Push-Pull Effect Simulation by the LBNP Device

LBNP (Lower body negative pressure) examination technique was initially applied in our case entirely as one of the Possibilities for preliminary indirect individual estimation of the pilot's positive gravitational acceleration (+Gz) tolerance. At present LBNP exposition is also used as a method of drill in anti-g maneuvers and for the simulation of the so-called Push-Pull effect. Pilot's +Gz tolerance can be affected by in particular the Push-Pull phenomenon. It is characterized by the rapid and significant decrease of blood pressure values accompanied by a slower return to normality as a result of compensation reaction. The tolerance decrease to the +Gz acceleration turns up during flights in aircraft in situation of +Gz action after previous impact of the negative acceleration. Just the slower return of blood pressure to the standard value after its previous rapid decrease is very dangerous reality during flights. At this period pilot's performance is reduced and an impairment of the vision and G-LOC can occur.