Monitoring, Swiss Federal Institute of Sport Magglingen (SFISM), Macolin 2532, Switzerland.
Mil Med. 2022 Oct 29;187(11-12):e1330-e1337. doi: 10.1093/milmed/usab509.
Objectively determining soldiers' fatigue levels could help prevent injuries or accidents resulting from inattention or decreased alertness. Eye-tracking technologies, such as optical eye tracking (OET) and electrooculography (EOG), are often used to monitor fatigue. Eyeblinks-especially blink frequency and blink duration-are known as easily observable and valid biomarkers of fatigue. Currently, various eye trackers (i.e., eye-tracking glasses) are available on the market using either OET or EOG technologies. These wearable eye trackers offer several advantages, including unobtrusive functionality, practicality, and low costs. However, several challenges and limitations must be considered when implementing these technologies in the field to monitor fatigue levels. This review investigates the feasibility of eye tracking in the field focusing on the practical applications in military operational environments.
This paper summarizes the existing literature about eyeblink dynamics and available wearable eye-tracking technologies, exposing challenges and limitations, as well as discussing practical recommendations on how to improve the feasibility of eye tracking in the field.
So far, no eye-tracking glasses can be recommended for use in a demanding work environment. First, eyeblink dynamics are influenced by multiple factors; therefore, environments, situations, and individual behavior must be taken into account. Second, the glasses' placement, sunlight, facial or body movements, vibrations, and sweat can drastically decrease measurement accuracy. The placement of the eye cameras for the OET and the placement of the electrodes for the EOG must be chosen consciously, the sampling rate must be minimal 200 Hz, and software and hardware must be robust to resist any factors influencing eye tracking.
Monitoring physiological and psychological readiness of soldiers, as well as other civil professionals that face higher risks when their attention is impaired or reduced, is necessary. However, improvements to eye-tracking devices' hardware, calibration method, sampling rate, and algorithm are needed in order to accurately monitor fatigue levels in the field.
客观地确定士兵的疲劳水平有助于防止因注意力不集中或警觉性下降而导致的伤害或事故。眼动跟踪技术，如光学眼跟踪（OET）和眼电图（EOG），常用于监测疲劳。眨眼 - 尤其是眨眼频率和眨眼持续时间 - 被认为是疲劳的易于观察和有效的生物标志物。目前，市场上有各种使用 OET 或 EOG 技术的眼动跟踪器（即眼动跟踪眼镜）。这些可穿戴眼动跟踪器具有一些优点，包括不引人注目的功能、实用性和低成本。然而，在现场实施这些技术以监测疲劳水平时，必须考虑到几个挑战和限制。本综述研究了眼动跟踪在现场的可行性，重点关注军事作战环境中的实际应用。
本文总结了关于眨眼动力学和现有可穿戴眼动跟踪技术的现有文献，揭示了挑战和限制，并讨论了如何提高现场眼动跟踪可行性的实用建议。
到目前为止，还没有可以推荐在苛刻工作环境中使用的眼动跟踪眼镜。首先，眨眼动力学受多种因素影响；因此，必须考虑环境、情况和个体行为。其次，眼镜的放置、阳光、面部或身体运动、振动和汗水会极大地降低测量精度。OET 的眼摄像头放置和 EOG 的电极放置必须有意识地选择，采样率必须最小为 200 Hz，软件和硬件必须具有鲁棒性，以抵抗任何影响眼跟踪的因素。
监测士兵的生理和心理准备状态，以及其他在注意力受损或降低时面临更高风险的民用专业人员，是必要的。然而，需要改进眼动跟踪设备的硬件、校准方法、采样率和算法，以便在现场准确监测疲劳水平。
