Nearinfrared Spectroscopy & Electro -Encephalography—the Design And Manufacture Of Eeg Part

Brain function research, brain disease diagnosis are more and more inseparable from the advanced medical equipment, such as MEG, EEG, fMRI, PET, fNIRS and other equipment.Compared to these devices, NEG(Nearinfrared spectroscopy &Electroencephalography)is a new type of instrument used in the research of brain science.It has digital EEG’scharacteristics ofhigh temporal resolution as well as fNIRS’ideal spatial resolution. The focus of this paper is mainly on the development of NEG’s high performance EEG amplifier.At present, the mainstreamEEG amplifier, the system noise is 2μ Vpp, bandwidth is generally 0.5Hz～100Hz,CMRR is about 110dB. With the development of EEG,many studies have shown that EEG signals contain useful information related to brain disease in the low frequency band near DC as well as the higher band of 100～1000Hz. At the same time, researchers pay more attention tothe micro-changes in EEG signals, which requires EEG amplifier with higher performance. In this paper, the NEG’s EEG amplifier with noise less than 1μVpp,bandwidth of DC～1000Hz,CMRR of 120dB and other high performance, will be conducive to depth-researchon brain function, brain disease.In this paper,the EEG amplifier is designed with four 8-channel EEG acquisition board working together. The 8-channel EEG board is divided into analog and digital parts. The function of the analog part is to realize the preprocessing of EEG signal and scalp impedance detection.The digital will filter the signals and send to the NEG’s control board. The isolation is also designed between theanalog and the digital.In order to test the performance of the instrument, the electrical safety test and the performance testhas been done in this paper according to GB9706 and JJG1043-2008. It also obtains the relevant test certificate. At the same time, a series of EEG experiments,ERP experiments and NEG experiment have been done. The results show that the high performance EEG designed in this paper can be used safely and effectively in brain science research and brain disease diagnosis.