IEEE Trans Neural Syst Rehabil Eng. 2021;29:2222-2231. doi: 10.1109/TNSRE.2021.3119873. Epub 2021 Nov 2.
In previous research, we found that modulating the assistance timing of dorsiflexion may affect a user's voluntary efforts. This could constitute a focus area based on assistive strategies that could be developed to foster patients' voluntary efforts. In this present study, we conducted an experiment to verify the effects of ankle dorsiflexion assistance under different timings using a high-dorsiflexion assistive system. Nine healthy and young participants wore a dorsiflexion-restrictive device that enabled them to use circumduction or steppage gaits. On the basis of the transition from the stance to the swing phase of the gait, the assistance timings of the high-dorsiflexion assistive system were set to have delays, which ranged from 0 to 300 ms. The index results from eight out of nine participants evaluated compensatory movements and revealed positive strong/moderate correlations with assistance delay times (r = 0.627-0.965, p <.001), whereas the other participants also performed compensatory movement when dorsiflexion assistance timing was late. Meanwhile, the results from tibialis anterior surface electromyography from six out of nine participants showed positive strong/moderate correlations with dorsiflexion assistance delay times (r = 0.598-0.922, p <.001), indicating that tuning the assistance timing did foster these participants' voluntary dorsiflexion movements. This result indicates that there should be a trade-off between ensuring voluntary dorsiflexion movements and preventing incorrect gait patterns at different assistance timings. The findings of this feasibility study indicate the potential of developing an adaptive control method to ensure voluntary efforts during robot-assisted gait rehabilitation based on assistance timing modification. A new assistance mechanism should also be required to stimulate and motivate a patient's voluntary efforts and should reinforce the effects of active gait rehabilitation.
在之前的研究中，我们发现调节背屈助力的时机可能会影响使用者的自主努力。这可能构成一个基于辅助策略的重点领域，这些策略可以被开发出来以促进患者的自主努力。在本研究中，我们使用一种高背屈辅助系统进行了一项实验，以验证不同时机下的踝关节背屈辅助效果。九名健康的年轻参与者佩戴了背屈限制装置，使他们能够使用回旋步态或跨步步态。根据步态从支撑相向摆动相的转换，高背屈辅助系统的辅助时机设置为延迟，延迟范围从 0 到 300 毫秒。除了一名参与者外，其余八名参与者的评估结果均显示出补偿运动与辅助延迟时间呈正强/中度相关（r = 0.627-0.965，p <.001），而当背屈辅助时机延迟时，这名参与者也进行了补偿运动。同时，九名参与者中的六名的胫骨前肌表面肌电图结果显示，与背屈辅助延迟时间呈正强/中度相关（r = 0.598-0.922，p <.001），这表明调整辅助时机确实可以促进这些参与者的自主背屈运动。这一结果表明，在不同的辅助时机下，应该在确保自主背屈运动和防止错误步态模式之间做出权衡。这项可行性研究的结果表明，基于辅助时机的调整，有可能开发出一种自适应控制方法，以确保机器人辅助步态康复过程中的自主努力。还需要一种新的辅助机制来刺激和激励患者的自主努力，并增强主动步态康复的效果。
