Optimized hip-knee-ankle exoskeleton assistance reduces the metabolic cost of walking with worn loads.
Optimized hip-knee-ankle exoskeleton assistance reduces the metabolic cost of walking with worn loads.
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DOI：
10.1186/s12984-021-00955-8
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发表时间：
2021-11-07
影响因子：
5.1
通讯作者：
Collins SH
中科院分区：
文献类型：
--
作者：
Bryan GM;Franks PW;Song S;Reyes R;O'Donovan MP;Gregorczyk KN;Collins SH
负重在很多职业中很常见，但长时间负重会增加疲劳和过度使用损伤。外骨骼可以通过降低代谢成本来对抗疲劳，减少肌肉活动以防止受伤，从而提高这些专业人士的生活质量。目前的外骨骼在辅助一个或两个关节时，相对于在没有辅助的情况下在设备中行走，已将负重行走的代谢成本降低了高达22%。更大的代谢减少可能与整个腿的优化援助。我们使用人在回路优化来优化髋-膝-踝外骨骼辅助，其中三名参与者没有额外的负载，轻负载（体重的15%）和重负载（体重的30%）。所有的负荷都是通过一个附有腰带的重量背心施加的。我们测量了代谢成本、外骨骼辅助、运动学和肌肉活动。我们进行了Friedman检验来分析磨损载荷的趋势，并进行了配对t检验来确定从无辅助条件到辅助条件的变化是否显著。对于所有测试条件，外骨骼辅助相对于在没有辅助的情况下在设备中行走降低了行走的代谢成本。外骨骼辅助使步行的代谢成本在无负荷的情况下降低了48%（p = 0.05），在轻负荷的情况下降低了41%（p = 0.01），在重负荷的情况下降低了43%（p = 0.04）。在轻负荷下较小的代谢减少可能是由于参与者训练不足或缺乏优化器收敛。所有测试条件下施加的总正功率相似，正膝关节功率随载荷增加略有下降。优化的扭矩定时参数在参与者和负载条件下是一致的，而优化的幅度参数各不相同。全腿外骨骼辅助可以减少步行时的代谢成本，同时携带一系列负载。在参与者和条件下一致的优化定时参数表明，代谢成本的降低对扭矩定时敏感。可变扭矩大小参数可以暗示扭矩大小应该针对个体定制，或者存在有用扭矩大小的范围。未来的工作应该测试是否将负载施加到外骨骼而不是人的躯干上会产生更大的好处。在线版本包含补充材料，可通过10.1186/s12984-021-00955-8获取。
Load carriage is common in a wide range of professions, but prolonged load carriage is associated with increased fatigue and overuse injuries. Exoskeletons could improve the quality of life of these professionals by reducing metabolic cost to combat fatigue and reducing muscle activity to prevent injuries. Current exoskeletons have reduced the metabolic cost of loaded walking by up to 22% relative to walking in the device with no assistance when assisting one or two joints. Greater metabolic reductions may be possible with optimized assistance of the entire leg. We used human-in the-loop optimization to optimize hip-knee-ankle exoskeleton assistance with no additional load, a light load (15% of body weight), and a heavy load (30% of body weight) for three participants. All loads were applied through a weight vest with an attached waist belt. We measured metabolic cost, exoskeleton assistance, kinematics, and muscle activity. We performed Friedman’s tests to analyze trends across worn loads and paired t-tests to determine whether changes from the unassisted conditions to the assisted conditions were significant. Exoskeleton assistance reduced the metabolic cost of walking relative to walking in the device without assistance for all tested conditions. Exoskeleton assistance reduced the metabolic cost of walking by 48% with no load (p = 0.05), 41% with the light load (p = 0.01), and 43% with the heavy load (p = 0.04). The smaller metabolic reduction with the light load may be due to insufficient participant training or lack of optimizer convergence. The total applied positive power was similar for all tested conditions, and the positive knee power decreased slightly as load increased. Optimized torque timing parameters were consistent across participants and load conditions while optimized magnitude parameters varied. Whole-leg exoskeleton assistance can reduce the metabolic cost of walking while carrying a range of loads. The consistent optimized timing parameters across participants and conditions suggest that metabolic cost reductions are sensitive to torque timing. The variable torque magnitude parameters could imply that torque magnitude should be customized to the individual, or that there is a range of useful torque magnitudes. Future work should test whether applying the load to the exoskeleton rather than the person’s torso results in larger benefits. The online version contains supplementary material available at 10.1186/s12984-021-00955-8.
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影响因子：
5.1
作者：
Lee S;Kim J;Baker L;Long A;Karavas N;Menard N;Galiana I;Walsh CJ
通讯作者：
Walsh CJ
影响因子：
25
作者：
Quinlivan, B. T.;Lee, S.;Walsh, C. J.
通讯作者：
Walsh, C. J.
影响因子：
1.2
作者：
Knapik, JJ;Reynolds, KL;Harman, E
通讯作者：
Harman, E
影响因子：
3.3
作者：
Selinger, Jessica C.;Donelan, J. Maxwell
通讯作者：
Donelan, J. Maxwell
影响因子：
3.7
作者：
Dembia CL;Silder A;Uchida TK;Hicks JL;Delp SL
通讯作者：
Delp SL