多焦视网膜电图局部反应的提取技术

目的：探讨多焦视网膜电图局部反应的提取技术。方法：由241个六边形构成图形刺激矩阵，每个六边形在相同的m序列(长度为2^14-1)控制下作闪烁变化，但依次延迟2^6位。各个六边形同时分别刺激视网膜的不同部位，用DTL微电极记录整个视网膜的混合反应信号。利用m序列的伪随机特征，采用互相关技术，使用快速沃尔什变换，分离提取出多焦视网膜电图的各个局部反应。结果：对记录信号与刺激序列作互相关处理，可以获得局部反应，这些局部反应是视网膜对应部位视功能的客观反映。结论：根据提取到的多焦视网膜电图局部反应，可以对视网膜的早期病变，视路功能的异常情况作出客观、精确、定量、快捷的诊断，多焦技术是临床视觉电生理的一项重要发展。

The Method of Extracting the Local Responses in Multifocal ERG

Objective: To evaluate the technique of extracting the local responses in multifocal electroretinogram. Methods: The stimulus matrix used in this study consists of 241 hexagonal elements, each one flashing individually according to the equivalent m-sequence with length 214-1, and in turn with relative lag of 26 among elements. The hexagonal array stimulated different regions of retina simultaneously. DTL tiny fiber electrode was used for derivation of mixed signal from the full retina. The single local response from each element was extracted by the Fast Walsh transform algorithm and the cross-correlation technique, which utilized the pseudorandom features of m-sequence. Results: The local responses in multifocal electroretinogram were extracted by cross-correlating the mixed signal with the stimulus sequence and reflected the function in the retina's different regions. Conclusion: The local responses in multifocal electroretinogram can be objectively, precisely, quantitatively and fast used in the early diagnosis of retinal diseases and visual path dysfunction. The multifocal technique is a new important development in clinical visual electrophysiology.