检验人工听骨力学性质的解析方法

ANALYTICAL METHOD FOR TESTING MECHANICAL PROPERTIES OF ARTIFICIAL OSSICULAR

传导性耳聋多由鼓膜或听骨链病变所致,人工中耳已在临床上广泛应用于传导性耳聋治疗.根据人工中耳结构试验和力学假设,用变分原理建立在任意时刻t点,人工鼓膜受迫振动位移与激发声压的关系,推导控制方程.采用分离变量法及贝塞尔函数对方程求解,得到鼓膜和听骨位移的解析解.通过与文献试验数据比较,感觉曲线形状与走势基本一致,证明了该方程是正确的,能够反映声音的传导机制.利用方程计算得到:质量小的材料传音效果好于质量大的;顶盘面积一定时,质量为某一特定值时传音效果更佳;该结果与相关文献的试验结果相符合.研究表明:该方程对于人工中耳数据的获得非常方便,并且能够优化人工听骨材料,特别是对质量的控制能达到科学的效果,避免测量因素及其他因素的干扰.该方法为耳生物力学的研究及应用提供了新的视点.

Transmission deafness is mainly caused by the pathological changes of eardrum or ossicular chain. Artificial middle ear has been applied in clinical treatment of conductive hearing loss. In the present aper, an analytical method for testing mechanical properties of artificial ossicular was proposed. The relationship between forced vibration displacement of tympanic membrane and activated sound pressure is established at the random time t using variation principles based on artificial middle ear structure and its mechanical hypotheses, and the controlling vibration equations are derived. Furthermore, the analytical solutions of tympanic membrane and artificial ossicular are obtained by separation of variables and Bessel function. The theoretical results agree well with the documented experimental data and reflect the mechanism of sound transmission. Better sound transmission efficiency in artificial material is obtained with smaller density, rather than heavier density. The proposed analytical method is efficient and convenient for vibration analysis of artificial middle ear and helpful for the optimization design of artificial ossicular.