This paper reviews three models that historically have been used to explain and describe the effects of greater than I g forces on humans: the hydrostatic column model, the blood oxygen saturation model, and the neurological model. We outline metrics that relate to each of the three models and offer a unified model based on integration of those models. The match between ground-based centrifuges and aircraft is examined, as is transfer of results from the centrifuge to the aircraft. Last, we examine the feasibility of using physiological, subjective, and performance metrics in the aircraft.
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