Exoskeleton footwear to improve walking performance and subject-reported preference.

本计画的长期目标是改善周边动脉病患的生活品质 疾病（PAD）使用辅助外骨骼。PAD是全身性动脉粥样硬化的表现， 会显著减少流向下肢的血液患有PAD的退伍军人接受血管成形术， 近端旁路和远端旁路手术的发生率比一般美国男性人群高10倍。 血液流动减少导致行走时疼痛，称为跛行。导致跛行疼痛 PAD导致患者走路更少，更慢，与健康人相比， 同行我们的研究已经确定了跛行患者行走模式的功能限制， 其中最突出和一致的是小腿后肌、踝跖屈肌的缺陷， 在行走过程中产生健康的踝关节扭矩和力量。设计合理的外骨骼可以让病人 使用PAD行走更长的时间而没有疼痛，或者行走完成日常活动所需的距离而压力更小 到受影响的腿。在PAD患者中实施EF之前，必须改进设计， 增加行走性能和实际患者使用。作为第一步，我们建议确定EF的效果 步行性能，重点是EF如何有助于生物踝关节扭矩的变化， 功率、能量成本和小腿肌肉氧合。我们将对健康的老年人进行测试， 舒适性，降低足部和小腿受伤的风险，并培养患者采用器械的高潜力 关于PAD然后将在PAD患者中评价EF。健康的老年人被选中 因为与PAD患者一样，他们在行走过程中产生的推离扭矩和功率较小 与健康的年轻人相比;使他们成为PAD限制的适当模型。我们的具体目标是： 目的1：确定产生更好行走的EF辅助力水平 老年人的表现。 目的2：确定产生更好的被试自报偏好的EF辅助力水平 在老年人的科目。 目的3：确定EF辅助水平对行走性能和受试者报告的 优先选择PAD患者。目标1和2的结果将指导在这一目标中测试的援助水平。 将从内布拉斯加州招募50名健康老年人用于目标1和2，以及25名PAD患者用于目标3。 以及西爱荷华州退伍军人事务部医疗中心和周边的奥马哈社区。目标1将测试 七个条件，包括五个级别的EF援助，EF没有弹簧和一个正常行走 条件将使用步态生物力学测量下肢扭矩和功率， 跑步机上跑三分钟肌肉氧合将用近红外光谱测量 的小腿肌肉。代谢车将用于测量能量成本。目标2将全面评估 受试者报告的不同EF援助水平的偏好。视觉模拟量表，感觉用力率 和疼痛，和可行性面试将提供舒适和适合，疲劳，和身体活动的困难， 主题沿着的可接受性，需求，和实用性的EF。目标3将评估步行 性能、能量成本、肌肉氧合和受试者报告的偏好， 在目标1和2中提出，但跑步机测试将是进行的最大步行距离测试 在两个不同的测试日。我们假设EF援助水平将满足受试者- 报告的偏好和步行性能目标。该提案将提供必要的 建立EF疗效并指导EF处方规范的基础知识， 供PAD患者使用。

The long term goal of this project is to improve the quality of life of patients with peripheral artery disease (PAD) using assistive exoskeletons. PAD is a manifestation of systemic atherosclerosis that significantly reduces blood flow to the lower extremities. Veterans with PAD undergo angioplasty, proximal bypass, and distal bypass procedures at rates 10 times higher than the general US male population. Reduced blood flow leads to pain during walking known as claudication. Claudication pain that results from PAD causes patients to walk less and slower, and lose independence compared with their healthy counterparts. Our research has identified functional limitations in the walking patterns of claudicating patients, the most prominent and consistent of which is a deficit of the psterior calf muscles, the ankle plantarflexors, to generate healthy ankle toruqe and power during walking. A properly designed exoskeleton will allow patients with PAD to walk longer without pain or walk the distance needed for completing daily activities with less stress to the affected leg. Before EF can be implemented in patients with PAD, the design must be improved to increase walking performance and actual patient use. As a first step we propose to determine the effect of EF on walking performance, focusing on the how EF contributes to changes in the biological ankle torque and power, energy cost, and calf muscle oxygenation. We will test healthy older adults to ensure and confirm comfort, decrease risk of injury to the foot and calf, and cultivate high potential for device adoption in patients with PAD. The EF will then be evaluated in patients with PAD. Healthy older individuals are selected for this initial phase because like patients with PAD, they produce less push-off torque and power during walking compared with healthy young; making them an appropriate model for PAD limitations. Our specific aims are: Aim 1: To determine the levels of EF assistance force level which produce better walking performance in older subjects. Aim 2: To determine the levels of EF assistance force which produce better subject-reported preference in older subjects. Aim 3: To determine the effect of EF assistance levels on walking performance and subject-reported preference in patients with PAD. Aims 1 and 2 results will guide the assistance levels tested in this aim. 50 healthy older adults for Aims 1 and 2, and 25 patients with PAD for Aim 3 will be recruited from the Nebraska and Western Iowa Veterans Affairs’ Medical Center and surrounding Omaha community. Aim 1 will test seven conditions, including five levels of EF assistance, the EF with no spring and one normal walking condition. Lower extremity torque and power will be measured using gait biomechanics on the treadmill for three minutes per condition. Muscle oxygenation will be measured with near infrared spectroscopy of the calf muscles. A metabolic cart will be used to measure energy cost. Aim 2 will thoroughly assess subject-reported preference across levels of EF assistance. Visual analog scales, rate of perceived exertion and pain, and feasibility interviews will provide the comfort and fit, fatigue, and physical activity difficulty of subjects along with the acceptability, demand, and practicality of the EF. Aim 3 will assess walking performance, energy cost, muscle oxygenation, and subject reported preference in the same manner as proposed in Aims 1 and 2, except the treadmill tests will be maximal walking distance tests performed across two difference testing days. We hypothesize there will be an EF assistance level to satisfy subject- reported preference and walking performance goals. This proposal will provide essential fundamental knowledge that will establish EF efficacy and guide prescriptive specifications for EF to be adopted for use by patients with PAD.