Brain-Computer Interface Allows Locked-in ALS Patient To Communicate Interview with:
Mariska Van Steensel PhD
Nick F. Ramsey, Ph.D.

Department of Neurology and Neurosurgery
Brain Center Rudolf Magnus
University Medical Center Utrecht
Utrecht, the Netherlands What is the background for this study? What are the main findings?

Response: Patients who are severely paralyzed due to for example ALS or brain stem stroke are often unable to speak (also called ‘ Locked-in State’), and therefore need assistive devices, such as an eye tracker, for their communication. When these devices fail (e.g. due to environmental lighting or eye movement problems), people may indicate yes or no with eye blinks in response to closed questions. This leaves patients in a highly dependent position, since questions asked may or may not represent their actual wish or comment.

In the current study, we used a technology called brain-computer interfacing (BCI), to allow a patient with late-stage amyotrophic lateral sclerosis (ALS) to control a communication device using her brain signals. The patient was implanted with subdural electrodes that covered the brain area that is normally responsible for hand movement. The electrodes were connected with wires, subcutaneously, to an amplifier/transmitter device that was placed subcutaneously under the clavicle. The patient was able to generate a signal equivalent to a mouse-click with this brain-computer interface by attempting to move her hand, and used it to make selections of letters or words on her communication device, with high accuracy and a speed of 2 letters per minute. She used the brain-computer interface system to communicate whenever she was outside, as her eye-tracker device does not function well in that situation.

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