Enhancing Therapist Capabilities in Robotic Therapy through Haptic Feedback and Immersive Virtual Reality: An Experimental Study

Abstract

To offer engaging neurorehabilitation training to stroke patients, robotic exoskeletons have emerged as a beneficial tool to train motor tasks. However, in robotic therapy, the therapists are often limited in how they can interact with the patients. The training programs with exoskeletons are often standardized, not allowing the therapist to directly manipulate them and customize the training for specific patient needs. This paper presents a novel telerehabilitation system incorporating a therapist-in-the-loop haptic interface and immersive virtual reality (IVR), aimed at improving the interaction dynamics between patients and therapists during rehabilitation sessions. We conducted a human factors study involving 36 participants grouped in pairs, assigned as "Leaders" or "Followers," where the Leader had to guide the Follower (positioned in the exoskeleton) to a specific arm pose related to activities of daily living (ADL). This task was done under two conditions: demonstration and teleoperation. In the demonstration condition, the Follower could see the Leader displayed on a 2D screen in front of them showing them visually what was the correct pose whereas in the teleoperation condition, there was no visual aid but the Leader could guide the Follower using the haptic device. The study explored the efficiency, workload, and user experience of both modalities. Results indicated that teleoperation significantly reduced the time to complete tasks and facilitated more efficient and smoother movement patterns. While Leaders experienced reduced workload and increased motivation with the teleoperation condition, Followers reported less workload but also decreased motivation, suggesting a trade-off between task ease and engagement. In conclusion, the teleoperation system improves the ability for the therapist to interact with the exoskeleton but can disengage the patient.