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目的为了把随机共振(stochastic resonance,SR)应用到视网膜上假体刺激中,研究了噪声对视网膜神经节细胞(retinal ganglion cells,RGC)电刺激响应及其信息传输的影响。方法 RGC用多房室模型模拟,运用附加Ornstein-Uhlenbeck(OU)过程或高斯白噪声的阈下信号输入到模型。观察RGC模型响应,功率模和互信息率来描述SR的特性。结果当一定的噪声附加到阈下信号时,RGC能够产生动作电位。随着2种噪声强度的增加,功率模和互信息率的变化曲线都呈现倒U型。与高斯白噪声相比,OU过程能够用较小的噪声强度产生更大的功率模和互信息率值。结论 RGC中存在SR现象;SR能够增加RGC对阈下信号的检测能力和信息传输能力;OU过程更容易产生SR,并且产生的SR效果更好。研究对降低视网膜上假体刺激阈值具有重要意义。
Objective To investigate the effect of noise on the electrical stimulation of retinal ganglion cells (RGC) and its information transmission in order to apply stochastic resonance (SR) to prosthetic retinal stimulation. Method RGC was modeled as a multi-compartment model and was applied to the model using a subthreshold signal attached to the Ornstein-Uhlenbeck (OU) process or Gaussian white noise. To observe the RGC model response, power mode and mutual information rate to describe the characteristics of SR. Results When certain noise is attached to the subthreshold signal, the RGC is able to generate an action potential. With the increase of two kinds of noise intensity, the curves of power mode and mutual information rate all show inverted U-shape. Compared with Gaussian white noise, the OU process can produce larger power mode and mutual information rate values with less noise intensity. Conclusion The SR phenomenon exists in RGC. SR can increase the detection ability and information transmission ability of RGC to sub-threshold signal. The OU process is easier to produce SR and the SR effect is better. Research is of great importance to reduce the stimulus threshold of prosthetic prosthesis.