50
Long Range Mount Installation
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view on the Host PC. If the camera image is horizontally flipped, this can be
corrected by pressing the
button on the left to rotate the camera image 180° and
then click on the vertical flip button.
Recommendation: Turn USE SEARCH LIMITS off and ONLY have one
eye in the camera’s view.
The EyeLink 1000 has the ability to track the eye no matter where it
falls in the camera’s view. This is highly desirable when the eye is
difficult to locate (i.e., at long distances!) and SEARCH LIMITS restricts
the area that can automatically track the eye.
10)
Select the Eye to Track and Adjust Thresholds.
Press the ‘A’ key for autothreshold, or
in the global camera view move the mouse cursor on top of the pupil position and
click the left mouse button. The camera image for the eye should now be displayed
in the zoomed thumbnail view. If the pupil is detected, a green box and crosshairs
will also be drawn.
Use the left or right cursor key to select the zoomed camera view. Adjust the camera
focus by turning the focusing ring of the lens. You may do the adjustment from the
side opposite to the illuminator to prevent the camera image or the illumination to
the eye from being blocked. Look closely at the eye image on the zoomed view while
turning the focusing ring until the eye image is clear. If a colored circle (CR signal)
appears near the pupil, the best focus will minimize the size of this circle.
The system is now ready to test. Please see the tutorial in the User Manual, though you may
wish to skim the contents of Chapter 8 first.
7.8
Installation in a MEG Room
The Long Range EyeLink 1000 is non-ferromagnetically optimized, made mostly of plastic,
aluminum and brass. The Fiber Optic Camera and Long Range Illuminator minimize electrical
noise and attach to the Mounting Bar using brass thumbscrews, plastic clips and aluminum
brackets. All of these features, coupled with excellent shielding, make the system ideal for a
MEG environment.
The Camera Head, Illuminator and Mount are located inside the MEG room, with DC power
entering the room through a waveguide along with a fiber optic cable, or with a rechargeable
battery system contained within the room to eliminate the need for cables to enter. Typically an
AC power supply is located outside the room and plugged into an isolated source as even this
inexpensive solution produces low noise. The Host PC too is situated outside of the MEG room,
though the camera images can be transferred and projected into the room via an application
running on the Display PC, making camera setup easily accomplished. As the only connection
between the room and the Host PC is fiber optic, no other isolated power outlets are required.
