Abstract: A arterial blood velocity-to-volume flow rate converter, including a pair of function generators a computer, and a multiplier, is incorporated within a system to objectively measure by non-invasive means the blood volume flow rate to the head of an occupant in a rapidly accelerating vehicle, and take corrective measures to stabilize the vehicle when that flow falls below a preselected lower limit for a predetermined length of time. A conventional ultrasonic Doppler velocimeter determines the blood velocity, subsequently feeding a representative signal to pressure function generator. The output therefrom is then fed to a cross-sectional area signal generator which determines the time-varying area of the artery, a signal representing such being fed to the multiplier along with the velocity signal to compute the flow.