A pilot study on the design and validation of a hybrid exoskeleton robotic device for hand rehabilitation

Study Design: An iterative design process was used to obtain design parameters that satisfy both kinematic and dynamic requirements for the hand exoskeleton. This design was validated through experimental studies. Introduction: The success of hand rehabilitation after impairments depends on the timing, intensity, repetition, and frequency, as well as task-specific training. Considering the continuing constraints placed on therapist-led rehabilitation and need for better outcomes, robot-assisted rehabilitation has been explored. Soft robotic approaches have been implemented for a hand rehabilitation exoskeleton as they have more tolerance for alignment with biological joints than those of hard exoskeletons. Purpose of the Study: The purpose of the study was to design, develop, and validate a soft robotic exoskeleton for hand rehabilitation. Methods: A motion capture system validated the kinematics of the soft robotic digit attached on top of a human index finger. A pneumatic control system and algorithms were developed to operate the exoskeleton based on three therapeutic modes: continuous passive, active assistive, and active resistive motion. Pilot studies were carried out on one healthy and one poststroke participant using continuous passive motion and bilateral/bimanual therapy modes. Results: The soft robotic digits were able to produce required range of motion and accommodate for dorsal lengthening, with trajectories of the center of rotation of the soft robotic joints in close agreement with the center of rotation of the human finger joints. Discussion: The exoskeleton showed the robust performance of the robot in applying continuous passive motion and bilateral/bimanual therapy. Conclusions: This soft robotic exoskeleton is promising for assisting in the rehabilitation of the hand.