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Traumatic brain injury (TBI) can be one of the most devastating injuries that can happen to a human being. Because the damage is invisible, TBI and stroke sufferers often have trouble convincing others that the injury is real, and the variety of symptoms make effective therapies harder to design and administer. But now one researcher at Loyola Marymount University in Los Angeles is investigating whether stroke and TBI survivors can benefit from using a driving simulator designed for auto racing to test for neurological deficits and retrain survivors to drive safely.
“I am in the early stages of a research project that will investigate the use of a driving simulators, such as the SimGear GT, for stroke recovery. The goal of the research is to see if training with simulators that provide motion feedback is more effective than the current clinical standard which often uses fixed-base simulators,” Brendan Smith, assistant professor of mechanical engineering at Loyola Marymount, told Digital Trends.
WHY RACING SIMULATORS ARE DIFFERENT
Modern racing simulators are much more complex than the driving setups designed for home gaming. A full racing simulator is designed to create an immersive virtual reality experience, including moving the entire platform to simulate G-forces and the actual motions of a vehicle.
A simulation will predict, with accuracy, what’s going to happen in the real world.
Keith Maher is a thought leader in VR simulation technology. He runs a company named VR Motionbased in Hillsboro, Oregon. Maher has built both racing simulators and public road training systems so he knows the difference between the two better than most. “The difference between a game and a simulation is that a game will give up reality so that it’s enjoyable, while a simulation will predict, with accuracy, what’s going to happen in the real world,” he explained.
Current racing simulator technology includes wraparound screens for a seamless view both in front of and beside the driver, and VR technology such as Oculus Rift goggles to provide the visual effects. Paul Stary, president and CEO of VirtualGT in Costa Mesa, California, is a specialist in making the virtual environment truly immersive.
“What happens is you have the conscious mind and the unconscious mind in conflict with one another,” Stary said. “The conscious mind is a willing participant, it wants the illusion to be real. When you sit in a simulator you experience a collection of effects like audio, vibration, motion, the visual image that’s produced, vibration in the controls, forced feedback effects, and so forth. All those effects come together to create this illusion. The subconscious mind compares what’s going on in the simulator against reality to determine if it’s real or not.”
The subconscious mind compares what’s going on in the simulator against reality to determine if it’s real or not.
Smith is testing whether a moving simulator is better than a basic fixed-base driving simulator for therapeutic use.
“Most simulators currently used for therapy are of the fixed-base variety,” he continued. “These simulators do not provide the motion feedback that is becoming the gold standard among the sim racing community. Without this feedback, driving is reduced from the rich interplay of visual, haptic, and vestibular sensations into a taxing visual exercise. Fixed-base simulators may therefore be inadequate clinical practice, because they neglect fundamental driving skills that patients relied on before having a stroke.”
THE COGNITIVE PART OF DRIVING
“Neurological injury, such as stroke, leads to a wide range of physical and cognitive impairments,” Smith noted. “There are adaptive technologies such as steering wheel knobs and handle attachments for the gas and brake pedals that can largely help with the physical side. But on the cognitive side, our theory is that many of the reflexes that drivers rely on can become interrupted by a stroke.”
Using a simulator allows researchers to test for those cognitive issues without putting the patient into an actual vehicle.
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“Before a stroke, most drivers can probably come to a stop at an intersection with minimal attention paid to the actual stopping,” Smith said. “Instead, drivers are more likely thinking about what to do next, looking to see if it will be clear to do so, and probably glancing behind and all around to make sure no one is doing anything out of the ordinary. Very little visual attention is needed to come to consistently come to a smooth stop at the right point. Drivers use a variety of other senses to perform maneuvers so consistently. This includes a person’s sense of balance, and contact pressure with the seat, both of which depend on the rate of accelerating, braking, or turning. We fear that neurological injury changes how these senses feel during driving and they require practice to relearn.”
Finding a safe place for patients to practice their driving and demonstrate what they can do is the key to effective testing and therapy.
If you can’t gauge deceleration by feel, you suddenly need to fixate on the pace at which distance to the stop is closing.
“Getting behind the wheel and actually practicing would probably lead to the quickest recovery, but it might be pretty dangerous,” Smith stated. “Fixed-base simulators might seem like they would help. After a stroke it can start to feel like everything on the road is happening too fast, and it’d be easy to think that any simulation would be good practice. However, my research team expects that driving becomes so overwhelming mostly because losing a few key reflexes suddenly means everything needs to be done by vision. If you can’t gauge deceleration by feel, you suddenly need to fixate on the pace at which distance to the stop is closing. Suddenly all the other demands of driving become secondary, and the chances of not seeing an unexpected hazard go up. Fixed-base simulation won’t retrain those reflexes, and must instead train new skills, which may be too demanding after a stroke.”
WHY FULL-MOTION VR SIMULATION TECHNOLOGY IS DIFFERENT
The motivation for using simulators with motion feedback is to retrain those key reflexes in a stroke or TBI survivor. By allowing each patient to practice the skills and develop the reflexes and the confidence to drive, the simulator empowers them to leverage all the sensation, movement, and cognitive ability they retain toward getting back behind the wheel safely.
“Currently we are running preliminary experiments to determine how motion sensation impacts nondisabled driver performance during simulated driving,” Smith explained. “If they do better with motion feedback than in fixed-base mode, this will be good evidence that motion-enabled simulators engage the reflexes that are critical to driving. Then we will begin testing whether stroke survivors also improve their driving ability more with motion sensation, ultimately testing whether this leads to greater on-road driving fitness as determined by professional driving evaluators. We are also considering broadening this study to survivors of traumatic brain injury (TBI) such as many of our veterans who have endured concussion or impact-related injuries.”
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Using full-motion simulators can test for deficits in a realistic simulation, and also help with recovery.
“What does this have to do with rehabilitation?” Smith asked. “First, after a stroke, everyday experiences often feel different. For instance, braking might suddenly feel like turning to the right, and many of the reflexes developed during years of driving may start giving incorrect information. Luckily, our brains are good at adapting to changes like this, we do it every time we learn anything, whether we have had a stroke or not. But this adaptation does require practice. And if the simulator-mediated therapy doesn’t involve motion sensation, this important part of their recovery will not happen.”
SIMULATOR MANUFACTURERS ARE ON BOARD
Racing simulator manufacturers have embraced the research into the therapeutic applications of their products. Zach Davis runs SimGear Simulators in Schaumburg, Illinois. SimGear provided the simulators in use at Loyola Marymount.
“I have a few family members who have had strokes. It’s amazing to be able to be a part of this project knowing it could help others in the future and understand more about the aftereffects of a stroke,” Davis said. “Now that they have the simulator, I look forward to seeing what other studies they use it for because now everyone has access to it at their facility.”
Chris Considine is the mover behind CXC Simulations in Los Angeles, California, and another leader in bringing racing simulation to medical research and therapy.
“Now that they have the simulator, I look forward to seeing what other studies they use it for because now everyone has access to it at their facility.”
“Starting 15 years ago, I was talking to people about this but nobody believed us,” Considine remembered. “Because of the nature of motorsports and way we train through simulation, it can really extend through many other disciplines. In motorsports everything happens so quickly that you have to fall back more on muscle memory. You don’t get time to think about your actions; you have to react. There are so many applications for that, and obviously stroke recovery is one of those. We also hear a lot about TBI from the NFL. There are so many applications; it never stops.”
As a mechanical engineer, Smith has a clear plan for his work.
“For our research, we will test the hypothesis that motion sensation is indeed a primary source of driver feedback regardless of stroke or age,” he said. “Then we will investigate whether extended training with a motion-enabled simulator, like the SimGear GT, can help stroke survivors relearn the sensation of braking, turning, and accelerating. We expect this will restore the reflexes that make driving maneuvers easier and allow stroke survivors to focus their attention on the finer points of safe driving.”