Individuals with chronic hemiparesis post-stroke exhibit gait impairments that require functional rehabilitation through training. Exoskeletal robotic assistive devices can provide a user with continuous assistance but impose movement restrictions. There are currently devices that allow unrestricted movement but provide assistance only intermittently at specific points of the gait cycle. Our design, a cable-driven active leg exoskeleton (C-ALEX), allows the user both unrestricted movement and continuous force assistance throughout the gait cycle to assist the user in new walking patterns. In this study, we assessed the ability of C-ALEX to induce a change in the walking patterns of ten post-stroke participants using a single-session training protocol. The ability of C-ALEX to accurately provide forces and torques in the desired directions was also evaluated to compare its design performance to traditional rigid-link designs. Participants were able to reach 91% ± 12% of their target step length and 89% ± 13% of their target step height. The achieved step parameters differed significantly from participant baselines ( ${p} < {0.05}$ ). To quantify the performance, the forces in each cable’s out of the plane movements were evaluated relative to the in-plane desired cable tension magnitudes. This corresponded to an error of under 2Nm in the desired controlled joint torques. This error magnitude is low compared to the system command torques and typical adult biological torques during walking (2–4%). These results point to the utility of using non-restrictive cable-driven architectures in gait retraining, in which future focus can be on rehabilitating gait pathologies seen in stroke survivors.

中文翻译：

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使用带有中风后参与者的电缆驱动主动腿外骨骼（C-ALEX）进行步态适应

中风后慢性偏瘫患者表现出步态障碍，需要通过训练来恢复功能。骨骼外机器人辅助设备可以为用户提供持续的帮助，但会限制运动。当前，有一些设备可以不受限制地运动，但只能在步态周期的特定时间点间歇地提供帮助。我们的设计是一个电缆驱动的主动腿外骨骼（C-ALEX），在整个步态周期中，用户可以不受限制地运动，并可以持续施加力，以帮助用户采取新的步行方式。在这项研究中，我们评估了C-ALEX使用单节训练方案来诱导十名中风后参与者的步行方式变化的能力。还评估了C-ALEX在所需方向上准确提供力和扭矩的能力，以将其设计性能与传统的刚性连杆设计进行比较。参与者能够达到目标步长的91％±12％和目标步高的89％±13％。达到的步骤参数与参与者的基线有显着差异（ $ {p} <{0.05} $ ）。为了量化性能，相对于平面内所需的电缆张力大小，评估了每条电缆在平面外运动中的力。这对应于期望的受控关节扭矩中的2 Nm以下的误差。与系统命令扭矩和行走过程中典型的成人生物扭矩相比，此误差幅度较小（2-4％）。这些结果表明在步态再训练中使用非限制性电缆驱动架构的实用性，其中将来的重点可能是使中风幸存者中看到的步态病理恢复。