Approximatley 20% of cervical spinal cord injury patients are paralysed in all four limbs. This exoskeleton may still be years away from being publicly available, but it has displayed “the potential to improve patients’ quality of life and autonomy”.
The patient, Thibault, fell 12 metres four years ago severing his spinal cord leaving him paralysed from the shoulders down; he trained for months using a video game avatar system to acquire the skills he would need to operate the exoskeleton, relearning natural movements.
“When you’re in my position, when you can’t do anything with your body… I wanted to do something with my brain. I can’t go home tomorrow in my exoskeleton, but I’ve got to a point where I can walk. I walk when I want and I stop when I want,” says the 28 year old man identified as Thibault.
“The brain is still capable of generating commands that would normally move the arms and legs, there’s just nothing to carry them out,” said Alim-Louis Benabid, professor emeritus at Grenoble and lead author of the study published in The Lancet Neurology.
Two recording devices that read sensorimotor cortex areas which control motor function were implanted between the brain and skin by a team of experts from the Hospital of Grenoble Alpes, biomedical firm Cinatech and the CEA research centre; these decoders transmit brain signals which are then translated by an algorithm into movements being thought about, and this system sends the physical commands that the exoskeleton executes.
Using the avatar/video game Thibault trained by thinking about performing physical tasks including walking and reaching out to touch objects. When the avatar/video game was combined with the exoskeleton he was able to cover the distance of 1.5 football pitches over many sessions.
Implants have been used in the past to stimulate muscles in patient’s bodies, this study is the first to use brain signals to control a robot exoskeleton, which potentially could lead to brain controlled wheelchairs for paralysed patients.
“This isn’t about turning man into machine but about responding to a medical problem,” said Benabid. “We’re talking about ‘repaired man’, not ‘augmented man’.”
Although the exoskeleton was noted to be a long way from being a usable clinical possibility, it does send a message of hope to tetraplegics that in the future they may be able to regain movement.
