An investigation on alpha-beta ratio of EarEEG system

Nowadays, brain-based technologies are further developed to improve the quality of life. However, these technologies are not widely used because the inconvenience of the protocol and the long lead connection of electrode placement. Most of EEG wearable devices in present are using EEG at frontal lobe. Therefore, the data that can accomplish from that area is limited. EarEEG has been developed to solve these problems. Instead of using the on-scalp recording system, EarEEG uses behind-the-ear and in-the-ear methods to measure the brain signal. By using this technology, the feasibility of brain computer interface (BCI) based technology is increased. It can be integrated into daily application realistically, but it lacks investigation on alpha-beta ratio which is the common value that has been used in lifestyle application. Therefore, in this study, we developed the EarEEG system comprised EarEEG electrode, wireless EarEEG amplifier, and software part for receiving, processing, and interfacing data. The EarEEG acquisition device is attached behind-the-ear of user and the EarEEG signal is measured. 6 subjects were included in the experiment to perform attention task and meditation task. The data from both methods were analyzed in orderly. The evidence shown that the alpha-beta ratio can be easier to distinguish compared to using frontal lobe or occipital lobe individually because of the placement of EarEEG. The ratio has same characteristic as the occipital lobe and can clearly observe same phenomena. The occipital lobe is difficult to measure due to hair and position. Therefore, it is difficult for current technology to observe the signal of this area in everyday living. EarEEG is the excellent alternative to employ BCI-based technology into daily living with more precise and meaningful application.