Experiments on the dynamic physical performance and physiological protection of a new type anti-G valve

Objective To evaluate the dynamic physical performance and physiological protection of a new type anti-G valve.Methods The experiments were carried out on human centrifuge.① The dynamic physical performance of No.1 F-type and S-type anti-G valve in wellbalanced state, 22° lean state and humidifying state were evaluated respectively in two configurations which anti-G valve at high-pressure class worked with KH-6 anti-G suit and at low-pressure class worked with KH-7 suit.② Twelve healthy male volunteers served as subjects for the human physiological protection experiments.The relaxed + Gz tolerance was measured first, then the +Gztolerance with anti-G suit.Two F-type anti-G valves were evaluated by 5 subjects using the above mentioned two configurations.One S-type anti-G valve was evaluated by the rest 7 subjects using the same two configurations.Results ① The outlet pressure of both F-type and S-type anti-G valve was in accordance with or slightly higher than the required upper limit.The delay between the reaching time of G plateau and stable peak pressure of 22° tilted No.1 F-type anti-G valve was mostly longer than 0.5 s both at low-pressure and high-pressure class.When in humidifying state, the delay was longer than 0.5 at low-pressure class and an obvious fluctuation of outlet pressure at high-pressure class was observed.For the S-type anti-G valve, under 22° lean state and humidifying state both at low-pressure and high-pressure class, the delay between the reaching time of G plateau and stable peak pressure was shorter than 0.5 s.And the time added the delay between G climbing and the starting time of outlet pressure ascending was shorter than 2 s.② +Gz tolerance increment provided by the No.2 F-type anti-G valve combined with KH-6 and KH-7 anti-G valve was 2.10 G (t= 14.00, P＜0.01 and 2.15 G (t=21.50, P＜0.01) respectively, and 2.20 G (t=23.52, P＜0.01) and 2.20 G (t=44.00, P＜0.01) for the No.3.+Gz tolerance increment provided by the S-type anti-G valve with KH-6 and KH-7 anti-G valve was 2.36 G (t=46.67, P＜0.01) and 2.21 G (t=28.74, P＜0.01) respectively.Conclusions The new type anti-G valve combined with anti-G suit could provide enhanced anti-G capability.The modification and enhancement to the structure of valve have a distinct positive effect on its adaptability to special states like lean or in humidification. Key words: Anti-gravity suits ;  Acceleration ;  Physical endurance ;  Anti-gravity valve ;  Human centrifuge ;