Hsieh Ming-Hwa, Huang Yin Hsuan, Chao Chia-Lun, Liu Chien-Hao, Hsu Wei-Li, Shih Wen-Pin
Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
The School and Graduate Institute of Physical Therapy College of Medicine, National Taiwan University, Taipei 10617, Taiwan.
Appl Bionics Biomech. 2020 Jul 9;2020:5927657. doi: 10.1155/2020/5927657. eCollection 2020.
In this research, we proposed a lower-limb soft exoskeleton for providing assistive forces to patients with muscle weakness during the preswing phase of a gait cycle. Whereas conventional soft exoskeletons employ two motors to assist each leg individually, we designed a single motor for actuation. Our design assists hip flexion for light weights and prevents some slip problems that can arise from rotary motors. The actuation mechanism was based on a pulley system that converted the power supplied by the single motor into linear reciprocating motions of a slider. When the single motor rotated, the slider moved linearly, first in one direction and then in the opposite direction. The slider pulled knee braces through cables with an assistive force of 100 N. The actuation was triggered when the system detected that the backward swing of the wearer's thigh had ended. A prototype was designed, fabricated, and examined with 7 subjects (average age, 24). Subjects were measured while they wore our exoskeleton in power-off and power-on modes. Comparisons proved that wearing the exoskeleton caused a negligible deviation of gait, and that the soft exoskeleton could reduce metabolic cost during walking. The research results are expected to be beneficial for lightweight soft exoskeletons and integration with exosuits that provide assistive forces through the wearer's entire gait.
在本研究中，我们提出了一种下肢软质外骨骼，用于在步态周期的摆动前期为肌无力患者提供辅助力。传统的软质外骨骼采用两个电机分别辅助每条腿，而我们设计了一个单一电机进行驱动。我们的设计在负载较轻时辅助髋关节屈曲，并防止旋转电机可能出现的一些滑动问题。驱动机构基于一个滑轮系统，该系统将单一电机提供的动力转换为滑块的线性往复运动。当单一电机旋转时，滑块做直线运动，先朝一个方向，然后朝相反方向。滑块通过缆绳以100 N的辅助力拉动膝盖护具。当系统检测到穿戴者大腿的向后摆动结束时，驱动被触发。设计并制造了一个原型，并对7名受试者（平均年龄24岁）进行了测试。在受试者穿戴我们的外骨骼处于断电和通电模式时对他们进行了测量。比较结果证明穿戴外骨骼导致的步态偏差可忽略不计，并且这种软质外骨骼可以降低行走过程中的代谢成本。研究结果有望对轻质软质外骨骼以及与通过穿戴者整个步态提供辅助力的外穿式套装的集成有益。
