Participant-specific and Generic Poromechanical Modelling of the Knee Joints

你知道吗，当你跳下地面时，膝盖软骨和半月板中的液体支撑着膝盖至少60%的冲击力。随着液体从组织中流出，液体压力会降低，如果你站着不动，你的膝盖会产生更多的组织变形。由于软骨没有血管，这种液体也完成了生命必需的代谢功能。我的团队开发了计算模型来理解流体压力和流量在膝关节的机械功能和组织代谢中的作用。人的膝关节是一个由关节软骨和半月板组成的活机构，其中含有65-80%的液体，在膝关节受压下产生流体压力和流动。计算机膝关节模型可以用来解释膝关节的正常功能以及运动损伤和手术对膝关节的影响。本研究通过两个方面取得进展：(1)确定膝关节软骨和半月板内流体压力和流量在负荷传递和组织代谢中的作用；(2)将从个体获得的研究成果推广到更大的群体。例如，膝关节生物力学的新知识将促进运动策略的设计，以减缓膝关节软骨的衰老过程。强健的膝关节模型也可用于开发下一代类人机器人。我的团队率先研究了膝关节的流体诱导力学，特别是孔隙力学，使用样本或参与者特定的建模：我们的模型是建立在猪样本或人类参与者的膝关节解剖基础上的。新鲜的猪膝盖被用来帮助模型开发，减少参与者的使用。这是我研究的创新之处，因为关于软骨和半月板的流体压力和流动的知识可能有助于组织工程。为了将研究成果扩展到不同的人群，我们将为每个亚人群开发一个通用的膝关节模型，该模型将用于潜在地预测数百万人的膝关节生物力学。通用模型将从参与者特定模型中进行修改，使用来自公共数据库的各种膝关节剖面的参数，代表目标人群。通过这种方法，通用模型将能够预测亚种群的生物力学行为，而不是少数参与者。通用模型可以更好地实现普遍的理解，这将促进实际应用。这项研究将提供充分测试的建模方法和样本通用模型免费提供给公众，用于纯粹的研究目的或临床应用。通用模型可用于预测目标人群正常和受损膝关节的生物力学，而参与者特定模型可用于辅助患者特定植入物的设计。

Did you know that the fluid in your knee cartilages and menisci supports at least 60% of the impact force to your knees when you land to the ground from a jump? The fluid pressure is reduced with fluid flowing out of the tissues and more tissue deformation in your knee will be developed if you stand still afterwards. The fluid also fulfills the life-essential metabolic functions, because cartilage has no blood vessels. My team develops computational models to understand the roles of fluid pressure and flow in the mechanical function and tissue metabolism of the knee. The human knee is a living mechanism that includes articular cartilages and menisci, which contain 65-80% fluid that produces fluid pressure and flow under knee compression. Computer knee models can be used to interpret the normal function of the knee and the consequences of sports injury and surgery on the knee. The proposed research enables advances through two aspects: (1) to determine the roles of the fluid pressure and flow in knee cartilages and menisci in load transmission and tissue metabolism; and (2) to extend research results obtained from individuals to a large population. As one example, new knowledge in knee biomechanics will facilitate the design of exercise strategies to slow down the aging process in knee cartilage. A robust knee model can also be used in developing next-generation humanoid robots. My team has pioneered the study of fluid-induced mechanics of the knee, specifically poromechanics, using specimen- or participant-specific modelling: our models are built on the knee anatomy of pig specimens or human participants. Fresh pig knees are used to aid model development and reduce the use of participants. This has been the innovative feature of my research as knowledge of fluid pressure and flow in cartilage and meniscus may aid tissue engineering. In order to extend research outcomes to a diverse population, we will develop one generic knee model for each sub-population that will be used to potentially predict the knee biomechanics for millions of people. The generic model will be modified from a participant-specific model using parameters derived from a variety of knee profiles from public databases, representing the targeted population. With this approach the generic model will enable predicting biomechanical behaviour for a sub-population rather than a few participants. A universal understanding may be better achieved with generic models, which will promote practical applications. This research will deliver fully tested modelling methods and sample generic models freely available to the public for pure research purposes or clinical applications. The generic models can be used to predict the biomechanics of normal and impaired knees for targeted populations, while the participant-specific models could be adapted to aid the design of patient-specific implants.