A robot test-bed for assistance and assessment in physical therapy

This paper describes an experimental test-bed that was developed to assist and assess rehabilitation during physical and occupational therapy. A PUMA 260 robot was used with a controller and interface software developed in-house. The robot is designed to operate in two modes: (1) passive and (2) active. In the passive mode, the robot moves the subject's arm through specified paths. In the active mode, a subject guides the robot along a predefined path overcoming specified joint stiffness. In this mode, the controller compensates for gravity so that the robot can support its own weight in an arbitrary configuration, The developed graphical interface enables display of the current configuration of the robot in real-time, and allows us to customize experiments for a subject, and collect force and position data during an experiment. The results of a preliminary study with healthy subjects using this test-bed are also presented along with issues involved in the choice of paths and interpretation of the results.