Assessment of Robot Interventions in a Task-based Rehabilitation: a case study.

This study is aimed at assessing of a robot intervention in a task-based upper-arm rehabilitation procedure. Robotic devices have significantly been useful to help therapists do the training procedure. However, due to the lack of quantifiable feedback regarding the level of intervention, effectiveness of various parameters, such as timing, intensity, etc., the training and its efficacy varies remarkably between institution and therapists. In this study, Universal Robot 5 (UR5) has been utilized to move an arm of healthy subjects over a circular path while the muscle activities are recorded through surface electromyography (sEMG); at the same time, all components of the forces applied to the robot have also been measured using Robotiq force sensors (FT300 sensor). System identification (SI) is performed to relate the amount of force in the UR5 to the level of muscle activity in the upper-arm through model. This model has been identified through the data obtained from four healthy subjects, and has been tested and verified with data from a fifth subject. In order to visualize the robot intervention and its efficacy, muscle activities have also been recorded while the subjects perform the task with no robot assistance. The data from this test setting have shown a good agreement in terms of signal profile which suggests robot has not introduced any complications in terms of force or stiffness to the subjects. This preliminary study provides an insight for data driven intervention procedure while robots are used in facilitating the muscle recruitment to complete the desired rehabilitation task, as some patients may not complete the task properly due to muscle weakness in a certain direction and location.