A soft wearable robot for the shoulder: Design, characterization, and preliminary testing

Abstract

In this paper, we present a soft wearable robot for the shoulder which has the potential to assist individuals suffering from a range of neuromuscular conditions affecting the shoulder to perform activities of daily living. This wearable robot combines two types of soft textile pneumatic actuators which were custom developed for this particular application to support the upper arm through shoulder abduction and horizontal flexion/extension. The advantage of a textile-based approach is that the robot can be lightweight, low-profile, comfortable and non-restrictive to the wearer, and easy to don like an item of clothing. The actuator's ability to fold flat when not in use allows the robot to be almost invisible under clothing, potentially allowing the user to avoid any stigma associated with using assistive devices in public. To abduct the arm, a textilebased pneumatic actuator was developed to fit within the axilla to push the arm upwards, while a pair of smaller actuators pivot the abduction actuator to allow for horizontal extension and flexion. The individual textile actuators were experimentally evaluated before being integrated into a wearable garment. Human subject testing was performed to evaluate the ability of the robot to assist the arm by monitoring changes in biological muscle activity when comparing the robot powered on and off. Preliminary results show large reductions in muscular effort in targeted muscles, demonstrating the feasibility and promise of such a soft wearable robot for the shoulder.

Untethered soft robotics

“…Pneumatic and hydraulic actuators have long been popular among soft actuation methods thanks to their relatively large actuation forces, fast response times, high work densities and large strains (Table 1). Much recent work has focused on incorporating established pneumatic actuators into robotic locomotion 21,22 , grasping 23 and wearable haptic 24 or assistive devices 10 .…”

“…1a. Electric and dynamically responsive materials with compliance comparable to these biological systems are particularly important for human-machine interaction, wearable computing 7,8 , health monitoring 9 and physically assistive robotics 10,11 , which provide intrinsic safety and comfort to the user.…”

A Parallel, 2-DOF Exoskeleton for the Human Shoulder: Device Characterization and Preliminary Results on Healthy Subjects

“…Nevertheless, sEMG measurements have also been used to assess exoskeleton performance. O'Neill et al was able to achieve 62.75% of muscle reduction on the lateral deltoid when performing abduction and 16.94% on the pectoralis major when performing horizontal flexion(35). Simpson et al also collected sEMG signals, but their data processing method was different from the one presented here (23).…”

Upper extremity exomuscle for shoulder abduction support

“…Specifically, exosuits have been created to assist with arm movements in stroke survivors [22]- [28]. In particular, several of these studies have examined how exosuit use affects muscular activity in healthy users and whether the exosuit limits the user's range of motion [22], [24], [25], [28]. Only one recent study has examined the effects of an upper extremity exosuit on stroke survivors.…”