Researchers have been using brain-computer interfaces (BCIs) to interact with patients suffering from locked-in syndrome for the last decade. What is brand-new is a system created by the Wyss Center for Bio and Neuroengineering in Switzerland that may finally allow even the most paralyzed patients communicate and create a new channel of communication with the outside world.
Locked-in syndrome has different degrees that depend on patient’s degree of movement. Therefore, how paralyzed is the patient will influence how the BCI system works. For example, those suffering from this syndrome at the earliest stage might control the system by raising or lowering their eyes and blinking. However, the problem arises when fully locked-in syndrome prohibits even that degree of movement.
Last studies have relied on optical keyboards to try to overcome this problem. However, the Wyss team developed a means of reading patient’s minds directly by measuring the flow of oxygenated blood flowing through their brains. The innovative study was published last week on the PLOS journal.
The team relied on the help of four patients who suffer from amyotrophic lateral sclerosis (ALS aka Lou Gehrig’s Disease), a motor neuron disorder that progressively destroys the nervous system’s ability to control the body’s muscles. The Wyss researchers first used near-infrared spectroscopy to measure the brain’s blood oxygenation and electroencephalography (EEG) to measure electrical activity levels. The patients were then asked basic yes or no questions while the machines recorded changes in those metrics.
But how does this work exactly? From my naive perspective, what I understand is that the machine records the blood flow and calculates how (it) changes during Y/N answers, and the computer develops a pattern of how yes and no answers look like. After a while and enough training, they know what the patient is “thinking” (when he thinks “yes,” or “no”) and from that, they calculate the answer. The Wyss system managed a 70 percent accuracy rate for the standard Y/N questions like “Is this your husband?”. More interestingly, when asked “Are you happy?” all four patients answered “yes”.
The Wyss team hopes to leverage this data into future research in hopes that people paralyzed by disease or injury can lead fuller lives.