Functional electrical stimulation (FES) induced cycling is a common rehabilitative technique for people with neuromuscular disorders. A challenge for closed-loop FES control is that there exists a potentially destabilizing time-varying input delay, termed electromechanical delay (EMD), between the application of the electric field and the corresponding muscle contraction. In this article, the FES-induced torque production and EMD are quantified on an FES-cycle for the quadriceps femoris and gluteal muscle groups. Experiments were performed on five able-bodied individuals and five individuals with neurological conditions. Closed-loop FES-cycling was applied to induce fatigue and torque and EMD measurements were made during isometric conditions before and after each minute of cycling to quantify the effect of fatigue on EMD and torque production. A multiple linear regression and other descriptive statistics were performed to establish a range of expected EMD values and bounds on the rate of change of the EMD across a diverse population. The results from these experiments can be used to assist in the development of closed-loop controllers for FES-cycling that are robust to time-varying EMD and changes in torque production.

中文翻译：

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FES循环过程中机电延迟的时变性质的表征

功能性电刺激（FES）诱导的骑行是神经肌肉疾病患者的常见康复技术。闭环FES控制的挑战是在施加电场和相应的肌肉收缩之间存在潜在不稳定的时变输入延迟，称为机电延迟（EMD）。在本文中，在股四头肌和臀肌组的FES循环中定量了FES引起的扭矩产生和EMD。实验针对五个健全的个体和五个患有神经系统疾病的个体进行。进行闭环FES循环以诱发疲劳和扭矩，并在每次骑车之前和之后的等距条件下进行EMD测量，以量化疲劳对EMD和扭矩产生的影响。进行了多元线性回归和其他描述性统计，以建立一系列预期EMD值以及跨各种人群的EMD变化率的界限。这些实验的结果可用于协助开发FES循环的闭环控制器，该控制器对于随时间变化的EMD和扭矩产生的变化具有鲁棒性。