Real-time quantification of muscle-tendon dynamics for individualized and adaptive robot-assisted locomotion

步行功能对生命功能和健康有着至关重要的作用。根据《美国残疾人：2010》 美国人口普查局的一份报告显示，大约有3060万15岁及以上的人患有身体缺陷 与行走有关，包括行走困难。这些限制代表了一个重要的医疗保健， 社会和经济问题，因为这些人有患合并症的风险，健康状况迅速下降， 并面临着与融入社区和重新加入劳动力相关的重大挑战。 踝关节功能受损被认为是导致老年人和老年人步态功能下降的主要因素 斯托克城的幸存者。最近的研究结果表明，踝关节辅助外衣可以改善中风后的步态。 生物设计实验室已经开发出新的软外骨骼系统(“外骨骼”)，它是由符合 材料，如织物和将力从小型执行机构包传递到脚踝和髋关节。通过触发 这些系统在步态周期的精心选择的阶段帮助用户，这些系统明显地减少了 运动的能量消耗，可以帮助纠正病态步态。与传统的刚性外骨骼相比， 这些系统重量轻、舒适，不会阻碍正常的关节运动。 大量研究证实，可穿戴的脚踝外骨骼或外骨骼可以显著降低 运动的新陈代谢成本，促进更有效的步态。然而，个人的利益差异很大，而且 适用于某些个人的辅助参数(例如应用的关节扭矩、正时)包括 对其他人来说适得其反。最先进的技术，如经验优化，在寻找 代谢最佳，但都是时间密集型的，往往仅限于测试的步态条件。此外，这些 到目前为止，方法无法对个体反应的差异提供机械解释，这种差异可能是 用于改进外衣的设计和功能。 这项提议旨在通过开发低成本和低成本的方法，迅速实现援助的个性化 剖面和便携式超声成像技术，可以可视化和测量肌肉和 腿内的肌腱。假设是直接测量趾屈肌的动力学- 使用超声成像的肌腱单位(MTU)将提供对潜在机制的重要洞察 人体与外衣辅助的互动。此外，从MTU动态导出的信号可以使 在不同的步态条件下，有效的个性化和适应性的外衣辅助。 开发的R21项目将导致创建和验证一个系统，以测量 脱套手术中腿部重要的MTU参数。丰富的生物力学数据集将提供 对用户反应的洞察，并将向研究人员提供。为老年人做好前期工作 个人将提供框架，将外衣技术的潜力扩展到更广泛的 临床用户，其中辅助策略是根据用户和真实世界移动的需求而定制的。

Walking function has a critical role in life functions and health. According to the Americans with Disability: 2010 report from the US Census Bureau, roughly 30.6 million individuals aged 15 years and older had limitations associated with ambulation including difficulty walking. These limitations represent a significant healthcare, societal and economic problem, as these people are at risk of developing co-morbidities, rapidly declining health, and face significant challenges associated with integrating into the community and rejoining the workforce. Impaired ankle function is thought to be a major contributing factor to the reduced gait function in elderly and stoke survivors. Recent results suggest that ankle-assisting exosuits can improve gait after stroke. The Biodesign Lab has developed new soft exoskeleton systems (“exosuits”) that are constructed from compliant materials such as fabrics and transmit force from small actuator packs to ankle and hip joints. By triggering actuation to assist the user at carefully-selected phases of the gait cycle, these systems demonstrably reduce the energetic cost of locomotion and can help correct pathological gait. Compared to traditional rigid exoskeletons, these systems are lightweight, comfortable, and do not hinder normal joint motions. Numerous studies have confirmed that wearable ankle exoskeletons or exosuits can significantly lower the metabolic cost of locomotion and promote more effective gait. However, individual benefit varies widely and the assistance parameters (e.g. applied joint torque, timing) that work well for some individuals are counterproductive for others. State-of-the-art techniques such as empirical optimization are successful in finding the metabolic optimum but are time intensive and often limited to the gait condition tested. Additionally, these methods so far fail to provide a mechanistic explanation for differences in individual response which could be used to improve exosuit design and function. This proposal targets a new approach for quickly individualizing assistance through the development of low- profile and portable ultrasound imaging technology that can visualize and measure the behavior of muscles and tendons within the leg. The hypothesis is that direct measurement of the dynamics of the plantarflexor muscle- tendon unit (MTU) using ultrasound imaging will provide essential insight into the mechanisms that underlie human interaction with exosuit assistance. Furthermore, signals derived from MTU dynamics can enable effective individualized and adaptive exosuit assistance in diverse gait conditions. This developmental R21 project will result in the creation and validation of a system to measure the state of important MTU parameters in the leg during exosuit operation. The rich biomechanics dataset will provide insights into user response and will be made available to researchers. The preliminary work with elderly individuals will provide the framework for extending the potential of exosuit technology to a broader range of clinical users where assistive strategies are customized to the user and the demands of real-world locomotion.