Maniglia A J, Abbass H, Azar T, Kane M, Amantia P, Garverick S, Ko W H, Frenz W, Falk T
Department of Otolaryngology-Head & Neck Surgery, Case Western Reserve University School of Medicine, USA.
Am J Otol. 1999 Sep;20(5):602-11.
A bioelectronic middle ear microphone (BMEM) has been developed in a laboratory bench model and successfully tested in fresh human temporal bones. A transducer actually has been bench-tested in our laboratory; it was implanted in chronic animal experiments (cats) as well as in humans for a period of 1 year as a driver of a semi-implantable electromagnetic middle ear hearing device (IDE, FDA approved). This BMEM is the result of the use of this same electromagnetic transducer used in a reverse mode. The applicability of the BMEM is for the development of a totally implantable cochlear implant using the eardrum as a diaphragm that transmits vibrations to a magnet cemented to the ossicles. This BMEM is to be powered by a lithium-ion implantable, rechargeable battery.
To test the efficacy of this BMEM, the experiment was divided into two parts: (1) bench model, and (2) fresh human temporal bones, using an air-core electromagnetic (EM) coil and a ferrite core EM coil for comparison.
In the bench model, the average displacement at 3 kHz was 0.95 microns (peak) for 4 V p-p and 1.65 microns (peak) for 10 V p-p. At 5 kHz, the measurements were somewhat higher. In fresh human temporal bones, with sound source in the ear canal (60 dB HL and 90 dB HL), the result was better with the magnet implanted on the head of the malleus with the incus removed. The ferrite core EM coil with the magnet implanted on the malleus with the incus removed was compared with the air-core EM coil. At 60 dB HL, the ferrite core EM coil yielded more than four times the amplitude of the EM coil. At 90 dB HL, the ferrite core EM coil produced more than five times the amplitude compared with the air-core coil.
This BMEM using an EM ferrite coil and a permanent magnet on the head of the malleus is more efficient when compared with an EM air-core coil. This BMEM may be applicable to the construction of a totally implantable cochlear implant. Further research is necessary to integrate this BMEM with the other components of the design concept of the totally implantable cochlear implant.
一种生物电子中耳麦克风（BMEM）已在实验室台式模型中研发出来，并在新鲜的人类颞骨中成功进行了测试。实际上，一种换能器已在我们实验室的实验台上进行了测试；它在慢性动物实验（猫）以及人类中作为半植入式电磁中耳听力装置（IDE，已获美国食品药品监督管理局批准）的驱动器植入了一年。这种BMEM是使用以反向模式运行的相同电磁换能器的成果。BMEM的适用性在于开发一种完全植入式人工耳蜗，该人工耳蜗利用鼓膜作为隔膜，将振动传递到粘结在听小骨上的磁体。这种BMEM将由植入式锂离子可充电电池供电。
为测试这种BMEM的功效，实验分为两部分：（1）台式模型，以及（2）新鲜人类颞骨，使用空心电磁（EM）线圈和铁氧体磁芯EM线圈进行比较。
在台式模型中，对于4V峰-峰值，3kHz时的平均位移为0.95微米（峰值），对于10V峰-峰值为1.65微米（峰值）。在5kHz时，测量值略高。在新鲜人类颞骨中，当声源位于耳道（60dB HL和90dB HL）时，去除砧骨并将磁体植入锤骨头部时结果更好。将去除砧骨并将磁体植入锤骨的铁氧体磁芯EM线圈与空心EM线圈进行了比较。在60dB HL时，铁氧体磁芯EM线圈产生的振幅是EM线圈的四倍多。在90dB HL时，与空心线圈相比，铁氧体磁芯EM线圈产生的振幅超过五倍。
与空心EM线圈相比，这种使用铁氧体磁芯线圈和锤骨头部永久磁体的BMEM效率更高。这种BMEM可能适用于完全植入式人工耳蜗的构建。有必要进行进一步研究，以将这种BMEM与完全植入式人工耳蜗设计理念的其他组件整合。
