Research On Wireless Broadband Multichannel Neural Signal Acquisition System Based On WIFI Technology

In the research of brain science,the electrical activity of neurons,especially the group electrical activity of neurons invivo,is of great significance to neuroscience.Therefore,it is self-evident that the development of advanced neural signal acquisition equipment plays an important role in brain science research.However,the traditional wired neural signal acquisition equipment also has some disadvantages,such as inconvenient installation and use,affecting the action of experimental animals.Therefore,it is of great significance to study a set of micro wireless invivo multichannel neural signal acquisition equipment which can be carried by experimental animals,as well as its supporting tool software and animal behavior experimental equipment.Therefore,based on the embedded Wi Fi/Bluetooth dual-mode on chip system(SOC)ESP32,this paper designs and implements a set of wireless implantable EEG signal acquisition system applied to free movement rats,and tests its signal acquisition and spike signal detection performance with analog function signal and experimental animal actual signal.The wireless invivo multichannel neural signal acquisition system designed in this paper is mainly composed of the lower computer hardware responsible for neural signal acquisition and communication and the upper computer software responsible for system control and data recording.The lower computer takes ESP32 wireless system on chip as the core,realizes the setting and acquisition control of the front-end of electrophysiological acquisition through SPI interface,and establishes Wi Fi AP to transmit the collected data to the upper computer PC in the form of Wi Fi data packet after packaging.The upper computer software software is written by Lab View,which is responsible for monitoring the UDP port of the upper computer PC to receive the data packets sent by the lower computer and restore the original data from them,and then respectively realize the waveform display,online time-frequency analysis,online separation of spikes signals and data recording.It is verified that the wireless invivo multichannel neural signal acquisition system proposed in this paper can achieve the predetermined function.The system can collect,transmit and store neural signals of 1 to 16 channels with 20 KSPS sampling rate,and realize on-line time-frequency analysis and spike signal detection.The performance of the system fully meets the needs of electrophysiological experiments,but the volume of the system is only 33 mm* 27 mm* 5 mm,and the weight is only 14.6g.Therefore,compared with the traditional wired invivo multi-channel neural signal acquisition system,it is more convenient to use.