Based On Stm32w Wireless Local Field Potential Dual Channel Signal Acquisition System Is Designed

Much more laboratories have been engaged in the research of brain computerinterface, the purpose of research is providing a movement ability or the ability tocommunicate with the outside experiment. In early research, the brain computer interfaceis mainly oriented to movement and sensory. In order to achieve brain computer interfacedesign, neural signal acquisition system is very important. Neural signal acquisitionsystem is a key factor of restricting the development of brain-computer interface. Itsperformance almost decides the stand or fall of brain-machine interface equipment.EEG signal acquisition system plays a very important role in the monitoring,diagnosis and treatment of the traditional neurological disorders of the brain. Thetraditional EEG signal acquisition system, due to its large scale equipment and theexistence of the electromagnetic shielding box restrict the animal activity. At the sametime, external shielding equipments will also affect animal behaviors, which will have animpact on normal animal cognitive activities. At present, many manufacturers at homeand abroad produce many kinds of EEG acquisition instruments. They can well meet theresearch needs of medical rehabilitation in accuracy and anti-jamming, but most of themhave the disadvantages of the complicated structure, difficult operation, large volume,inconvenient movement and a high price. This paper presents a realization of wirelessmulti-channel signal acquisition system of the local field potential, laying a goodfoundation for the research of brain-computer interface system.Difficulties of mobile measurement are the main disadvantages of the traditionalLocal Field Potential (LFP) acquisition of animal. In our work, a novel portable LFPacquisition system is designed. This system is based on Cortex-M3microprocessorSTM32W which integrates a2.4GHz, IEEE802.15.4compliant transceiver, a singlepower supply, smaller size, greater amplification factor, higher impedance and wirelesstransmission. Moreover, it has the feature of multi-channel synchronized collection. Datacompression is adopted to avoid the limit of wireless channel and lower the powerconsumption. Simulated results are presented, which are in good agreement withmeasured results. The wireless EEG acquisition system is mainly composed of two parts: the frontanalog part and the back-end digital part. The front-end analog circuits amplify the weakEEG signals by instrumentation amplifier, and filter out almost all the high frequencyinterference by the RF filter circuit, and then through the low pass filter to reduce thenoises. The digital part realizes the transformation from the analog signal to the digitalsignal and the wireless transmission of the signal. The hardware realization mainlyincludes the external high-speed AD acquisition chip and STM32W108microcontroller.The microcontroller does the work of data processing and transmission. The AD chip isAD7912which is produced by Analog, and its effective bits is10, and has characteristicsof the high transmission speed, low power, dual channel continuous approximation. Itshighest data transmission rate can reach1MSPS. The system uses the Labview to showLFP signal and does the corresponding processing.