Study On EEG Circuit Based On The ARM

With the increasing development of science and technology, EEG is widely used, from medical to military. EEG contains information including physiol- ogical, psychological and pathology.At past,"consciousness move things" was imagined, now it has become a reality.It is not so freely, but there have been germinated, that is the Brain Machine Interface.Currently there are many organizations in the research of EEG in the world, but it is still in laboratory stage, failed to popularize spreads,low speed of communication, and the effect is not stable. Electroencepha -logram is common to people, but still limited to the hospital. There is a fatal weakness in the hospital electroencephalographis whish istoo big to do real-time monitoring, such as certain diseases in medical treatment when its incidence features cannot was discovered in time.This thesis analyzing the related features of EEG deeply, designed a set of EEG acquisition plan. Signal acquisition of the main into four levels, including rf filter, instrument amplifier, high-pass filltering, low-pass filter, common-mode rejection of circuit and the last stage amplifier. The main MCU is STM32 processor,which has more extensive application in the market and sufficient supply. it has rich peripherals, do not need the extra A/D chip, can simulate brain electrical signals into digital signals. Through the SD card storage circuit we can collecte the signals into SD card, convenient shift. In order to do experiments of Brain MachineInterface,we reserve the USB port.EEG acquisition system has certain social value which is designed inthis paper. The results of this experiment show that the system can get clear signals,it is valuable to the later applications.