AIMTo observe the protection effect of a new combined anti-G measure which was composed of KH-x anti-G suit, unassisted PBG (positive pressure breathing for G, PBG) and PHP maneuver. The problem of fatigue and pain when using this measure was also discussed.

METHODSFive fully qualified centrifuge subjects were exposed to 5 groups of +Gz exposure: (1) relaxed tolerance, (2) KH-x and KT-x, (3) PBG, (4) 6.5 G 45 s, (5) 9.0 G 15 s. The subjective feeling of fatigue and pain induced by +Gz exposure was evaluated by the questionnaire after runs.

RESULTSThere was no incidents of G-induced lose of consciousness in this study. The protective effect of KH-x and KT-x was 2.3 G while it was 1.7 G for PBG. All the subjects have accomplished the 4th and 5th runs. The pain has developed on neck, waist, arm and hands. The problem of waist pain was very significant.

CONCLUSIONThe new combined anti-G measure could meet the requirement of +9.0 Gz protection for high performance plane. How to prevent the occurrence of neck injury and alleviate the pain induced by G when using this measure should be studied further.

Acceleration ; Adult ; Aerospace Medicine ; Fatigue ; prevention & control ; Gravity Suits ; Humans ; Male ; Pain ; prevention & control ; Space Suits ; Young Adult

AIMTo investigate the +Gz protection provided by tilt-back seat and GZ-2 anti-G suit.

METHODS6 subjects were exposed to centrifuge and onset rate is 3 G/s. First, their relaxed +Gz tolerances were determined while using tilt-back seat of 13 degrees. Secondly, it was their +Gz tolerance provided by pressurized GZ-2 anti-G suit and tilt-back seat of 13 degrees. Finally, their +Gz tolerances while using pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees were determined. The difference between the first and the third result was the +Gz protection that pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees offered.

RESULTS+Gz protection of pressurized GZ-2 anti-G suit and tilt-back seat of 13 degrees was 3.06 G, and +Gz protection of pressurized GZ-2 anti-G suit and tilt-back seat of 45 degrees was 4.13 G, which had an increase of 1.06 G.

CONCLUSIONTilt-back seat of 45 degrees can greatly enhance +Gz tolerances of human.

Adolescent ; Aerospace Medicine ; instrumentation ; methods ; Centrifugation ; Gravity Suits ; Humans ; Hypergravity ; Male ; Posture ; Protective Clothing ; Young Adult

Adolescent ; Adult ; Blood Pressure ; Gravity Suits ; Heart Function Tests ; Humans ; Male ; Positive-Pressure Respiration ; Young Adult

AIMTo assess the +Gz protection afforded by an advanced bladder anti-G system in the centrifuge against a capstan anti-G system.

METHODSTow centrifuge experiments were completed, respectively, by two groups of six male subjects. In the first experiment, subjects using advanced bladder anti-G system, the +Gz protection afforded by this anti-G system was determined. Then they were exposed to simulated air combat maneuver (SACM)I with leg straining, the +Gz-time tolerance was determined. In the second experiment, subjects using capstan anti-G system, the +Gz protection afforded by this anti-G system was determined. Then they were exposed to SACMII with anti-G straining maneuver, the +Gz-time tolerance was determined.

RESULTSThe anti-G effectiveness of the advanced bladder system was 5.33 G, which was significantly higher than that of the capstan system by 1.35 G (P < 0.01). All subjects of the two groups passed themselves SACM, but the effort, fatigue, and heart rates of the first group subjects were lower than those of the second group subjects.

CONCLUSIONThe results demonstrate that the +Gz protection afforded by the advanced bladder anti-G system is significantly higher than that by the capstan system.

Adult ; Aerospace Medicine ; instrumentation ; Aviation ; instrumentation ; Centrifugation ; instrumentation ; Equipment Design ; Gravity Suits ; Humans ; Male ; Physical Endurance ; physiology ; Young Adult