Yu M Z, Wu L Z, Wu D Z
Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou, P.R. China.
Doc Ophthalmol. 1990 Nov;76(1):37-46. doi: 10.1007/BF00140496.
The visual pursuit test is a method that collects and analyzes the characteristics of pursuit eye movements and examines the function of the eye movement system. This paper analyzes the model parameters of the smooth pursuit eye movement system in order to explore a method for improving the analysis. The input-output relationship of the smooth pursuit system can be expressed by a quasilinear model. We compute the model parameters (gain, phase, spectral purity, cross covariance) by digital signal processing. Eye movement is recorded by electrooculogram. Both eyes are tested individually. The visual target moves at frequencies of 0.2, 0.4, 0.8, 1.2, and 1.6 Hz. Ranges are gain, 1.01 to 0.70; phase, -0.1 degree to -66 degrees; spectral purity, 0.97 to 0.70; and cross covariance, 0.99 to 0.26. We tested 40 normal subjects as well as patients with ataxia (8), vertigo (18), and ophthalmoplegia (9). The oculomotor system of normal subjects functions as a linear system in the performance of this test at 0.2 to 0.8 Hz. The spectral purity dropped to about 0.70 at 1.6 Hz. The variability of all measures increases greatly at 1.6 Hz, which indicates that this target motion exceeds the tracking ability of many normal subjects and that the oculomotor system of normal subjects functions as a nonlinear system in this condition. Statistical tests show no significant differences between sex, age, and the two eyes. The model parameters tentatively proved effective in clinical application.
视觉追踪测试是一种收集和分析追踪眼球运动特征并检查眼球运动系统功能的方法。本文分析了平稳追踪眼球运动系统的模型参数，以探索一种改进分析的方法。平稳追踪系统的输入-输出关系可用准线性模型表示。我们通过数字信号处理来计算模型参数（增益、相位、频谱纯度、互协方差）。眼球运动通过眼电图记录。双眼分别进行测试。视觉目标以0.2、0.4、0.8、1.2和1.6赫兹的频率移动。范围为增益，1.01至0.70；相位，-0.1度至-66度；频谱纯度，0.97至0.70；互协方差，0.99至0.26。我们测试了40名正常受试者以及共济失调患者（8例）、眩晕患者（18例）和眼肌麻痹患者（9例）。在0.2至0.8赫兹的测试中，正常受试者的动眼系统表现为线性系统。在1.6赫兹时，频谱纯度降至约0.70。在1.6赫兹时，所有测量值的变异性大幅增加，这表明该目标运动超出了许多正常受试者的跟踪能力，并且在这种情况下正常受试者的动眼系统表现为非线性系统。统计测试表明性别、年龄和双眼之间无显著差异。模型参数在临床应用中初步证明是有效的。
