A groundbreaking new technology unveiled this week could enable paraplegics to walk again by sending signals wirelessly from the brain to the lower part of the spine.
The neuroprosthetic interface, developed by an international team of scientists and technicians, acts as bridge between the brain’s motor cortex and the spine. Brain signals are picked up by an implant in the skull and then translated by a small computer, which relays the information — wirelessly and immediately — to electrodes implanted in the spine.
The spinal electrodes are placed in the lumbar region, below the injury or lesion that otherwise prevents signals from passing through the nerves. The electrodes, in turn, stimulate the neural pathways that activate leg muscles when walking or running. The interface essentially creates a wireless connection between the brain and the spine, potentially allowing those with spinal injuries to walk again.
So far, the system has only been tested on monkeys, but initial results indicate that the system could work with humans, according to the research team.
David Borton, assistant professor of engineering with Brown University and co-author of the new study, said that spinal stimulation studies with humans are being evaluated, but there are no clinical trials in the works just yet.
“The current paper shows encouraging evidence that such brain recording and spinal stimulation could be used in a human rehabilitation context, but no studies are currently planned,” Brown said in an email to Seeker.
According to the study, officially published today in the journal Nature, two rhesus monkeys were outfitted with the neuroprosthetic earlier this year. Both monkeys had one leg paralyzed by a spinal cord lesion. On June 23, 2015, the first monkey regained control of its paralyzed leg, less than one week after the initial injury. The second monkey recovered within two weeks. Both animals were able to walk again, without training, both on the ground and on treadmills.
The neuroprosthetic interface was conceived at EPFL in Switzerland, and developed together with an international network of collaborators including Irish medical device company Medtronic, Brown University and the German research institution Fraunhofer ICT-IMM. Testing was performed in collaboration with the University of Bordeaux, Motac Neuroscience and the Lausanne University Hospital (CHUV).
EPFLAs you might imagine, the technical details are complex (you can peruse the research paper itself at Nature) but the system basically consists of five components: the brain implant, a brain-recording device, a computer, an implantable pulse generator and a spinal implant.
The brain implant technology has previously been deployed to control movement in prosthetic hands and, in one case, a patient’s fully paralyzed hand. But this is the first time it’s been used for spinal injuries.
The computer element of the system extracts specific intentional information from the brain implant, then translates the data using special algorithms. The data is beamed wirelessly to the pulse generator, which delivers the instructed patterns of simulation to the spinal implant. The spinal implant activates groups of muscles in the paralyzed leg, inducing flexing and extension movements.
“The link between the decoding of the brain and the stimulation of the spinal cord — to make this communication exist — is completely new,” said neurosurgeon Jocelyne Bloch of the Lausanne University Hospital, in press materials accompanying the research publication.”For the first time, I can imagine a completely paralyzed patient able to move their legs through this brain-spine interface.”
Pretty amazing. EPFL has put together a helpful video on the whole process: