Indexing Behavioral Decrements by Computerized Assessment of Stance

平衡感觉器官允许人保持直立姿势，并将物体定位在图像清晰度最好的中央视野中。长期以来，医生一直使用姿势和步态作为损伤和疾病的指示器；同样，药物和酒精会在其他健康的人身上产生平衡障碍。因此，稳定性的变化在临床和研究环境中都被用作中枢神经系统功能的总体指标。尽管存在一些临床电池，但这些电池往往很昂贵，而且需要笨重的固定设备。在实验工作中，还没有一种便携的、自动评分的、负担得起的方法来测量姿势稳定性。在这项工作的第一阶段，我们假设仅测量头部位置就足以代表整体稳定性，设计并建造了一个使用新的视频记录和图像捕获技术的原型设备，并开发了用于根据视频记录自动分析头部运动的软件。评估了16项姿势测量，并根据测量特性选择了一项进一步使用。使用该原型，我们分析了头部运动，并获得了三个关键结果：a)单个受试者的头部运动与小组在不那么复杂的“摔倒时间”测量上的结果完全一致，表明该方法对个人测量有用；b)随着酒精剂量的增加，发现更多和更大的头部运动；以及c)两名飞行员在使用飞行模拟器后姿势稳定性显著下降。这项研究的潜在商业应用可以用来衡量中枢神经功能，它可以与日常生活中的表现联系起来，a)作为工作场所的适应指数；b)测量与新开发的虚拟现实系统相关的越来越多的报道的后遗症；c)索引疾病、药物治疗或药物使用的时间-病程变化；以及d)评估老年、体弱或其他临床人群中L的后遗症稳定性。

The sensory organs of balance permit a person to maintain upright posture and to position objects in the central field of vision where image clarity is best. Physicians have long used stance and gait as pointers to damage and disease; likewise drugs and alcohol will produce balance disturbances in otherwise healthy individuals. Changes in steadiness have thus served in both clinical and research settings as an overall index of central nervous system functioning. Although some clinical batteries exist, these tend to be expensive and require cumbersome, fixed apparatuses. There has not been a portable, automatically scored, and affordable way to measure postural stability in experimental work. In Phase I of this effort, we hypothesized that measures of head position alone could adequately represent overall steadiness, designed and built a prototype device using new video recording and image capturing technology, and developed software for automated analysis of head movements from video records. Sixteen postural measures were evaluated, and one was selected for further use based on measurement properties. Using the prototype, we analyzed head movements and obtained three key results: a) Head movements for a single subject showed perfect agreement with group results on a less sophisticated "time to fall" measure, showing that the approach was useful for individual measurement; b) more and larger head movements were found with increasing doses of alcohol; and c) two aviators showed significant decreases in postural steadiness after using a flight simulator. POTENTIAL COMMERCIAL APPLICATIONS OF THE RESEARCH A general measure of central nervous function which can be connected to performance in everyday life could be used, a) as a fitness-for-duty index in the workplace; b) to measure aftereffects which are increasingly being reported in connection with the newly developing virtual reality systems; c) to index time-course change of disease, drug therapy, or drug usage; and d) to assess postura l stability in the elderly, infirm, or other clinical populations.