Captain Trevor Greene, after being severely injured in Afghanistan, has regained hope of walking with the help of Carolyn Sparrey, SFU assistant professor of mechatronic systems engineering, and a sophisticated exoskeleton technology.
Greene was on tour in Afghanistan in 2006 when he suffered an axe attack from a teenage boy; the axe was buried five cm into his brain. While he survived his life threatening injuries, he lost the ability to walk.
The captain had been working with Ryan Darcy, professor of neuroscience at SFU, for nearly five years during which Darcy used MRIs to monitor his recovery.
About a year ago, Greene was introduced to Sparrey. Said Sparrey, “We had a brainstorming session essentially where myself and several other engineers from SFU and Dr. Darcy were all in a room thinking about what the next step towards Trevor’s rehab [was] and how we get him to his goal of being able to walk.”
The idea for the exoskeleton suit, which was paid for by fundraising through the Canadian Legion’s poppy sales, came from Greene’s wife, Debbie.
According to Sparrey, an exoskeleton is “essentially an assistive device for walking.” It contains a pelvic band to attach at the waist and a metal frame that extends the length of the leg and attaches at the feet. The frame is rigid on the outside, but contains motors at the hip and joints to “drive the movement of walking,” as Sparrey outlined.
Sparrey explained that an exoskeleton was not originally recommended since it is usually reserved for spinal cord injuries and not brain injuries: “With Trevor, because of the axe being very localized to one very specific part of his brain, [. . .] it only took out primarily the motor areas of his brain.”
Greene is the first patient with a brain injury to use the exoskeleton for rehabilitation. The hope is that the suit helps take advantage of his brain’s capacity for neuroplasticity. Sparrey elaborated, “Everybody’s brain is always rewiring and making new connections. [. . .] And so what we’re hoping with this system is [that] by doing an action, by pushing his body through an action, it’s just triggering the pathways to rehabilitate the brain and redrive those connections back to the brain.”
The team of SFU researchers and engineers working with Greene intends to use MRIs (functional magnetic resonance imaging) and MEG (magnetoencephalography) to monitor whether his neural links are being established.
They are going a step further and also looking at his overall health metrics, such as blood pressure and digestion, to keep an eye on his overall quality of life. Sparrey added, “We’re also looking at his functional gains [. . .] not just in terms of walking, but in terms of things like being able to sit upright, and core strength, reaching strength, flexibility.”
What are Greene’s wishes for his recovery? He hopes to one day climb to the base of Mt. Everest by himself. Sparrey noted that it is difficult to determine a prognosis.
“Trevor, at every step, has exceeded anything that anyone expected of him,” Sparrey said. “And because it’s a new technology and it hasn’t been applied to Trevor’s kind of injury before, we really aren’t putting a limit on how much recovery we think he can get. So, if he wants to drive that hard and has that target, I would not put a limit of whether or not he can get there.”
