Since the National Intrepid Center of Excellence opened in 2010, Biomedical Engineer Sarah Kruger has operated the center’s Computer Assisted Rehabilitation Environment (CAREN).

The CAREN is a large-scale virtual-reality system used to evaluate and treat NICoE patients with traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD).

Now, her team is collaborating with researchers at the Naval Health Research Center (NHRC) to scale the technology down to a mobile system, with the long-term goal of making the novel therapy more attainable throughout both the Military Health System and the Defense Intrepid Network for TBI and Brain Health.

“Head-mounted display technology has become more affordable and accessible over the past couple of years,” said Kruger. “It’s also portable. So we want to leverage what we’ve learned about the [CAREN] system and see if we can make it possible to use similar treatments without committing the space or funding to a CAREN.”

In the CAREN, the patient stands or walks on a treadmill in the middle of a circular platform while interacting with virtual environments projected in front of them onto a 9-foot-tall, 180-degree screen. The platform can tilt in all directions to mimic a rocking boat, an uphill climb, or other scenarios as a ring of motion-capture cameras track movement, allowing for real-time modifications to the environment.

Monitoring the patient’s behavior, physical therapists can assess and treat conditions such as vestibular dysfunction - one of the most common complaints following a TBI - and PTSD.

In initial discussions about using head-mounted displays for treatment, NICoE physical therapists expressed concern that the devices might be too heavy for their many patients with neck pain. So the NICoE and NHRC teams evaluated several different headsets and, after positive feedback from clinicians, chose an augmented-reality (AR) based head-mounted display which has a lightweight visor that allows digital content to be layered over the existing real-world environment.