Study On The Key Technology Of Portable Brain Computer Interface Based On Wi-Fi

Brain-computer interface(BCI)can be used to monitor the electroencephalogram(EEG)activity and motor imagery control machine by connecting the human brain and the computer.No matter in the domain of clinical medicine,psychology and cognitive science,or mechanical control and applications of the intelligent Internet things,BCI technology has an important position and inestimable development potential.In the past,the size of BCI devices was large and its power consumption were very high.These shortages brought a lot of obstacles for the practical use and commercialization.In order to solve these problems,based on BCI portable and low-power consumption technology,the in-depth study was conducted in this article.And a brain-machine interface scheme was designed based on Wi-Fi.These improvements can make the BCI technology applied in much more fields.In this dissertation,the key technology of BCI was studied both from hardware and software.For hardware,how to make BCI portable,low-power consumption,anti-noise was studied.And Wi-Fi communication problems were solved.The portable realization of BCI was described by discussing the process and the devices selection of the printed circuit board(PCB).The low-power implementation was presented by analyzing the processor,power management and Wi-Fi low-power mode.The anti-noise was made up of the right-leg drive(RLD),low-noise power,analog front end(AFE),active electrodes,electromagnetic separation and shielding.Finally,the basic communication was described from the point of the User Datagram Protocol(UDP)based on the network and Transmission Control Protocol(TCP).On the software side,both the embed software used in the EEG sensor hardware and the EEG signal acquisition software for the personal computer systems were developed.The embed software was mainly oriented for the specific hardware to achieve driving the EEG sensor device and reading the analog-to-digital converter(ADC)data.Also,it could make the Wi-Fi System on Chip(SoC)transmit data,analyze user's commands to control the specific hardware status,read the battery data,control the power management system and reduce the power consumption.The application software for computer terminal was designed mainly for the specific users.It could provide users the interactive interface to display the real-time EEG wave while processing and checking the EEG data in background.At the same time,it could convert the EEG data format,storage the EEG data and complete the cloud synchronization.From the above,the EEG sensor and the EEG acquisition software was designed and implemented.The EEG sensor can be worn on the human body which could collect the weak electrical signals at the amplitude level of 1?V,and transmit the real-time EEG data through the Wi-Fi wireless technology to the LAN network.The back-end of the EEG acquisition software allowed users to collect the EEG data on the personal computer.It could give users voice prompt,guide the user how to operate and display the real-time EEG.The whole project reached the technology requirements of EEG acquisition.And for the portable brain-machine interface hardware,it has the advantages of small size,low power consumption and high precision.The software is easier for users.The brain-machine interface has already been used in the depression risk prediction system and the electrocardiogram of human-computer interaction system.The depression risk prediction system using the brain-machine interface could not only get the EEG data from the users,but also monitor their psychological pressure state for a long time.Thus it could help the professional psychological doctors evaluate the depression level.The electrocardiogram of human-computer interaction system using brain-machine interface could get the electrocardiogram from the EEG signals.According to these signals,users could control the robot.