Balancing in Virtual Reality: UD researchers search for answers in the Cave
The Control of Balance and Locomotion (CoBal) Lab at University of Delaware's STAR Campus uses a Virtual Reality Cave to study balance issues in people ranging from healthy older adults to people suffering from Parkinson’s Disease and concussions.
UD intern contributor DJ McCauley takes us inside the VR Cave and we talk to a UD researcher working with it.
The hallway in front of me looked a bit like a scene from inside the Death Star - rounded grey hexagonal corners in a never-ending corridor. The walls were moving, though; shifting from side to side and swaying as Jaclyn Caccese operated the controls from a computer situated twenty feet behind me.
"I'm just going to mess with your vision a little bit," Dr. Caccese said as the corridor tilted to the right. I couldn't help myself - I took a step to the left to catch myself from falling onto the corridor floor.
But the corridor wasn't really there. Instead, a concave screen was in front of me, a split-belt treadmill under my feet, and a sweatband with four small baubles ornamented my forehead. To complete the look: a harness strapped around my shoulders like a backwards backpack, hooked to a sturdy metal frame surrounding the screen. With the lights out I could have sworn I was wandering through a Star Wars set, albeit one that felt like it was at sea. With the lights on the surroundings took the feeling of behind-the-scenes footage when the cameras are no longer rolling. All of these components made up the virtual reality cave.
You might think of virtual reality as exclusive to the goofy headsets worn by video-gamers at the mall, but this VR cave is used by the Control of Balance and Locomotion (CoBal) Lab at University of Delaware's STAR Campus, run by Dr. John Jeka. This diverse, interdisciplinary team includes bioengineers, neuroscientists, and kinesiologists. They focus their research efforts on populations that suffer from balance issues, like athletes post-concussion, children with cerebral palsy, older adults, and individuals suffering from Parkinson's disease.
In all of these cases, balance is affected, and balance is a big-ticket health issue. According to the CDC, fall injuries and their ensuing medical care add up to a hefty $50 billion in medical fees each year, particularly in older adults. Finding ways to prevent falls could potentially ease these costs. For younger individuals and athletes, finding ways to overcome balance issues may not only lower healthcare costs, but prevent further injury.
The VR cave helps researchers by giving them a way to manipulate what people see, while at the same time monitoring how they move their bodies. As I tried out the cave setup with Dr. Caccese guidance, it was disconcerting how well the VR system responded to my own movement when she wasn't manipulating the controls. I quickly forgot that it was just a screen in front of me, rather than a never-ending hallway.
The baubles on my forehead were reflective, designed to work with the motion-capture cameras mounted around the screen. As I moved my head, the image on the screen also moved. In a real trial, more motion-capture dots would be placed along my limbs and joints to give the computer system a more precise picture of my body movement.
Meanwhile, force plates in the treadmill below my feet could take in information about my gait and the location of my steps. With all this information, researchers can change the images on the cave screen and see how a person's body reacts.
Researchers are still are not sure how the brain works with the inner ear and the musculoskeletal system to keep people standing tall. The inner ear’s role is particularly hard to pin down since it is difficult to manipulate and monitor. Also known as the vestibular system, the small, fluid-filled organ inside the ear acts like the accelerometer in your phone. It senses your head movement and direction, sending the message along to the brain. In some cases, researchers will attach a small electronic device behind the ear, sending an electric pulse into the vestibular system that makes one feel like everything is swaying, even in a still room, allowing researchers to see how the body reacts when the system is directly stimulated.
Likewise, muscles and tendons send information about the body's physical location to the brain. Small nerve endings called proprioceptors sense tension in the joints, particularly in the ankles, telling the brain were to put one's feet. Together with vision and the vestibular system, these three mechanisms undergo a complex dance to take in one's surroundings and adjust, keeping one from going head-over-heels.
According to Dr. Caccese, the relationships between vision, the inner ear, and proprioception are not well understood, and research at the CoBal Lab seeks to fill in the gaps.
For all the different populations affected by balance issues, one of these three mechanisms might be working incorrectly. Dr. Caccese, for example, focuses her research efforts on balance issues in soccer players approximately two weeks to six months after being diagnosed with a concussion. Changes to vision can be much more difficult to handle after a concussion. Think of how visual stimuli from phone, computer screens, TVs, and the written word is limited for concussed individuals.
"If we can understand how vision is affected after a concussion," Dr Caccese said, "we might be able to get these athletes to rely more on other ways to balance."
Meanwhile, Dr. David Grenet is working to understand how Parkinson's patients move in different scenarios. "People with Parkinson's disease may or may not use the same mechanisms as the general population to overcome balance issues," said the post-doc, hailing from Australia’s University of New South Wales, Sydney. "If we can figure out how they are dealing with balance issues, and where they fall short, maybe someone else can find out how to help."
Dr. Grenet's project is in its beginning stages, and is taking willing participants with Parkinson's disease from across the state of Delaware. So far, pilot tests for the study conducted last year showed promising results.
Though the CoBal Lab is laying the foundation for understanding balance mechanisms, the future of virtual reality in healthcare might not be limited to basic research. There are less than 100 virtual reality caves in research institutions across the world, but VR headsets are becoming more and more commonplace. It could be that portable headsets or augmented reality goggles become a tool for doctors and therapists to help individuals overcome balance issues.
As technology continues to get better and better, healthcare interventions created using research like the findings from the CoBal Lab may be the next step in helping athletes recover from concussions or Parkinson's patients prevent a disastrous fall. Dr. Caccese pointed to improvements in head-mounted displays, saying, "The better they get, the better they will be in a clinical setting."