Researchers have developed an electronic, temporary facial tattoo aimed at measuring the mental workload of its wearers. This innovation could be particularly beneficial for individuals in high-pressure jobs, such as air traffic controllers, allowing them to signal when they need a break.
In the past year, various high-profile incidents have underscored the dangers of overworking staff. A tragic example occurred in January, when a collision in the air between a helicopter and a passenger airplane resulted in the loss of 55 lives. During this incident, it was revealed that staffing at Reagan National Airport Tower was “not normal”. Moreover, typically, one air traffic controller was managing tasks meant for multiple controllers.
The aforementioned cases highlight critical issues, including the urgent need for improved systems to evaluate the mental load of high-stakes jobs that require sharp focus, as stated by the scientists behind the new “e-Tattoo” in their research published in the journal on May 29th device.
The e-tattoo functions by detecting brain waves from the wearer’s forehead, leveraging that data to evaluate the mental effort exerted. Its creators assert that this method provides a quicker and more precise assessment compared to current techniques.
The prevailing method for gauging mental workloads relies on self-reports. Individuals track their exhaustion and disclose when they feel it, as noted by Nanshu Lu, a Professor of Engineering at the University of Texas at Austin. Unfortunately, “humans often struggle to accurately assess their mental performance,” Lu explained to Live Science.
Consequently, researchers have sought objective physiological markers of mental fatigue by examining brain activity. The most invasive method involves EEG, where precisely placed electrodes measure the electrical signals emanating from the scalp.
Related: What is burnout?
Conventional EEG devices resemble shower caps, necessitating a conductive medium, like a special gel, for a stable connection to the scalp. Additionally, the numerous wires extending from the electrodes into the data-collecting machine often create a cumbersome appearance likened to wearing a bowl of electric spaghetti.
Lu’s innovative system was developed in collaboration with co-authors and UT engineering teams, utilizing disposable polymer-based adhesive tattoos customized to fit the user’s facial shape. It incorporates a lightweight battery and electrode system that records brain waves from the forehead.
Brain waves are categorized into various frequencies, ranging from slower (delta and theta) to faster (alpha, beta, gamma). Previous studies link specific brain wave patterns to varying levels of mental workload.
Lu and Sentis conducted preliminary pilot studies to evaluate the devices. In one instance, six participants donned caps while completing a challenging memory test. As difficulty increased, participants exhibited a rise in delta and theta wave activity, while alpha, beta, and gamma waves showed a reduction, indicating heightened mental workload.
The collected data was then processed by a Machine Learning Model to estimate the mental workloads experienced by participants across different task challenges. The model’s predictions were closely correlated with self-reported workloads obtained via the NASA Task Load Index, a survey-based assessment tool.
The correlation between e-tattoos and the NASA index “is analogous to utilizing brain sensors across a cap,” Sentis remarked to Live Science. Interestingly, user perspiration actually aided the system by lowering electrical impedance, gradually enhancing recording accuracy. “The longer it’s worn, the better it performs,” said Gert Cauwenberghs, a professor of bioengineering at the University of California, San Diego, who was not part of the research.
Nevertheless, this new methodology does have limitations. Currently, the system can only record from hairless skin, such as the forehead, while traditional EEG caps can gather data from multiple electrodes across the scalp. The team aims to address this by employing an ink-based circuit printing technique directly onto the scalp.
The existing system captures data in real time, akin to traditional EEGs, but its electrical data analysis is performed individually by a computer. Lu mentioned that high-pressure professionals would likely benefit from immediate feedback and ratings. The next objective for the team is to develop a neural network (a distinct form of artificial intelligence model) on the tattoo’s Bluetooth chip. This would enable comprehensive recording and analysis to be handled directly by the tattoo itself.
“Whether for pilots, drivers, or robotic system supervisors, individuals engaged in critical tasks will likely experience significant mental workloads,” Sentis stated. “We envision these sensors being utilized in real time imminently,” he added.
Cauwenberghs concurred that the technology may soon be commercially viable but raised concerns regarding whether employers and employees are ready to embrace such a pervasive tool in the interest of safety.
Source: www.livescience.com