内淋巴积水豚鼠前庭器的形态变化及外膜半规管力学建模与分析

发布时间：2018-01-24 21:18

本文关键词： 内淋巴积水前庭器膜半规管三维重建流固耦合生物力学　出处：《复旦大学》2012年博士论文　论文类型：学位论文

【摘要】：人和哺乳动物的内耳由骨迷路和膜迷路两套复杂管道组成,其中膜迷路内充满内淋巴液,并含有位觉感受器(前庭器)和听觉感受器(耳蜗)。前庭器由三个半规管、椭圆囊和球囊组成,感受自身运动状态及头部在空间位置,并与身体的平衡调节有关。半规管是头部角加速度感受器,机械刺激是前庭器感知头部位置变化的始动因素。内淋巴积水(endolymphatic hydrops, EH)是由于各种原因导致内淋巴产生过多或吸收障碍引起的内耳膜迷路内淋巴液增多,又称膜迷路积水。梅尼埃病(Meniere's disease, MD)是一种特发性膜迷路积水综合征,临床表现为反复发作性眩晕,感音神经性听力下降,耳鸣和耳胀闷感。一般认为其病因和发病机制与EH密切相关。EH可引起蜗管、球囊、椭圆囊的膨胀。蜗管的膨胀可能改变基底膜振动的行波方式,影响MD患者的听力,而半规管、椭圆囊的膨胀是否影响膜半规管内淋巴液与壶腹帽的相互作用,导致MD患者产生前庭症状,尚未见文献报道。本研究在光镜和电镜下观察正常和EH对豚鼠前庭终器的形态学影响,发现豚鼠外膜半规管壶腹嵴毛细胞纤毛束(hair cell bundles, HBC)的损伤存在明显的区域差别,外半规管壶腹嵴嵴顶和椭圆囊斑微纹处的HBC损伤最为严重。在Micro-CT图像清晰显示前庭器膜性壁的基础上进行三维(three-dimensional,3D)重建,观察豚鼠前庭器结构的形态、空间位置及相互毗邻关系；测量外膜半规管和椭圆囊在垂直于流体流动方向横断面的管径,结果显示外膜半规管横断面为椭圆形,其长径和短径之比恒定；椭圆囊和壶腹长径与短径之比明显大于外膜半规管。EH豚鼠椭圆囊和外膜壶腹的管径明显增大,而外膜半规管管径无明显改变,该模型为研究内淋巴液在外膜半规管和椭圆囊的流动特征、内淋巴液与壶腹嵴的相互作用提供了形态几何参数。借助逆向工程软件Geomagic Studio对MIMICS重建输出的3D表面模型进行去除毛噪、修补和曲面优化等处理,分别建立前庭膜迷路、外膜半规管和椭圆囊的三维几何模型。根据外膜半规管和椭圆囊各部分的管径测量结果,建立正常和EH豚鼠外膜半规管和椭圆囊二维(two-dimensional,2D)有限元模型,分析正常和EH豚鼠头部旋转过程中内淋巴液与壶腹帽的流固耦合作用,结果显示由于内淋巴液的惯性作用而滞后于半规管的运动而引起壶腹帽的变形,产生的位移和剪切应变有所不同。提示壶腹帽剪切应变可能是带动壶腹嵴毛细胞纤毛偏转的主要因素,EH豚鼠椭圆囊和半规管壶腹的膨大导致壶腹帽剪切应变的增加或振幅增大,可能是EH豚鼠壶腹嵴嵴顶HBC损伤的重要原因之一本研究探讨EH对豚鼠前庭器形态和功能的影响,利用外膜半规管2D有限元模型,模拟EH豚鼠在头部水平旋转运动过程中,内淋巴液和壶腹帽的流固耦合作用,分析外膜半规管壶腹嵴HBC受损的力学因素。EH后豚鼠球囊、椭圆囊和膜壶腹存在不同程度的膨胀,而膜半规管未见明显改变。EH对豚鼠外半规管壶腹嵴HBC的损伤在嵴顶最为明显。壶腹帽的最大剪切应变集中在壶腹嵴嵴顶附近,EH时明显增加。EH时椭圆囊和壶腹的膨胀,影响了内淋巴液对壶腹帽的作用,壶腹嵴嵴顶附近壶腹帽的剪切应变的增大或振幅增加,可能导致此处HBC的损伤。上述研究结果有助于理解EH发生发展过程中前庭器损伤的力学因素,加深对前庭的病理生理过程的认识。
[Abstract]:Human and mammalian inner ear membranous labyrinth and bone lost by two sets of complex pipes, the membranous labyrinth filled with endolymph, and contains statoreceptor (vestibular) and auditory receptors (cochlea). The vestibular apparatus is composed of three semicircular canals, utricle and saccule, feel the body and head in motion the spatial location, and associated with the balance of the body. The head is semicircular adjustment angle acceleration sensor, mechanical stimulation is initiating factors of vestibular perception changes in head position. Endolymphatic hydrops (endolymphatic hydrops EH) is due to various reasons caused by the inner ear membrane endolymphatic excessive or absorption disorders caused by lost endolymph increased. Also called hydrolabyrinth. Meynier's disease (Meniere's disease MD) is an idiopathic hydrolabyrinth syndrome, the clinical manifestations of recurrent vertigo, sensorineural hearing drop, tinnitus and ear swelling stuffy Generally the etiology and pathogenesis of the disease is closely related with EH.EH can be caused by balloon expansion, cochlear duct, utricle. Expansion wave may change the way the basilar membrane vibration of the cochlea, semicircular canal and effect of MD patients, the hearing, the utricle would not affect the interaction of semicircular duct expansion in lymph fluid and ampulla cap that leads to the generation of vestibular symptoms in patients with MD has not been reported in the literature.
This study observed the effect of normal morphology and EH on vestibular organs of guinea pigs under light microscope and electron microscope, found in guinea pig outer membrane semicircular canal crista hair cell stereociliary bundles (hair cell, bundles, HBC) there are significant regional differences in damage, HBC damage and lateral semicircular canal crista crest utricle striola at most serious. Based on the three-dimensional Micro-CT images clearly show the vestibular membrane on the wall (three-dimensional, 3D) reconstruction, were observed in the guinea pig vestibular structure morphology, spatial location and adjacent relationship; measurement of semicircular duct and utricle in the direction perpendicular to the fluid flow cross-sectional diameter, results show that the lateral semicircular duct cross-section is oval the long diameter and short diameter ratio constant; utricle and ampulla of long and short diameter ratio is significantly greater than the outer canal.EH utricular and ampulla Vater diameter increased significantly, while the outer half There is no significant change in the diameter of the tube. This model provides a morphological parameter for studying the flow characteristics of the inner lymph in the semicircular canal and the utricle of the outer membrane, and the interaction between the inner lymph and the ampullary crest.
To remove noise by 3D hair surface model of reverse engineering software Geomagic Studio MIMICS to reconstruct the output, repair and optimization processing, respectively establish the vestibular labyrinth, a three-dimensional geometric model of semicircular duct and utricle. According to each part of the utricle and semicircular duct diameter measurement results, the establishment of normal and EH guinea pig semicircular duct and ellipse sac (two-dimensional, 2D) two-dimensional finite element model, analysis of the role of EH and normal guinea pig head rotation during the endolymph and cupula the fluid solid coupling. The results show that due to the inertia of the endolymph by behind the movement caused by the deformation of semicircular canal cupula, displacement and shear strain caused by different tips. Ampulla cap shear strain may be a major factor driving the crista of cilia deflection, EH utricular and semicircular canal enlargement caused cupula shear The increase of strain or amplitude may be one of the important reasons for the HBC damage to the crest of the crest of the ampullary crest of EH guinea pigs
This study investigated the effects of EH on the morphology and function of vestibular apparatus, using semicircular duct 2D finite element model, simulation of EH in guinea pig head horizontal rotation process, effects of endolymph and cupula the fluid solid coupling analysis of outer membrane, semicircular canal crista HBC damage mechanics factor.EH of guinea pigs after saccule, utricle and membrane there are different degrees of swelling of membrane, and semicircular canal had no obvious change.EH canal of guinea pig crista ampullaris lateralis HBC damage in crest is most obvious. The maximum shear strain of the cap is located near the crista crest, significantly increased.EH EH expansion utricle and ampulla, affect the function of endolymph of ampulla the cap of the crista ampullaris crest shear strain near the cupula increased or increased the amplitude, here may lead to HBC damage. The research results are helpful to understand the vestibular damage process of the occurrence and development of EH The mechanical factors deepen the understanding of the pathophysiological process of the vestibule.

【学位授予单位】：复旦大学
【学位级别】：博士
【学位授予年份】：2012
【分类号】：R764

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