otometrics ICS Impulse USB User Manual page 14

User Guide
3. Ask the patient to look at the left dot, then at the right dot. In the
to track the pupil.
Note Use the Real Time Trace window to monitor incoming data. By observing the head trace (orange/blue/pink)
•
and the eye trace (green), you can tell if the patient is moving their head or eyes (instead of staring at the fixation
dot), blinking excessively, or not following instructions being given (not cooperating).
4. If the cross-hair fails to track the pupil (jumps around and does not stay centered on the pupil), move the threshold
slider to make further adjustments.
In the calibration procedure, the patient is asked to switch their gaze between the two dots that appear when the
lasers are on. As the patient's gaze switches, the system tracks the movement of the pupil.
Note
• When a patient cannot be calibrated (for example the vision is so poor that the patient cannot see the fixation
dot or laser beams dots), click
The eye movement between the two laser beam dots is measured and calibrated against the known values between
the two laser beam dots. The calibration values relate to the pixel location that equates to 7.5 degrees left and right
of center. The difference between the left and right equates to the number of pixels for a 15 degree movement of
the eye. These values are used to analyze eye movement during the impulse testing.
Caution
•
trols or adjustments, or performance of procedures other than those specified herein, may result in hazardous radi-
ation exposure.
Run
5. Click
6. Ask the patient to face the fixation dot and hold the head still.
7. Ask the patient to follow the laser beam dot.
14
Default
to use the calibration default values (∆ = 21).
During this procedure one laser at a time will turn on. Do not look directly at the lasers. Use of con-
.
Video
window, check that the cross-hair continues
Otometrics - ICS Impulse USB