Shepherd Max K, Rouse Elliott J
Annu Int Conf IEEE Eng Med Biol Soc. 2016 Aug;2016:2228-2231. doi: 10.1109/EMBC.2016.7591172.
Individuals with post-stroke hemiparesis often have difficulty standing out of a chair. One way to potentially improve sit-to-stand is to provide knee extension assistance using a powered knee exoskeleton. An exoskeleton providing unilateral, partial assistance during sit-to-stand would need to be torque-controllable. There are no knee exoskeletons on the market suitable for conducting experiments assisting stroke patients with sit-to-stand, so to enable such experiments a research device was developed. The purpose of this report is to present the design of a novel knee exoskeleton actuator that uses a fiberglass leaf spring in series to improve torque-controllability, and present a characterization of the actuator performance. The actuator is capable of the required torque and speed for sit-to-stand, has high bandwidth (25 Hz), low output impedance at low frequencies (<;0.5 Nm), and excellent torque tracking. An orthotic brace built upon this actuator will enable an in-depth study on the biomechanical effects of providing stroke subjects with knee extension assistance during sit-to-stand.
中风后偏瘫患者往往难以从椅子上站起来。一种可能改善从坐起到站立动作的方法是使用动力膝关节外骨骼提供膝关节伸展辅助。在从坐起到站立过程中提供单侧、部分辅助的外骨骼需要具备扭矩可控性。市面上没有适合进行辅助中风患者从坐起到站立实验的膝关节外骨骼，因此为了开展此类实验，研发了一种研究装置。本报告的目的是介绍一种新型膝关节外骨骼致动器的设计，该致动器串联使用玻璃纤维板簧以提高扭矩可控性，并展示该致动器的性能特征。该致动器能够提供从坐起到站立所需的扭矩和速度，具有高带宽（25赫兹）、低频时低输出阻抗（<0.5牛米）以及出色的扭矩跟踪能力。基于这种致动器构建的矫形支具将能够深入研究在从坐起到站立过程中为中风患者提供膝关节伸展辅助的生物力学效应。
