Chapter 2 Hcgsn - Geodesic Sensor Net Technical Manual

chapter 2
HCGSN
2
CHAPTER
T
he HCGSN retains EGI's patented geodesic tessellation of the head (Figure 2-1),
which is the hallmark of the Geodesic Sensor Net design. The HCGSN also
employs the non-abrasion high-impedance application method used with the
GSN 200.
The HCGSN comes in two configurations:
• with sponge inserts : for standard 2-hour recordings using the HydroCel Saline
electrolyte solution (described in "Preparing the Electrolyte Formulation" on
page 58)
• without sponge inserts : for extended 12-hour recordings using the HydroCel HS
electrolyte formulation (described in "Preparing the Electrolyte Formulation"
on page 58)
The HCGSN is available in 32-, 64-, 128-, and 256-channel versions, as well as in a
variety of sizes (see Appendix B, "Net Sizing and Sensor Layouts," for sizing chart and
sensor maps). Because the HCGSN is designed to provide more coverage of lower
sections of the head, its sensor layouts are different from those for the GSN 200.
Therefore, EEG files acquired with the GSN 200 are incompatible with those acquired
with the HCGSN. (For information about the GSN 200, see Chapter 3.)
Geodesic Sensor Net Technical Manual
Figure 2-1. 128-channel HCGSN, front (left) and side (right) views
S-MAN-200-GSNR-001 • January 31, 2007
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