A brain implant developed by researchers at Duke University could ultimately enable individuals to communicate solely through their thoughts. This breakthrough has the potential to revolutionize communication methods for those who are rendered unable to speak by neurological conditions.
The brain prosthetic, a collaborative invention of neuroscientists, neurosurgeons, and engineers at Duke, can decode signals from the brain’s speech center to predict the sounds a person is attempting to articulate.
Dr. Gregory Cogan is a professor of Neurology at Duke University’s School of Medicine and one of the lead researchers involved in the project.
“There are many patients who suffer from debilitating motor disorders, like ALS (amyotrophic lateral sclerosis) or locked-in syndrome, that can impair their ability to speak,” said Dr. Cogan. “But the current tools available to allow them to communicate are generally very slow and cumbersome.”
With existing technology enabling speech decoding at about 78 words per minute, which is roughly half the average speaking rate, there is a substantial need for improvement.
The novel device designed by Dr. Jonathan Viventi’s biomedical engineering lab at the Duke Institute for Brain Sciences has the capacity to capture detailed brain activity with unprecedented resolution.
According to the experts, they have packed 256 microscopic brain sensors onto a postage stamp-sized piece of flexible, medical-grade plastic. This sensitivity allows for the differentiation of signals from densely packed neurons, which is crucial for the precise prediction of speech.
The brain implant was put to the test with the assistance of Duke University Hospital neurosurgeons, including Dr. Derek Southwell, Dr. Nandan Lad, and Dr. Allan Friedman. The team enlisted four patients undergoing unrelated brain surgeries to trial the implant in a strictly timed 15-minute window.
“I like to compare it to a NASCAR pit crew,” said Dr. Cogan. “We don’t want to add any extra time to the operating procedure, so we had to be in and out within 15 minutes. As soon as the surgeon and the medical team said ‘Go!’ we rushed into action and the patient performed the task.”
The testing involved a simple task where patients repeated nonsensical words, allowing the device to record brain activity related to speech movements. The recorded data were then processed by a machine learning algorithm, managed by Suseendrakumar Duraivel, to gauge the accuracy of speech prediction based on brain activity.
The results were promising: certain sounds were predicted with up to 84 percent accuracy. Although accuracy varied and decreased in more complex scenarios, it is notable that the decoder performed at an average accuracy rate of 40 percent based only on a 90-second data sample from each participant.
This early success has spurred further development, supported by a substantial $2.4M grant from the National Institutes of Health.
“We’re now developing the same kind of recording devices, but without any wires,” said Dr. Cogan. “You’d be able to move around, and you wouldn’t have to be tied to an electrical outlet, which is really exciting.”
While this innovative speech prosthetic is not ready for commercial release, the research may lead to a future where natural speech could be mimicked closely.
“We’re at the point where it’s still much slower than natural speech, but you can see the trajectory where you might be able to get there,” said Dr. Viventi.
Motor disorders are a group of neurological conditions that primarily affect the body’s ability to control movement. These disorders can result from damage or disease affecting the nervous system, particularly in areas that are involved in the planning, control, and execution of movement.
Some motor disorders are present from birth, while others may develop later in life due to various causes, including degenerative diseases, infections, trauma, and conditions that deprive the brain of oxygen.
Here are a few notable types of motor disorders:
Also known as Lou Gehrig’s disease, ALS affects motor neurons in the brain and spinal cord that control voluntary muscle movement. The disorder is progressive, leading to the loss of ability to initiate and control all voluntary movement, potentially leading to total paralysis in the late stages.
A chronic and progressive movement disorder, Parkinson’s disease involves the malfunction and death of vital nerve cells in the brain, many of which produce dopamine. Symptoms may include tremors, stiffness, slowness of movement, and impaired balance and coordination.
Multiple sclerosis is an autoimmune disorder affecting the central nervous system, leading to widespread disruption of nerve impulses. This disruption can cause a range of motor problems, from mild difficulties with coordination to severe impairments in mobility.
Cerebral palsy is a group of disorders that affect a person’s ability to move and maintain balance and posture. It is caused by abnormal brain development or damage to the developing brain, affecting a person’s ability to control their muscles.
This disorder is characterized by involuntary muscle contractions that cause repetitive or twisting movements. The movements may be painful and can affect a single muscle, a group of muscles such as those in the arms, legs, or neck, or the entire body.
Strokes can cause motor disorders when the blood supply to part of the brain is diminished or interrupted, leading to cell death in areas that manage muscle control.
Treatment and management of motor disorders can include medications to manage symptoms, physical therapy to maintain muscle strength and function, surgery in certain cases, and assistive devices.
In addition, adaptive technologies like the brain implant by Duke University researchers have the potential to improve the quality of life for individuals with motor disorders by enabling better communication and interaction with their environment.
The study is published in the journal Nature Communications.
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