Evaluating the Effect of Robot Feedback on Motor Skill Performance in Therapy Games

For individuals with a motor skill disorder, repetition of recommended therapy exercises is essential for motor improvement. Moreover, external feedback of performance is an important component of therapy such that individuals can correct their exercises and improve their performance. However, direct feedback is typically only provided by an expert therapist during weekly or monthly therapy sessions, which limits improvement on a daily basis. In order to promote the repetition of recommended exercises in a home setting, several serious games have been developed to promote compliance with therapy interventions. To advance this work, we have developed a novel framework to couple serious games with a robot playmate that provides corrective feedback during interaction. The playmate continuously tracks the user's kinematic performance and autonomously provides objective verbal and nonverbal cues in order to increase the efficacy of the intervention. To determine how various cues affect an individual's kinematic performance, we have tested the complete system with 20 able-bodied adults. Namely, we computed the total amount of time it took the participants to successfully complete a reaching task as a function of the verbal or nonverbal cues received. The results show that movement times improve at a faster rate for the group provided with both verbal and nonverbal feedback versus verbal feedback alone. Exit surveys also suggest that the system was deemed enjoyable by the targeted population.