Relaxed Tolerance Following HSG.

摘要

INTRODUCTION. Changes in relaxed +Gz tolerance impacts the support required from G protective measures and may affect the capability of the aircrew to reengage following exposure to HSG. During and post-HSG, simultaneous physiological events which could increase or decrease G-tolerance are activated. METHODS. This study exposed 6 male centrifuge subjects to a GOR (Gradual Onset Rate = 0.067 G/second) acceleration to their subjective G-tolerance limit. Following a rest period, the subjects were exposed to a 7+GZ ROR (Rapid Onset Rate = 1.0 G/second) acceleration for 60 seconds. Immediately after the ROR the subjects were reexposed to the GOR and taken to their relaxed tolerance limit. RESULTS. The subjects relaxed tolerance on the first GOR (pre-HSG) was 5.4 +Gz +/- 0.7 (X +/- SD) and their second GOR tolerance (post-HSG) was 4.5 +/- 0.6. Statistical significance via Student's T Test (2 tailed) was p=0.065, but 5 of 6 subjects had a reduction in post-HS (i tolerance. Electrocardiogram and heart rate evaluations provided an indicator of the cardiovascular response. CONCLUSIONS. This study suggests that relaxed +Gz tolerance is lowered following a high G exposure. Such a post-HSG reduction in relaxed tolerance would place a greater burden on the pilot's G protective systems thereby limiting one's ability to fully utilize the capability of the aircraft. R laxed tolerance, High sustained +Gz, G-Tolerance.