Grimm Florian, Gharabaghi Alireza
Division of Functional and Restorative Neurosurgery, Department of Neurosurgery, and Centre for Integrative Neuroscience, Eberhard Karls University Tuebingen Tuebingen, Germany.
Front Neurosci. 2016 Jun 23;10:284. doi: 10.3389/fnins.2016.00284. eCollection 2016.
Stroke patients with severe motor deficits cannot execute task-oriented rehabilitation exercises with their affected upper extremity. Advanced rehabilitation technology may support them in performing such reach-to-grasp movements. The challenge is, however, to provide assistance as needed, while maintaining the participants' commitment during the exercises. In this feasibility study, we introduced a closed-loop neuroprosthesis for reach-to-grasp assistance which combines adaptive multi-channel neuromuscular stimulation with a multi-joint arm exoskeleton. Eighteen severely affected chronic stroke patients were assisted by a gravity-compensating, seven-degree-of-freedom exoskeleton which was attached to the paretic arm for performing reach-to-grasp exercises resembling activities of daily living in a virtual environment. During the exercises, adaptive electrical stimulation was applied to seven different muscles of the upper extremity in a performance-dependent way to enhance the task-oriented movement trajectory. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. Closed-loop neuromuscular stimulation could be well integrated into the exoskeleton-based training, and increased the task-related range of motion (p = 0.0004) and movement velocity (p = 0.015), while preserving accuracy. The highest relative stimulation intensity was required to facilitate the grasping function. The facilitated range of motion correlated with the upper extremity Fugl-Meyer Assessment score of the patients (p = 0.028). Combining adaptive multi-channel neuromuscular stimulation with antigravity assistance amplifies the residual motor capabilities of severely affected stroke patients during rehabilitation exercises and may thus provide a customized training environment for patient-tailored support while preserving the participants' engagement.
患有严重运动功能障碍的中风患者无法用其受影响的上肢进行以任务为导向的康复训练。先进的康复技术或许能帮助他们完成这种抓握动作。然而，挑战在于要根据需要提供协助，同时在训练过程中保持参与者的积极性。在这项可行性研究中，我们引入了一种用于抓握辅助的闭环神经假体，它将自适应多通道神经肌肉刺激与多关节手臂外骨骼相结合。18名受严重影响的慢性中风患者由一个重力补偿式七自由度外骨骼提供辅助，该外骨骼附着在患侧手臂上，用于在虚拟环境中进行类似于日常生活活动的抓握训练。在训练过程中，以与表现相关的方式对上肢的七块不同肌肉施加自适应电刺激，以增强以任务为导向的运动轨迹。针对每块目标肌肉的刺激强度都是个性化的，且保持在阈下水平，即不会产生明显的辅助效果。闭环神经肌肉刺激能够很好地融入基于外骨骼的训练中，并增加了与任务相关的运动范围（p = 0.0004）和运动速度（p = 0.015），同时保持了准确性。抓握功能的实现需要最高的相对刺激强度。所促进的运动范围与患者的上肢Fugl - Meyer评估得分相关（p = 0.028）。将自适应多通道神经肌肉刺激与抗重力辅助相结合，可增强严重受影响中风患者在康复训练期间的残余运动能力，从而可能为患者量身定制支持提供一个定制化的训练环境，同时保持参与者的参与度。
