Posts Tagged ‘Virtual Reality

Virtual Reality enhanced stroke rehabilitation system

Rehabilitation following stroke must address both the underlying deficits (range of motion, strength, and coordination) and the skilled use of the arm for the performance of ADL. Ideas gleaned from motor learning research suggest that rehabilitation should include a large amount of practice that contains not only repetition of an activity but performance of that activity in a way that promotes solving new and novel motor problems. In this sense, using VR technology may assist the rehabilitation process by allowing the systematic presentation of practice trials of a given task to a degree not fully possible in traditional therapy. The potential advantages of using VR technology in rehabilitation are (1) interactivities to motivate stroke patients including video and auditory feedback and (2) manipulability to allow the therapist to tailor treatment sessions focusing on the deficits specific to an individual and increasing task complexity as appropriate. In addition, trials in VRSRS can be presented in such away as to require both repetition and problem solving for the promotion of motor learning without boredom due to its game features. Research to date has found that the use of VR in motor rehabilitation for individuals post-stroke is feasible to address deficits in reaching, hand function, and walking. Nonetheless, important issues such as usability in designing applications of VRSRS have been often neglected or at least not firmly established because using VRSRS as a therapeutic intervention is still in its infancy. In the following sections, we will describe the concept of human factors design and how we have applied the concept to one of our applications of VRSRS, the Reaching Task.

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Virtual Reality’s Advantages over Video Playback

Much of the research on anticipatory behavior insporting scenarios has employed temporal occlusion,which controls the amount of visual information presented to participants. This method displays a video of a prerecorded sporting event and stops at key moments such as racquet and ball contact for tennis, or foot and ball contact for soccer. Participants then must predict what would happen next on the basis of the information they saw. Although this method is common, observing a video differs considerably from observing the same informationin a game-like scenario. For example, Jaeho Shim and Les Carlton observed a progressive decrease in expert performance in tennis when participants reacted to video images, compared to real-life situations. In this study, the performance deterioration could be due to the lack of presence (the feeling of being in a realistic environment) that participants might have felt because of the absence of interactivity and of a 3D display of the sport scenario.

Players must see other players’ key body parts and the ball, so some researchers also use portable eye-tracking systems to analyze players’ visual search behavior when performing anticipatory skills. Such systems can identify where a player’s eyes are looking to determine which visual information sources that player uses to make anticipatory judgments about where a ball will go. Although this approachis useful, determining each information source’s relative weight and role in providing pertinent prospective information for the player still remains difficult.

Virtual reality (VR) can overcome many of these limitations and has several advantages over video presentation. First, in a virtual environment, subjects and simulated opponents can interact with one another while the experimenter carefully controls and modifies the type of information the immersed player can see at any time. Second, VR lets researchers systematically control and tune all factors affecting the player’s judgment, ensuring reproducibility between trials. Monitoring this tuning’s effects on the player’s behavior in real time can ensure ecological validity. Third, by tracking head movements in real time, researchers can update the player’s viewpoint in the virtual environment in real time, which helps enhance the player’s feeling of presence. Finally,VR displays are stereoscopic, giving the player vital depth information—something severely lacking in 2D video displays. Because of these advantages, the players’ perspective and behavior in a virtual environment correspond far more closelyto their perspective and behavior in real-life environments.

For example, Benoit Bideau and his colleagues recently showed that an interactive, immersive virtual handball court with a realistically animated handball player throwing the ball toward the goal elicited expert handball goalkeeper responses similar to real-world responses. This important study helps validate VR technology as a way to examine anticipatory responses in elite players, with the researchers observing a high level of behavioral presence.

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