Two cortical implants composed of 64 electrodes are positioned epidurally over the sensorimotor cortex to collect ECoG signals. A processing unit predicts motor intentions and translates these predictions into the modulation of epidural electrical stimulation programs targeting the dorsal root entry zones of the lumbosacral spinal cord. Stimulations are delivered by an implantable pulse generator connected to a 16-electrode paddle lead.
A team of Swiss and French neuroscientists and neurosurgeons reported that they have re-established the communication between the brain and spinal cord with a wireless digital bridge, allowing a paralyzed person to walk again naturally. The subject, a 40-year-old man who suffered a spinal cord injury following a bicycle accident that left him paralyzed over 10 years ago, was able to regain natural control over the movement of his paralyzed legs, allowing him to stand, walk, and even climb stairs.
The brain computer interface (BCI) involves 2 electronic implants: 1 on the brain, the other on the spinal cord. The technology for the brain implant, called WIMAGINE®, was implanted above the region of the brain that is responsible for controlling leg movements. A neurostimulator connected to an electrode array was positioned over the region of the spinal cord that controls leg movement.
“Thanks to algorithms based on adaptive artificial intelligence methods, movement intentions are decoded in real time from brain recordings,” said team member Guillaume Charvet, head of the BCI program at the French Alternative Energies and Atomic Energy Commission. “These intentions are then converted into sequences of electrical stimulation of the spinal cord, which in turn activate leg muscles to achieve the desired movement. This digital bridge operates wirelessly, allowing the patient to move around independently.”
Rehabilitation supported by the digital bridge enabled the subject to recover neurological functions that he had lost since his accident. Researchers were able to quantify remarkable improvements in his sensory perceptions and motor skills, even when the digital bridge was switched off. This digital repair of the spinal cord suggests that new nerve connections have developed.
