第一作者田佳彬男，博士生，1986年生

通信作者饶柱石男，教授，博士生导师，1962年生

人工中耳悬浮式压电振子的优化设计

田佳彬， 饶柱石， 塔娜， 许立富

(上海交通大学机械系统与振动国家重点实验室，上海200240)

摘要：为了优化人工中耳悬浮式压电振子的植入效果，设计了一种位移放大结构用于改善振子的输出特性。首先采用微CT扫描和逆向成型技术建立了包括外耳道、中耳和简化耳蜗的人耳有限元模型，通过与文献的实验数据比对验证模型的有效性。然后建立人耳与悬浮振子的耦合力学模型，通过有限元的耦合场分析研究加入位移放大结构前后的人工中耳植入效果。研究结果表明，采用位移放大结构后，振子于中高频段的等效声压级得到明显提升，可以有效降低压电振子的功耗。

关键词：人工中耳；压电振子；有限元建模；位移放大结构

基金项目：国家自然科学

收稿日期：2013-11-08修改稿收到日期：2014-04-03

中图分类号:TH785文献标志码：A

Optimal design of a floating mass type piezoelectric actuator for implantable middle ear hearing devices

TIANJia-bin,RAOZhu-shi,TANa,XULi-fu(State Key Laboratory of Mechanical System and Vibration, Shanghai Jiaotong University, Shanghai 200240, China)

Abstract:To optimize the implant performance of a floating mass type piezoelectric actuator for implantable hearing devices, a displacement amplifier was designed to improve the output characteristics of the actuator. A finite element model of human ear consisting of the external ear canal, middle ear and simplified cochlea was constructed via micro-computer tomography imaging and the technique of reverse engineering. The validity of the model was verified by comparing the model-derived results with experimental data from reference. Then an ear-actuator coupled mechanical model was developed, and the multi-field coupling was considered to study the implant performance of the actuator before and after the displacement amplifier was added. The results showed that the adoption of displacement amplifier can increase the equivalent sound pressure level of the actuator in the middle and high frequency ranges, and the power consumption can effectively be reduced at the same time.

Key words:implantable hearing devices; piezoelectric actuator; finite element modeling; displacement amplifier

近年来，人工中耳作为感音神经性听力损伤的治疗手段已经取得了较大的发展。与传统助听器的声激励不同，人工中耳是将外界的声信号转化成机械信号后直接激励听骨链，因此具有负反馈小，语音清晰度高和高频增益强等特点[1]。人工中耳按其激励源的不同可以分为电磁式和压电式，按其植入方式的不同则分为部分植入式和全植入式。其中，由于压电式较电磁式具有频带宽，制造成本低以及抗电磁干扰等优点，近年来已有多篇文献对惯性压电式人工中耳的植入特性进行了研究[2-3]。……