Brain activity has traditionally been assessed using large and often expensive technology that has limited its use to specific clinical settings. Small wearable devices that can assess brain activity are hoped to improve the diagnosis and monitoring of brain diseases like dementia or depression. However, unlike other health-related measurements that can be taken at home, such as blood pressure or weight, brain activity currently needs to be evaluated by highly trained medical staff using bulky and expensive equipment. Thus, scans tend to be infrequent, and changes are often not immediately noted or treated. To combat these problems, the development of small wearable devices using electroencephalography - where electrodes measure electrical activity on the scalp as an estimate of the underlying brain activity - has recently begun. However, such devices are usually painful when worn long-term and often have low signal-to-noise ratios, which limits their sensitivity.

Researchers at Osaka University (Suita, Japan) have now developed a wearable device that is unobtrusive and comfortable, which can measure brain activity in everyday situations - and its technology may potentially monitor many other health indicators as well. The performance of their device was so good that the researchers were able to conduct sleep-stage classification, which requires very clear brain activity readings. Another highlight of the device was its stickiness - it remained in place during a range of different activities during the testing process, although the research team admits they still need to work on its adhesion during activities that cause a lot of sweating. Given the current demand for imperceptible, wearable health sensors, the development of this new device has huge clinical and commercial potential. By measuring brain activity and other health-related factors in daily life, diseases are much more likely to be diagnosed and treated earlier, leading to positive health outcomes for millions of people worldwide.

“We were able to fuse together organic and inorganic materials to create a stretchable and transparent sensor sheet that can be worn on the forehead, is gentle to the skin, and is invisible to the eye,” said Teppei Araki, lead author of the study. “Unlike conventional wearable devices, our multifunctional electrode system has medical device-like performance, is easy to apply, and is comfortable to wear for long periods of time.”

“One other key advantage of our sensor sheet is its range of possible applications,” added Tsuyoshi Sekitani, senior author of the study. “It can potentially be used to remotely assess many other health indicators, such as electrocardiograms, pulse waves, blood oxygen saturation, or blood flow.” 

http://m.allmycbs.com/en/index.asp