A wireless bridge can help people with spinal cord injuries
An international team of scientists make important a step toward treating a number of spinal injuries that result in patients losing mobility in their limbs. Researchers were able to bypass the damaged nerve tissue in the spinal cord, creating a wireless digital bridge between the brain and spinal cord below the damaged area.
The project is led by scientists from the École Polytechnique Fédérale de Lausanne (EPFL). Help was provided to a 38-year-old man who suffered a cervical spine injury 10 years ago as a result of falling from a bicycle, Sciencealert reports. Before that, he was involved in a program to help rehabilitate people with spinal injuries.
In particular, the patient underwent an epidural spinal cord stimulation procedure, in which an implant with electrodes is installed in the spine and a stimulator is placed under the skin. Such a platform, based on the readings of the motion sensors in the stimulator, creates impulses in the responsible areas of the spinal cord and forces the muscles of the limbs to do work, and the person to move, albeit very limited.
Since the patient still had electrodes in the spine (spinal cord), the scientists decided to feed them a control signal from the brain. To do this, they create a digital wireless bridge because the nerve tissue between the spinal cord and the brain has been torn as a result of trauma. To read the signals from the brain, sensors with their arrays of electrodes are implanted in the patient’s skull. The electrode control unit receives external inductive wireless power at a frequency of 13.56 MHz, and the recorded brain activity is transmitted by another antenna – a decimeter antenna at a frequency of 405 MHz.
The data is received and decoded by a receiving device (laptop), which the patient carries in a backpack on his back. First, the algorithm is trained to recognize brain activity in response to commands to perform certain leg movements, and then it is trained to synchronize the patient’s wishes to move the limbs with signals transmitted to the spinal cord and further to target leg muscles .
As a result of the training, the digital interface helps the patient to do what became impossible for him after the injury – to walk on uneven terrain and maintain balance with crutches. The platform also works well at home, not only under the supervision of doctors. In addition, part of the neural pathways in the brain are restored and the patient can perform a number of actions even without artificial stimulation.
One day, such technologies will be able to return people with spinal disabilities to an active life. If the system works in one patient, it may work in others, the researchers note in their paper in the journal Nature.