Gsn 200 - Geodesic Sensor Net Technical Manual

chapter 3

GSN 200

3
CHAPTER
T
he GSN 200 features EGI's patented dense-array EEG sensors held in a tension
structure that stretches over the subject's head (Figure 3-1). The sensors' contact
with the surface of the head is achieved using electrolyte-wetted sponges and without
abrasion of the scalp. The GSN 200 uses EGI's HydroCel Saline electrolyte solution,
which is described on page 59.
The GSN 200 comes in three densities (64, 128, and 256 channels), and in a variety of
sizes (see Appendix B, "Net Sizing and Sensor Layouts," for sizing chart and sensor
maps). The sensor layouts for the GSN 200 are different from those for the HCGSN;
consequently, EEG files acquired with the GSN 200 are incompatible with those
acquired with the HCGSN. (For information about the HCGSN, see Chapter 2.)
Application and servicing of the GSN 200 are similar to those of the HCGSN.
Complete instructions on how to apply the Net are given in Chapter 6, "Applying the
GSN." You should also study Chapter 7, "Rinsing and Disinfecting," to understand
how to rinse, disinfect, and dry GSNs before and after application.
Figure 3-2 shows the parts of the GSN 200. Note that each sensor is wired to an
individual pin on the Hypertronics connector. Figure 3-3 shows front, side, and back
Geodesic Sensor Net Technical Manual
Figure 3-1. 128-channel GSN 200, front and side views
S-MAN-200-GSNR-001 • January 31, 2007
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