Analysis of Exact Electrode Positioning Systems for Multichannel-EEG

Electroencephalography (EEG) consists on the recording of brain electrical activity along the scalp surface. The potentials generated in the brain are acquired using electrodes covering the head. This method is efficient, but in most cases the operator should deal with bad locations and slipping, which generate motion artifacts and localization errors in posterior brain imaging and connectivity analyzes. The aim of this work is to elaborate a reference framework addressed to the currently available electrode positioning methods for EEG in terms of efficiency, viability, and placement error. With this purpose, different procedures for electrode localization were considered in this study: manual methods, EEG-caps, Magnetic Resonance Imaging EEG electrode localization, digitization, 3D laser scanner, and photogrammetry. We found that the method with higher accuracy is digitization; but it requires a controlled environment and the system itself is expensive. In terms of implementation time, the 3D hand-held laser scanner and photogrammetry provided the better results and can be used in uncontrolled clinical environments.