不同激振位置对压电式人工中耳听力补偿性能的影响

Effects of Different Stimulating Positions on the Hearing Compensation Performance of Piezoelectric Middle Ear Implant

研究不同激振位置对压电式人工中耳听力补偿性能的影响,确定压电式人工中耳最优激振位置。建立人耳有限元模型,并通过和相关实验数据进行对比验证模型的可靠性。基于该模型,分别在鼓膜脐部、砧骨体、砧骨长突和圆窗施加相同的位移驱动,通过检测镫骨足底板位移及基底膜的最大位移,分析这些位置的激振对人工中耳听力补偿性能的影响。结果表明,以镫骨足底板位移为评估标准会低估圆窗激振的高频听力补偿效果。砧骨长突激振下的基底膜特征位置处的运动位移大于激振鼓膜脐部及激振砧骨体时的位移值,其中激振砧骨体时的基底膜特征位置处运动位移最小;激振圆窗时的基底膜特征位置处运动位移在低频段小于激振其他位置时对应的位移值,但在中、高频段其激振效果最好。在频率低于400 Hz时,砧骨长突激励听力补偿效果最好,圆窗激励听力补偿效果最差。当频率大于1 k Hz时,圆窗激励听力补偿效果比其他位置好。以传统的镫骨足底板响应为评估标准,将低估圆窗激振式人工中耳的听力补偿效果。

To study the influence of stimulating positions on the hearing compensation performance of piezoelectric middle ear implant （MEI） and ascertain the optimal position for this type of MEIs, we established a finite element model of human ear, The reliability of the model was verified by comparing the model-predicted results with the experimental data. Based on the model, the displacement stimulation was applied to the umbo, incus body, incus long process and round window. Then, the stimulating positions on the piezoelectric MEI＇s performance was studied by analyzing the corresponding displacements of the stapes footplate and basilar membrane. Using the displacement of stapes as an evaluation criterion, the round-window stimulation＇s performance was underestimated at higher frequencies. Compared with the umbo and incus body, basilar membrane displacement at the characteristic place was greater under the incus long process excitation. Basilar membrane displacement at characteristic place was the smallest when under the excitation of incus body. Basilar membrane displacement of the round-window stimulation at the characteristic place was smaller than that at the other positions at lower frequencies, but the exciting effect was the best at middle and high frequencies. In conclusion, the hearing compensation effect of incus long process excitation was the optimum, and the hearing compensation effect of round window excitation was the worst at frequencies below 400 Hz. When the frequency was higher than 1 kHz, the hearing compensation effect of round window excitation was better than that at the other positions. The traditional evaluation criteria that use the stapes footplate displacement would underestimate the performance of the round-window stimulating type MEI.