偏瘫步态的生物力学仿真与康复研究

Hemiplegic gait is a gait movement disorder frequently caused by stroke, hemiplegia and cerebral palsy and typically influenced by abnomally higher or lower tone of related muscles in the body. Two difficult problems in the field of rehabilitation of hemiplegic gait include the prognosis of effects of releasing techniques of the contractured muscles and effects of muscle strengthen training of the low toned muscles. Using human dynamics simulation, this proposed study will establish a dynamics model of human body with inclusions of skeletal and muscluar systems to allow accurate estimation of muscles and joint reaction forces related to hemiplegic gait. Based on the analysis of data from multi-modal brain function map, force ground reaction forces measured from a force platform and electromoygraphic data (EMG), this study will explore the relationships between the factors related to the brain injury and dynamics of the gait. Optimal surgical options will be detemined through the simulation of hemiplegic gait by adjusting muscle force inputs and simulate the effect of releasing techniques of muscle contracture . The second part of the project is to develop an Intelligent Multi-channel Dynamic Electiical Stimulation system (IMDES) that will be used to dynamically stimulate affected muscles of patients with pathlogical Hemiplegic gait during walking. The outcomes of the research are to improve the contractability of the affected muscles, walking ability, and exploit the patterns of magnetoencephalographic data and their relationships with gait improvements. The anticipated outcomes of this study will include the development and validation of the new IMDES system, and develop innovative rehabilitation theory and methods by combining voluntary muscle contraction and electrically stimulated contraction to improve gait movement patterns, and the exploration of relationship between the gait re-training and rehabilitation and brain functional reorganizations

偏瘫步态是脑卒中、脑瘫、儿麻等高发性疾病造成患者运动功能障碍，形成人体部分肌张力过高（肌挛缩）或过低（肌无力）的特征步态。而针对挛缩肌群松弛术效果的"预测"和无力肌群的动态收缩训练，是偏瘫步态康复的两大难题。本课题拟采用人体动力学模拟方法，建立包括肌肉系统的偏瘫患者步态动力学模型，模拟计算患者相关肌力数据；结合多模态脑功能图、测力台、表面肌电测量分析，探讨造成患者步态异常的脑损伤因素、动力学原因，及其相互关系。通过患者偏瘫步态的仿真，调整肌力输入，模拟挛缩肌群松弛术的效果，探讨最佳手术方案。研制智能化的多通道动态电刺激仪，在患者步行训练中对肌力低下的肌群进行动态电刺激，改善肌肉收缩功能，提高行走能力，同时探索脑功能重组数据变化规律。项目成果，不仅是新仪器的研发，而且在人体肌肉的主动收缩和电刺激的强制收缩相结合的训练理论和方法上、在步态康复和脑功能重组之间规律研究上实现创新。

本项目以解决偏瘫步态康复中动力学仿真、脑功能评价和诊疗方法的若干问题为目标，完成的工作和取得的成果包括：对90多名患者进行偏瘫步态影像解析，揭示偏瘫步态的特点、特征和相关规律。分别用LIFEMOD软件和OpenSim软件建立包括肌肉系统的人体步行动力学模型，计算相关肌力数据，经统计处理，提出人体步行下肢动力学数据常模。通过对患者偏瘫步态的动力学仿真和优化，揭示了造成步态异常的动力学原因，据此确定诊疗措施、目标肌群和康复运动处方，有效提高了康复效果。研究提出了动态电刺激理念，研制了单通道和多通道动态电刺激仪，针对“肌无力”患者，根据动力学模拟结果，设定专门动态电刺激程序，在患者步态训练中加以动态电刺激，最大化的模拟正常步行肌肉运动感觉，促进脑功能重组和步态康复。针对“肌痉挛”患者，由模拟结果，确定肉毒素注射方案和步态训练运动处方，效果显著。在多模态脑功能影像与脑功能网络特性关联性研究方面取得进展。通过对偏瘫患者动态电刺激步态训练前后的脑功能医学影像数据分析研究，发现动态电刺激踝背屈肌群时，有明显的契前叶激活及小脑幕下激活，而常规康复组则没有，其结果揭示了动态电刺激促进卒中患者脑功能重塑机理。创建股骨颈有限元模型与人体动力学模型耦合的数值模拟方法。分别建立了步行、下蹲、单腿站立、前后弓步、左右弓步等不同步态动力学模型，把肌肉载荷数据转化到髋关节有限元模型坐标中，耦合计算出股骨颈部位的应力，研究不同步态中其应力变化的规律。研究发现，步行和向前弓步走可分别有效提高股骨颈部位松质骨和密质骨应力刺激，是预防股骨颈骨折最佳锻炼方法。这些成果解决了偏瘫步态康复临床理论中的一些基础性科学问题，包括揭示偏瘫步态动力学特征，建立人体步行动力学数据常模，提出动态电刺激促进卒中患者脑功能重塑机理，创建股骨颈有限元模型与人体动力学模型耦合的数值模拟方法等。