| Neuroscience is a discipline that studies the human brain and nervous system,involving multiple fields such as neuroanatomy,physiology,and computer science.In today’s society,neuroscience plays an increasingly important role and is considered a crown jewel.With deepening research on the brain,studies have shown that external stimulation can effectively regulate internal brain activity.Among them,electrical stimulation is widely used in neural modulation research due to its convenience and effectiveness.Neural modulation based on electrical stimulation requires precise synchronization of electroencephalography(EEG)and electrical stimulation,which requires the smallest possible synchronization delay between EEG and electrical stimulation.This article designs a portable EEG and electrical stimulation synchronization system with a synchronization delay of less than 50 μs.The system can collect and process EEG data in real-time,supporting experimental paradigms such as motor imagery(MI),steady-state visual evoked potentials(SSVEP),alpha wave detection,etc.In addition,the system includes three electrical stimulation modes: transcranial direct current stimulation(t DCS),transcranial alternating current stimulation(t ACS),and functional electrical stimulation(FES).Electrical stimulation timing is controlled by the application program,and experimenters can freely set electrical stimulation timing according to experimental needs.The main work of this article includes hardware platform construction and software system design.In terms of hardware,an integrated hardware platform was constructed with Xilinx’s ZYNQ-7000 multi-core heterogeneous chip as the core,integrating a 16-channel EEG acquisition circuit,an 8-channel electrical stimulation circuit,a ZYNQ-7000 main control circuit,a USB-UART and other peripheral interface circuits.The system is powered by a lithium battery to be more portable and flexible without relying on a computer.In terms of software,a Linux embedded system was built based on ZYNQ-7000,and applications were developed for displaying EEG waveforms,controlling electrical stimulation,synchronizing EEG-electrical stimulation based on SSVEP,and synchronizing EEG-electrical stimulation based on MI.The system can parallelly collect16-channel EEG data,analyze them in real-time,and control the output of electrical stimulation under the control of ZYNQ-7000.In order to verify the synchronization function,practicality,and safety of the synchronization system,a series of tests involving performance indicators of the EEG acquisition circuit and the electrical stimulation circuit,synchronization delay testing,synchronization function testing,and EEG experiments were carried out in this paper.The results of the performance testing and functional testing indicate that the various performance indicators of the system meet the design requirements.The EEG experiments included alpha wave detection experiments,MI-based synchronized EEGelectrical stimulation experiments,and SSVEP-based synchronized EEG-electrical stimulation experiments,which verified the synchronization function of the system,the timing control function of t ACS and FES under the application program,and the practicality and safety of t ACS and FES. |
