Blood Flow Measurements Under High-G Conditions: Early Prediction of Gz Tolerance

摘要

A method is presented for the prediction of man's +Gz tolerance in human centrifuge experiments without exposing the subject to excessive levels of positive gravity. The parameter that is measured is blood velocity in the temporal artery using an ultrasonic doppler velocimeter. Rather than using the cessation of forward blood velocity as an end point in +Gz tolerance studies, it is possible to use physiologic compensatory responses to decreased cerebral blood pressure as predictors of ultimate cessation of blood flow to the head. Five subjects were exposed to five different +Gz onset ramps and the results are discussed in this report.