SR Research EyeLink 1000 Installation Manual page 64

from the magnetic field will introduce greater vibrations in the eye movement recordings. For
this reason it is recommended to position the Tray Mount at the end of the bore.
The Tray Mount has a hole cut out beneath the screen so that the operator can reach in to
adjust the position of the Mounting Bar and focus the lens. It is expected that during Camera
Setup and calibration, the image from the camera will be projected onto the screen (either the
optional Tray Mount screen or the screen provided by the user) so that the effects of the
operator's adjustments can be monitored.
For binocular recording, the post holding the Mounting Bar should be centered as pictured in
the bottom right images of Figure 7-12.
Use with the Siemen's 32 Channel Head Coil. For use with the 32 channel Siemens head
coil (monocular only) the post needs to be displaced to the side of the eye-to-be-tracked. The
mounts in the left image in Figure 7-11 and also Figure 7-12 left and top are all configured for
tracking a subject's right eye if used with the 32 channel Siemen's head coil.
Note that placement of the illuminator is as peripheral as possible and that the Camera Head is
as far toward the center of the Mounting Bar as possible. This may shift the placement of these
components from the recommend positions on the scale, but they remain separated and
importantly, have a more lateral view of the eye through the mask of the head coil. It is feasible
that both the Illuminator and Camera Head be placed on the same side of the Mounting Bar to
make the camera view slightly more peripheral.
To optimize the eye tracking the subject's head should be elevated as high as possible without
touching the mask of the head coil. For optimal brain imaging, ensure that the head remains
centered in the head coil – padding one side of the head so it is held more laterally will result in
better eye tracking but may produce inferior brain images.
7.9.1.2
Screen Mount (all scanner types)
The Screen Mount is designed to clamp to the bottom of a user-supplied screen that is situated
outside and at the end of the bore. Once clamped onto the bottom of the screen frame, the
height of a ball head holding the Mounting Bar can be adjusted to provide the optimal view of
the eye in the head coil mirror. Loosening the knob of the Screen Mount allows the component
holding the Mounting bar to slide up and down. The optimal Mounting Bar position from an
eye-tracking stance is as high in the field of view as possible, without blocking the bottom of
the display.
There are two Screen Mount configurations. The mounts are available for narrow (37 mm
width) or wide (75 mm) screen frames. An optional rubber bumper takes up a further 9 mm of
this gap. The bottom of the Camera Head and Illuminator are a minimum of 150 mm above
where the clamp mounts onto the screen with a maximum height of 395 mm.
For binocular recording the Screen Mount, and hence the Mounting Bar, should be centered at
the end of the bore. For use with head coils that provide visual obstacles when viewed directly
from behind (e.g., the 32 channel Siemens head) the eye tracker will need to be displaced to the
56 Long Range Mount Installation
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