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Volume 37
Number 14
March 17, 2005 |
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Pitt researchers are using virtual reality programs to study and treat people with balance disorders.
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| Pitt researchers are using virtual reality programs to study and treat people with balance disorders. |
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A checkerboard wall appears to move or change its pattern at Pitt’s Medical Virtual Reality Center (MVRC).
University researchers and rehabilitation specialists are tapping virtual reality technology — including visual simulations that immerse participants into artificial environments that seem real — to study and treat people with dizziness and balance disorders. About 30 percent of people aged 65 and older experience dizziness, a condition that can make something as simple as shopping an intolerable experience.
Researchers have completed preliminary studies suggesting that MVRC’s virtual reality displays might help people with dizziness find their grounding and live normal lives.
“We have the data. And I think we’ll have some answers that will help people,” said Patrick Sparto, director of the lab and assistant professor in the physical therapy, otolaryngology and bioengineering departments. “It’s the beginning of an exciting period.”
Pitt is among only a handful of universities in the country, including Northwestern University and the University of North Carolina-Charlotte, harnessing virtual-reality technology to treat a variety of conditions including dizziness, anxiety, post-traumatic stress for war veterans and fear of flying. Pitt currently is using the technology only to study and treat balance disorders.
The multi-disciplinary talents of so many Pitt medical and engineering specialists is what makes MVRC work, according to Sparto. MVRC researchers include: Joseph Furman, professor in the otolaryngology, neurology, bioengineering and physical therapy departments; Mark Redfern, professor in the bioengineering, otolaryngology and rehabilitation science departments, and Sue Whitney, assistant professor of physical therapy and otolaryngology. The center is supported by the Eye and Ear Foundation and the National Institutes of Health.
In the MVRC lab at Eye and Ear Institute, Whitney works with engineers to fine-tune the virtual environments. Her research has come a long way from the one projection screen and treadmill she used 15 years ago, she said.
The virtual reality display room, about 6 feet by 10 feet, is set up to accommodate one standing person. When an image is projected on the room’s four screens — one on the floor, another directly in front of a subject and two more to the subject’s right and left the subject is totally immersed in the visual display.
According to Whitney, the trick is to synchronize the four screens — each with their own respective computer and all driven by a master computer — within a millisecond.
For a subject standing in the room, the system provides a congruous image in motion. For example, the most basic program features the movement of simple black and white patterns. But like a bad 1960s flashback, the black and white patterns move toward the subject, producing a feeling akin to standing in front of ocean surf. Or the pattern moves away, much like the view from the rear window of a speeding car.
When a subject is immersed in this environment, researchers can record how well a person maintains balance while standing or moving. The subject stands on a metal plate embedded with sensors that measure how much the subject wiggles and sways. Electrodes placed around the eyes record eye movement and a headband, also equipped with a sensor, tracks head placement and movement. Subjects are outfitted with waist harnesses to prevent them from falling.
Determining the stability, or lack of it, in people with balance problems has become important because of the growing number of cases. In addition to the prevalence of dizziness in older people, Whitney said that about 60 percent of all people with head injuries have problems with dizziness.
Many people with dizziness have problems negotiating complex visual environments such as grocery stores.
“The super stores can make people who are dizzy really go off,” she said. “Some can’t ever go into those kinds of stores.” Other problematic areas for those patients include being in a crowd or anyplace where there’s a lot of motion. “People have tough times dealing with riding in a car and seeing a picket fence or viewing sunlight through the trees,” Whitney said.
That’s where Whitney’s rehabilitation work and the new virtual reality model “Grocery World” come in. In “Grocery World,” the aisles can be widened or narrowed; the Diet Pepsi and Tide detergent can be piled high on shelves or obliterated. The ability to strip down an environment then build it up allows people with balance disorders to slowly acclimate to real world-sensations, Whitney said.
MVRC plans to begin using “Grocery World” as treatment for patients with dizziness sometime this fall.
“The idea with rehabilitation is to start with simple things and add more. So you slowly add more products and you bring the aisles in closer. You can’t do that in real life,” Whitney explained. The key to the therapy is the interface between patient and therapist, she added. “The patient can report their tolerances and the therapist can immediately adjust the rehabilitation. It’s a process of increasing the patient’s tolerance for experiencing and being around motion.”
A new treadmill, customized by the School of Engineering, will be added to the lab in about three months. The treadmill will allow a subject’s own rhythm of walking to set the pace of visual movements displayed in a virtual reality program. “This will give subjects a normal sense of motion,” Whitney said. The virtual world will move at their speed instead of at a predetermined rate. Whitney said that she looks forward to working with the new equipment, which may help subjects feel more comfortable with the virtual reality programs. “The technological advances keep enhancing what the lab can do.”
—Mary Ann Thomas
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