糖尿病足足底软组织力学退变及其补偿机制研究

The population of diabetes in China is over 114 million, and nearly one fifth of the patients suffer from constant foot ulcers, and even amputation. According to the degenerative properties of plantar soft tissue in diabetic foot, applying adaptive foot pad for corresponding mechanical compensation is an important means of active protection, but the existing studies are still limited to static research, which greatly limits the design level and preventive outcome. Based on our previous study, the mechanical degeneration of the diabetic plantar soft tissue often had gait-related and time-related characteristics, so there is an urgent need to realize in vivo kinematic measurement and modeling analysis. This project is planned to use fluoroscopic registration technology in combination with a plantar force measuring device, which was established and verified in our previous studies, to dynamically obtain stress and strain of plantar soft tissue during gait cycle, and calculate their viscous and elastic properties and the change trend after long-term repeated load, so as to take the lead in building the in vivo database of mechanical degeneration characteristics for early diabetic plantar soft tissue; Then patient specific digital models are built, and the real-time bone trajectory and ground reverse force would be applied for continuous loading, to innovatively analyze the dynamical mechanical match between foot pad and plantar soft tissue, and create optimal fitting attributes for foot pad to realize the best mechanical compensation. The research achievement will break through the existing technical bottleneck, and provide effective mechanical compensation for early diabetic foot under full gait cycle and repeated load, so as to reduce the risk of later foot ulcer or amputation.

我国糖尿病人超1.14亿，近1/5长期受足部溃疡困扰，乃至截肢。针对糖尿病足退变的足底软组织属性，适配足垫进行对应的力学补偿是主动防护的重要手段，但现有研究仍局限在静态，极大限制了其设计水平与防护功能。我们前期研究提示，糖尿病人足底软组织力学退变具有步态相关性及时间相关性特征，故实现动态力学测算与建模分析具有迫切需求。本项目拟利用我们前期搭建并验证的荧光透视配准技术结合足底测力装置，动态采集步态周期中足底软组织的应力应变数据，测算其粘弹性力学参数及重复载荷后的变化趋势，率先建立早期糖尿病人足底软组织力学退变特征的在体数据库；同时构建患者特异性数字模型，并利用实时骨骼运动轨迹及地面反力连续加载，创新性地分析足垫与足底软组织间的力学动态匹配性，拟合最优足垫属性以实现最佳力学补偿。研究结果将突破现有技术瓶颈，为早期糖尿病足提供全步态周期与重复载荷下的有效力学补偿，降低后期溃疡或截肢的风险。

我国糖尿病人超1.14亿，约有15％～20％在其病程中发生足部溃疡，并长期带创面生存。针对糖尿病足退变的足底软组织属性，适配足垫进行对应的力学补偿是主动防护的重要手段，但现有研究仍局限在静态，极大限制了其设计水平与防护功能。.本项目主要研究内容分为四部分：①纳入不同分级的早期糖尿病人作为实验对象，通过在体实验计算其足底软组织的粘、弹力学属性及参数，并观察长时间行走后的变化，从而完善不同糖尿病人足底软组织力学特征的在体数据库；②利用在体数据和快速建模的方法构建各糖尿病人的患者特异性足部有限元模型，动态加载并分析不同属性的糖尿病足垫与足底软组织间的“力学匹配性”，拟合最优解决方案；③依据各糖尿病人拟合的最优解决方案分别试制相应的糖尿病足垫进行适配，通过与新纳入的另一批佩戴标准预制足垫的早期糖尿病人对比随访，完成初步的临床验证。.项目重要结果包含：①早期糖尿病人足底软组织力学特征较正常足发生退变，可能表现为粘、弹性力学参数改变，能量损失增多，内部应力持续升高，对时间依赖性加载的敏感性增加等，但不同的糖尿病人可能有不同的表现形式和程度；②构建并验证了一种基于受试者足底软组织在体力学属性建立特异性足踝部有限元模型，通过比较不同材料对该模型加载后的足部内部应力，得出最优足垫粘弹属性为重复载荷后足底软组织所测的在体粘弹属性，为定制化足垫的材料属性设置提供了科学指导。③基于患者足底软组织力学退变的特异性，及其与糖尿病足垫的长时间的动态匹配性，可从力学角度定制最优的防护足垫，降低糖尿病足溃疡发生率。.本项目科学意义在于：率先建立完备的糖尿病足足底软组织力学退变特征的在体数据库，并探索其最优的动态力学补偿方案；为今后的工程设计还原更为真实、全面的病理软组织状态，为个性化生物力学防护提供科学依据与优化途径。项目成果将为突破糖尿病足溃疡主动防护的技术瓶颈、有效预防或延缓溃疡发生提供有力支持。