Technology Enhanced Functioning
Virtual Reality on Stroke Rehabilitation Paolo Tonin About six hundred million people live with disabilities of various types all around the world. The majority of these disabilities originate from neurological lesions and the process of recovery emerges as one of the most relevant topic in the World Health Organization. A new or recurrent stroke is the main cause of disability in the industrial world, affecting the ability of a wide population to perform daily activities independently. Rehabilitation interventions are of utmost importance for this population. Recent studies in motor control, motor learning, and in the mechanisms of recovery after stroke produced a major impact in the field of neurorehabilitation. These acquisitions may lead to the development of scientifically based therapies, hopefully, more effective than current ones. Although, little is known about the mechanisms by which therapeutic measures influence motor recovery, some neuro-physiological studies on healthy subjects have reported that appropriate feedback on the nature of the movement pattern (knowledge of performance) and some variables of outcome (knowledge of results) may help to temporarily or permanently improve motor performance. Virtual Reality (VR) is a computer simulation which gives the user the impression of being and interacting in a real three-dimensional environment. Virtual Environments are a three-dimensional data set describing an artificial environment based on real world that the user interacts with. VR could be immersive or not immersive. The immersive VR systems may produce negative effects (Motion sickness syndrome, Photic seizures, Migraines, Hearing loss, Trauma, Eyestrain), not found during not immersive experiences. Virtual Reality (VR) systems have been proposed as useful tools in post stroke rehabilitation for both, motor rehabilitation, of upper limb particularly and cognitive rehabilitation. To create a virtual motor task, the therapist moves the handling object (for instance an envelope, a hammer, or a glass) connected to a receiver, inside the VE. The raw data are recorded by the tracking system. A dedicate software transforms the raw data in the movement of a virtual object that changes position corresponding to the real object motion. The motor task is automatically adapted to the patient's anthropomorphic characteristics. According to the patient's arm motor deficit, the therapist may orient the target. The location of the starting position, the target and the other objects, virtually represented in the arm workspace, determines the type and the difficulty of movement requested; the therapist could add virtual obstacles to increase the task complexity. VR may be exploited to provide the CNS with artificially generated information about the arm movement and the context, particularly showing: the patient's motor performance in the VE in real time (in the same frame of reference); the representation of the whole arm; the correct movement to the patients; a real-time feedback of the mismatch between desired and actual movement; the result of patient's performance, supplied via a reward based method with a numeric score; trace of the patient trajectory and repeated animation of trajectory after the task. Using treatment interventions created in virtual environments, practice conditions can be manipulated to explicitly engage motivation, cognitive processes, motor control, and sensory feedback- based learning mechanisms. The presentation will be focused on principles of motor learning underlying the VR systems for post-stroke patients; on the results of recent meta-analysis on the effects of VR; on the efficacy of systems specifically created for rehabilitation and of the commercial gaming systems.