Kim Sungho, Cho Taehwan, Lee Yongkyun, Koo Hyojin, Choi Booyong, Kim Dongsoo
Aerosp Med Hum Perform. 2017 Aug 1;88(8):737-742. doi: 10.3357/AMHP.4781.2017.
G-induced loss of consciousness (G-LOC) is mainly caused by failure to sustain an oxygenated blood supply to the pilot's brain because of the sudden acceleration in the direction of the +Gz axis, and is considered a critical safety issue. The purpose of this study was to develop G-LOC warning algorithms based on monitoring electromyograms (EMG) of the gastrocnemius muscle on the calf.
EMG data was retrieved from a total of 67 pilots and pilot trainees of the Korean Air Force during high-G training on a human centrifugal simulator. Seven EMG features were obtained from root mean square (RMS), integrated absolute value (IAV), and mean absolute value (MAV) for muscle contraction, slope sign changes (SSC), waveform length (WL), zero crossing (ZC), and median frequency (MF) for muscle contraction and fatigue.
Out of seven EMG features, IAV and WL showed a rapid decay before G-LOC. Based on these findings, this study developed two algorithms which can detect G-LOC during flight and provide warning signals to the pilots. The probability of G-LOC occurrence was detected through monitoring the decay trend for representing muscle endurance and climb rate of the IAV and WL value during sudden acceleration above 6 G, representing muscle power. The sensitivity of the algorithms using IAV and WL features was 100% and the specificity was 66.7%.
This study suggests that a G-LOC detecting and warning system may be a customized, real-time countermeasure by improving the accuracy of detecting G-LOC.Kim S, Cho T, Lee Y, Koo H, Choi B, Kim D. G-LOC warning algorithms based on EMG features of the gastrocnemius muscle. Aerosp Med Hum Perform. 2017; 88(8):737-742.
重力引起的意识丧失（G-LOC）主要是由于 +Gz 轴方向的突然加速导致无法维持向飞行员大脑供应含氧血液，被认为是一个关键的安全问题。本研究的目的是基于监测小腿腓肠肌的肌电图（EMG）来开发 G-LOC 预警算法。
在人体离心机模拟器上进行高重力训练期间，从韩国空军的 67 名飞行员和飞行学员中获取 EMG 数据。从均方根（RMS）、积分绝对值（IAV）和平均绝对值（MAV）获取了七个用于肌肉收缩的 EMG 特征，以及用于肌肉收缩和疲劳的斜率符号变化（SSC）、波形长度（WL）、过零（ZC）和中频（MF）。
在七个 EMG 特征中，IAV 和 WL 在 G-LOC 之前显示出快速衰减。基于这些发现，本研究开发了两种算法，可在飞行期间检测 G-LOC 并向飞行员提供警告信号。通过监测在超过 6G 的突然加速期间代表肌肉耐力的 IAV 和 WL 值的衰减趋势以及代表肌肉力量的爬升率来检测 G-LOC 发生的概率。使用 IAV 和 WL 特征的算法的灵敏度为 100%，特异性为 66.7%。
本研究表明，G-LOC 检测和预警系统可能是一种通过提高 G-LOC 检测准确性的定制实时对策。
金 S、赵 T、李 Y、古 H、崔 B、金 D。基于腓肠肌 EMG 特征的 G-LOC 预警算法。航空航天医学与人类表现。2017；88（8）：737 - 742。
