Yeiser Aaron J, Wawrzynek Emma F, Zhang John Z, Graf Lukas, McHugh Christopher I, Kymissis Ioannis, Olson Elizabeth S, Lang Jeffrey H, Nakajima Hideko Heidi
MIT Electrical Engineering and Computer Science (EECS) Department, Cambridge, MA, 02139.
MIT Mechanical Engineering Department.
J Micromech Microeng. 2024 Aug;34(8). doi: 10.1088/1361-6439/ad5c6d. Epub 2024 Jul 18.
We present the "UmboMic," a prototype piezoelectric cantilever microphone designed for future use with totally-implantable cochlear implants.
The UmboMic sensor is made from polyvinylidene difluoride (PVDF) because of its low Young's modulus and biocompatibility. The sensor is designed to fit in the middle ear and measure the motion of the underside of the eardrum at the umbo. To maximize its performance, we developed a low noise charge amplifier in tandem with the UmboMic sensor. This paper presents the performance of the UmboMic sensor and amplifier in fresh cadaveric human temporal bones.
When tested in human temporal bones, the UmboMic apparatus achieves an equivalent input noise of 32.3 dB SPL over the frequency range 100 Hz to 7 kHz, good linearity, and a flat frequency response to within 10 dB from about 100 Hz to 6 kHz.
These results demonstrate the feasibility of a PVDF-based microphone when paired with a low-noise amplifier. The reported UmboMic apparatus is comparable in performance to a conventional hearing aid microphone.
The proof-of-concept UmboMic apparatus is a promising step towards creating a totally-implantable cochlear implant. A completely internal system would enhance the quality of life of cochlear implant users.
我们展示了“鼓膜麦克风（UmboMic）”，这是一种为未来与完全植入式人工耳蜗配合使用而设计的压电悬臂式麦克风。
UmboMic传感器由聚偏二氟乙烯（PVDF）制成，因其杨氏模量低且具有生物相容性。该传感器设计用于安装在中耳，测量鼓膜脐部下方的运动。为了使其性能最大化，我们与UmboMic传感器协同开发了一种低噪声电荷放大器。本文介绍了UmboMic传感器和放大器在新鲜人类尸体颞骨中的性能。
在人类颞骨中进行测试时，UmboMic装置在100Hz至7kHz的频率范围内实现了32.3dB SPL的等效输入噪声、良好的线性度，并且在约100Hz至6kHz的范围内频率响应平坦度在10dB以内。
这些结果证明了基于PVDF的麦克风与低噪声放大器配合使用的可行性。所报道的UmboMic装置在性能上与传统助听器麦克风相当。
概念验证的UmboMic装置是朝着创建完全植入式人工耳蜗迈出的有希望的一步。一个完全内置的系统将提高人工耳蜗使用者的生活质量。
