UCD is studying the device to restore speech


BrainGate2 will use brain implants and machine learning

SACRAMENTO — UC Davis Health is recruiting volunteers for a clinical trial to build a “neurological prosthesis” to restore speech to people who have lost — or are losing — the ability to speak. The research is for people with neurological injuries or progressive neurological diseases, such as spinal cord injury, stroke, and amyotrophic lateral sclerosis.

With this study, UCD joins BrainGate, an ambitious consortium of universities and academic medical centers investigating how brain-computer interfaces can be used to restore neurological function in people with paralysis. The technology is also sometimes referred to as brain-machine interfaces or neuroprostheses.

BrainGate’s goal is to use this technology to “turn thoughts into action” for people with paralysis. Some of the consortium’s studies turned “neural” handwriting into text output to a computer and helped participants with paralysis control a robotic arm and hand.

The UC Davis researchers are focusing on a condition known as anarthria, where people want to speak but are unable to control their vocal cords or mouth in a way that would produce audible speech.

“Losing the ability to speak is devastating. Existing communication assistive technologies available to people living with paralysis, such as eye trackers and sip-and-puff devices, are slow, cumbersome, and require considerable effort on the part of the user and provider. their carer,” David Brandman said.

Brandman is an assistant professor in the Department of Neurological Surgery and the lead researcher at the study site. He is also co-director of the UC Davis Neuroprosthetics Laboratory and will lead the study surgeries. “I hope brain-computer interface technology will one day restore functional independence to people with paralysis.”

Lost signals

With some illnesses and injuries, the areas of the brain responsible for language and the desire to speak are intact, but the signals cannot reach the nerves and muscles that need to receive command impulses to produce sound.

With this new study, researchers hope to ‘read’ brain signals meant to move the muscles involved in speech – the tongue, jaw, lips, larynx and diaphragm – and translate the person’s intention to speak. into comprehensible speech produced by a computer. .

The researchers explain that the technology cannot read minds or detect inner monologues and thoughts. The experimental technology is developed solely to communicate signals generated in the brain as part of intentional speech.

“By implanting electrodes capable of recording from individual brain cells involved in speech generation, we hope to enable participants to communicate by simply trying to speak,” said Sergey Stavisky.

Stavisky, a neuroscientist and neuroengineer, is an assistant professor in the Department of Neurological Surgery. He is the scientific leader of the study and co-director with Brandman of the UC Davis Neuroprosthetics Lab.

“There are a lot of open questions. We hope to learn what brain cells do when a person tries to speak. For example, what type of information does this brain activity contain? What does this have to do with the movements or sounds the person is trying to make? With this study, we anticipate that we will be able to answer these questions and many more,” Stavisky said.

Technology is evolving

Implants have been used in the brain to help relieve symptoms of the disease for decades. Hundreds of thousands of people around the world have been implanted with deep brain stimulation devices. The technology is commonly applied to help people with Parkinson’s disease, tremors and epilepsy. In deep brain stimulation, implants that generate electrical impulses are used to manage symptoms of neurological diseases.

What is different about the BrainGate2 clinical trial is that the implants are not there to stimulate nerve cells. Instead, they are there to “listen” to them.

Participants accepted into the study will have tiny, specialized devices known as Utah Arrays implanted in the region of their brain that generates speech. The United States Food and Drug Administration has authorized testing of the devices in clinical trials.

The arrays get impulses from nerve cells – neural recordings – which are transmitted to two small metal pedestals at the top of the head. The pedestals are about half an inch in diameter. From there the signals can be connected to a computer.

To turn nerve cell signals into intended speech, researchers will rely on advanced machine learning techniques to create sophisticated computer algorithms. They predict that these algorithms will be able to accurately decode neural patterns in speech. The computer-decoded speech can then be combined with text generation or synthetic speech synthesis devices.

Stavisky notes that research groups are testing and improving these advanced medical devices that can potentially apply recent advances in computing and neuroscience to provide new ways to treat paralysis.

“It is an exciting time. We still have a lot to learn and there is no guarantee that it will work. Based on the progress of this field and the strength of our interdisciplinary research team, I hope that we can quickly make substantial progress toward restoring the ability of people who have lost the ability to speak to have naturalistic conversations in real time,” Stavisky says.

Leigh Hochberg, BrainGate Consortium and Clinical Trial Director, said, “I am thrilled to welcome David, Sergey and the wonderful community of neuroengineers at UC Davis to the BrainGate clinical trials. Their scientific and clinical knowledge will undoubtedly lead to breakthroughs in restoring communication. Hochberg is a neurointensivist at Massachusetts General Hospital, a faculty member at Brown University and Harvard Medical School, and director of the VA RR&D Center for Neurorestoration and Neurotechnology at Providence VA Health System.

To be eligible, participants must:

* be over 18 and live within three hours of the greater Sacramento area.

* suffer from paralysis of the arms and legs or have difficulty speaking.

* have a medical diagnosis such as spinal cord injury, stroke, ALS or other motor neuron degenerative disorder.

To learn more about the study, visit Braingate.org or contact [email protected]

– UC Davis Health


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