Development and Evaluation of a Smartphone-Based Electroencephalography (EEG) System

The aim of the study was to design, develop and evaluate a general-purpose EEG platform which integrates with a smartphone. The target specification was a system with 19 EEG channels and data stored onto the smartphone via a Wi-Fi connection. The hardware was developed using three ADS1299 integrated circuits, and the game engine, Unity, was used to develop the smartphone app. An evaluation of the system was conducted using recordings of alpha waves during periods of eye closure in participants (Bland-Altman statistical comparison with a clinical grade EEG system). The smartphone was also used to deliver time-locked auditory stimuli using an oddball paradigm to evaluate the ability of the developed system to acquire event related potentials (ERP) during sitting and walking. No significant differences were found for the alpha wave peak amplitude, frequency and area under the curve for the intra-system (two consecutive periods of alpha waves) or inter-system (developed smartphone-based EEG system versus FDA-approved system) comparisons. ERP results showed the peak amplitude of the auditory P300 component to deviant tones was significantly higher when compared to standard tones for sitting and walking activities. It is envisaged that our general-purpose EEG system will encourage other researchers to design and build their own specific versions rather than being limited by the fixed features of commercial products.