EGi Geoscan, User Manual, Page: 54 / 115

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FOR SCIENTIFIC RESEARCH PURPOSES
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2018-10-26 | GeoScan User Manual
 The infraorbital sensors are positioned directly below the pupils.

The facial sensors are positioned symmetrically and evenly down the
cheeks.
 The ears are sitting in their earholes with uniform crescents of space
behind both ears.

The left and right mastoid sensors are positioned similarly on their
side of the head.

The bottom row of sensors is positioned on the neck at the base of
the head.
5.2 GeoScan Stages
In 5 to 10 minutes, you will do the following:
 Template. Select the sensor template that matches the sensor
layout of the GSN being worn by the subject.
The template predicts the locations of the sensors in that GSN, while the
remaining steps verify and/or correct those predictions.
 Scan. Move the handheld scanner around the subject’s head to
record the physical locations of EEG sensors.
 Probe. Probe the fiducial skull landmarks (nasion, left
preauricular, and right preauricular) to confirm those locations
for the software.
 Align. Probe a few strategic sensors to align the 3D sensor cloud
with the sensor template.
 Label. Review the labels in the 3D sensor cloud and make any
changes necessary before exporting the 3D coordinate file.
 Export. Export the sensor locations as a 3D coordinate file.
 Convert.
Use the GPS Solver software to convert GeoScan 3D
coordinate .txt files into one of several formats for use in Net Station,
BESA, MATLAB, etc.