Researchers at the University of California, Berkeley, have created wireless earpieces that monitor brain waves to prevent nodding off at the wheel. Equipped with electrodes that detect ‘alpha’ waves, these devices can flag up the imminent onset of sleep, thus reducing the risk of road traffic accidents. The earpieces demonstrated a high level of accuracy when tested on volunteers and could be useful not only for drivers, but also for operators working in potentially hazardous environments.
A new type of wireless earpiece created by the University of California (Berkeley campus) could greatly reduce the risk of road traffic accidents caused by drowsiness. The new device performs a kind of continuous electroencephalogram on the driver, enabling the detection of ‘alpha’ waves that signal the imminent onset of sleep, which is difficult to control. As reported by the US researchers in the scientific journal Nature Communications, this type of earpiece appears to be way more effective than other ‘appliances’ that attempted to exploit the same principle in the past. In fact, it delivers better results than any of the other devices that can be installed in the cabin, such as those developed for measuring blink frequency, or those used to detect other body signals, or driving style, which can predict a sudden ‘need’ to sleep.
An ‘array’ of mini electrodes
As we were saying, the Californian earpieces detect brain waves in the same way as a traditional electroencephalogram (EEG), which doctors use to measure electrical activity in the brain. Unlike EEGs, which measure brain waves using a series of electrodes arranged on the head (or on the scalp, to be precise), the earpieces work using built-in electrodes that are designed to make contact with the ear canal. While the signals recorded in this way are weaker than those picked up by an EEG, the earpieces appear to be sensitive enough to detect alpha waves, which increase when a person closes their eyes or starts to fall asleep. Data collected by the earpieces are then sent wirelessly to an external receiver that raises the alarm if necessary.
The Berkeley bioengineers were able to achieve this by relying on an ‘array’ of electrodes made of different metals that conduct electricity, all contained within the earpieces. To ensure that the devices are correctly positioned at all times (a problem that has hindered the use of this technique in recent years), the earpieces were ‘designed’ with an inner part and an outer part, which applies gentle pressure on the walls of the outer ear to guarantee correct positioning.
Reliable in 93% of cases
The devices were tested on nine volunteers who carried out boring, repetitive tasks in a dimly lit room for a total of 35 hours of recording. In the various tests, the earpieces demonstrated the ability to identify the onset of alpha waves in 93% of cases.
They can therefore be considered as a possible tool to be offered not only to drivers but to people who perform repetitive operations with potentially hazardous machines, especially – as emphasised by the US National Safety Council – in the construction and mining industries.
The study’s senior author, Rikky Muller, associate professor of electrical engineering and computer sciences at the University of California, said: “I was inspired when I bought my first pair of Apple's AirPods in 2017. I immediately thought, 'What an amazing platform for neural recording!’ We believe that this technology has many potential uses, and that classifying drowsiness is a good indicator that the technology can be used to classify sleep and even diagnose sleep disorders.”
