CAREER: Virtual Prototyping of Artificial Knees

这份职业建议书寻求在人工膝关节的计算建模方面建立一个综合的教育和研究基础。两个主要目标是(1)开发一个虚拟原型环境，可用于改善人工膝关节的磨损和功能，以及(2)为美国南部最大的科学博物馆创建两个关于膝关节功能的工程分析展览。2002年，美国估计进行了375,000次膝关节置换(TKR)，如果目前的趋势继续下去，从现在到2020年将进行超过1000万次。提高这些植入物的寿命和功能的能力将对全球数百万将在未来几年接受膝关节置换的膝骨性关节炎患者的生活质量产生重大影响。目前用于研究TKR功能和磨损的实验和计算方法有很大的局限性。用于测量磨损的膝关节模拟器机器昂贵且耗时，而同时预测运动和接触压力的动态有限元方法需要数小时或数天的CPU时间。因此，这两种方法都不适合膝关节植入物设计和手术定位问题的设计敏感性和优化研究。此外，这两项研究都不允许在更大的肌肉骨骼系统的活体负荷环境中研究人工膝关节的功能。这项研究为研究TKR的功能和磨损提供了一种全新的方法。该方法将弹性接触理论和多体动力学理论相结合，形成了一个混合仿真环境，兼有多体动力学快速动态模拟和弹性精确预测接触压力的优点。该方法的速度足够快，可以集成到肌肉骨骼系统的更大动态系统模型中，为人工膝关节的虚拟样机提供了一个独特的在体计算环境。将根据现有和新的实验数据，分四个阶段对环境进行广泛评估，以确保最终产品是可预测的。与这些活动平行的是为佛罗里达州坦帕市的科学与工业博物馆开发的两个膝关节力学展品。展品将采用研究计划中调查的工程概念和方法，并向公众开放。其中一个展览将是一个膝关节模型库，参观者可以操纵它们来学习自然、受伤、关节炎和人造膝盖的力学，另一个展览将是一个多媒体展览，参观者可以在其中使用与研究计划中相同的工程软件创建和分析简单的膝盖模型。参与博物馆项目的少数族裔和经济困难儿童将担任展品评估员，让他们接触到医学中的工程学。

0239042FreglyThis CAREER proposal seeks to develop an integrated educational and research foundation in computational modeling of artificial knees. The two main objectives are (1) develop a virtual prototyping environment that can be used to improve wear and functionality in artificial knees, and (2) create two exhibits on engineering analysis of knee function for the largest science museum in the southern U.S. An estimated 375,000 total knee replacements (TKRs) were performed in the USA in 2002, and if current trends continue, over 10 million will be performed between now and the year 2020. The ability to improve the longevity and functionality of these implants would make a significant impact on the quality of life for the millions of knee osteoarthritis sufferers worldwide who will receive knee replacements in the coming years. Current experimental and computational methodologies for studying TKR functionality and wear have significant limitations. Knee simulator machines used to measure wear are costly and time consuming, while dynamic finite element methods that predict motion and contact pressures simultaneously require hours or days of CPU time. Consequently, neither is appropriate for design sensitivity and optimization studies of knee implant design and surgical positioning issues. Furthermore, neither allows the study artificial knee function within the in vivo loading environment of the larger musculoskeletal system. This study proposes a fundamentally new approach for studying TKR functionality and wear. The approach integrates elastic contact theory with multibody dynamics theory to produce a hybrid simulation environment that possesses the advantages of both - fast dynamic movement simulation from multibody dynamics and accurate contact pressure prediction from elasticity. The method is fast enough to be integrated into a larger dynamic systems model of the musculoskeletal system, providing a unique in vivo computational environment for virtual prototyping of artificial knees. The environment will be extensively evaluated in four stages against existing and new experimental data to ensure that the final product is predictive. Paralleling these activities is the development of two exhibits on knee mechanics for the Museum of Science and Industry in Tampa, FL. The exhibits will take the engineering concepts and methods investigated in the research plan and make them accessible to the general public. One exhibit will be a bank of knee models that visitors can manipulate to study natural, injured, arthritic, and artificial knee mechanics, and the other will be a multimedia exhibit at which visitors can create and analyze simple knee models using the same engineering software as in the research plan. Minority and economically disadvantaged children participating in museum programs will serve as exhibit evaluators to expose them to the use of engineering in medicine.