Techniques to enhance safety in acceleration research and fighter aircrew training.

Acceleration (+Gz) research and aircrew training using human centrifuges involves considerable stress that can alter normal cardiovascular and neurologic function even in completely healthy individuals. It is clear that electrocardiographic rate, rhythm, and conduction disturbances are frequently associated with +Gz exposures. These cardiac changes can result in altered perfusion of the central nervous system (CNS) to an extent which exceeds that induced by the +Gz stress alone. Although centrifuge-based research and training have a proven record of overall safety, there is finite risk associated with such stressful exposures, and adverse events have been observed. It is, therefore, extremely important to continually develop improved avenues to enhance human safety during centrifuge exposure. We have implemented techniques that can be immediately employed by centrifuge medical personnel to reduce the potential for significant CNS embarrassment and possible injury. These include techniques to 1) reduce excessive parasympathetic tone that may result in marked bradycardia and transient asystole post +Gz stress, and 2) manually controlled inflation and pulsation of the anti-G suit to enhance CNS perfusion post +Gz stress.