Integration of 3D Action Observation Therapy and Rehabilitation Exercises in Mixed Reality: A Feasibility Study on Post-Stroke Patients

Action Observation Treatment (AOT) represents a novel top-down rehabilitative approach, based on the exploitation of the mirror neuron system, which aims to restore motor function in patients with functional impairments, through an observation-execution matching. Actually, in a typical AOT session, the patient is first required to observe a video with a recorded action and then perform the same task. This method presents a great potential in magnifying the efficacy of standard rehabilitative therapies. The main goal of this paper was to report the design and development of an innovative rehabilitation system exploiting AOT through the integration of 3D immersive video display and the realization of rehabilitation exercises in a Mixed Reality (MR) environment; the system included, for each exercise, different levels of difficulty, that are all customizable to the patient’s characteristics. The system was preliminary tested in a feasibility study focused on the rehabilitation of upper limb in post-stroke patients. Overall usability was assessed and several metrics bases on kinematic data acquired with wearable sensors were also explored, thus to monitor the advances and automatize the choice of the difficulty level through the rehabilitation session. First person 3D immersive display was highly tolerated by the subjects with no critical events registered; furthermore, MR approach demonstrated to be very suitable, safety and well-accepted by the patients, with a good level of engagement. These preliminary findings provided evidence about the feasibility of the proposed approach and the efficacy of the system in the clinical context.