Tateno Takashi, Nishikawa Jun, Tsuchioka Nobuyoshi, Shintaku Hirofumi, Kawano Satoyuki
Special Research Promotion Group, Graduate School of Frontier Biosciences, Osaka University Osaka, Japan ; Biomedical Systems Engineering, Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University Sapporo, Japan.
Front Neuroeng. 2013 Nov 26;6:12. doi: 10.3389/fneng.2013.00012. eCollection 2013.
To improve the performance of cochlear implants, we have integrated a microdevice into a model of the auditory periphery with the goal of creating a microprocessor. We constructed an artificial peripheral auditory system using a hybrid model in which polyvinylidene difluoride was used as a piezoelectric sensor to convert mechanical stimuli into electric signals. To produce frequency selectivity, the slit on a stainless steel base plate was designed such that the local resonance frequency of the membrane over the slit reflected the transfer function. In the acoustic sensor, electric signals were generated based on the piezoelectric effect from local stress in the membrane. The electrodes on the resonating plate produced relatively large electric output signals. The signals were fed into a computer model that mimicked some functions of inner hair cells, inner hair cell-auditory nerve synapses, and auditory nerve fibers. In general, the responses of the model to pure-tone burst and complex stimuli accurately represented the discharge rates of high-spontaneous-rate auditory nerve fibers across a range of frequencies greater than 1 kHz and middle to high sound pressure levels. Thus, the model provides a tool to understand information processing in the peripheral auditory system and a basic design for connecting artificial acoustic sensors to the peripheral auditory nervous system. Finally, we discuss the need for stimulus control with an appropriate model of the auditory periphery based on auditory brainstem responses that were electrically evoked by different temporal pulse patterns with the same pulse number.
为了提高人工耳蜗的性能，我们将一个微型设备集成到听觉外周模型中，目标是制造一个微处理器。我们使用一种混合模型构建了一个人工外周听觉系统，其中聚偏二氟乙烯被用作压电传感器，将机械刺激转换为电信号。为了产生频率选择性，在不锈钢基板上设计了狭缝，使得狭缝上方膜的局部共振频率反映传递函数。在声学传感器中，基于膜中局部应力产生的压电效应生成电信号。共振板上的电极产生相对较大的电输出信号。这些信号被输入到一个模拟内毛细胞、内毛细胞 - 听觉神经突触和听觉神经纤维某些功能的计算机模型中。一般来说，该模型对纯音脉冲和复合刺激的反应准确地代表了高自发率听觉神经纤维在大于1kHz的一系列频率以及中到高声压水平下的放电率。因此，该模型提供了一个理解外周听觉系统中信息处理的工具，以及将人工声学传感器连接到外周听觉神经系统的基本设计。最后，我们基于由相同脉冲数的不同时间脉冲模式电诱发的听觉脑干反应，讨论了使用适当的听觉外周模型进行刺激控制的必要性。
