Optimizing Exoskeleton Assistance for Faster Self-Selected Walking.
Optimizing Exoskeleton Assistance for Faster Self-Selected Walking.
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DOI：
10.1109/tnsre.2021.3074154
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Collins SH
中科院分区：
文献类型：
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作者：
Song S;Collins SH
自主选择的步行速度是移动性的一个重要方面。外骨骼可以提高步行速度，但这些变化背后的机制和性能上限尚不清楚。人在回路优化是一种用于识别外骨骼特征的技术，该外骨骼特征使辅助的益处最大化，这对于实现能源经济的大幅改善至关重要。在这项研究中，我们使用人在回路优化来测试是否可以通过踝关节外骨骼辅助来大幅提高自主选择的步行速度。健康的参与者（N = 10）被指示在自行步速的跑步机上以舒适的速度行走，同时穿着拴系的踝关节外骨骼。一种算法依次应用不同的外骨骼扭矩模式，并估计速度最佳模式，然后在单独的试验中进行评估。在扭矩针对速度进行优化的情况下，参与者的行走速度比普通鞋快42%（1.83 m s−1 vs. 1.31 m s−1; Tukey HSD，p = 4 × 10−8），速度增加6%至91%。参与者使用速度优化的扭矩比使用能量消耗优化的扭矩（1.55 m s-1）或选择用于诱导慢速行走的扭矩（1.18 m s-1）走得更快。具有速度优化扭矩的步态特征在参与者中变化很大，运输代谢成本的变化范围从减少31%到增加78%，平均减少2%。这些结果表明，踝关节外骨骼可以促进自主选择的步行速度的大幅增加，这可能有利于老年人和其他步行速度降低的人。
Self-selected walking speed is an important aspect of mobility. Exoskeletons can increase walking speed, but the mechanisms behind these changes and the upper limits on performance are unknown. Human-in-the-loop optimization is a technique for identifying exoskeleton characteristics that maximize the benefits of assistance, which has been critical to achieving large improvements in energy economy. In this study, we used human-in-the-loop optimization to test whether large improvements in self-selected walking speed are possible through ankle exoskeleton assistance. Healthy participants (N = 10) were instructed to walk at a comfortable speed on a self-paced treadmill while wearing tethered ankle exoskeletons. An algorithm sequentially applied different patterns of exoskeleton torque and estimated the speed-optimal pattern, which was then evaluated in separate trials. With torque optimized for speed, participants walked 42% faster than in normal shoes (1.83 m s−1 vs. 1.31 m s−1; Tukey HSD, p = 4 × 10−8), with speed increases ranging from 6% to 91%. Participants walked faster with speed-optimized torque than with torque optimized for energy consumption (1.55 m s−1) or torque chosen to induce slow walking (1.18 m s−1). Gait characteristics with speed-optimized torque were highly variable across participants, and changes in metabolic cost of transport ranged from a 31% decrease to a 78% increase, with a decrease of 2% on average. These results demonstrate that ankle exoskeletons can facilitate large increases in self-selected walking speed, which could benefit older adults and others with reduced walking speed.