Leysieffer H, Baumann J W, Müller G, Zenner H P
Universitätsklinik für Hals-Nasen-Ohrenheilkunde, Tübingen.
HNO. 1997 Oct;45(10):792-800. doi: 10.1007/s001060050158.
Implantable hearing aids can form the basis of new surgical techniques for dealing with hearing problems originating in the inner ear, provided they are fully implantable. Accordingly, a comprehensive, interdisciplinary, combined project was initiated at the ENT clinic of the University of Tübingen which was to conclude with operations to improve hearing via fully implantable hearing aids. A novel electromechanical transducer for implantable hearing aids based on the piezoelectric principle is described. Unlike the piezoelectric transducers reported so far, this transducer does not rely on the bimorphic principle but on a circle-shaped, heteromorphic combination system consisting of a piezoceramic disc and metal membrane. The transducer can be hermetically sealed and is designed for implantation into the mastoid. Transfer of mechanical oscillations to an ossicle in the middle ear is effected by a directly fixed coupling rod or via suitable coupling elements. The transducer is highly tuned with a resonance frequency at the upper end of the spectral transfer range (greater than 10 kHz). Below this resonance and down to low frequencies, the frequency response of elongation is smooth with amplitudes of around 20 nm. At low and middle frequencies of up to 1 kHz, these vibration amplitudes correspond to sound-pressure levels of around 90 dB SPL. At higher frequencies of up to 10 kHz, the output level increases to about 130 dB SPL. Nonlinear distortions are also very small at the highest levels (less than 0.1%) throughout the whole transfer range. Electric power consumption at maximum levels is in the range of a few microwatts and is therefore significantly lower than that of electromagnetic systems. Particularly, this makes it possible to use the transducer in fully implantable hearing aids for rehabilitation of sensorineural hearing loss.
植入式助听器可以成为治疗内耳听力问题的新手术技术的基础，前提是它们能够完全植入。因此，图宾根大学耳鼻喉科诊所启动了一个全面的、跨学科的联合项目，该项目将以通过完全植入式助听器改善听力的手术作为结束。本文描述了一种基于压电原理的新型植入式助听器机电换能器。与迄今为止报道的压电换能器不同，这种换能器不依赖于双压电晶片原理，而是基于一个由压电陶瓷圆盘和金属膜组成的圆形、异形组合系统。该换能器可以进行气密密封，并设计用于植入乳突。机械振动通过直接固定的耦合杆或合适的耦合元件传递到中耳的听小骨。该换能器在频谱传输范围的上限（大于10 kHz）处具有共振频率，从而实现了高度调谐。在该共振频率以下直至低频，伸长的频率响应平滑，振幅约为20纳米。在高达1 kHz的低频和中频下，这些振动幅度对应于约90 dB SPL的声压级。在高达10 kHz的较高频率下，输出电平增加到约130 dB SPL。在整个传输范围内，最高电平下的非线性失真也非常小（小于0.1%）。最大电平下的电力消耗在几微瓦范围内，因此明显低于电磁系统。特别是，这使得该换能器能够用于完全植入式助听器中，以恢复感音神经性听力损失。
