A ‘mind reading’ brain implant has enabled an American man to communicate again after a devastating stroke robbed him of the ability to speak.
The device works by picking up electrical signals that are sent by the brain to the vocal tract when the patient tries to pronounce code words.
A computer then translates these into letters, allowing words and then sentences to be projected onto a screen — at a rate of seven words per minute.
The 36-year-old patient, known only as Pancho, is the first to try the device, which the makers hope can be rolled out more widely within a decade.
Scientists at the University of California, San Francisco, say it could be used for people with a host of other speech-depriving conditions, including cerebral palsy.
Pancho was paralyzed from the neck down at the age of 20 by a pontine stroke, a type that can cause locked-in syndrome – where people can only move their eyes.
He is said to have been overjoyed with the device and used it to tell them he hates the hospital food.
The patient known only as Pancho suffered a stroke at age 20 that did not damage his brain, but left him unable to move and speak. He is shown above with the implant in it, trying to type out words using electrical signals from his brain
What is a pontine battle?
A pontine cerebrovascular accident is a type of stroke that occurs in the pontine region of the brainstem.
The rare strokes can be fatal or leave victims paralyzed or with locked-in syndrome — where people can only move their eyes.
It can lead to extensive loss of motor functions and other defects.
A patient’s exact symptoms will vary depending on the severity of the pontine stroke, as well as the specific location.
This is because cranial nerves have different functions in different parts of the brainstem and in the pons itself.
For example, a stroke at the back of the pons can lead to ataxia, a condition characterized by loss of muscle coordination.
Other common symptoms of a stroke include double vision, lightheadedness, and lightheadedness.
After a pontine stroke, some patients also experience difficulty swallowing, speech impediments, numbness, and even paralysis of one side of the body or both.
The device – which contains 128 sensors – was implanted on the surface of the brain under the skull.
To use it, the patient tries to mouth code words from NATO’s phonetic alphabet, such as Alpha, Bravo, Charlie, and Delta.
For example, to say the word cat, the patient should try to say the words Charlie-Alpha-Tango.
A computer analyzes these signals and translates them into the specific letter they represent.
Scientists found that it took about two seconds to translate each letter.
This is equivalent to about 29 characters per minute, or seven words.
It takes 20 seconds to complete sentences like ‘how are you?’ to ‘say’, or about 10 seconds to type ‘hello’.
In total, 1,000 words were spelled by the patient with the device — or 85 percent of the words used in everyday spoken English.
The scientists said this can be expanded to 9,000 words.
The computer got about one in 16 letters wrong.
dr. Sean Metzger, a neurosurgeon involved in the study, said the patient “has really enjoyed using this device because it allows him to communicate with us quickly and easily.”
“I had to learn a lot about him,” he added, and that the patient “really didn’t like the food where he lives.”
dr. Patrick Degenaar, a neuroprosthesis expert at Newcastle University who was not involved in the study, called the results “impressive.”
The patient can still growl and moan, but cannot pronounce complete words.
He previously communicated by using a pointer attached to the top of a baseball cap to type words on a screen.
The electrode was implanted in his brain in 2019, after which scientists trained him to translate different brain waves into specific letters.
A year and a half ago, he’d had a pontine stroke, in which a blood clot disrupts blood flow to the brainstem’s punch area.
The rare stroke can be fatal or leave patients with paralysis, although the exact symptoms vary depending on the location of the stroke.
Estimates suggest that nearly 5 million Americans live with some form of paralysis, while 700,000 have cerebral palsy.
The study was published in the journal nature communication.