基于眼外肌本构模型的眼球运动建模及临床应用研究

发布时间：2018-06-08 07:12

本文选题：眼外肌 + 本构关系　；参考：《太原理工大学》2016年博士论文

【摘要】：眼外肌疾病严重影响着人类的正常生活,其中仅斜视的发病率就高达1%~5%。近年来,由眼外肌Pulley(眼外肌上的结缔组织,具有改变眼外肌路径的作用)异位引起的眼外肌疾病也受到了越来越多的关注。眼外肌疾病的治疗可分为非手术疗法和手术疗法,其中手术疗法占很大的比重。眼外肌手术量的准确性是眼外肌手术成功与否的关键。目前,眼科医生一般参考经验值来确定眼外肌的手术量。用生物力学的方法建立眼球运动模型,给出确定眼外肌手术量的方案,对实现眼外肌疾患手术量的个性化设计具有重要的理论价值和临床实际意义。眼球的运动主要受六条眼外肌及其他眼眶组织的支配。在眼球运动的建模中,眼外肌力学本构关系的输入、眼外肌Pulley功能的给定及眼眶组织对眼球运动的阻力刚度的设定都是先决条件。由于人眼眶解剖的难度且受伦理道德的约束,目前还没有文献报道出六条眼外肌收缩的力学本构关系,Pulley对双眼视的生物力学意义还不清楚,其他眼眶组织对眼球运动的贡献也有待进一步确定。本文的目的是通过研究眼外肌收缩的力学本构关系、眼外肌Pulley对双眼视的生物力学意义及眼眶组织对眼球运动的阻力,建立相应的眼球运动模型,为临床确定眼外肌疾病的治疗方案提供理论指导。本文主要完成了以下工作:(1)提出了第一眼位神经兴奋水平下人眼外肌收缩的力学本构关系。基于前人实验所得外直肌的长度-张力关系,假设在第一眼位神经兴奋水平下其余五条眼外肌的长度-张力曲线可在外直肌长度-张力曲线的基础上沿张力轴平移得到,分别建立了单线眼外肌和三线眼外肌的眼球运动模型;结合第一眼位的静力平衡方程及张应力增量平方和最小的优化方程,分别用两种模型得到了第一眼位神经兴奋水平下六条眼外肌收缩的力学本构关系。通过与已有实验数据对比验证了所得本构关系的合理性;对比眼外肌单线模型和三线模型的计算结果,证明了基于单线模型推导眼外肌收缩的力学本构关系是简单有效的。(2)首次从生物力学角度论证了pulley存在对双眼视的生物学意义。建立了无pulley、被动pulley和主动pulley三类眼球运动模型,分别用这三类模型模拟了正常生理范围内的水平双眼运动,其中对眼球运动过程中伸长的眼外肌,弱化神经的支配作用只考虑其被动力;应用文献中眼外肌的被动拉伸数据结合空间力系的静平衡方程,分别得到了三类模型中眼外肌对眼球的作用力,并对眼球的受力状态进行分析。分析结果表明无pulley模型中左眼沿文中y轴方向的受力明显大于pulley模型中左眼沿该方向的受力;与pulley模型相比,无pulley模型双眼沿文中x轴方向和y轴方向受力的差异都比较大,这将会导致双眼发生不均等的变形,进而导致双眼对视觉目标的距离发生误判;可见pulley对双眼视有重要的生物力学意义。(3)获得了兔眼眶组织对眼球运动的阻力及阻力刚度。对15只体重为2.41±0.13kg的健康新西兰大白兔全麻后,用instron5544电子万能材料试样机对其眼眶组织进行了在体拉伸测试;统计分析了含四条眼外肌及不含眼外肌的眼眶组织在眼球水平转动和垂直转动过程中对眼球运动的阻力;用线性回归方法得到了8种不同眼球运动状态下眼眶组织对眼球运动的阻力刚度。实验结果表明无论是对于眼球的水平转动还是垂直转动,若将转动过程中发挥主导作用的两条直肌剪断,剩余四条眼外肌对眼球运动的阻力很小;含四条次要眼外肌的眼眶组织的阻力刚度与不含眼外肌的眼眶组织的阻力刚度之间有统计学差异,结果表明在兔眼水平转动和垂直转动的建模中这两种刚度不能通用。这一研究可为眼球运动建模中选择眼眶组织对眼球运动的阻力刚度提供参考。(4)从生物力学角度为临床斜视手术方案的个性化设计提供了方法。通过建模分别用眼外肌缩短术和眼外肌后退术对水平外斜视和水平内斜视进行了矫正。分别给出了眼外肌缩短量和后退量对斜视眼位的矫正量。将模型计算值与实际手术数据的回归值进行了对比,验证了本文所得眼外肌手术矫正方法的有效性;也进一步验证了本文所得眼外肌力学本构关系的合理性。所得眼外肌手术矫正量的回归公式可为临床眼科医生提供相应的术前指导。该方法可对眼外肌手术的矫正量进行个性化的术前预测。
[Abstract]:Extraocular muscle disease seriously affects human normal life, of which the incidence of only strabismus is as high as 1%~5%. in recent years. The extraocular muscle disease caused by ectopic muscle Pulley (the connective tissue on the extraocular muscles and the role of changing the extraocular muscle path) has also attracted more and more attention. The treatment of extraocular muscle diseases can be divided into non operative treatment. The accuracy of the operation volume of the extraocular muscles is the key to the success of the extraocular muscle operation. At present, the ophthalmologists generally refer to the experience value to determine the operation volume of the extraocular muscles. A biomechanical method is used to establish the eyeball motion model and to give a scheme to determine the volume of the extraocular muscles and to realize the eye. The individualized design of the volume of external muscle disease has important theoretical and clinical significance. The movement of the eyeball is dominated by six extraocular muscles and other orbital tissues. In the modeling of the eye movement, the input of the mechanical constitutive relation of the extraocular muscles, the determination of the Pulley function of the extraocular muscles and the resistance stiffness of the orbital tissue to the eye movement There are no reports of the mechanical constitutive relations of six extraocular muscles, the biomechanical significance of Pulley on binocular vision is not clear, and the contribution of other orbital tissues to the movement of the eyeball remains to be further confirmed. The purpose of this article is to understand the purpose of this article. After studying the mechanical constitutive relation of the extraocular muscle contraction, the biomechanical significance of the Pulley in the eye and the resistance of the orbital tissue to the movement of the eyeball, the corresponding ocular movement model was established to provide theoretical guidance for the treatment of the extraocular muscle disease. The following work was completed: (1) the first eye nerve was proposed. Based on the length tension relationship of the external rectus muscle, the length tension curve of the other five extraocular muscles at the first eye nerve excitation level can be moved along the tension axis of the external rectus muscle on the basis of the length tension curve of the external rectus muscle, and the unilateral extraocular muscles and the single line extraocular muscles are established respectively. The model of the eyeball movement of the three line extraocular muscles; combined with the static equilibrium equation of the first eye position and the minimum equation of the tensional stress increment square and minimum, the mechanical constitutive relation of six extraocular muscles under the first eye nerve excitation level was obtained by two models. Reason; comparing the calculation results of the unilateral and three line model of the extraocular muscles, it is proved that the mechanical constitutive relation of the extraocular muscle contraction based on the single line model is simple and effective. (2) the biological significance of pulley to binocular vision is demonstrated from the biomechanical point of view for the first time. The three types of eyeball movement without pulley, passive pulley and active pulley are established. In the model, the horizontal binocular movement in normal physiological range is simulated with these three models, in which the extrophthalmos elongated in the eye movement and the innervation of the weakening nerve are only considered to be driven. The passive stretching data of the extraocular muscles in the literature combined with the static equilibrium equation of the spatial force system, the three types of models are obtained respectively. The force of the muscles to the eyeball and the stress state of the eyeball is analyzed. The results show that the force in the Y axis direction in the left eye in the non pulley model is obviously greater than that in the left eye in the pulley model. Compared with the pulley model, there is a larger difference in the force between the square direction and the Y axis in the X axis without the pulley model. It can lead to unequal deformation of the binocular, which leads to the misjudgement of the distance between the eyes and the visual target. It can be seen that pulley has an important biomechanical significance to the binocular vision. (3) the resistance and resistance stiffness of the rabbit orbital tissue to the eye movement are obtained. After the general anesthesia of 15 healthy New Zealand rabbits with a weight of 2.41 + 0.13kg, instron5544 The electronic universal material specimen machine tested its orbital tissue in body stretching test, and analyzed the resistance to eyeball movement during the horizontal and vertical rotation of the eyeball with four extraocular muscles and the non ocular muscles, and the eye movement of the orbital tissue under 8 different eye movements was obtained by linear regression. The experimental results show that no matter the horizontal or vertical rotation of the eyeball, if the two rectus muscles that play the leading role in the rotation process are cut, the remaining four extraocular muscles have little resistance to the eye movement, and the resistance stiffness of the orbital tissue containing four minor extraocular muscles and the resistance of the orbital tissue without the extraocular muscles There are statistical differences between the stiffness and the results show that these two kinds of stiffness can not be used in the modeling of horizontal and vertical rotation of the rabbit eye. This study can provide reference for the selection of orbital tissue for the resistance stiffness of eyeball motion in the modeling of eyeball motion. (4) from the biomechanical point of view, the individualized design of the approach to the surgical approach to the bed strabismus is provided. Methods. The correction of horizontal exotropia and horizontal strabismus was performed with extraocular muscle shortening and extraocular muscle regressive operation. The correction amount of the extraocular muscle shortening and retreating amount to the strabismus position were given respectively. The ratio of the calculated value to the actual surgical data was compared. The validity of the positive method further validates the reasonableness of the mechanical constitutive relationship of the extraocular muscles. The regression formula for the correction of the extraocular muscle surgery can provide the clinical ophthalmologists with corresponding preoperative guidance. This method can be used to predict the correction of the extraocular muscle surgery.
【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R777.4

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