[Analysis on time-frequency feature of rabbit cortical somatosensory evoked potential]

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 single-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.