A System Of The EEG Signal Acquisition And Processing Based On STM32

Brain-machine interface technology is the technology used to set up directcommunication between brain and external equipments. It’s one of the hot topics in thefield of modern biomedical engineering. The main aim of the technology is to help thedisabled to achieve the manipulation of the external equipments through the head. So itcan make up for these shortages of the disabled. The central part of this technology is tocollect and process EEG signal. This paper puts forward a kind of system based onwireless acquisition and processing, in this way we can achieve the acquisition and thefollowing processing of mice’s EEG..This system is divided into two parts in terms of construction: the transmittingpart and the receiving part. This task is to collect and process the EGG of the livingmice, so the circuit must be light enough to be fixed into mice’s brains. At the same timethe circuit board should have the function of wireless transmitting. Under theserequirements, the receiving circuit board can receive these signals and correspond withprincipal computer.The introduction part firstly presents the researching significance of brain-machineinterface technology and the research status by domestic and overseas; secondlyintroduces the sources and the major tasks of this topic.In the second chapter, this paper fully compares these features of the EGG and allkinds of brain-machine interface technology. Through the understanding of thesefeatures, the EGG acquisition and processing system which we want to design mustmeet some speciality and features, which provides academic references and researchareas.The third part introduces the integrated frame work of this system, andcomparatively presents the composition of every part in this system. The transmitting and receiving parts are made up of MPU, A/D converter, serial into USB, power chipsand so on. Here we specially introduce the function of these components and thereasons why they are used for this design. MPU with RF module chip stm32w108 ismade by ST company, and A/D conversion chip is a kind of AD7993.The forth chapter is the most important part of this paper which describes thedesign of the front analog circuit. This part gives a full instruction of its structure andconstruction theory. We describe each level of circuit from the beginning to the end. Weintroduce schematics，their functions and all used operational amplifier and filter chipsin detail. The first lever of the circuit play the most important role in our design，so weuse instrumentation amplifier INA118 to make sure that the common mode rejectionratio is high enough. The front analog circuit occupies an import position in the wholesystem. Because of its position, it is responsible for the collection of the most originalanalog signal. So its high-performance should be strongly required. Therefore, we spenta lot of time and energy researching this part.In the last part of this paper, we introduce the related simulation and some actualtesting results. Also the last part lists some production situation of the circuit board. Andthen we draw some conclusions and the outlook based on the overall design of thissystem. Meanwhile this paper introduces and analyzes the related questions andunfinished tasks.