Cerebral hemodynamics and brain functional activity during lower body negative pressure.

Introduction: Exposure to high +Gz acceleration forces on a centrifuge or in an aircraft can severely decrease cerebral blood perfusion and cause rapid G-induced loss of consciousness. However, milder acceleration may gradually reduce cerebral blood flow and affect cognitive function in subtler ways. This study used lower body negative pressure (LBNP) to mimic +Gz circulatory effects in order to study cerebral hemodynamics and brain function.

[Changes of human cerebral blood flow velocity and blood oxygen saturation under lower body negative pressure in upright seated position].

Objective. To investigate the effect of lower body negative pressure (LBNP) in upright seated position on cerebral blood flow velocity, heart rate (HR), and blood oxygen saturation (SaO2) in human. Method.