Geodesic Sensor Net - Initial Adjustments

6: Applying the GSN
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Geodesic Sensor Net Technical Manual S-MAN-200-GSNR-001 • January 31, 2007
8 Verify that the subject’s eyes are closed, then gently move the chin strap
underneath the subject’s chin and secure it using the cord lock.
Initial Adjustments
The initial adjustments usually involve adjusting sensors so that the ears and eyes are
comfortable, righting overturned sensors to sit perpendicular to the scalp, and using
the face straps to adjust the chin strap, eye electrodes, and ear electrodes so that most
of the tension of the geodesic structure is directed downward.
Also, be sure to check for even spacing of the sensors. If the sensors are unevenly
spaced, you may need to reapply the Net.
1 Make sure the ears are not pinned down by
the Net structure, adjusting as necessary.
(The HCGSN features cut-out sections for
the ears; the ears should sit completely in
these sections and the bottoms of these
sections should not pinch the bottoms of
the ears. See Figure 6-12.)
2 Check the back of the Net, making sure the sensors are perpendicular to the
scalp (Figure 6-13).
3 Check for symmetry by standing directly in front of the subject and making
sure that the nasion sensor is aligned with the nasion. If adjustment is needed
(for an example, see Figure 6-14, where the nasion is off-center), grasp large
Figure 6-13. Upturn tilted sensors; check the back of the head
The HCGSN has a
snugger fit than the
GSN 200, so make
sure:
1. The ears are not
caught in the ear
cut-out sections.
2. Sensors are not
impinging on the
eyes; adjust eye bands,
as needed.
3. The front bands
around the eyes are not
impinging on the eyes;
adjust bands, as
needed.
4. Cord locks are not
resting on the jaw bone;
adjust bands, as
needed.
Hint: When adjusting
the bands, move the ear
and eye band beads
closer to the chin strap
bead.
Figure 6-12. The HCGSN
features cutouts for the ears