Electrical and Electronics Engineering Department, Hacettepe University, Beytepe Campus, Ankara 06800, Turkey.
Ann Biomed Eng. 2010 Apr;38(4):1539-47. doi: 10.1007/s10439-010-9950-4. Epub 2010 Feb 9.
In this study, photogrammetric coordinate measurement and color-based identification of EEG electrode positions on the human head are simultaneously implemented. A rotating, 2MP digital camera about 20 cm above the subject's head is used and the images are acquired at predefined stop points separated azimuthally at equal angular displacements. In order to realize full automation, the electrodes have been labeled by colored circular markers and an electrode recognition algorithm has been developed. The proposed method has been tested by using a plastic head phantom carrying 25 electrode markers. Electrode locations have been determined while incorporating three different methods: (i) the proposed photogrammetric method, (ii) conventional 3D radiofrequency (RF) digitizer, and (iii) coordinate measurement machine having about 6.5 mum accuracy. It is found that the proposed system automatically identifies electrodes and localizes them with a maximum error of 0.77 mm. It is suggested that this method may be used in EEG source localization applications in the human brain.
在这项研究中，同时实现了对人头上 EEG 电极位置的摄影测量坐标测量和基于颜色的识别。使用一个约 20 厘米高的旋转的 2MP 数码相机，并在预定义的停止点以等角位移间隔采集图像。为了实现完全自动化，电极已用彩色圆形标记进行标记，并开发了一种电极识别算法。该方法已使用携带 25 个电极标记的塑料头模型进行了测试。在整合三种不同方法的同时确定了电极位置：（i）提出的摄影测量方法，（ii）传统的 3D 射频（RF）数字化仪，以及（iii）具有约 6.5 µm 精度的坐标测量机。结果发现，所提出的系统可以自动识别电极并将其定位，最大误差为 0.77mm。建议该方法可用于人脑的 EEG 源定位应用。
