Im Chang-Hwan, Hwang Han-Jeong, Che Huije, Lee Seunghwan
Department of Biomedical Engineering, Yonsei University, Wonju, 220-710 Korea.
Physiol Meas. 2007 Sep;28(9):1101-13. doi: 10.1088/0967-3334/28/9/011. Epub 2007 Sep 5.
In the present study, we introduce an electroencephalography (EEG)-based, real-time, cortical rhythmic activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, not on the subject's scalp surface, with a high temporal resolution. In the monitoring system, a frequency domain inverse operator is preliminarily constructed, considering the subject's anatomical information and sensor configurations, and then the spectral current power at each cortical vertex is calculated for the Fourier transforms of successive sections of continuous data, when a particular frequency band is given. A preliminary offline simulation study using four sets of artifact-free, eye-closed, resting EEG data acquired from two dementia patients and two normal subjects demonstrates that spatiotemporal changes of cortical rhythmic activity can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under a Pentium4 3.4 GHz environment. The first pilot system is applied to two human experiments-(1) cortical alpha rhythm changes induced by opening and closing eyes and (2) cortical mu rhythm changes originated from the arm movements-and demonstrated the feasibility of the developed system.
在本研究中，我们介绍了一种基于脑电图（EEG）的实时皮质节律活动监测系统，该系统能够以高时间分辨率监测受试者皮质表面而非头皮表面的皮质节律活动的时空变化。在该监测系统中，考虑受试者的解剖信息和传感器配置，预先构建频域逆算子，然后当给定特定频带时，针对连续数据的连续片段的傅里叶变换计算每个皮质顶点处的频谱电流功率。使用从两名痴呆患者和两名正常受试者获取的四组无伪迹、闭眼、静息EEG数据进行的初步离线模拟研究表明，在奔腾4 3.4 GHz环境下分析18通道EEG数据时，皮质节律活动的时空变化可在皮质水平上进行监测，最大延迟时间约为200毫秒。首个试验系统应用于两项人体实验——（1）睁眼和闭眼引起的皮质α节律变化，以及（2）源于手臂运动的皮质μ节律变化——并证明了所开发系统的可行性。
