Vision-Assisted Interactive Human-in-the-Loop Distal Upper Limb Rehabilitation Robot and its Clinical Usability Test

In the context of stroke rehabilitation, simple structures and user-intent driven actuation are relevant features to facilitate neuroplasticity as well as deliver a sufficient number of repetitions during a single therapy session. A novel robotic treatment device for distal upper limb rehabilitation in stroke patients was developed, and a usability test was performed to assess its clinical feasibility. The rehabilitation robot was designed as a two-axis exoskeleton actuated by electric motors, consisting of forearm supination/pronation and hand grasp/release, which were selected based on a kinematic analysis of essential daily activities. A vision-assisted algorithm was utilized for user-intent extraction in a human-in-the-loop concept. A usability test was performed on six physiatrists, five biomedical engineers, five rehabilitation therapists, two chronic stroke patients, and two caregivers of the patients. After sufficient instruction, all subjects tested the robot for a minimum of 10 min and completed the evaluation form using a 7-point Likert scale. The participants found the device interesting (5.7 +/- 1.2), motivating (5.8 +/- 0.9), and as having less possibility of causing injury or safety issues (6.1 +/- 1.1); however, the appropriateness of difficulty (4.8 +/- 1.9) and comfort level (4.9 +/- 1.3) were found to be relatively low. Further development of the current device would provide a good treatment option as a simple, low-cost, and clinically feasible rehabilitation robot for stroke.