Uluşan Hasan, Yüksel M Berat, Topçu Özlem, Yiğit H Andaç, Yılmaz Akın M, Doğan Mert, Gülhan Yasar Nagihan, Kuyumcu İbrahim, Batu Aykan, Göksu Nebil, Uğur M Birol, Külah Haluk
Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey.
METU-MEMS Research and Applications Center, Ankara, Turkey.
Commun Eng. 2024 Sep 14;3(1):132. doi: 10.1038/s44172-024-00275-4.
Realizations of fully implantable cochlear implants (FICIs) for providing adequate solution to esthetic concerns and frequent battery replacement have lacked of addressing system level criteria as a complete device. Here, we present a full-custom FICI that considers design of both an implantable sensor for wide range sound sensing and a signal conditioning circuit for electrical stimulation of the auditory nerve. The microelectromechanical system (MEMS)-based acoustic sensor utilizes multiple cantilever beam structures to sense and filter the mechanical vibrations on the ossicular chain. The area optimized bilayer design of the piezoelectric sensor met with the volume limitation in the middle ear while achieving high signal-to-noise-ratio. The sensor outputs are processed by a current mode low-power signal conditioning circuit that stimulates the auditory neurons through intracochlear electrodes. The FICI is validated with an in vivo model where the electrical auditory brainstem response (eABR) of the animal was observed while applying sound excitation. The eABR results demonstrate that the system is able to evoke responses in the auditory nerves of a guinea pig for sound range of 45-100 dB SPL within the selected frequency bands.
为解决美观问题和频繁更换电池提供充分解决方案的完全植入式人工耳蜗（FICI），一直缺乏将系统级标准作为一个完整设备来考量。在此，我们展示了一种全定制FICI，它兼顾了用于宽范围声音感知的植入式传感器设计以及用于听觉神经电刺激的信号调理电路设计。基于微机电系统（MEMS）的声学传感器利用多个悬臂梁结构来感知和过滤听骨链上的机械振动。压电传感器的面积优化双层设计在满足中耳体积限制的同时实现了高信噪比。传感器输出由电流模式低功耗信号调理电路处理，该电路通过鼓阶电极刺激听觉神经元。通过体内模型对FICI进行了验证，在施加声音刺激时观察动物的电听觉脑干反应（eABR）。eABR结果表明，该系统能够在选定频段内，对45 - 100 dB SPL的声音范围在豚鼠的听觉神经中诱发反应。
