Closed-Loop Neuromuscular Electrical Stimulation Method Provides Robustness to Unknown Time-Varying Input Delay in Muscle Dynamics
Closed-Loop Neuromuscular Electrical Stimulation Method Provides Robustness to Unknown Time-Varying Input Delay in Muscle Dynamics
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DOI：
10.1109/tcst.2019.2926945
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发表时间：
2020-11-01
影响因子：
4.8
通讯作者：
Dixon, Warren E.
中科院分区：
文献类型：
--
作者：
Obuz, Serhat;Duenas, Victor H.;Dixon, Warren E.
神经肌肉电刺激 (NMES) 通常用于运动障碍患者（例如中风或脊髓损伤后）的康复。闭环 NMES 有望促进协调肢体运动，但技术挑战仍然存在。特别是，在施加电刺激和随后的肌肉收缩之间存在潜在的不稳定延迟，该延迟会随着肌肉疲劳而变化。在本文中，我们开发了一种闭环 NMES 方法来产生下肢跟踪，尽管存在未知的时变输入延迟、不确定的非线性肢体动力学和附加有界干扰。一种新颖的滤波误差信号是使用过去状态在恒定估计延迟间隔上的有限积分来设计的。控制开发基于一种方法，该方法在基于 Lyapunov 的稳定性分析中使用 Lyapunov-Krasovskii 泛函来证明最终有界跟踪。提供了健康个体和患有神经系统疾病的参与者的实验结果，以证明所开发的控制器的性能。
Neuromuscular electrical stimulation (NMES) is commonly used to rehabilitate people with motor impairment (e.g., following stroke or spinal cord injury). Closed-loop NMES holds the promise to facilitate coordinated limb motion, but technical challenges remain. In particular, there is a potentially destabilizing delay between the application of the electrical stimulation and the ensuing muscle contraction, which changes as muscle fatigues. In this brief, a closed-loop NMES method is developed to yield lower limb tracking, despite an unknown time-varying input delay, uncertain nonlinear limb dynamics, and additive bounded disturbances. A novel filtered error signal is designed using the past states in a finite integral over a constant estimated delay interval. The control development is based on an approach that uses Lyapunov-Krasovskii functionals in a Lyapunov-based stability analysis to prove ultimately bounded tracking. Experimental results in healthy individuals and participants with neurological conditions are provided to demonstrate the performance of the developed controller.