39-year-old man who had been completely paralyzed for four
years was able to voluntarily control his leg muscles and take thousands of
steps in a “robotic exoskeleton” device during five days of training — and for
two weeks afterward— a team of UCLA scientists reports this week.
This is the first time that a person with chronic, complete
paralysis has regained enough voluntary control to actively work with a robotic
device designed to enhance mobility.
In addition to the robotic device, the man was aided by a
novel noninvasive spinal stimulation technique that does not require surgery.
His leg movements also resulted in other health benefits, including improved
cardiovascular function and muscle tone.
The new approach combines a battery-powered wearable bionic
suit that enables people to move their legs in a step-like fashion, with a
noninvasive procedure that the same researchers had previously used to enable
five men who had been completely paralyzed to move their legs in a rhythmic
motion. That earlier achievement is believed to be the first time people who
are completely paralyzed have been able to relearn voluntary leg movements
without surgery. (The researchers do not describe the achievement as “walking”
because no one who is completely paralyzed has independently walked in the
absence of the robotic device and electrical stimulation of the spinal cord.)
In the latest study, the researchers treated Mark Pollock,
who lost his sight in 1998 and later became the first blind man to race to the
South Pole. In 2010, Pollock fell from a second-story window and suffered a
spinal cord injury that left him paralyzed from the waist down.
At UCLA, Pollock made substantial progress after receiving a
few weeks of physical training without spinal stimulation and then just five
days of spinal stimulation training in a one-week span, for about an hour a
day.
“In the last few weeks of the trial, my heart rate hit 138
beats per minute,” Pollock said. “This is an aerobic training zone, a rate I
haven’t even come close to since being paralyzed while walking in the robot
alone, without these interventions. That was a very exciting, emotional moment
for me, having spent my whole adult life before breaking my back as an
athlete.”
“It will be difficult to get people with complete paralysis
to walk completely independently, but even if they don’t accomplish that, the
fact they can assist themselves in walking will greatly improve their overall
health and quality of life,” said V. Reggie Edgerton, senior author of the
research and a UCLA distinguished professor of integrative biology and
physiology, neurobiology and neurosurgery.
The procedure used a robotic device manufactured by
Richmond, California-based Ekso Bionics which captures data that enables the
research team to determine how much the subject is moving his own limbs, as
opposed to being aided by the device.
“If the robot does
all the work, the subject becomes passive and the nervous system shuts down,”
Edgerton said.
The data showed
that Pollock was actively flexing his left knee and raising his left leg and
that during and after the electrical stimulation, he was able to voluntarily
assist the robot during stepping; it wasn’t just the robotic device doing the
work.
“For people who
are severely injured but not completely paralyzed, there’s every reason to
believe that they will have the opportunity to use these types of interventions
to further improve their level of function. They’re likely to improve even
more,” Edgerton said. “We need to expand the clinical toolbox available for
people with spinal cord injury and other diseases.”
Iron 'ElectriRx' Man: Overground Stepping in an Exoskeleton
Combined with Noninvasive Spinal Cord Stimulation after Paralysis
Gad, Parag ; Gerasimenko, Yury ; Zdunowski, Sharon ;
Sayenko, Dimitry ; Haakana, Piia ; Turner, Amanda ; Lu, Daniel ; Roy, Roland ;
Edgerton, V Reggie
37th Annual International Conference of the IEEE Engineering
in Medicine and Biology Society (EBS)
We asked whether coordinated voluntary movement of the lower
limbs could be regained in an individual having been completely paralyzed
(>4 yr) and completely absent of vision (>15 yr) using a novel strategy –
transcutaneous spinal cord stimulation at selected sites over the spinal vertebrae
with just one week of training. We also asked whether this stimulation strategy
could facilitate stepping assisted by an exoskeleton (EKSO, EKSO Bionics) that
is designed so that the subject can voluntarily complement the work being
performed by the exoskeleton. We found that spinal cord stimulation enhanced
the level of effort that the subject could generate while stepping in the
exoskeleton. In addition, stimulation improved the coordination patterns of the
lower limb muscles resulting in a more continuous, smooth stepping motion in
the exoskeleton. These stepping sessions in the presence of stimulation were
accompanied by greater cardiac responses and sweating than could be attained
without the stimulation. Based on the data from this case study it appears that
there is considerable potential for positive synergistic effects after complete
paralysis by combining the overground stepping in an exoskeleton, a novel
transcutaneous spinal cord stimulation paradigm, and daily training.
In a hallway of Simon Fraser University, retired Canadian Forces captain Trevor Greene is doing something he has not been able to do since being struck in the head by an axe in Afghanistan in 2006.
ReplyDeleteMr. Greene, 50, is walking.
It doesn’t come easily. He is wearing an exoskeleton, a framework of black metal pieces and struts that encase his legs, and is powered by a battery in a slick backpack. He leans on a walker. His wife, Debbie, is ahead of him. Behind him, Jay Courant, whose U.S.-based company ReWalk developed the technology, is spotting him.
There’s a whirring sound as Mr. Greene takes his steps forward, lurches awkwardly and focuses on the exercise so intently that the rest of the hallway – the specialists, his wife and a Globe and Mail reporter and photographer – seem to fall away.
His brain injury came in an infamous incident. While meeting village elders in Afghanistan, Mr. Greene had removed his military helmet. A male youth came at the captain from behind and hit him in the head with an axe, inflicting serious injuries that forced his evacuation to Germany and then Canada for treatment.
On Thursday, Mr. Greene is scheduled to demonstrate his new skills at a news conference, displaying an ability he has been honing, with the exoskeleton, since June. Mr. Greene is taking steps along his own journey, aiming to eventually walk unaided...
“I hope it gives them hope because that’s critical. The current medical wisdom holds that within six months of a brain injury, you don’t improve,” Mr. Greene said in an interview before suiting up.
But he hopes his experience helps to stir others’ fighting spirit.
“After six months, the doctors give up on brain-injury survivors. Most importantly, the survivors give up. They accept their lot,” he said. “I am hoping to change that.”...
He has trained with a walker with two people helping him. But the exoskeleton has helped him move on his own.
Asked what the experience was like, he says, simply, that it was “wild,” smiling broadly as he savours the “liberating” memory. “It can get me close to walking, close enough that I can use other training to actually walk.”
Researchers have seen signs of remarkable recovery in his brain that reflect Mr. Greene’s determination to get better. Asked about that determination, he says, “I was pretty easygoing before I got in the army. The army gave it to me.”
Indeed, he is the co-author with Ms. Greene and others, of Long-Term Motor Recovery After Severe Traumatic Brain Injury: Beyond Established Limits, just published in the Journal of Head Trauma and Rehabilitation.
http://www.theglobeandmail.com/news/british-columbia/injured-soldier-walks-again-with-help-of-exoskeleton/article26390061/
video: http://www.cbc.ca/player/News/Health/ID/2675754621/