Paralyzed People Can Communicate Again With Brain-Computer Interface

Electronic gadgets like tablets and other mobile handsets are an essential component of modern day life. However, a person with paralysis completely loses the ability to operate them. A new study shows that this can be made possible by using a brain-computer interface (BCI). The BrainGate consortium, made up of scientists, engineers and physicians, has developed a BCI that can be operated by a paralytic patient, just by thinking about moving the cursor and clicking it, using a virtual Bluetooth mouse. The study has been published in the journal PLOS ONE.

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Study Participants

The clinical trial was carried out on three participants who had quadriplegia. Two of the participants had lost the ability to move their arms and legs due to amyotrophic lateral sclerosis (ALS), a disease that destroys the nerves of the brain and spinal cord, which control movement. The third participant was paralyzed due to spinal cord injury. These three participants were enrolled in the clinical trial to assess the safety and feasibility of application of the new BrainGate BCI device.

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How Does the BrainGate Brain-Computer Interface (BCI) Work?

The participants had a sensor attached to an area of the brain called the motor cortex. This capsule-sized implant is able to pick-up brainwave signals generated by the motor cortex that are associated with planning of intended movements. These signals are decoded and passed on to an external Bluetooth device, which was configured to function similar to a wireless mouse. This virtual mouse was then aligned with a standard Google Nexus 9 tablet.

The participants were plugged-in to the device and asked to perform standard tasks to assess how well they were able to operate a variety of commonly used apps, and move between apps. It has been shown that a similar type of device can enable paralyzed patients to operate robotic arms and regain mobility in their limbs.

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Study Findings

The BrainGate BCI enabled the participants to pass their thoughts for communicating with the outside world. They could smoothly perform typical operations such as e-mailing, chatting, and music/video streaming and sharing. They were delighted to be able to communicate with their family, friends, co-participants, as well as the research staff.

One of the participants, who was a musician, was even able to play the piano on a digital interface.

Dr. Jaimie Henderson, MD, John and Jene Blume – Robert and Ruth Halperin Professor of Neurosurgery, Department of Neurology, Stanford University Medical Center, USA, and a senior author of the study, said: “For years, the BrainGate collaboration has been working to develop the neuroscience and neuroengineering know-how to enable people who have lost motor abilities to control external devices just by thinking about the movement of their own arm or hand.” He added: “In this study, we’ve harnessed that know-how to restore people’s ability to control the exact same everyday technologies they were using before the onset of their illnesses. It was wonderful to see the participants express themselves or just find a song they want to hear.”

The study found that:

• The participants could make up to 22 point-and-click operations per minute on various apps
• They could also type up to 30 characters per minute using standard text apps used for sending e-mails and other writing activities

Dr. Paul Nuyujukian, PhD, MD, who is an Assistant Professor at the Department of Bioengineering, Neurosurgery, and (by courtesy) Electrical Engineering and Director of the Brain Interfacing Laboratory, Stanford University, USA, and the lead author of the study, indicated that it was great to see how quickly and effortlessly the study participants learned to use the new BrainGate system and perform the tasks assigned to them, as well as for pursuing their own interests.

Jose Albites Sanabria, who performed this research as a doctoral student in Biomedical Engineering at Brown University, USA, indicated that the technology had immense potential to restore rapid and reliable communication for patients who had lost their power to speak due to paralysis. This would enable them to effectively communicate with their family, friends, as well as interact with their health care providers.

Expert Comments

Dr. Krishna Shenoy, PhD, Hong Seh and Vivian W. M. Professor of Engineering, Stanford University, USA, and a senior author of the study, said: “The assistive technologies that are available today, while they’re important and useful, are all inherently limited in terms of either the speed of use they enable, or the flexibility of the interface.” He added: “That’s largely because of the limited input signals that are available. With the richness of the input from the BCI, we were able to just buy two tablets on Amazon, turn on Bluetooth and the participants could use them with our investigational BrainGate system right out of the box.”

Dr. Leigh Hochberg, MD, PhD, Professor of Engineering, Brown University, Director, Center for Neurotechnology and Neurorecovery, Neurocritical Care and Acute Stroke Services, Department of Neurology, Massachusetts General Hospital, and Director, VA RR&D Center for Neurorestoration and Neurotechnology (CfNN), the Providence VA Medical Center, USA, and a senior author of the study, felt that there was a huge potential for the restorative capabilities of BCIs, used in the present study.

“When I see somebody in the neuro-intensive care unit who has had an acute stroke and has lost the ability to move or communicate, I’d like to be able to say, ‘I’m very sorry this has happened, but we can restore your ability to use the technologies you were using before this happened, and you’ll be able to use them again tomorrow,’” Hochberg said. “And we are getting closer to being able to tell someone who has been diagnosed with ALS, ‘even while we continue to seek out a cure, you will never lose the ability to communicate.’ This work is a step toward those goals.”

Funding Source

The research was funded by the Stanford Medical Scientist Training Program; Stanford Office of Postdoctoral Affairs; Craig H. Neilsen Foundation; Stanford Neurosciences Institute; Stanford BioX-NeuroVentures, Stanford Institute for Neuro-Innovation and Translational Neuroscience, as well as many other organizations.

Reference:

1. Cortical control of a tablet computer by people with paralysis - (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0204566)

Source-Medindia