基于生理结构的三维肌肉数学模型构建与力学特性研究

The mechanical properties of muscles has been a focus of soft tissue biomechanics research, some scholars focus on the micro (muscle filament sliding theory), some scholars focus on the macro (Hill model), but has been the lack of a bridge between the micro and macro, namely the relationship between muscle microstructure mechanics and macro-movement mechanics. Firstly, this project is based on the physiological structure of skeletal muscle to build the geometric model of the tubular muscle bundle; to build the movement mechanics and deformation characteristics of the tubular model based on elasticity theory. The movement of mechanical relationship between the muscle bundles is analyzed, and projective transformation laws are used to put each muscle bundle together. Secondly, based on the morphological characteristics of three-dimensional muscle, the muscle bundle mathematical model and muscle bundle movement mechanics relationships, build the mathematical model of three-dimensional muscle, and explore the relationship between muscle three-dimensional morphological changes its mechanical properties. Finally, the upper extremity biceps, triceps and lower extremity quadriceps, biceps femoris are used as the research object. Mathematical model to determine the parameters of the three-dimensional muscle-driven muscle movement, and compared with the acquisition of muscle morphology by magnetic resonance imaging technology to verify the accuracy of the mathematical model of three-dimensional muscle. The study of this project will promote the integration and development of the various disciplines of physiology, chemistry and elasticity in the field of muscle biomechanics.

肌肉的运动力学特性一直是软组织生物力学研究的一个重点，有的学者着眼于微观（肌丝滑行理论），有的学者着眼于宏观（Hill模型），但是微观和宏观之间一直缺少一个桥梁，即肌肉微观组织力学与宏观运动力学之间的关系。本项目首先，基于骨骼肌的生理结构，构建管状肌束的几何模型；根据弹性力学理论，构建该管状模型的运动力学及形变特性；分析肌束间的运动力学关系，利用投影变换规律将各肌束有机的组合在一起。然后，基于三维肌肉形态特征、肌束数学模型以及肌束间运动力学关系，构建三维肌肉数学模型，并探究肌肉三维形态变化与其力学特性之间的关系。最后，以上肢肱二头肌、肱三头肌及下肢股四头肌、股二头肌为研究对象，用确定参数的三维肌肉数学模型，驱动肌肉运动，并与通过核磁技术采集的肌肉形态对比，从而验证三维肌肉数学模型的准确性。本项目的研究将促使生理学、化学及弹性力学等各学科在肌肉生物力学领域的融合和发展。

骨骼肌收缩产生的肌力是人体进行各种运动的原动力，利用骨骼肌软组织的医学图像处理与重建技术，可以有效分析骨骼肌的形态与骨骼肌的力学特性之间的关系。本项目首先对20名成年健康男性志愿者分别进行了下肢屈膝0°-90°运动范围MRI断层测量实验，及上肢屈肘运动0°-90°运动范围MRI断层测量实验；基于水平集理论，建立了人体骨骼肌软组织自适应轮廓快速分割算法，利用MATLAB开发平台，快速重建了下肢股四头肌和股二头肌及上肢肱三头肌和肱二头肌的三维模型。其次，对上述20名成年健康男性志愿者进行了下肢屈膝0°-90°运动范围及上肢屈肘运动0°-90°运动范围内，下肢股四头肌和股二头肌及上肢肱三头肌和肱二头肌的sEMG信号及膝关节和肘关节的关节力矩测量实验。最后，通过建立基于肌束单元的三维骨骼肌模型与sEMG信号及关节力矩的之间的数学关系，揭示了骨骼肌在人体肌肉骨骼系统运动过程中收缩发力的客观规律。