The mechanical assistance provided by exoskeletons could potentially replace, assist, or rehabilitate upper extremity function in patients with mild to moderate shoulder disability to perform activities of daily living. While many exoskeletons are active (e.g. motorized), mechanically passive exoskeletons may be a more practical and affordable solution to meet a growing clinical need for continuous, home-based movement assistance. In the current study, we designed, fabricated, and evaluated the performance of a wearable, passive, cable-driven shoulder exoskeleton (WPCSE) prototype. An innovative feature of the WPCSE is a modular spring-cam-wheel system that can be custom designed to compensate for any proportion of the shoulder elevation moment due to gravity over a large range of shoulder motion. The force produced by the spring-cam-wheel system is transmitted over the superior aspect of the shoulder to an arm cuff through a Bowden cable. The results from mechanical evaluation revealed that the modular spring-cam-wheel system could successfully produce an assistive positive shoulder elevation moment that matched the desired, theoretical moment. However, when measured from the physical WPCSE prototype, the moment was lower (up to 30%) during positive shoulder elevation and higher (up to 120%) during negative shoulder elevation due primarily to friction. Even so, our biomechanical evaluation showed that the WPCSE prototype reduced the root mean square (up to 35%) and peak (up to 33%) muscular activity, as measured by electromyography, of several muscles crossing the shoulder during shoulder elevation and horizontal adduction/abduction movements. These preliminary results suggest that our WPCSE may be suitable for providing movement assistance to people with shoulder disability.

中文翻译：

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穿戴式被动式电缆驱动式肩外骨骼的设计与性能评估

外骨骼提供的机械协助可能会替代，协助或恢复轻度至中度肩部残疾患者进行日常生活活动的上肢功能。尽管许多外骨骼是主动的（例如，电动的），机械上被动的外骨骼可能是一种更实用，更实惠的解决方案，可以满足不断增长的基于家庭的连续运动辅助的临床需求。在当前的研究中，我们设计，制造和评估了可穿戴，被动，线缆驱动的肩部外骨骼（WPCSE）原型的性能。WPCSE的一项创新功能是模块化的弹簧凸轮轮系统，该系统可以定制设计，以补偿在大范围的肩部运动中由于重力引起的任何比例的肩部抬高力矩。弹簧凸轮轮系统产生的力通过Bowden电缆在肩部的上方传递到袖带。机械评估的结果表明，模块化的弹簧凸轮轮系统可以成功地产生与所需的理论力矩相匹配的辅助正肩部抬高力矩。但是，从物理WPCSE原型进行测量时，主要是由于摩擦，在正向肩膀抬高时，力矩较小（最高30％），在负向肩膀抬高时力矩较高（最高120％）。即使如此，我们的生物力学评估显示，WPCSE原型通过肌电图测量可降低均方根（最高35％）和峰值（最高33％）肌肉活动，肩部抬高和水平内收/外展运动过程中穿过肩膀的几块肌肉的运动。这些初步结果表明，我们的WPCSE可能适合为肩部残障人士提供运动帮助。