DiScenna A O, Das V, Zivotofsky A Z, Seidman S H, Leigh R J
Department of Biomedical Engineering, Department of Veterans Affairs Medical Center, Case Western Reserve University, Cleveland, OH, USA.
J Neurosci Methods. 1995 May;58(1-2):89-94. doi: 10.1016/0165-0270(94)00162-a.
We have evaluated a video-based method for measuring binocular horizontal and vertical eye movements of human subjects by comparing it with the magnetic search coil technique. This video tracking system (VTS) uses multiple infrared light sources and small video cameras to simultaneously measure the positions of reflected corneal images and the center of the pupil. The system has a linear range of approximately +/- 40 degrees horizontally and +/- 30 degrees vertically, a sampling rate of 120 Hz (180 Hz with the head fixed), and system noise with standard deviation of < 0.04 degree. The binocular eye-tracking system is light-weight (190 g), being mounted on goggles that, with the eyes in primary position, permit a field of view of 60 degrees horizontally and vertically. The VTS is insensitive to translations of the tracker relative to the eyes. By placing the video preprocessing unit on a cart, eye movements may be recorded while subjects walk through distances up to 100 feet. In comparison with the magnetic search coil technique, the VTS generally provides reliable measurements of horizontal and vertical eye position; eye velocity is noisier than corresponding coil signals, but superior to electro-oculography.
我们通过将基于视频的方法与磁搜索线圈技术进行比较，评估了一种用于测量人类受试者双眼水平和垂直眼动的方法。这种视频跟踪系统（VTS）使用多个红外光源和小型摄像机来同时测量反射角膜图像的位置和瞳孔中心。该系统的水平线性范围约为+/-40度，垂直线性范围约为+/-30度，采样率为120Hz（头部固定时为180Hz），系统噪声标准差<0.04度。双目眼动跟踪系统重量轻（190克），安装在护目镜上，当眼睛处于初始位置时，水平和垂直视野均为60度。VTS对跟踪器相对于眼睛的平移不敏感。通过将视频预处理单元放置在推车上，可以在受试者行走长达100英尺的距离时记录眼动。与磁搜索线圈技术相比，VTS通常能提供可靠的水平和垂直眼位测量；眼速度比相应的线圈信号噪声大，但优于眼电图。
