort from hunger or sleepiness due to the absence of the Earth's day-and-night cycle, and psychological disturbances caused by confinement and isolation. These problems, however, are generally prevented by intensive preflight training in high-powered simulators and by careful design of equipment and spacecraft. The 19th-century French physiologist Paul Bert is generally regarded as the father of modern aviation medicine. His classic observations of the effects of both high and low air pressure on balloonists were used extensively beginning in World War II and prompted a broad and vigorous program of research. In 1948 the first unit for space research in the world was established in the United States, and as major technological advances were made in space flight, space medicine became recognized as an important medical specialty. Specialists in civil and military aerospace medicine establish and apply appropriate medical standards for the certification and selection of pilots and other flight personnel to assure that they have no physical limitations or medical conditions that could impair their performance. Physicians who are trained in aerospace medicine are known as flight surgeons. Aerospace medical specialists plan and help to carry out flight-crew training in first aid and in the prevention of illness and injuries among passengers; they also assist in training paramedical personnel in the aerial transportation of patients. Such specialists also apply the principles of preventive medicine to avert the spread of disease by air travel. In addition, they conduct postflight medical evaluations of astronauts to identify any adverse effects of space flight on the body. During space flight, they monitor physiologic responses of astronauts and advise them on the management of in-flight medical problems. Beyond the scope of clinical medicine, they often help to develop the vehicles, emergency systems, and protective equipment for manned aerospace flight.