【作者】 雷巍；

【导师】 朱兴华； 董心；

【作者基本信息】 吉林大学 ， 生物医学工程， 2007， 硕士

【摘要】 骨质疏松症作为中老年多发的退行性疾病已经成为一个社会性的健康问题而备受大家的关注。利用计算机这种强大的工具来进行计算机模拟和数值计算是目前国内外研究的主流趋势。本论文的研究工作是在国内外实验研究成果基础上,给出一个问卷调查,根据峰值骨量和骨重建阈值等初始值的不同,在时间历程上模拟骨质疏松的程度。并结合实验,给出一套能较精确测量骨应变场的软件。而且通过试验计算得出结果,初步讨论其精度及分析其效率。本论文包含两个主要部分。第一部分依据骨的功能适应性和力学调控系统理论,遵循骨重建的生理过程,给出一个问卷调查,对于被调查者给出的不同情况,用计算机模拟其一段时间的骨质疏松情况。并给出保健建议,在一定程度上起到防病的作用。第二部分在第一部分提出的骨质疏松过程计算模型的基础上,结合数字图像相关中的亚象素位移测量方法,设计了一套在非接触情况下,测量物体应变场的应用软件。这对骨、椎间盘、软组织等形状不规则和变形不便于直接测量的物体的精确测量很有帮助。本论文的研究为骨质疏松的预防和治疗打下了理论基础,具有一定的临床指导意义。更多还原

【Abstract】 Osteoporosis, a epidemic disease affecting the middle-old ages, has been a social healthy problems that is focused by peoples. There are fewer physical tasks due to the fast developments of mechanical industry and the information industry; and because of the highly developed vehicles and roads, people do not usually walk on foot. As a result, human bones are lack of exercises, and the bone mass is reduced, which help to spread the diseases. Among these bone diseases, osteoporosis is easy to taken, hard to heal, and is very harmful. With the unceasing improvements of the living quality standard, the pathogenesis, prevention and treatment of the osteoporosis have been gradually focused as one of the hotspot healthy problems.When people are 30 to 40 years old, the time of the peak bone mass is passing and the bone mass begins to lose. When people become old, the muscle power, especially the muscle explosive power, falls down, and with the fewer activities, the force acting on the bones reduces; In the biological aspects, because of the old age, climacteric and other factors, the hormone reduces and it is easy to make the bone resorption faster than the bone formation, leading to the osteoporosis.The computer simulations and numerical computations are the main trend of the home and abroad researches. Base on the home and abroad testing researches, a questionnaire has been given in this dissertation, simulating the degree of the osteoporosis in the time history, accordingto the difference of the original values of the peak bone mass and bone remodeling threshold. With experiments, a suit of software, which can relatively exactly measure the strain field, is given. Through the experiment results, the exactness and the efficiency is analyzed originally.By comparing different sub-pixel registration methods in DIC, the article choose the widely used sub-pixel registration using quadratic surface fitting as one of the Digital Image Correlation methods in experimental solid mechanics. All factors affecting calculation sensitivity are discussed in this paper. The results show that the most impact on calculation is the subset size at integral displacements search while impacts of different correlation functions on the calculated displacement can be ignored. The basic assumption of the gradient-based DIC is the rigid body translation of concerned subset, but this assumption is contradictory to real circumstances. The basic assumption of the Newton-Rapshon method presented is the uniform deformation of the subset. In this paper the impacts of this two different assumptions of interrogated subset on calculation is also investigated. The theoretical errors analysis show that the zero-shape functions and the first-shape functions yield the identical subset center displacements, while the first-shape functions and the second-shape functions yield the identical subset strains.There are two parts in this dissertation. The first part gives a questionnaire, according to the function adaptability and the mechanics adjustment system theory, following the physical process of the bone remodeling, utilizing the osteoporosis computational model and its interface. For different situations given by the informants, the parameters, such as the porosity, micro-injury and BMU activating frequency, which is closely related to the osteoporosis, and the condition of the osteoporosis in a period of time are simulated using the computers. After the simulation, the experts’advices and healthcare are given, which will prevent the disease in certain degree. This prevention and cure will be the new direction of utilizing the computational models.In the first part, a mechanics-biology factor coupled model is built to reflect the degree of the osteoporosis in a certain extent. However, some original data cannot be determined and cannot be measured exactly in the conclusion validation. In order to apply the model in practical problems and solve the specific problems in the testing process, the second part designs a suit of digital image correlation method to measure the surface information. With this method, the spoke bone and other bones, the inter-vertebral disk and other soft tissues, can be measured exactly by the untouched method, such as the photo, video and so on. Using the sub pixel displacement measuring method in the digital image correlation, a suit of software is designed, which measures the strain field under non-touch condition. It helps a lot in exactly measuring the bones, inter-vertebral disk, soft tissues and other things whose shape is irregular and the test pieces that is not convenient to be measured directly.This dissertation creates a new mode for researching the prevention and treatment of the osteoporosis, and in certain degree, ask the healthy persons to keep healthy and examine regularly. It also provides a new direction for the multi-subject infiltration of medics, biological mechanics, computers and so on.更多还原