Satherley B L, Jones R D, Bones P J
Department of Electrical and Electronic Engineering, University of Canterbury, Christchurch, New Zealand.
Australas Phys Eng Sci Med. 1996 Sep;19(3):183-93.
An EEG spectral topography system has been developed to produce maps of the time-averaged spectra of a 16-channel EEG. The design of this system is based upon the discussions of the contentious issues of topography presented in Part I and a theoretical study of two-dimensional interpolation techniques. The comparison of techniques is based upon simulated electric fields on a three-layer spherical head model. Four two-dimensional interpolation techniques are investigated: bilinear, nearest neighbour, bicubic splines, and thin-plate splines. The most accurate method, a 2nd degree thin-plate spline, is employed in the new topography system. The EEG spectral topography system adopts the following procedures: the EEG is recorded using the 16 channel ipsilateral-ears montage; spectral analysis is applied to several overlapping epochs, relatively free of artifacts, of length 5.12 s; the averaged frequency spectrum is divided into specified frequency bands; for each channel, the average spectral component of each band is mapped onto a plane representing the head; and the maps are completed using 2nd degree thin-plate spline interpolation. A particular aim of the development was to produce a topography system compatible with the present EEG recording system at Christchurch Hospital. This has been achieved and, consequently, the topography system is of immediate clinical use. The system is currently part of a major clinical study.
已经开发出一种脑电图频谱地形图系统，用于生成16通道脑电图的时间平均频谱图。该系统的设计基于第一部分中提出的关于地形图有争议问题的讨论以及二维插值技术的理论研究。技术比较基于三层球形头部模型上的模拟电场。研究了四种二维插值技术：双线性、最近邻、双三次样条和薄板样条。新的地形图系统采用了最精确的方法——二阶薄板样条。脑电图频谱地形图系统采用以下步骤：使用16通道同侧耳电极连接方式记录脑电图；对几个长度为5.12秒、相对无伪迹的重叠时段进行频谱分析；将平均频谱划分为特定频段；对于每个通道，将每个频段的平均频谱成分映射到代表头部的平面上；并使用二阶薄板样条插值完成图谱绘制。开发该系统的一个特定目标是生产一个与克赖斯特彻奇医院现有的脑电图记录系统兼容的地形图系统。这一目标已经实现，因此，该地形图系统可立即用于临床。该系统目前是一项重大临床研究的一部分。
