Department of Biomedical engineering, College of Medicine, Dankook University, Cheonan, Republic of Korea.
Hear Res. 2011 Feb;272(1-2):187-92. doi: 10.1016/j.heares.2010.10.017. Epub 2010 Nov 3.
Electromagnetic floating-mass transducers for implantable middle-ear hearing devices (IMEHDs) afford the advantages of a simple surgical implantation procedure and easy attachment to the ossicles. However, their shortcomings include susceptibility to interference from environmental electromagnetic fields, relatively high current consumption, and a limited ability to output high-frequency vibrations. To address these limitations, a piezoelectric floating-mass transducer (PFMT) has recently been developed. This paper presents the results of a comparative study of these two types of vibration transducer developed for IMEHDs. The differential electromagnetic floating-mass transducer (DFMT) and the PFMT were implanted in two different sets of three cadaveric human temporal bones. The resulting stapes displacements were measured and compared on the basis of the ASTM standard for describing the output characteristics of IMEHDs. The experimental results show that the PFMT can produce significantly higher equivalent sound pressure levels above 3 kHz, due to the flat response of the PFMT, than can the DFMT. Thus, it is expected that the PFMT can be utilized to compensate for high-frequency sensorineural hearing loss.
用于植入式中耳听力设备（IMEHD）的电磁悬浮质量换能器具有手术植入程序简单和易于与听小骨连接的优点。然而，它们的缺点包括易受环境电磁场干扰、电流消耗相对较高以及输出高频振动的能力有限。为了解决这些限制，最近开发了一种压电悬浮质量换能器（PFMT）。本文介绍了为 IMEHD 开发的这两种振动换能器的比较研究结果。差分电磁悬浮质量换能器（DFMT）和 PFMT 被植入两组三个不同的人尸颞骨中。根据 ASTM 标准描述 IMEHD 的输出特性，对由此产生的镫骨位移进行了测量和比较。实验结果表明，由于 PFMT 的平坦响应，PFMT 可以在 3 kHz 以上产生显著更高的等效声压级，而 DFMT 则不能。因此，预计 PFMT 可用于补偿高频感音神经性听力损失。
