EAGER: Enabling Virtual Reality for Aquatic Rehabilitation of Persons with Disabilities

University Of Texas At San Antonio, San Antonio TX

Investigators

Abstract

Because Virtual Reality (VR) technology (e.g., a head mounted display with a full body tracking system) typically cannot be used underwater, what impact aquatic VR would have on user interaction is mostly unknown, and potential important underwater applications such as pool-based physical rehabilitation remain unrealized. There has been only minimal research on aquatic VR in general, and none of that work has investigated its effects on people with disabilities. Prior research has demonstrated that VR-enhanced rehabilitation can offer many benefits, such as increased motivation through immersive games and the ability to practice in a safe environment, but VR has yet to be applied in practice to aquatic rehabilitation. In this exploratory research the PI will seek to determine effective system and interaction approaches for aquatic VR that maintain rehabilitation motivation and maximize exercise performance by disabled persons, specifically for individuals with Multiple Sclerosis (MS) who commonly have proprioceptive and balance deficits. The PI's preliminary work suggests that a video see-though display, body tracking via inertial measurement units, and head positioning via optical tracking will enable an effective aquatic VR system. The PI's hypothesis is that aquatic VR will enable members of the target population to perform exercises significantly better than on land. If this hypothesis is found to be supported, the project will represent a critical step towards the grand challenge of universal usability of VR, and will in particular afford a deeper understanding of the effectiveness of VR as a medium for rehabilitation. To test his hypothesis, the research will include two thrusts. One of these will seek to determine viable system approaches for enabling aquatic VR. In preliminary work, the PI devised a prototype system consisting of a novel combination of off-the-shelf components. A waterproof smart phone was attached to a dive mask, to enable a 3DOF tracked stereoscopic view of the virtual underwater environment. A second waterproof smart phone was attached to the user's chest, allowing for 3DOF body orientation tracking, punch detection and haptic feedback. The virtual sounds of the game were delivered through a pair of waterproof headphones, which also allowed real sounds to be heard underwater. The other thrust in this project will determine through a series of empirical studies how aquatic VR affects human performance of rehabilitation exercises, Considering the known advantages of aquatic rehabilitation over land-based, the working hypothesis here is that aquatic VR will enable persons with disabilities to experience significantly less fatigue, maintain balance better, and exercise longer with increased resistance than land-based virtual rehabilitation, and that it may also improve motivation compared to traditional aquatic rehabilitation. In preliminary work, the PI developed Shark Punch, a prototype aquatic VR game in which players must fight for their lives in a real underwater environment against a virtual Great White shark. From a rehabilitation perspective, this game focuses on improving joint mobility, and flexor and extensor muscle strength, through punching exercises. In the game, the shark first circles the player and then ferociously attacks, trying to bite the player. After it bites, it retreats back to circling the player from a distance. A bite can only be prevented if the player lands a real punch on the virtual shark's nose. If the user successfully punches the shark, the shark is stunned for a few seconds and then swims back to a safe distance from the player.