兔皮层体感诱发电位时频特征分析

Analysis on Time-Frequency Feature of Rabbit Cortical Somatosensory Evoked Potential

分析兔皮层体感诱发电位的时域和频域特性。兔麻醉开颅,从大脑体感运动皮层引导诱发电位。连续多次刺激,以3 800 H z采样率采样。测量每次诱发电位各个波形成分的峰潜伏期。分析诱发电位的功率谱。比较单次和叠加平均电位的时频特性。结果显示诱发成分时域变异性在一个刺激周期内随时间逐渐增大,诱发电位的频谱包括3个主要频谱包。叠加平均技术使信号产生波形融合,新波形产生,后发放成份消失等多种畸变。

This experiment was carried out to analyze the time-frequency feature of rabbit cortical somatosensory evoked potential （SEP）. Rabbit was narcotized and subjected to craniotomy. SEP was from sensory and motor cortex. Stimulation was continuing many times and signal was sampled at 3 800 Hz. The peak latency of each waveform was measured. Power spectrum of SEP was analyzed. The time-frequency feature of single-trial was compared with that of average SEP. It was found that the variability of slngle-trial SEP latency enlarges with time in a stimulation period. The spectrum of SEP includes three main frequency spectrum packages. The technique of summation makes a lot of signal aberration such as waveform confluence, new waveform emerging and after-discharging components dismissing.