In medicine, unfortunately, are very severe cases of paralysis, when a person is awake but can not move or speak. Patients of this kind is not possible to fully communicate, they can only think. And just the mind of the people in the majority of cases clear, people are aware of their position and situation. Now scientists have developed an implant for the human brain that allows paralyzed patients to communicate through the computer. Man's thoughts turn into words and whole sentences. In this case, the patient does not need mediation physician.
"This is the world's first implantable system that works without the need for assisting with the doctors," - says neuroscientist and project leader Nick Ramsay School of Medicine of the University Utrehskogo.
The implant was recently tested in a clinical setting. The first person to receive such a system became Hanneke de Bruijne. In 2008, she was diagnosed with amyotrophic lateral sclerosis (ALS), and now it is totally paralyzed.
ALS - a slowly progressive, incurable degenerative disease of the central nervous system in which there is loss of both upper (motor cortex of the brain) and lower (front spinal horn and nucleus of the cranial nerves) motor neurons, which leads to paralysis and subsequent muscle atrophy. It is characterized by progressive motor neuron lesion, followed by paralysis (paresis) of limbs and muscle atrophy.
The patient has remained able to manage the muscles of the eyeballs, that is, to make the eyes move. During a meeting with the author of the project, it retained this ability and breathe on their own, without the artificial lung system. Two years later, the ability to breathe it was lost, so that the life she keeps the respirator. However, the eye muscles still work, though this is only temporary. Not so long ago established patient communication system that works by tracking the movement of her eyes.
Nick Ramsay has decided to develop a system whose operation does not depend on the movement of the eye patients, or any other physical activity. For example, Stephen Hawking, also affected amyotrophic lateral sclerosis, working with the machine, which tracks the movement of the muscles of his cheeks.
Such a system, according to experts, can only be a device that can monitor the electrical activity of the brain. The project manager says that the device is a system that reads minds. In general, you could say that. Various implants readers activity of brain cells, there is already a long time. For example, these are the systems used to create bionic prostheses that replace people of their own limbs.
But here we are talking about the device, which should help the patient not to make a prosthesis movement, and to demonstrate their ideas. And Ramsey and his colleagues immediately decided to create a system that would work not only in the clinical setting, but also at home, without anyone's help. The basic working element of the system - implant that is surgically implanted in the human brain. In this part of the computer system has two electrodes. They are implanted in the cortex, which controls movements of the person. Fine adjustment of the electrodes is critical. One of them is located in the part of the brain cortex, which is responsible for the movement of the right hand. And the second - in the region, is only activated when a person begins to count down.
These electrodes are connected to a transmitter implanted in the patient's shoulder. It transmits data to a computer, located in front of the patient, which has the ability to keep track of everything that happens on the screen.
When the patient is looking at the display, she sees the virtual square, moving spell. Once the box is held in the letter that she wanted, female mind is a movement of the right hand, press that letter. Her brain is quite capable of generating a signal which is supplied in a normal situation in the arm muscles. This electrical signal is detected by the transmitter and sent to the computer. The letter, marked by the patient, is released. From the letters forming the words, the words - sentences. The system almost does not make mistakes, its accuracy is around 95%.
"The use of such a system - this is a slow process. Writing words can take several minutes. But the patient is training, and the work goes faster, "- said one of the study participants. He added that earlier the woman had to choose the letter about 50 seconds. Who is she takes only 20 seconds.
This system, according to its developers is much more reliable than the former, which reads eye movements. The fact is that in bright sunlight the sensor does not work, and the paralyzed woman loses the ability to communicate. But the new system works in any lighting condition.
"Now I can communicate and outside the home, when my eye movement tracking system is not working. I feel more independent and self-confident when I'm in the street ", - says Bruijne.
Of course, the system needs to go through many more trials before it will approve, and developers will be able to give it to other people. In addition, the authors of the project are going to add the number of electrodes and improve the signal processing system. This, according to them, would accelerate the process of communication.
The results of their work, scientists set out in the New England Journal of Medicine.
Referenced Materials:
- https://en.wikipedia.org/wiki/Amyotrophic_lateral_sclerosis
- http://edition.cnn.com/2016/11/12/health/als-brain-implant-communication/
- https://www.newscientist.com/article/2112562-first-home-brain-implant-lets-locked-in-woman-communicate/
- http://www.nejm.org/doi/full/10.1056/NEJMoa1608085?query=featured_home#t=article