为了在记录和分析细胞外神经元单元动作电位(即锋电位)时能够正确选择滤波频率范围,分析了不同下限和上限截止频率时锋电位的波形失真、信噪比以及分类正确率的变化过程.锋电位信号是利用微电极阵列采集的大鼠海马区神经元信号.结果表明,下限截止频率小于100Hz且上限截止频率大于5 000Hz时,滤波造成的锋电位波形失真较小.对于锋电位的检出和分类这2种数据处理,它们的上限截止频率最佳范围一致,为3~5kHz.但是,对于下限截止频率,锋电位检出的最佳频率为500~600Hz,而锋电位分类的最佳频率却在200Hz左右,这是由于锋电位分类的正确率与信噪比和波形的失真都相关.
In order to determine the proper filtering frequency ranges for accurately recording and analyzing the extracellular neuron unit action potential(i.e.,spike),changes in spike waveform distortion,signal-to-noise ratio(SNR),and accuracy of spike classification under different lower and higher cut-off frequencies were investigated.The spike signals were recorded from rat hippocampal regions by microelectrode arrays.The results show that with lower cut-off frequency≤100 Hz and higher cut-off frequency≥5 kHz,the spike waveform distortions caused by filtering are small.The optimized higher cut-off frequency ranges for spike detection and spike classification are both at 3-5 kHz.However,the optimized lower cut-off frequency for spike detection is 500-600 Hz,whereas for spike classification the frequency is about 200 Hz.The reason is that the accuracy of spike classifications depends on both the SNR and the waveform distortion.