Virtual Reality

At HERL, we have numerous ongoing projects for which we have built and used computer simulation environments for purposes such as designing and tuning interfaces like joysticks, measuring driving performance, promoting exercise, and modeling of accessible environments. Our current work is aimed at building three-dimensional (3D) simulation environments that can be used not only as training tools but also as useful clinical assessment tools to measure specific outcome parameters.

We have developed a 3D driving simulation environment which we have imported into HERL’s Computer Assisted Rehabilitation ENvironment (CAREN) system (developed by Motek Medical of the Netherlands). The CAREN system is a computer-generated immersive 3D simulation, projected on huge screens. Floor rollers have also been added to the system, which can simulate rolling over a variety of surfaces with with either a testing wheelchair or a user’s own wheelchair.

We are currently using our Virtual Reality environment to test several different projects. One of the most promising technologies we have developed and which has application for use in 3D simulation environments is the HERL Isometric Joystick (IJ). The IJ has a user-friendly clinical tuning interface that allows a user or clinician to customize it using a program that displays on a computer screen. We have also developed a 3D driving simulation for testing the HERL IJ and other joysticks. Another is MeBot, a wheelchair that climbs stairs and traverses difficult environments such as ice; the CAREN system, used with specialized rollers, can simulate different terrains wheelchairs must negotiate. In addition, we are using the system to test theories about postural control in prosethetic leg users. 

Using this 3D environment we are able to collect data on collisions, errors between desired and actual trajectories, and elapsed time. We have been able to use this technology to test driving skills in individuals with Traumatic Brain Injury and Attention Deficit Disorder. We also learnt to apply filters to the joystick for individuals with movement disorders and tremors. In addition, we created a non-immersive but enhanced 2D simulation environment that we used to test driving skills of subjects with Spastic Cerebral Palsy as part of an NIH K12 award. This system also incorporates realistic wheelchair ballistics and the virtual wheelchair responds in real time to subject commands with no time delay. 

Using the technology we have developed at HERL, we are currently working on a repeated measures study to examine if computer-based and virtual reality-based assessment tools are as effective as a real world power wheelchair driving test, the Power Mobility Road Test (PMRT) used in wheel chair clinics to assess driving performance in power wheel chair users. We are also trying to study if these tests would be helpful in identifying objective parameters that would help improve power wheelchair driving performance. This study will serve as a platform for future research in using 3D environments for home based training tools and clinical assessment tools to improve mobility for individuals with disabilities by improving driving skills and treating cognitive, sensory, or motor impairments that may impair driving.

Our study suggests that using a 3D environment is just as good as using a real-world test. Moreover, an immersive virtual environment is better for testing any wheelchair technology that may be unsafe or inappropriate to test in the real world. This study will serve as a platform for future research in using 3D environments for home based training tools and clinical assessment tools to improve mobility for individuals with disabilities by improving driving skills and treating cognitive, sensory, or motor impairments that may impair driving.