摘要目的 评价硬脑膜外电刺激经硬脑膜-脑脊液-软脑膜传递通路到达视皮层后的基本特征,以验证硬脑膜外电刺激视皮层假体方案的可行性.方法 实验研究.采用单方波电流从猫硬脑膜外刺激视皮层,通过改变刺激信号的类别、参数,记录皮层电压信号的变化,并与电极-组织界面相应的研究文献做比较,来观察由硬脑膜-脑脊液-软脑膜构成的传导通路对刺激信号的衰减影响.结果 改变刺激信号的类别,记录到的皮层电压信号与文献结果一致；当刺激电流单脉冲脉宽增加时,皮层电压峰峰值Vp-p增加不明显,相位发生明显的变化；当单方波电流的幅值增加时,皮层电压Vp-p的幅值也增加;当刺激电极与记录电极之间的距离减小时,记录电极所记录到的电压升高.当电极深度从0、200、400、600、800 μm依次递增时,记录电压的幅值逐渐减小.结论 硬脑膜外电刺激信号经硬脑膜-脑脊液-软脑膜传递到达视皮层后,仍然为有效信号,硬脑膜外电刺激视皮层假体方案是可行的.

abstractsObjective To evaluate the elementary characteristics of electrical stimulation on the cortex transferred from dura mater in order to verify the feasibility of a visual neuroprosthetic strategy based on epidural electrical stimulation.Methods This was an experimental study.A single square current was selected to stimulate the visual cortex of the cat through dura mater.The stimulus class and parameters of the single square current were varied and the voltage signal of the visual cortex was recorded.The visual cortex signal was recorded on paper and analyzed to study the attenuation of the transmission passing through dura mater, cerebrospinal fluid and pia mater. Results The cortical recordings agreed with some published experimental results when the stimulus type was altered.When the single-square current stimulus pulse width increased, the recorded voltage of the Vp-p phase changed noticeably but the Vp-p amplitude only changed within a narrow range.When the stimulus amplitude of the single-square current increased, the recorded voltage of the cortical Vp-p amplitude also increased.When the distance between the stimulating electrode and recording electrode decreased, the recorded voltage of the Vp-p amplitude increased.When the depth of the recording electrode gradually increased from 0 μm, 200 μm, 400 μm, 600 μm, 800 μm, the cortical recording of the vohage's amplitude decreased.Conclusion Cortical stimulation is still an effective signal,which originates from the epidural electrical stimulus by passing through dura mater,cerebrospinal fluid and pia mater.The strategy that epidural electrical stimulation can affect the visual cortex is verified to be feasible.