Soft Robotic Rehabilitation Exoskeleton (REHAB Glove) for Hand Therapy

Abstract

This paper presents the design, control, and validation of a soft robotic exoskeleton system, the REHAB Glove, for hand rehabilitation. The system is comprised of five hybrid soft-and-rigid robotic digits that apply controlled flexion and extension motion to fingers. The previous actuator design of the soft robotic digit was improved for kinematic compatibility with anatomical motions of the hand in relation to range of motion, center of rotation, and dorsal skin lengthening. The design was validated using motion capture and analysis. A position control algorithm, which controls finger angular trajectories (angular position and velocity), was developed based on motion sensor feedback. The operation of this algorithm was verified using a 90° digit tip trajectory with two angular velocities of 15°/sec and 30°/sec. A pilot study was carried out with five healthy individuals to evaluate the performance of the REHAB Glove in providing therapeutic schemes. The results show that the REHAB Glove is able to provide controlled motion compatible with the kinematics and dynamics of the human.

Design Criteria of Soft Exogloves for Hand Rehabilitation-Assistance Tasks

“…Nevertheless, low repeatability is the main drawback during this process [48]. Recent developments involve thermomethods [34], inverse flow injection [42,82], lost wax molding [88], or fused deposition modeling with 3D printing at home to reduce SEG costs and facilitate its acquisition [89]. However, there is still room to improve SEG materials and fabrication with low costs.…”

“…Authors in [21] use DCX22 motors, a control board TMS320F2808®, and Simulink®. Additionally, graphical user interfaces (GUI)® have been implemented as a communication channel for SEG systems [88,91]. A broad range of operation and control possibilities exists to select microcontrollers and interfaces relying on desired real-time response, accuracy, number of components involved in the operation and control strategies, and specific requirements of each SEG system.…”

“…Other methods have opted for using mathematical models together with the finite element method (FEM) for hand and finger trajectory characterization [67]. To assess patient satisfaction when using SEG systems, questionnaires have been considered [88].…”

“…According to [51], an effective soft exoglove should achieve, without problems, 2 hours of continuous operation or from 4 to 6 hours of intermittent operation. Moreover, the runtime of batteries should be more than one hour in order to guarantee the development of a rehabilitation protocol session [100] until its completion or exert from 15 to 20 minutes of passive guidance [88]. Normally, lithium-polymer batteries are used since they can last 3.8 hours of continuous operation [23,51].…”

“…Moreover, the runtime of batteries should be more than one hour in order to guarantee the development of a rehabilitation protocol session [ 100 ] until its completion or exert from 15 to 20 minutes of passive guidance [ 88 ]. Normally, lithium-polymer batteries are used since they can last 3.8 hours of continuous operation [ 23 , 51 ].…”