基于真实头模型的EEG参考电极标准化技术

目的 :研究基于真实头模型的参考电极标准化技术并验证它的有效性。方法 :基于真实头模型的等效源技术 ,建立了由以头表某点或平均电位为参考点的实际记录近似得到以无穷远点为参考的记录的方法。由于无穷远点的电位可假设为常数零 ,因此可称该方法为真实头模型的参考电极标准化技术 (REST)。对真实头模型全空间内任意位置的源的实际头表记录进行REST处理 ,然后计算经REST处理后的近似记录与以无穷远点为参考的记录之间的相对误差 ,以此检验该技术的有效性。结果 :对于真实头模型REST是有效的 ,尤其对重要的表层皮质区域更为有效 ,它的应用可以降低因非零的参考电位而引入头表记录的干扰。结论 :采用参考电极标准化技术能得到更真实的脑电 (EEG)记录 ,从而可能对脑电的应用产生重要的影响。

A STUDY ON REST FOR A REALISTIC HEAD MODEL

Objectives: To investigate the reference electrode standardization technique (REST) and its efficiency in realistic head model application. Methods: Based on the equivalent source model for a realistic head model, we found an approach to obtain approximately the potential with a reference at infinity from that with a scalp point reference or with the average reference. Since the potential of a point at infinity can be assumed to be zero, this method is a reference electrode standardization technique. For each cube center point of the whole inner space of realistic head model,relative error (RE) of dipoles was deduced between the standardized potential and that with a reference at infinity. Thus effectiveness of this technique was confirmed. Results: REST is an efficient method and is more effective for the most important superficial cortex region. REST could reduce the distortion of the scalp recordings resulted from the none-zero reference. Conclusion: With REST, better scalp EEG can be derived. Therefore this technique may bring important affections to the EEG application.