初始压力与支撑刚度对圆窗激振听力补偿影响的数值研究

The effect of preload and support's stiffness on the performance of round window stimulation: a numerical analysis

为了研究初始压力与支撑刚度对圆窗激振式人工中耳听力补偿性能的影响,建立了包括作动器和支撑体在内的人耳力学有限元模型。该模型基于一位无任何听力损伤病史的成年人的右耳,采用微计算机断层扫描技术(Micro-CT)和逆向成型技术建立而成,并通过与相关实验数据进行对比,验证了模型的可靠性。基于该模型,通过在圆窗上施加不同幅值的初始压力和改变支撑体的支撑刚度,对比分析相应的基底膜动态响应变化,研究其对圆窗激振听力补偿性能的影响。结果表明:初始压力的施加将恶化低频段的听力补偿效果,但提高了圆窗激振中高频段的听力补偿性能;相对于现有临床上所用的筋膜支撑作动器的方法,采用刚度较大的钛合金作为支撑结构,将在全频段提升圆窗激振的听力补偿性能。

To investigate the influence of the preload and supporting stiffness on the hearing compensation performance of round window stimulation, a coupling finite model composed of a human ear, an actuator and a support was established. This model was constructed based on a complete set of micro-computed tomography （Micro-CT） images of a healthy adult＇s right ear by reverse engineering technology. The validity of the model was verified by comparing the model＇s calculated results with experimental data. Based on this model, we applied different amplitude preloads on the actuator, and changed the support＇s stiffness. Then, the influences of the actuator＇s preload and the support＇s stiffness were analyzed by comparing the corresponding displacements of the basilar membrane. The results show that after applying a preload on the actuator, its hearing compensation performance was increased at the middle and high frequencies, but was deteriorated at low frequencies; besides, compared with using the fascia as the actuator＇s support in clinical practice, utilizing the titanium alloy to fabricate the support would enhance the hearing compensation performance of the round window stimulation in the whole frequency range.