An Adaptive Neuromuscular Controller for Assistive Lower-Limb Exoskeletons: A Preliminary Study on Subjects with Spinal Cord Injury.
An Adaptive Neuromuscular Controller for Assistive Lower-Limb Exoskeletons: A Preliminary Study on Subjects with Spinal Cord Injury.
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DOI：
10.3389/fnbot.2017.00030
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发表时间：
2017
影响因子：
3.1
通讯作者：
Ijspeert AJ
中科院分区：
文献类型：
--
作者：
Wu AR;Dzeladini F;Brug TJH;Tamburella F;Tagliamonte NL;van Asseldonk EHF;van der Kooij H;Ijspeert AJ
多功能性对于可穿戴外骨骼控制器对用户和环境的响应都很重要。这些特征对于脊髓损伤(SCI)患者尤其重要，在SCI患者中，积极招募自己的神经肌肉系统可以促进运动恢复。在这里，我们展示了一种新颖的、受生物启发的神经肌肉控制器(NMC)的能力，它使用腿部肌肉的动力学模型来辅助脊髓损伤受试者的步态。该控制器具有鲁棒性、模块化和适应性强等优点。该控制器只需要很少的输入(即关节角度、站姿和摆动检测)，可以分解为相关的控制模块(例如，仅控制膝盖或臀部)，并可以在模拟中生成不同速度和地形的步行。我们在7名受试者(N=7，4名完全性截瘫，2名不完全截瘫，1名健康)的下肢膝关节和髋关节机器人步态训练器上对该控制器进行了初步评估，以确定NMC是否能够实现正常行走。在实验期间，SCI受试者在跑步机上依靠体重行走，并可以使用扶手。在控制器的帮助下，受试者能够以行走SCI受试者的快步行速度行走--从0.6m/S到1.4m/NMC。测量的关节角度和NMC提供的关节扭矩与健康受试者穿鞋行走时的运动学和生物关节扭矩符合得很好。在扭矩之间发现了一些差异，如站立中附近缺乏膝关节屈曲，但关节角度轨迹似乎没有受到太大影响。NMC还调整了其扭矩输出，以更快的速度提供更多的关节功，从而提供更大的关节角度和步长。我们还发现，在健康人身上观察到的最佳速度-步长曲线出现在大多数受试者身上，尽管在较快的速度下步长相对较长。因此，由于几乎没有传感器，也没有针对不同人体测量和行走能力的受试者进行多种行走速度或调整的预定义设置，NMC使SCI受试者能够以几种速度行走，包括接近健康的速度，以一种健康的方式。这些初步结果为未来神经肌肉控制器在可穿戴原型上的应用提供了希望，这些原型适用于真实世界的行走条件。
Versatility is important for a wearable exoskeleton controller to be responsive to both the user and the environment. These characteristics are especially important for subjects with spinal cord injury (SCI), where active recruitment of their own neuromuscular system could promote motor recovery. Here we demonstrate the capability of a novel, biologically-inspired neuromuscular controller (NMC) which uses dynamical models of lower limb muscles to assist the gait of SCI subjects. Advantages of this controller include robustness, modularity, and adaptability. The controller requires very few inputs (i.e., joint angles, stance, and swing detection), can be decomposed into relevant control modules (e.g., only knee or hip control), and can generate walking at different speeds and terrains in simulation. We performed a preliminary evaluation of this controller on a lower-limb knee and hip robotic gait trainer with seven subjects (N = 7, four with complete paraplegia, two incomplete, one healthy) to determine if the NMC could enable normal-like walking. During the experiment, SCI subjects walked with body weight support on a treadmill and could use the handrails. With controller assistance, subjects were able to walk at fast walking speeds for ambulatory SCI subjects—from 0.6 to 1.4 m/s. Measured joint angles and NMC-provided joint torques agreed reasonably well with kinematics and biological joint torques of a healthy subject in shod walking. Some differences were found between the torques, such as the lack of knee flexion near mid-stance, but joint angle trajectories did not seem greatly affected. The NMC also adjusted its torque output to provide more joint work at faster speeds and thus greater joint angles and step length. We also found that the optimal speed-step length curve observed in healthy humans emerged for most of the subjects, albeit with relatively longer step length at faster speeds. Therefore, with very few sensors and no predefined settings for multiple walking speeds or adjustments for subjects of differing anthropometry and walking ability, NMC enabled SCI subjects to walk at several speeds, including near healthy speeds, in a healthy-like manner. These preliminary results are promising for future implementation of neuromuscular controllers on wearable prototypes for real-world walking conditions.