Stamoulis Catherine, Chang Bernard S
Harvard Medical School, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215.
Int IEEE EMBS Conf Neural Eng. 2009 Jun 23;2009:514-517. doi: 10.1109/NER.2009.5109346.
Developmental brain malformations often cause intractable and in many cases generalized and/or multifocal seizures. Surgical intervention is not possible in these cases as it is difficult to isolate the epileptogenic foci. Scalp EEG signals recorded during such seizures include coupled contributions from different sources. If it was possible to decouple these contributions based on differences in both their signatures and inter-arrival times at different electrodes, it would subsequently be possible to estimate the locations of the seizure foci. For this purpose, we applied matched filtering to scalp EEG data from 3 patients with multifocal seizures, using patient-specific source-related short EEG segments as the template waveforms. These segments were assumed to be seizure-related based on distinct sets of inter-arrival times at different channels and alternating signal polarities. We present preliminary results and demonstrate that matched filtering can be successfully applied to extract decoupled signal components from the EEG, generated by potentially distinct sources, and thus with distinct inter-arrival times but partially overlapping spectra.
发育性脑畸形常导致难治性癫痫，在许多情况下还会引发全身性和/或多灶性癫痫发作。由于难以分离致痫灶，这些病例无法进行手术干预。此类癫痫发作期间记录的头皮脑电图信号包含来自不同来源的耦合信号。如果能够根据信号特征及其到达不同电极的时间差异来分离这些信号，那么随后就有可能估计出癫痫灶的位置。为此，我们对3例多灶性癫痫患者的头皮脑电图数据应用了匹配滤波，使用患者特异性的与源相关的短脑电图片段作为模板波形。基于不同通道的不同到达时间集和交替的信号极性，这些片段被假定与癫痫发作相关。我们展示了初步结果，并证明匹配滤波可以成功应用于从脑电图中提取解耦的信号成分，这些成分由潜在的不同来源产生，因此具有不同的到达时间但频谱部分重叠。
