中耳结构动力响应对不同病理圆窗封闭的反馈

Feedback of Dynamic Responses from the Middle Ear for Round Window Closure with Different Pathology

目的研究耳蜗圆窗病变对中耳结构力学行为的影响。方法依据临床健康志愿者右耳CT扫描结果,将CT扫描数据数值化导入PATRAN软件进行人耳三维有限元模型重建,并应用NASTRAN软件进行流固耦合频率响应分析,通过数值模拟方法探讨中耳结构动力响应对内耳耳蜗圆窗病变的反馈。结果硬化症导致的圆窗封闭比先天性圆窗封闭使镫骨振幅下降更多,最大达到30. 2 dB,且后者不会对镫骨振动速度产生明显影响。相位角方面,硬化症情况下镫骨和圆窗均最多产生90°变化,且两者保持180°差值;而先天性圆窗封闭情况下镫骨最大有270°变化,同时圆窗相位角变化消失。结论基于振幅、速度和相位角,镫骨动力行为会对先天性和硬化症导致的圆窗封闭形成不同的反馈表现,研究结果可为未来临床上诊断及修复圆窗病变提供理论支撑。

Objective To analyze the influence of round window lesion on dynamic responses from the middle ear.Methods Based on CT scan images of healthy human ear,the three-dimensional finite element model of human ear was rebuilt by PATRAN software,then NASTRAN software was applied to conduct coupled solid-fluid frequency response analysis. The feedback of round window lesion on dynamic response of the middle ear was investigated by numerical simulation. Results Round window closure caused by sclerosis led to more decline in amplitude of stapes than congenital round window closed,maximally can reach 30. 2 d B,and the latter had no obvious influence on velocity of stapes. In term of phase angle,on condition of sclerosis,change of phase for stapes and round window reached 90° at most and kept a difference value of 180°. In contrast,on condition of congenital round window closed,change of phase for stapes reached 270° at most,meanwhile change of phase for round window disappeared. Conclusions The dynamic response of the middle ear showed different feedback to congenital and otosclerotic round window fixation based on amplitude,velocity and phase. The research findings provide the theoretical basis for diagnosing and fixing round window lesion in future.