Brain Computer Interface Helps Paralyzed People to Regain Tactile Sense

Imagine the moment when your fingertips touch the grass, the sole of your feet touches the comfort of the beach, and even the burning sensation of being too close to the fire. Most of these people think that the habitual feeling is an unimaginable experience for people with spinal cord injury (SCI) , and these people are by no means a minority. There are about 288,000 people. The good news is that the latest developments in the " brain-computer interface " field today may bring new hope to these people, and they have the opportunity to regain interaction with the world around them.

This year, "CELL" published a heavy study from the Battle Memorial Institute in Columbus, Ohio. The researchers implanted a computer chip into the brain of a patient with spinal cord injury and transmitted neural signals to the computer. They found a way to amplify the patient's subtle touch. This kind of computer chip not only has the opportunity to restore normal movement of paralyzed patients , but also restore tactile sensation. The researchers said that they achieved 90% accuracy in the experiment compared to chance.

This improved motion and tactile sensing technology allows spinal cord injury patients to regain their autonomy and better control their bodies in their daily lives. The technology to restore the movement and sensation of patients with spinal cord injury is actually not unique. BMI research scientist Patrick Ganzer said that the reason for their research is that the sensory recovery is achieved in the human body. "Now there have been many similar jobs. Installing artificial limbs on amputees is like robotic limbs," Ganzer said. With these robotic arms, patients can move their fingers and toes, but dealing with contact feedback is tricky. Other research groups are also using similar brain-computer interface methods to try to restore the patient's motor control and tactile nerves, but they use direct Stimulate the brain to do this. The new problem solved by the Ganzer team is that instead of letting patients use robotic arms, but using their own hands, it is really challenging to achieve this. In a paper published in the journal Cell on Thursday, the researchers tested Ian Burkhart, a 28-year-old spinal cord injury patient, who lost his right arm sensation and mobility in a car accident 10 years ago. In order to restore the movement and touch of Burkhart's right hand, the research team must first issue the source of the relevant instruction to Burkhart's brain .

Ganzer told that their system works by first collecting neural signals from implants implanted on the surface of Burkhart's brain and then sending them to a nearby computer. Computers use intelligent algorithms to decompose these data streams into motion information and sensory information. The second information flow is the key, the authors write, because previous studies believe that patients like Burkhart no longer produce these sensory signals . However, this new study found that these touch-based neural signals still exist, only at very, very low levels, so that patients like Burkhart cannot "feel" them. To make these elusive touch signals easier to perceive, the research team improved their signal strength through algorithms.

Finally, the computer transmits the processed data back to Burkhart by stimulating forearm electrodes for movement and haptic armbands for haptics. When blindfolded by Burkhart and asked him to complete an action task such as grabbing an object, the researchers found that the addition of stimulants far exceeded chance and the detection rate was as high as 90%. For the future, Ganzer said, the research team is working hard to develop an experimental model that is equally effective at home and in the laboratory, so that patients with SCI can better control their own world. Ganzer said, "One of our main goals now is to make this system portable so that it can be installed in a wheelchair and installed at home. We hope this technology will eventually be at home rather than in the laboratory.