A Wearable Soft Robotic Exoskeleton for Hip Flexion Rehabilitation

Abstract

Leg motion is essential to everyday tasks, yet many face a daily struggle due to leg motion impairment. Traditional robotic solutions for lower limb rehabilitation have arisen, but they may bare some limitations due to their cost. Soft robotics utilizes soft, pliable materials which may afford a less costly robotic solution. This work presents a soft-pneumatic-actuator-driven exoskeleton for hip flexion rehabilitation. An array of soft pneumatic rotary actuators is used for torque generation. An analytical model of the actuators is validated and used to determine actuator parameters for the target application of hip flexion. The performance of the assembly is assessed, and it is found capable of the target torque for hip flexion, 19.8 Nm at 30°, requiring 86 kPa to reach that torque output. The assembly exhibits a maximum torque of 31 Nm under the conditions tested. The full exoskeleton assembly is then assessed with healthy human subjects as they perform a set of lower limb motions. For one motion, the Leg Raise, a muscle signal reduction of 43.5% is observed during device assistance, as compared to not wearing the device. This reduction in muscle effort indicates that the device is effective in providing hip flexion assistance and suggests that pneumatic-rotary-actuator-driven exoskeletons are a viable solution to realize more accessible options for those who suffer from lower limb immobility.

Pioneering healthcare with soft robotic devices: A review

“…Major wearable rehabilitation devices using soft robotic technologies include soft robotic gloves and soft robotic exosuits. [86][87][88] Research on other wearable rehabilitation devices, such as elbow sleeves 77,89 and hip flexion exoskeleton, 80 are also receiving attention. Soft robotic gloves are mainly used for post-stroke rehabilitation.…”

“…Reproduced under terms of the CC-BY license. 80 Copyright 2022, The Authors, published by Frontiers. (E) 3D-printed soft robotic prosthetic hand with multi-articulating capabilities.…”

“…(D) Wearable soft robotic exoskeleton for hip flexion rehabilitation. Reproduced under terms of the CC‐BY license 80 . Copyright 2022, The Authors, published by Frontiers.…”

A bioinspired modular soft robotic arm

“…Unlike traditional robotic assemblies made from plastics, metals, and other rigid materials, soft robots are made from soft materials such as silicone elastomers, rubbers, and textiles [2]. In recent years, soft robotics have begun to play an essential role in various fields, such as manipulations [3][4][5][6][7][8][9], biomimetics [10][11][12][13][14][15][16][17][18], and rehabilitation [19][20][21][22][23][24][25]. These soft robotics applications are driven by the inherent safety of soft materials, which confers a safer human-robot interaction environment than traditional mechanical robots with rigid structures and materials.…”

Sarcomere‐Inspired Multilayer Artificial Muscle Units for Hyperconfigurable Robotic Applications

“…SPAs' simple working principle of expansion/contraction with positive and negative pressure requires mechanically preprogramming the SPAs to achieve diverse motions. Examples include McKibben actuators, [6,[14][15][16][17] circumferential reinforced actuators, [3,[18][19][20] pouch motors, [21][22][23] and smart morphologies, [5,[24][25][26] which have been used in a wide range of applications such as medical, [27,28] assistive technologies, [29][30][31][32][33] robotic end-effectors, [34,35] and locomotion. [17,[36][37][38] However, these methods are often designed for a specific application, which lacks versatility and requires substantial resources when applied to new applications.…”