中耳畸形对圆窗激振听力补偿性能影响的数值分析

Numerical Analysis on Sound Compensation Performance of Round Window Stimulation in Middle Ear Malformation

目的研究中耳畸形对圆窗激振性能的影响,为圆窗激振式人工中耳的优化提供理论支持。方法构建包含两腔不对称的非螺旋耳蜗的人耳有限元模型,并与实验数据进行对比,验证模型的可靠性。基于该模型,通过改变相应组织的材料属性,分别模拟听骨链固定、听骨链融合、听小骨缺损3种中耳畸形对圆窗激振性能的影响。结果中耳畸形主要影响圆窗激振式人工中耳的低频性能,听骨链固定和听骨链融合对圆窗激振起恶化效果。镫骨固定对圆窗激振补偿性能的影响最大,恶化量高达47.93 d B;听小骨缺损可提高圆窗激振的性能,最大改善量为6.24 d B。结论中耳畸形对圆窗激振的低频性能有影响,临床植入圆窗激振式人工中耳时需要针对性地提高其作动器的输出量。

Objective To study the influence of middle ear malformation on the performance of round window stimulation,so as to provide references for optimization of the round window stimulation middle ear implant.Methods The finite element model of human ear including an asymmetrical two-cavity non-helical cochlea was constructed and compared with experimental data to verify reliability of the model.Based on this model,the effects of three kinds of middle ear malformation,i.e.,ossicular chain fixation,ossicular chain fusion and ossicular defect on round window stimulation were simulated by changing material properties of the corresponding tissues.Results The middle ear malformation mainly affected the low-frequency performance of round window stimulation.The ossicular chain fixation and the ossicular chain fusion had a deteriorating effect on round window stimulation.The stapes fixation had the greatest effect on the performance of round window stimulation,with the reduction as high as 47.93 dB.Ossicles defects could improve the performance of round window stimulation,with the maximum increment of 6.24 dB.Conclusions The middle ear malformation had an effect on the low frequency performance of round window stimulation.It is necessary to specifically increase output of the actuator when implanting the round window stimulation middle ear implant.