A Game For Life: Amputees Learn Movement Through Virtual Reality

The future of physical therapy lies in virtual reality -- at least at the University of South Florida in Tampa, where a new rehabilitation system on campus resembles a video game in some ways.

The CAREN (Computerized Augmented Rehabilitation Environment) system is a room-sized piece of medical and engineering equipment that allows researchers to study more effective ways to help improve mobility or balance in those with prosthetics or limb loss. 

It works by combining a safe, secure environment with innovative motion and visual technology to create a 3D experience for patients. 

Wearing a safety harness and walking on a split-belt treadmill in the room-sized system, study participants and, eventually, amputee patients, can engage in audio-visual balance games, explore virtual environments, or use an avatar to simulate activities from driving to digging on a 180-degree surround screen. 

CAREN also offers the multidisciplinary team of researchers a means to study and address patients with limb loss and cognitive trauma caused by stress, stroke or traumatic brain injury.

Simulating Real-World Scenarios

The integration of many technologies into one system makes CAREN unique in the medical field, says Jason Highsmith, an assistant professor in the USF Health School of Physical Therapy & Rehabilitation Sciences.

Interactive games allow for physical rehabilitation coupled with cognitive tasks, like requiring someone to dig for objects in a virtual world while still walking on a treadmill. Gait training in terms of distraction could help improve balance, mobility and coordination in patients who suffer from PTSD, traumatic brain injury or stroke.

Activities like a boat driving game, walking through a combat environment or hiking up rough mountainside terrain can be simulated on the system’s large surround screen. Visual tracking technology allows researchers to evaluate a patient’s gait or study a participant’s performance in real-time and to adjust the system on the spot. 

The benefit of this technology: “You can add complexity to the environment,” says Highsmith. 

The small group of clinicians and engineers who are certified to operate the CAREN system include Highsmith and Stephanie Carey, an assistant research professor in the USF College of Engineering.

“We feel it’s highly motivating, because a lot of the demos can be put in terms of a video game,” Carey says. “For rehab, you can see where you’ve been and where you’re going.”

Building A Virtual Reality

The CAREN system is so big that in order to fit in USF’s Center for Assistive, Rehabilitation & Robotics Technologies building, construction to house the electronics for the large motion base underground was the first step. Installation took more than two weeks (see video).  

Above the motion base, a split-belt treadmill is secured to a platform at ground level. The split is important, because it allows researchers to evaluate each limb or prosthetic individually. A safety harness ensures patient safety and lets them push their limits during physical activity and balance exercises without fear of falling or injury.

The large screen that surrounds the platform combines visual from three high-end projectors into a seamless, 180-degree visualization. Using small reflective markers for motion analysis, researchers place the patient in a virtual world.

Force plates and kinetic instrumentation in the treadmill let researchers study ground reaction forces -- measuring things like how much force you’re pushing down on the ground with, or how much shock your joints are being subjected to.

“Unlike a typical rehab program, we can change a lot of things on the fly, in real time, based on the information we’re collecting,” Carey explains. “It’s very dynamic and unique.”

A Better Fit For Amputees

CAREN researchers could provide prosthetic assessment to amputees and persons with limb loss in the future.

“There are very few systems across the country, so it’s not practical to say every amputee should be using this system,” Carey explains. “But it’s a good place to start.”

Typically, a person with a prosthetic device gets it fitted in a gait lab and learns to walk in a flat ground setting. By bringing together motion capture, sound and treadmill technology, the CAREN system gives researchers the opportunity to assess prosthetics individually. 

“We can give them a jumpstart, and then they can go back to their homes and reap some of the benefits from an intensive rehab program,” Carey says.

Highsmith aims to help persons with limb loss and prosthetics improve basic function, symmetry and efficiency with their walking. 

CAREN is supported largely by a $450,000 grant from the National Science Foundation, and it is one of a small number of virtual reality rehab systems across the United States. It is currently the only non-Department of Defense installation in the country. CAREN systems are used primarily in military-rehab settings for assessment.

The CAREN equipment grant request was led by principle investigators Drs. Rajiv Dubey and Kyle Reed from the USF College of Engineering; Dr. Sudeep Sarkar, from Draper Laboratories; Dr. Sandy Quillen, from the USF School of Physical Therapy & Rehabilitation Sciences; and Dr. David Diamond, from JA Haley VA Hospital.

It Takes A Team Effort

“It’s a collaborative effort, where you have to involve a lot of people from different backgrounds,” says Carey. “It’s a great representation of where the medical field is going.”

From clinicians who consult with patients to engineers who program the software, “it takes a village to run it,” Highsmith says. “This is high-tech equipment that requires an interdisciplinary team -- that is key.”

The team is preparing to seek research grant funding for maintenance, warranty and operation costs, “so it’s a self-sustaining system,” says Carey. Goals include things like a travel budget for far away patients, or the opportunity for clinical groups to come in and use the system.

Each CAREN operator has completed two levels of training on software, treadmill functions and environment interactions. Currently, several graduate students are being trained for use in their studies, and multiple successful patient demonstrations have been given.

“One of the things we pride ourselves on here at USF is that we really are collaborative,” Carey says. “We have meetings to talk specifically about this piece of equipment and how we can better help the community.”

Highsmith, who has been at USF since 2005, is dual licensed in physical therapy and prosthetics and also holds a PhD in medical science. 

Carey trained in biomedical engineering, studying undergrad at the University of Florida before earning a masters at the University of Miami. She worked with the Miami Project, studying spinal cord injury, and then worked for several years for a motion capture company in Colorado. Along with her role at USF, Carey works one day a week at the nearby JA Haley VA Hospital

The two have previously published papers on other human performance projects, using primarily motion analysis technology. 
“The next frontier is to take these new technologies and figure out the best way to maximize patient benefit,” says Highsmith. “There’s a tremendous opportunity here. It’s pretty cool just to be on the front edge of it.” 

Justine Benstead is a freelance writer who can usually be found walking her dog in her South Tampa neighborhood, drinking far too much coffee, tweeting @JustineinTampa, and taking photos with her trusty Nikon. Comments? Contact 83 Degrees.

Read more articles by Justine Benstead.

Justine Benstead is a feature writer for 83 Degrees Media in the Tampa Bay region of Florida.
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