Use of portable EEG sensors to detect meditation

Portable single channel EEG recording systems are inexpensive compared to the standard traditional systems. These single-channel EEG recorders are based on dry electrodes and allow for simple recording setup. These systems are still under research for understanding their utility for many user-centric healthy lifestyle applications. This paper attempts to examine single-channel dry electrode based portable Neurosky Mindwave EEG system for its utility in detecting meditation state. In order to achieve this goal, data is recorded with both single-channel EEG system and a 19-channel regular EEG recording system for 20 subjects during meditation. Data is pre-processed for artifact removal via independent component analysis. Next, it is studied via power spectral density and compared for both the systems. Similar spectrum was observed with both the devices for subjects under meditation, although amplitude levels differed across subjects and across devices. Since many subjects may only be in the state of rest and not in meditation, data was explicitly captured during rest with the single electrode recorder to understand and differentiate the two psycho-physiological states of meditation and rest. During meditation, higher energy is observed in the delta band compared to the alpha band, whereas opposite (delta band energy is lower to alpha) is observed in the rest state. Meditation state was also studied during different phases, i.e., at the start, in the middle, and at the end of the meditation. A companion Android app is also developed to detect meditation using the single-channel EEG device.