A novel feedback control technique for the local oscillation amplitude in an artificial cochlear sensory epithelium that mimics the functions of the outer hair cells in the cochlea is successfully developed and can be implemented with a control time on the order of hundreds of milliseconds. The prototype artificial cochlear sensory epithelium was improved from that developed in our previous study to enable the instantaneous determination of the local resonance position based on the electrical output from a bimorph piezoelectric membrane. The device contains local patterned electrodes deposited with micro electro mechanical system (MEMS) technology that is used to detect the electrical output and oscillate the device by applying local electrical stimuli. The main feature of the present feedback control system is the principle that the resonance position is recognized by simultaneously measuring the local electrical outputs of all of the electrodes and comparing their magnitudes, which drastically reduces the feedback control time. In this way, it takes 0.8 s to control the local oscillation of the device, representing the speed of control with the order of one hundred times relative to that in the previous study using the mechanical automatic stage to scan the oscillation amplitude at each electrode. Furthermore, the intrinsic difficulties in the experiment such as the electrical measurement against the electromagnetic noise, adhesion of materials, and fatigue failure mechanism of the oscillation system are also shown and discussed in detail based on the many scientific aspects. The basic knowledge of the MEMS fabrication and the experimental measurement would provide useful suggestions for future research. The proposed preliminary prototype high-speed feedback control can aid in the future development of fully implantable cochlear implants with a wider dynamic range.

中文翻译：

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人工耳蜗感觉上皮模拟外毛细胞功能的原型高速反馈控制。

一种模拟人工耳蜗感觉上皮细胞中局部振荡幅度的新型反馈控制技术已得到成功开发，该技术模仿了耳蜗中外毛细胞的功能，并且可以在数百毫秒的控制时间内实现。人工耳蜗感觉上皮的原型已从我们先前的研究中得到改进，能够根据双压电晶片压电膜的电输出即时确定局部共振位置。该设备包含沉积有微机电系统（MEMS）技术的局部图案化电极，该技术用于检测电输出并通过施加局部电刺激来使设备振荡。本反馈控制系统的主要特征是这样的原理，即，通过同时测量所有电极的局部电输出并比较它们的大小来识别谐振位置，从而大大减少了反馈控制时间。以这种方式，需要0.8 s的时间来控制设备的局部振荡，相对于先前使用机械自动镜台扫描每个电极的振荡幅度的研究而言，控制速度大约是上次的一百倍。此外，还基于许多科学方面，详细显示和讨论了实验中的固有困难，例如针对电磁噪声的电学测量，材料的粘附性以及振动系统的疲劳破坏机理。MEMS制造的基本知识和实验测量将为将来的研究提供有用的建议。拟议的初步原型高速反馈控制可以帮助将来开发具有更宽动态范围的完全可植入人工耳蜗。