Human middle ear imaging, physiology, and biomechanics

描述（由申请人提供）：该项目的总体目标是了解人类中耳形态学与导致生理反应的生物力学过程之间的关系。这项研究背后的理由是，由于缺乏对结构与中耳声音传输关系的了解，导致中耳修复的成功率不理想，并且难以解释耳声发射。我们的方法是将中耳分解成三个子系统，每个子系统都通过形态和生理测量以及三维数学分析相结合来表征。这些子系统是：(1)与耳道耦合的离体鼓膜，(2)离体锤骨-incus复合体，(3)离体镫骨踏板。对于每个子系统和完整的中耳，将使用高分辨率微ct图像对单个尸体耳朵进行成像。对微ct图像进行分割合并，得到耳道、鼓膜、听小骨、韧带和肌腱的三维体积重建，并进一步分析得到所需的形态学。为了确定基于形态学的子模型的生物力学参数，进行了动态测量。为了确定耳膜亚系统的特征，将砧骨取出，测量来自不同部分的速度，包括前、下、后部分。将制定一个数学模型，结合耳膜的解剖特征，包括其在耳道中的角度位置，圆锥形及其高度组织的周向和径向纤维层。通过从颞骨剥离鼓膜和镫骨分离出锤骨-incus复合体，为了描述其特征，将测量几个点的三维速度。一个弹性模型的锤骨-incus子系统将开发，包括锤骨-锤骨关节滑移，韧带和肌腱附着。为了表征stapes子模型，将进行反向声阻抗测量。我们的研究结果将通过结合每个子模型对完整的中耳进行基于解剖学的数学分析。在解构之前，对颞骨耳朵的正向和反向声学测量将用于测试对尸体耳朵进行分析的有效性。与在尸体耳膜中一样，将测量来自活体受试者耳膜不同部分的速度，并进行类似的分析，以获得其体内生物力学参数。该研究将为中耳声音传输的结构基础提供坚实的基础，并将在听力保健的许多领域得到应用。

DESCRIPTION (provided by applicant): The overall goal of this project is to understand the relationship between human middle ear morphemetry and the biomechanical processes that lead to physiological responses. The rational behind this study is that a lack of knowledge about the relationship between structures and middle ear sound transmission has resulted in unsatisfactory success of middle ear repairs and difficulties in interpreting otoacoustic emissions. Our approach is to deconstruct the middle ear into three sub systems that are each characterized through a combination of morphological and physiological measurements as well as three-dimensional mathematical analyses. The sub systems are: (1) the isolated tympanic membrane coupled to the ear canal, (2) the isolated malleus-incus complex, and (3) the isolated stapes footplate. For each sub system and for the intact middle ear, high-resolution microCT images will be used to image individual cadaveric ears. The microCT images are segmented and combined to obtain three-dimensional volume reconstructions of the ear canal, eardrum, ossicles, ligaments and tendons, which are further analyzed to obtain the desired morphemetry. Dynamic measurements are made in order to determine the biomechanical parameters of the morphologically based sub models. To characterize the eardrum sub system, the incus is removed, and the velocity from different sections, including anterior, inferior, and posterior sections will be measured. A mathematical model will be formulated, incorporating anatomical features of the eardrum, including its angular placement in the ear canal, conical shape and its highly organized circumferential and radial fiber layers. To characterize the malleus-incus complex, isolated by dissecting the eardrum and the stapes from the temporal bone, three-dimensional velocity at several points will be measured. An elastic model for the malleus-incus sub system will be developed that incorporates he incudo-malleolar joint slippage, ligaments and tendon attachments. To characterize the stapes sub model, reverse acoustic impedance measurements will be made. The outcome of our studies will result in an anatomically based mathematical analysis of the intact middle ear by combining each of the sub models. Measurements of forward and reverse acoustic measurements from the temporal bone ears, before deconstruction, will be used to test the validity of the analyses developed for cadaver ears. As in cadaver eardrums, the velocity from different sections of the eardrum of living subjects will be measured and similar analysis performed to derive its in-vivo biomechanical parameters. The studies will provide a solid foundation for the structural basis for middle ear sound transmission and will have applications in many areas of hearing health care.