数字信号处理器在脑-机接口系统中的应用

An Application of DSP in Brain-Computer Interface

本文研究数字信号处理器 (DSP)在基于稳态视觉诱发电位的脑 机接口系统中的应用 ,同时详细介绍了系统的构成及各部分的设计与实现方法 ,并展示了初步的实验结果。本系统主要由刺激器、模拟放大电路、DSP核心电路和控制外设的红外发射电路组成。所选用的都是低功耗、高速的芯片 ,以满足实用性和实时性的要求。软件部分采用汇编语言编程 ,主要包括控制信号采集、 5 0Hz陷波和带通滤波、快速傅立叶变换、特征提取和识别。经过测试 ,该系统不仅可以将输入的正弦波正确地检测出来 ,而且对于接入的实际脑电中的诱发响应也能很好地检测和识别。因此使用DSP使脑 机接口系统的小型化、实用化是可行的。

An application of Digital Signal Processor(DSP) in Brain Computer Interface System based on Steady State Visual Evoked Potential(SSVEP) is presented in this paper. System design and implementation are described in detail, and results of preliminary test are provided. This system mainly consists of four parts:stimulator, analog amplifiers, DSP circuit, and the infrared wave radiation circuit to control peripherals. We selected chips of low power consumption and high speed performance to meet practicability and real time requirement. The software, which was developed by using the assembly language, includes mainly control of data collection, 50Hz notch filtering and the band pass filtering, FFT, and feature extraction and recognition. Results of experiments with this system are acceptable. We could detect not only input sine signals but also evoked response in actual EEG. Therefore, the application of DSP to make BCI compact and of practical applications is feasible.