眼外肌力学行为及相关的眼球运动建模研究

发布时间：2018-06-13 00:07

本文选题：初张力 + 单轴拉伸实验　；参考：《太原理工大学》2014年博士论文

【摘要】：眼球运动建模研究有助于一些眼疾的临床诊断和治疗,比如斜视、眩晕、眼震等。眼外肌控制眼球的运动,是眼球运动建模必不可少的要素。人体解剖发现人眼组织包含6条眼外肌,分别是外直肌、内直肌、上直肌、下直肌、上斜肌和下斜肌。本文的主要目的是研究眼外肌的力学行为并建立与之相关的眼球运动模型,采取的研究手段主要包括数学力学建模、动物实验测试、数值模拟等,研究内容主要是：推算第一眼位时眼外肌的初张力；哺乳动物眼外肌被动拉伸实验研究；眼球运动建模研究。第一眼位往往作为眼球运动模型的初始位置,眼球悬停在第一眼位的力学平衡依赖于6条眼外肌的贡献,这6条眼外肌在第一眼位的施力情况是眼球运动建模首要解决的问题。文中收集了包括眼外肌系统的几何坐标参数和经典的人眼外肌被动拉伸实验数据等方面的文献内容,利用力学平衡原理和数学优化的手段,推算出6条眼外肌控制眼球悬停于第一眼位的力。推算模型的建立考虑了近年眼科研究流行的观点,眼球运动主要依靠自身系统的机械作用而非神经作用,因而在建模过程中有意识地弱化了神经支配方面的影响。用离体实验的手段,分析了哺乳动物的眼外肌被动力学行为。选用狐眼外肌为试验试件,因狐眼位置与人眼位置类似,均长在脸的正前方。从当地的养殖基地收集到一定数量的眼外肌试件,在实验室环境下对各试件行单轴拉伸实验测定眼外肌的被动力学性能,之后用Ogden超弹性模型分析相应的实验数据。将分析所得的眼外肌超弹性参数的平均值作为数值建模研究的模拟输入参数,建立了相应的眼外肌被动拉伸的有限元模型,以验证有限元建模方法的有效性。与实验结果相比较,发现分析结果的误差与模拟结果的误差之间没有统计学差异。另外,用相同的实验方法进一步研究了三种不同眼位哺乳动物(狐、猪、羊)的眼外肌被动力学行为之间的差异。根据前人提出的有关眼外肌滑车组织的主动滑车假说,用数学力学建模的办法建立了眼球运动的主动滑车模型。因解剖的难度,至今未见有关眼外肌主动力学行为方面的详细的实验数据报道,在建模的过程中,将优化方法补充到力学平衡方程中求解眼外肌控制眼球运动的力。之后,与无滑车的眼球运动模型对比,发现在眼球大幅内旋运动时主动滑车能够维持内直肌的力学优势,验证了现代眼球运动理论认为眼外肌滑车是眼外肌的功能性起点的观点。
[Abstract]:The study of eye movement modeling is helpful for the clinical diagnosis and treatment of some eye diseases, such as strabismus, vertigo and nystagmus. The extraocular muscle controls eye movement, which is an essential element of eye movement modeling. Human anatomy revealed that there were 6 extraocular muscles in the human eye, namely, the external rectus, the medial rectus, the superior rectus, the inferior rectus, the superior oblique and the inferior oblique. The main purpose of this paper is to study the mechanical behavior of the extraocular muscles and to establish the related eye movement models. The research methods mainly include mathematical mechanical modeling, animal experimental testing, numerical simulation and so on. The main contents of this study are as follows: the initial tension of the extraocular muscle in the first eye position; the experimental study on the passive stretching of the extraocular muscle in mammals; and the modeling of eye movement. The first eye position is often used as the initial position of the eye movement model. The mechanical balance of the eye hovering in the first eye position depends on the contribution of the six extraocular muscles. The force of the six extraocular muscles in the first eye position is the most important problem to solve in the eye movement modeling. In this paper, the geometrical coordinate parameters of the extraocular muscle system and the classical experimental data of the passive stretching of the extraocular muscle are collected. The principle of mechanical balance and the means of mathematical optimization are used. The force of 6 extraocular muscles to control the eye hovering at the first eye position was calculated. The establishment of the model takes into account the popular viewpoint of ophthalmology research in recent years. Eye movement mainly depends on the mechanical action of its own system rather than on the role of nerve, so the influence of innervation is attenuated consciously in the process of modeling. The dynamic behavior of extraocular muscle in mammals was analyzed in vitro. The external muscle of fox eye was chosen as the test specimen. Because the position of fox eye was similar to that of human eye, it was long in front of face. A certain number of extraocular muscle specimens were collected from the local breeding base. The passive mechanical properties of the extraocular muscles were measured by uniaxial tensile tests in laboratory environment. The corresponding experimental data were analyzed by Ogden hyperelastic model. The average value of superelastic parameters of extraocular muscles is taken as the input parameters of numerical modeling, and the corresponding finite element model of passive stretch of extraocular muscles is established to verify the validity of the finite element modeling method. Compared with the experimental results, it is found that there is no statistical difference between the errors of the analysis results and the simulation results. In addition, the difference of the dynamic behavior of the extraocular muscle in three different eye position mammals (fox, pig, sheep) was studied with the same experimental method. According to the hypothesis of active pulley about the extraocular muscle trochlear tissue, the active pulley model of eye movement was established by mathematical mechanics modeling. Due to the difficulty of anatomy, no detailed experimental data on the main dynamic behavior of the extraocular muscle have been reported. In the process of modeling, the optimization method is added to the mechanical balance equation to solve the force of the extraocular muscle to control the eye movement. Then, compared with the model of eye movement without trochlear, it was found that the active trochlear could maintain the mechanical superiority of the medial rectus when the eyeball was in large internal rotation. The conclusion that the pulsatile of extraocular muscle is the functional starting point of extraocular muscle is verified in modern eye movement theory.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R779.6

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