As part of the BrainGate 2 research project, US scientists have created the first computer-brain interface that allows the use of a commercially available touch pad.
Three tetraplegic patients managed to control a tablet by thinking of microelectrodes implanted in their brains. This is the result of a study published in the journal PlosOne on 21 November.
The goal of the researchers was to improve the lives of patients with paralysis and allow them to access electronic devices, such as a touch pad, to perform functions like writing e-mails or shopping. on the Internet.
Microelectrodes in the brain to record neurons
Two of the three study participants have amyotrophic lateral sclerosis (or Charcot's disease) and breathe by mechanical ventilation. Both are right-handed and, because of their pathology, they can not get effective movements with the right hand. The microelectrodes in the cerebral cortex had been implanted in their brain long before the clinical study. These electrodes, implanted in the region that controls the movements of the right hand, register neuronal activity.
The third patient has tetraplegia due to cervical spinal cord injury. At home, the electrodes were implanted in the motor cortex of the hand but also in the right arm.
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For the first time, a commercial device for the brain of the computerized interface
The device works as follows. The patient looks at the tablet and thinks where to point the cursor and click. The neurons, which normally allow the right hand to move the cursor and click, are activated even if, due to the disease, this activation does not correspond to a movement of the hand. The electrodes record this brain activity and send a signal to the tablet via Bluetooth.
Looking at the tablet, they decide where to point the cursor and where to click. The experiment worked. For three days, they were asked to perform tasks such as writing letters, using weather apps or music programs. The patients were able to perform 22 clicks per minute and write an average of 30 characters per minute.
This is the first time a commercial device is used for these studies: it has not been modified to perform the search. It is therefore a tablet like any other, connected directly to the thoughts of patients.
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The chance to play again
"The most rewarding part of the study was when the patients did just what they wanted", says dr. Paul Nuyujukian, first author of the study. And indeed, when the researchers asked the patients what they wanted to do, one of them expressed the desire to play the piano, the other to write, the third to make purchases on the Internet. Two participants also had a conversation via a chat. The result has always been positive. All three have found the use of the intuitive and natural tablet.