Wearer-Prosthesis Interaction for Symmetrical Gait: A Study Enabled by Reinforcement Learning Prosthesis Control
Wearer-Prosthesis Interaction for Symmetrical Gait: A Study Enabled by Reinforcement Learning Prosthesis Control
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DOI：
10.1109/tnsre.2020.2979033
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发表时间：
2020-04-01
影响因子：
4.9
通讯作者：
Huang, He
中科院分区：
文献类型：
--
作者：
Wen, Yue;Li, Minhan;Huang, He
随着机器人假体的进步，RESE-Archers试图改善截肢者的步态性能（例如步态对称性），而不是恢复规范性膝盖运动学/动力学。然而，关于假体机械/控制如何影响佩戴者的步态表现，例如步态对称性，稳定性等，知之甚少。这项研究旨在研究机器人跨性伪造的假体机械对人类佩戴者步态对称性的影响。我们先前设计的增强学习（RL）补充控制能够实现研究，该控制同时调整了12个控制参数，这些控制参数确定了整个步态周期的假体机械。 RL控制设计促进了与人类在循环中的人类机构机械师的安全探索。在RL控制器调整控制参数时，招募了受试者并在跑步机上使用机器人际交往假体行走。测量了稳定时间对称性，步长对称性和双侧前后（AP）脉冲。数据分析表明，机器人膝盖力学的变化导致下肢运动的运动变化，因此导致步态颞空间对称性度量。在所有受试者中，LIMB AP冲动测量值都一致地解释了步态对称性：姿势时间对称性与净limb ap aP脉冲显着相关，并且步长对称性与制动和推进性脉冲脉冲对称性显着相关。结果表明，有可能个性化转际假体控制，以改善时间空间步态对称性。但是，单独调整假体机制不足以最大程度地提高步态对称性。相反，实现步态对称性可能需要在佩戴者的整体肢体控制和自适应控制假体关节之间进行协调。结果还表明，基于RL的假体调整系统是研究佩戴者 - 假体相互作用的潜在工具。
With advances in robotic prostheses, rese-archers attempt to improve amputee's gait performance (e.g., gait symmetry) beyond restoring normative knee kinematics/kinetics. Yet, little is known about how the prosthesis mechanics/control influence wearer-prosthesis' gait performance, such as gait symmetry, stability, etc. This study aimed to investigate the influence of robotic transfemoral prosthesis mechanics on human wearers' gait symmetry. The investigation was enabled by our previously designed reinforcement learning (RL) supplementary control, which simultaneously tuned 12 control parameters that determined the prosthesis mechanics throughout a gait cycle. The RL control design facilitated safe explorations of prosthesis mechanics with the human in the loop. Subjects were recruited and walked with a robotic transfemoral prosthesis on a treadmill while the RL controller tuned the control parameters. Stance time symmetry, step length symmetry, and bilateral anteroposterior (AP) impulses were measured. The data analysis showed that changes in robotic knee mechanics led to movement variations in both lower limbs and therefore gait temporal-spatial symmetry measures. Consistent across all the subjects, inter-limb AP impulse measurements explained gait symmetry: the stance time symmetry was significantly correlated with the net inter-limb AP impulse, and the step length symmetry was significantly correlated with braking and propulsive impulse symmetry. The results suggest that it is possible to personalize transfemoral prosthesis control for improved temporal-spatial gait symmetry. However, adjusting prosthesis mechanics alone was insufficient to maximize the gait symmetry. Rather, achieving gait symmetry may require coordination between the wearer's motor control of the intact limb and adaptive control of the prosthetic joints. The results also indicated that the RL-based prosthesis tuning system was a potential tool for studying wearer-prosthesis interactions.