Ryoo Han C, Hrebien Leonid, Shender Barry S
School of Biomedical Engineering, Science and Health Systems, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
Biomed Sci Instrum. 2002;38:1-7.
Noninvasive monitoring of the relative change in oxygen saturation (rSO2) in cerebral tissue by near-infrared multi-wavelength spectroscopy (NIRS) was investigated in humans under high acceleration (+Gz) stress. These profiles included sustained 15-second +Gz plateaus and repeated short duration +Gz pulses of varying duration. The end points in this study were loss of consciousness due to high +Gz exposure (GLOC). In many cases subjects demonstrated cognitive and physical symptoms related to reduced cerebral blood flow without frank unconscious, which has been called Almost Loss of Consciousness (ALOC). Both the rSO2 levels during and after the +Gz exposures and the total time subjects were incapacitated after GLOC were recorded. It was found that while the drop in rSO2 at the onset of GLOC was lower during pulse exposures as compared to sustained exposures, the total time to recovery from GLOC was longer during the sustained runs. By applying a better understanding of the nature and timing of +Gz-induced changes in cerebral tissue oxygenation, more efficient control systems for personal protective gear for pilots of high performance aircraft can be implemented.
在人体处于高加速度（+Gz）应激状态下，研究了通过近红外多波长光谱法（NIRS）对脑组织中氧饱和度相对变化（rSO2）进行无创监测。这些情况包括持续15秒的+Gz平台期以及持续时间不同的重复短时长+Gz脉冲。本研究的终点是因高+Gz暴露导致意识丧失（GLOC）。在许多情况下，受试者表现出与脑血流量减少相关的认知和身体症状，但未出现明显昏迷，这被称为近乎意识丧失（ALOC）。记录了+Gz暴露期间及之后的rSO2水平以及受试者在GLOC后丧失能力的总时间。结果发现，与持续暴露相比，脉冲暴露期间GLOC开始时rSO2的下降幅度较小，但持续暴露后从GLOC恢复的总时间更长。通过更好地理解+Gz引起的脑组织氧合变化的性质和时间，可以实施更高效的高性能飞机飞行员个人防护装备控制系统。
