Research Review of Laplacian Electrodes for Brain-computer Interface

‍ ‍Brain-computer Interface （BCI） is a new type of human-computer interaction， which have been used in military， medical， entertainment and other fields. Electroencephalogram （EEG） is widely used for brain-computer interfaces due to its fast response in time-domain. However， EEG has low spatial resolution and is hard to locate the brain source activity， which is because of the volume conductor effect always form a spatial low-pass filter between the scalp and the EEG source and weaken EEG signals. Surface Laplacian （SL） mapping of scalp potential can enhance the high frequency components near the measured points， which can provide more local information of the brain. Therefore， EEG signals that collected from the concentric ring Laplacian electrode has higher spatial resolution， which can improve the poor spatial localization ability of traditional EEG signals. In order to clarify the current application status and development trend of concentric ring Laplacian electrodes in the field of EEG acquisition， this paper has summarized the design principle， technical improvement and Laplacian electrodes’ application for EEG acquisition. Furthermore， this paper had discussed the existing problems of Laplacian electrodes and pointed out its future development trend.