ALS Patients, Others Wanted for Brain-Computer Interface Research | BrainGate’s BCI trial in paralyzed patients continues to recruit at 5 US sites

A clinical trial is evaluating whether a new implantable brain-computer interface (BCI) is able to decode brain signals – those that research has shown are linked to hand- or speech-based tasks – and transform them into actions for people. people with neurological diseases or injuries.

The study, called BrainGate2 (NCT00912041).

The trial is recruiting now ALS patients, muscular dystrophy, spinal cord injury, stroke or other neuromuscular conditions, at five US sites. Additional trial sites may open in the future, the researchers noted, but for now the study centers are in Georgia, Massachusetts and Rhode Island, as well as two cities in California.

Participants, who can be between the ages of 18 and 75, must live within a three-hour drive of the study site and be available for brain surgery and regular assessments. A 13 month commitment is required.

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A BrainGate initiative

The pilot trial, launched in 2009, is an initiative of BrainGate, a consortium of international universities and academic medical centers focused on the research, development and testing of brain-computer interface technologies. The goal of BCI is to restore the communication skills, mobility and independence of people with neurological disease, injury or limb loss.

In some of these patients, the areas of the brain responsible for certain movements and speech are intact. However, the signals cannot reach the nerves and muscles that need to receive command impulses to perform such functions.

BCI technologies commonly use machine learning to interpret movement intention nerve impulses from the motor cortex – a region of the brain responsible for voluntary movement – ​​and transform them into specific digital actions.

Machine learning is a form of artificial intelligence that uses algorithms to analyze data, learn from its analyses, and then make a prediction about something.

Some of the consortium’s previous studies have enabled the conversion of neural signals from attempted writing movements in text output in a computer in real time. They also helped participants with paralysis control a robotic arm and hand.

In BrainGate 2, the goal is to obtain preliminary safety data on the experimental BrainGate BCI device – found in previous studies to help paralyzed people type faster. This trial will also assess whether the technology allows people with paralysis, including those with severe speech impairment, to recover several abilities that normally rely on the hands or speech.

Participants, who must have incomplete or complete paralysis of the arms and legs or speech difficulties, will undergo surgery to have Utah Arrays implanted – tiny square grids with 100 micro-electrodes – into the motor cortex and in speech-related areas.

The networks obtain impulses from nerve cells which are transmitted to one or two small metal bases placed above the head. From there, the signals can be connected to a computer, which will decode them into digital signs using sophisticated algorithms created by advanced machine learning techniques.

The ultimate goal is to allow participants to control a computer cursor and other assistive devices, including communication software such as email, with only their thoughts.

Researchers at the University of California, Davis (UC Davis) site of the trial are particularly interested in using the BCI to “read” brain signals meant to move muscles involved in speech – specifically the tongue. , jaw, lips, voice box and diaphragm. The team wants to translate these signals into understandable speech produced by a computer.

“Losing the ability to speak is devastating,” said David Brandman, MD, PhD, lead researcher of the trial at UC Davis, in a university press release.

“Existing assistive communication technologies available to people living with paralysis, such as eye trackers and sip-and-blow devices, are slow, cumbersome, and require considerable effort from both the user and the provider. their caregiver,” Brandman said.

Brandman, who will lead the study surgeries, is an assistant professor in the department of neurological surgery at UC Davis. He is also co-director of the UC Davis Neuroprosthetics Laboratory, along with Sergey Stavisky, PhD, who works as the study’s scientific lead and is an assistant professor in the same department.

“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,” Stavisky said.

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Research on the brain-computer interface

The scientists anticipate that the resulting algorithms will be able to accurately decode neural patterns into speech, which can then be paired with text-generating or speech-to-speech devices.

“We hope to know what brain cells do when a person tries to speak,” Stavisky said.

“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.

The neuroscientist also pointed out that several research groups and companies are testing and improving BCIs to recover functions lost with certain neurological and neurodegenerative diseases.

Notably, data from clinical trials have shown that Synchron Stentrodean innovative BCI that does not require surgery to be implanted, enabled four ALS patients to communicate and perform daily tasks online using “only their thoughts”.

“Based on the progress of this field and the strength of our interdisciplinary research team, it is my hope that we can quickly make substantial progress towards restoring the ability of people who have lost the ability to speak to have real-time naturalist conversations,” Stavisky said.

Leigh Robert Hochberg, MD, PhD, BrainGate Consortium Lead and BrainGate 2 trial sponsor, said, “I am delighted to welcome David, Sergey, and the wonderful community of neuroengineers at UC Davis to the BrainGate clinical trials. .

“Their scientific and clinical insights will undoubtedly lead to breakthroughs toward restoring communication,” added Hochberg, a neurointensivist at Massachusetts General Hospital, one of the other BrainGate 2 trial sites.

He is also a faculty member at Brown University and Harvard Medical School, and director of the Veterans Rehabilitation (VA) Research and Development Center for Neurorestoration and Neurotechnology at Providence VA Health System.

In addition to study centers at Massachusetts General and UC Davis, patients are enrolled at Stanford University School of Medicine, also in California, and Emory University School of Medicine, in Georgia, and Providence VA Medical Center, Rhode Island.

“I hope brain-computer interface technology will one day restore functional independence to people with paralysis,” Brandman said.