By Elizabeth Lockwood Health.milOctober 19, 2009
Skyscrapers loom overhead as a woman talks on her cell phone. Businessmen on the street shake hands and a school bus slows for a stop sign. An Elvis impersonator walks by.
Elvis impersonator aside, the scene could be one on any city street. But for Sgt. Ramond Acosta, this experience is much more than run of the mill. Acosta, who suffered head injuries in Iraq in 2008, is strolling through a virtual scene created especially for him in the Computer Assisted Rehabilitation Environment, or CAREN, a new therapeutic technology at Walter Reed Army Medical Center in Washington.
CAREN is a revolutionary tool that provides therapists the ability to tailor its use to meet a patient's specific needs. Chiefly comprised of a large, tilting motion platform embedded with a treadmill, CAREN looks like a pedestal of honor. Standing on the platform and secured by a harness, a patient faces a single, curved screen that immerses him or her in the action of a virtual world.
As one of only three such systems in the U.S., and one of only four in the world, Walter Reed's CAREN is a groundbreaking physical therapy option for wounded warriors. The system can accommodate patients with different injuries or diagnoses, including those who require assistive devices like canes. It also accommodates patients who request that their therapists walk or stand with them on the platform.
Since becoming available in fall 2007 as part of the new Military Advanced Training Center (MATC) at Walter Reed, CAREN has been used by more than 200 patients, many of whom sing its praises.
Staff agree. Sarah Kruger, the biomedical engineer who operates CAREN, aptly described herself as a "personable engineer" who enjoys interacting with patients to understand exactly what they like and don't like about the virtual worlds they experience. Her skills serve as a perfect complement to physical therapist Barri Schnall, who can identify subtle clues about a patient's gait, balance, comfort and ability from observing time spent on CAREN, asking questions and providing suggestions.
"The revolutionary aspect is we can utilize this piece of equipment to help acclimate patients and return them to activities of daily living," said Kruger. "We can challenge them and do so in a way that's very systematic and doesn't frustrate the patient but allows them to have a positive benefit each time."
Acosta's head injuries, a result of an IED explosion that threw him from his vehicle to the road, left him feeling dizzy and disoriented. After recovering from multiple broken bones and a collapsed lung, he was referred to Walter Reed where he has used CAREN as an integral part of his physical therapy. After about two months using CAREN, he says he's seen a "dramatic change" in the way he interacts with the world outside of Walter Reed.
"I'm able to come to a stop better in cars," Acosta said. "I used to have a problem stopping and going because of motion and balance. Now when I get in a car and come to a stoplight I'm not dizzy. When I have to stop, I can actually stop."
Comparing CAREN to the Nintendo Wii gaming console, Acosta called CAREN a "Wii on steroids." Still, while the technology is similar, it is not the same.
"Not only do you use your hands [like you do with Nintendo's Wii], you use the whole function of your body," Acosta said.
Kruger elaborated, saying that it's CAREN's sophisticated motion capture system that most differentiates it from something like the Nintendo Wii. Motion capture, where infrared cameras track patient movements via reflective markers placed on the patient's body, is what allows the patient to interact with or progress through the virtual world.
And it's the many different scenes and "worlds" CAREN provides that keeps patients involved and interested in their therapy.
"My favorite thing when using the CAREN lab is the really cool programs - you can change the scenery. You can be in the city and then the next minute you're skiing or you're walking in the wilderness," Acosta said. "They can change it so you're walking up a hill or down a hill or moving between people. It gets you going so you're always alert at all times. You have to adapt to your habitat really quickly."
This unique adaptability and power to challenge patients in multiple and varied ways while still keeping them safe and secure are what makes CAREN so advantageous.
"We've had a really great response to the treadmill," Kruger said. "Without any handrails or upper body support, they really have to work on their lower body. It's more like real-world walking. We've had a lot of patients come back to say they are more trusting of their prosthetics and they are feeling more comfortable in everyday settings - not just in therapy."
Acosta excitedly reported on his progress. "I used to come off elevators and be really disoriented because of the way it would drop or if it would stop suddenly," he said. "But now, because I've worked on it so much, I can come off an elevator and just walk off without any problems."