圆窗激励式人工中耳传声力学特性研究

发布时间：2018-04-25 00:32

本文选题：圆窗激励式人工中耳 + 人耳听觉系统　；参考：《中国矿业大学》2017年硕士论文

【摘要】：作为感音神经性听力损伤的有效治疗手段,近年来,人工中耳取得了较大的发展。人工中耳将外界的声信号转化成机械信号后直接激励听骨链或圆窗,以实现对患者听力的补偿,具有语音清晰度高,无声反馈小和高频增益强等特点。传统人工中耳如砧骨激励式和鼓膜激励式人工中耳等,需要依赖完整的听骨链,然而,一些感音神经性听力损伤患者还伴有听骨链损坏的传导性聋,导致传统人工中耳装置难以有效地补偿患者听力。而基于耳蜗逆向激励原理设计的圆窗激励式人工中耳避开了听骨链,直接激振耳蜗圆窗,从而有效地避免上述问题。现有的临床报道显示,圆窗激励式人工中耳对不同患者的植入效果具有较大的差异,且其增益明显低于理论预期。此外,国内尚未有任何一款人工中耳产品问世,而我国听力损伤患者人口众多,因此,有必要开发出一套能够稳定、有效补偿患者听力的圆窗激励式人工中耳。为解决上述问题,本文对圆窗激励式人工中耳传声力学特性进行研究,从设计参数和患者自身病情两方面对圆窗激励式人工中耳所表现出差异性的原因进行探究,并提高其输出增益,为开发出一套高性价比的圆窗激励式人工中耳打下理论基础,具体如下:首先,本文采用CT和逆向成型技术建立了人耳有限元模型,并对该模型的响应特性如基底膜选频特性等进行计算,验证了其可信度;其次,基于该人耳有限元模型,系统分析了振子横截面积、振子质量、振子支撑刚度、隔膜厚度、隔膜杨氏模量及圆窗上初始预压力的变化对圆窗激振式人工中耳听力补偿性能的影响,并提出对该类人工中耳优化设计的建议;然后,探究了部分听骨链缺失以及耳硬化症等典型传导性病变对圆窗激励效果的影响,指出应具有针对性地提高圆窗激励式人工中耳激振力输出,使它的实际增益满足理论预期;最后,自行搭建用于测试圆窗激励式人工中耳对听力的补偿效果的实验台,基于该实验台,测试所选压电叠堆的动态性能,并采用简化物理模型模拟圆窗,验证了基于有限元模型计算的振子横截面积的变化、引入隔膜与否对圆窗激励效果在趋势上的影响。
[Abstract]:As an effective treatment for sensorineural hearing impairment, artificial middle ear has made great progress in recent years. The artificial middle ear converts the external sound signal into mechanical signal and directly stimulates the auditory chain or round window to realize the compensation of the patient's hearing. It has the characteristics of high speech clarity, small silent feedback and strong high frequency gain. Traditional artificial middle ears, such as incus stimulation and tympanic membrane stimulation, need to rely on complete auditory chain. However, some patients with sensorineural hearing loss also have conductive deafness due to auditory chain damage. As a result, the traditional artificial middle ear device is difficult to compensate the patients' hearing effectively. However, the circular window driven artificial middle ear based on the reverse excitation principle of cochlea avoids the ossicular chain and directly stimulates the cochlear window, thus effectively avoiding the above problems. The current clinical reports show that there are great differences in the effect of circular window stimulation artificial middle ear implantation in different patients, and its gain is obviously lower than the theoretical expectation. In addition, there has not been any artificial middle ear product in China, and there is a large population of hearing loss patients in China. Therefore, it is necessary to develop a round window inspired artificial middle ear which can stabilize and effectively compensate the hearing of patients. In order to solve the above problems, this paper studies the acoustic mechanical characteristics of the round window stimulated artificial middle ear, and explores the reasons for the difference of the round window inspired artificial middle ear from the two aspects of design parameters and patient's condition. And improve its output gain, lay a theoretical foundation for developing a set of high performance-price ratio circular window excitation artificial middle ear. The details are as follows: firstly, the finite element model of human ear is established by using CT and reverse molding technology. The reliability of the model is verified by calculating the response characteristics of the model, such as the frequency selection characteristics of the substrate membrane. Secondly, based on the finite element model of the ear, the transverse area, the mass, the stiffness and the thickness of the diaphragm are systematically analyzed. The influence of Young's modulus of diaphragm and initial prepressure on the hearing compensation performance of round window induced artificial middle ear, and some suggestions for optimal design of this kind of artificial middle ear are put forward. This paper probes into the influence of some typical conductive diseases such as ossicular chain loss and ear sclerosis on the stimulation effect of round window. It is pointed out that the output of stimulating force of round window type artificial middle ear should be improved in order to make its actual gain meet the theoretical expectation. Finally, the experiment bench is built to test the hearing compensation effect of the round window stimulation artificial middle ear. Based on the experiment platform, the dynamic performance of the selected piezoelectric stack is tested, and the circular window is simulated by a simplified physical model. The change of the cross section area of the oscillator based on the finite element model is verified, and the influence of the diaphragm or not on the trend of the excitation effect of the circular window is verified.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R764;R318.1

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