Automatic removal algorithm of electrooculographic artifacts in non-invasive brain-computer interface based on independent component analysis / 生物医学工程学杂志

The non-invasive brain-computer interface (BCI) has gradually become a hot spot of current research, and it has been applied in many fields such as mental disorder detection and physiological monitoring. However, the electroencephalography (EEG) signals required by the non-invasive BCI can be easily contaminated by electrooculographic (EOG) artifacts, which seriously affects the analysis of EEG signals. Therefore, this paper proposed an improved independent component analysis method combined with a frequency filter, which automatically recognizes artifact components based on the correlation coefficient and kurtosis dual threshold. In this method, the frequency difference between EOG and EEG was used to remove the EOG information in the artifact component through frequency filter, so as to retain more EEG information. The experimental results on the public datasets and our laboratory data showed that the method in this paper could effectively improve the effect of EOG artifact removal and improve the loss of EEG information, which is helpful for the promotion of non-invasive BCI.

Neuronal Responses in the Globus Pallidus during Subthalamic Nucleus Electrical Stimulation in Normal and Parkinson's Disease Model Rats

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been widely used as a treatment for the movement disturbances caused by Parkinson's disease (PD). Despite successful application of DBS, its mechanism of therapeutic effect is not clearly understood. Because PD results from the degeneration of dopamine neurons that affect the basal ganglia (BG) network, investigation of neuronal responses of BG neurons during STN DBS can provide informative insights for the understanding of the mechanism of therapeutic effect. However, it is difficult to observe neuronal activity during DBS because of large stimulation artifacts. Here, we report the observation of neuronal activities of the globus pallidus (GP) in normal and PD model rats during electrical stimulation of the STN. A custom artifact removal technique was devised to enable monitoring of neural activity during stimulation. We investigated how GP neurons responded to STN stimulation at various stimulation frequencies (10, 50, 90 and 130 Hz). It was observed that activities of GP neurons were modulated by stimulation frequency of the STN and significantly inhibited by high frequency stimulation above 50 Hz. These findings suggest that GP neuronal activity is effectively modulated by STN stimulation and strongly dependent on the frequency of stimulation.

Removing TMS-induced artifacts from EEG / 国际生物医学工程杂志

The combination of transcranial magnetic stimulation and electroencephalogram (TMS-EEG) is an effective means for understanding the network of brain functions.The development of TMS-EEG,however,has been hampered by strong TMS-induced artifacts in the electrode leads.This article first introduces the TMS technology and expounds the causes of TMS-induced artifacts.According to the source of the artifact,the study reviews the artifact removing methods reported in the recent ten years regarding TMS discharge,muscle artifacts and auditory artifacts and residual artifacts.Perspectives of the related techniques are introduced at the end of the article.It is expectable that there will be a great breakthrough not only on the TMS theory but also in clinical research due to the attractive prospect in application and high research value of TMS.TMS-induced artifacts will be well solved at that time.