Research On The Biomechanical Modeling And Simulation Of Human Musculoskeletal System

Human musculoskeletal system is the requisite part for human movement in daily life. It is also fundamental for the interaction between human body with outside environment, and provide the subsistence for the organs. It is very important to research the biomechanical characteristics of human musculoskeletal system.This dissertation is based on the key project"China mechanical virtual human"supported by National Natural Science Foundation. The object of this project is to develop a integrated computational platform for biomechanical analysis of human musculoskeletal system. This platform includes three modules, the 3D geometrical models and system integratation module, the human musculoskeletal system kinematics and kinetics analysis integration module, and the human musculoskeltal system finite element models and analysis integration module. To the integration problems in the project, the key technologies were studied and the integrated computational platform was developed. The main contents are listed as following:1. Based on the human anatomical characteristics, the system integration of human musculoskeletal 3D geometrical models and simulation software package were developed. An integrated human musculoskeletal system is the base of the whole China mechanical virtual human project. First, a global coordinate system was developed according to the anatomics. The transformation between segmental local coordination and the global coordination were finished. Then, the anatomical kinematics of joints were defined. The muscle attachment positions to the skeletal system were measured, and muscles were modeled as force line to be assemblied into the human skeleton models. A human musculoskeletal 3D geometrical simulation software package was developed under Microsoft VisualStudio 2005 environment. 2. The integration of kinematics and kinetics analysis module were developed. Combining with NDI motion capture system, the human musculoskeletal motion capture and analysis module was developed, and was integrated with the human musculoskeletal kinetics analysis module.3. A wavelet-based method was proposed to predict muscle forces from surface electromyography (EMG) signals in weightlifting motor task. EMG signals of biceps brachii, triceps brachii and deltoid muscles were recorded when subject did a standard weightlifting motor task. The wavelet-based algorithm was used to process raw EMG signals and extract features which could be input to the Hill-type muscle force models to predict muscle forces. Through comparison the results from the proposed method and conventional inverse dynamic computation method, the proposed method was validated. A component mode synthesis analysis method was also proposed and validated by femur modal analysis in a gait experiment.4. Based on the parallel computing technology, the human musculoskeletal system integrated finite element model was built. According to the human joints characteristics, the finite element models of human joint system were built, include ankle joint, knee joint, hip joint and so on. The muscle forces were built as loads condition in the integrated finite element model.5. Bending lift was chosed as the typical movement and the motion capture experiment was implemented. The motion process was devided as four static phases. The muscle forces were assigned as the loads condition. The ground reaction forces were assigned as the boundary condition and the stress distribution of whole human skeleton were analyzed. The parallel computing was finished on Dawning 4000A super computer platform in Shanghai Super Computing Center. Through testing of different parallel computing scheme, the best parallel computing platform was confirmed. The China mechanical virtual human integrated biomechanical computing platform was validated.