漏斗胸合并脊柱侧弯微创矫形过程的数值模拟

发布时间：2018-04-28 17:19

本文选题：漏斗胸合并脊柱侧弯 + 微创矫形　；参考：《天津理工大学》2015年硕士论文

【摘要】：漏斗胸是一种先天性疾病,其病症为胸骨体向内凹陷,导致前胸下部成漏斗状,造成对心脏压迫,影响患者的心肺功能,约有30%漏斗胸患者伴有特发性脊柱侧弯畸形。临床上已经发现,胸腔凹陷畸形与脊柱侧弯的弓形畸形位于同一侧时,进行漏斗胸矫形后,多数患者的脊柱侧弯症状得到改善,反之,脊柱侧弯症状加重。研究漏斗胸合并脊柱侧弯的矫形过程可以采用实验方法和数值模拟方法。受伦理限制,目前无法通过在体的电测试验获得胸廓骨骼的应变分布规律,同时因为无法获得漏斗胸合并脊柱侧弯的尸体标本也无法进行尸体的电测试验。目前对漏斗胸合并脊柱侧弯微创矫形过程进行数值模拟已经成为获取矫形过程中位移场和应力应变场的主要方法。本文对漏斗胸微创矫形过程进行数值模拟的目的是认识漏斗胸合并脊柱侧弯微创矫形的机理,确定漏斗胸矫形对脊柱侧弯的影响因素,为临床NUSS手术提供合理的理论依据,同时为人工骨胸廓模型和动物胸廓矫形实验提供参考。文中采用Mimics、Geomagic studio及Pro/E软件重建了一例漏斗胸合并脊柱侧弯患者的前胸廓模型,模型中包括胸骨、肋骨及胸椎。作者发展了一种保证间盘与锥体的密切粘接的间盘建模方法,较好地解决了在Mimics软件中创建椎间盘困难的问题。采用ANSYS软件模拟了漏斗胸合并脊柱侧弯微创矫形的过程,模拟中考虑了几何非线性的影响。为解决数值模拟实验验证方面的困难,文中还采用ABAQUS软件对漏斗胸合并脊柱侧弯的矫形过程进行了数值模拟,对两种计算结果进行了比较。文中分别对不考虑间盘和考虑间盘的两种模型进行了数值模拟,分析了间盘对矫形过程的影响。数值模拟分析结果显示患者经矫形后胸骨被抬高,漏斗胸症状得到明显改善,同时脊柱弯曲程度有所减轻,证实胸腔凹陷畸形与脊柱侧弯的弓形畸形在同一侧时,漏斗胸矫形有助于改善脊柱侧弯畸形。计算结果显示椎间盘具备吸收脊柱变形的功能。根据数值计算结果设计的手术方案已经在北京军区总医院的临床手术中应用,手术结果显示,患者漏斗胸症状和脊柱侧弯程度的改善与数值模拟预测的结果一致。作者根据数值模拟得到的胸廓位移场和应力应变场分布规律,提出了进行人工骨胸廓模型和动物胸廓模型电测试验的指导性建议。
[Abstract]:Funnel chest is a congenital disease, which is caused by the depression of the body of the sternum, leading to the funnel shape of the lower part of the anterior chest, resulting in the compression of the heart and affecting the cardiopulmonary function of the patients. About 30% of the patients with funnel chest have idiopathic scoliosis deformity. It has been found that the deformity of chest cavity and the arch deformity of scoliosis are located on the same side. After correction of funnel chest, the symptoms of scoliosis in most patients have been improved, whereas the symptoms of scoliosis have been aggravated. Experimental method and numerical simulation method can be used to study the orthopedic process of funnel chest combined with scoliosis. Due to the limitation of ethics, it is impossible to obtain the strain distribution law of thoracic skeleton by in vivo electrical test, and it is also impossible to carry out the electrical test of cadaver because of the inability to obtain the specimen of funnel chest combined with scoliosis. At present, numerical simulation of minimally invasive orthopedic process of funnel chest combined with scoliosis has become the main method to obtain displacement field and stress-strain field in orthopedic process. The purpose of numerical simulation of funnel chest minimally invasive correction is to understand the mechanism of funnel chest combined with minimally invasive correction of scoliosis, to determine the influencing factors of funnel chest correction on scoliosis, and to provide a reasonable theoretical basis for clinical NUSS operation. At the same time, it provides reference for the model of artificial bone and animal thoracic orthopedic experiment. The anterior thoracic model of a patient with funnel chest associated with scoliosis was reconstructed by using the Mimicsof Geomagic studio and Pro/E software. The model included sternum, ribs and thoracic vertebrae. In this paper, the author develops a method to ensure the close bonding between the disc and the cone, which solves the problem of creating intervertebral disc in Mimics software. The process of minimally invasive correction of funnel chest combined with scoliosis was simulated by ANSYS software. The effect of geometric nonlinearity was considered in the simulation. In order to solve the difficulty of numerical simulation, the correction process of funnel chest combined with scoliosis was simulated by ABAQUS software, and the two results were compared. In this paper, two kinds of models without and without disc are numerically simulated, and the influence of disc on the orthopedic process is analyzed. The results of numerical simulation showed that the sternum was raised after correction, the pectus funnel symptoms were obviously improved, and the degree of spinal curvature was alleviated. It was proved that the deformity of thoracic cavity and the arcuate deformity of scoliosis were on the same side. Correction of funnel chest helps to improve scoliosis. The results show that the disc absorbs the deformation of the spine. The surgical scheme designed according to the numerical results has been applied in the clinical operation of Beijing military region General Hospital. The results show that the improvement of pectus funnel symptoms and the degree of scoliosis are consistent with the results predicted by the numerical simulation. According to the distribution of displacement field and stress and strain field of thoracic by numerical simulation, the author puts forward some guiding suggestions for the electric measurement test of artificial bone thoracic model and animal thoracic model.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R682

【参考文献】