Zeiss humphrey HFA II-i series, Руководство по обслуживанию на месте

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General Information Humphrey Field Analyzer II - i
Confidential and Proprietary
Field Service Guide
1 - 14 52235C1105
1.7.3 Head Tracking / Auto Pupil / Vertex Monitoring
These three features are dependent on the Gaze Tracking system. If Gaze Tracking has
successfully initialized, any of these three features can be utilized.
Head Tracking
The Head Tracking feature is designed to lessen the appearance of a trial lens artifact
image when the patient's eye is off center in relation to the center of the trial lens holder.
The intent is to reduce the possibility of inducing an arc-like defect or ring scotoma in the
patient's field test results.
Head Tracking is active when the trial lens holder is in the up position and Head Tracking
has been set to ON in the setup menu. The Head Tracking feature will track the center of
the eye in relation to the trial lens holder. If the patient's eye moves from the center of the
trial lens holder by more than 3 mm for more than one consecutive sample, the head
tracking feature will gently move the chinrest and headrest to automatically reposition the
patient's eye in the center of the trial lens holder. The tracking will stop if the eye doesn’t
follow the correction. Tracking begins when the test is started. This feature will operate
properly only if the patient properly rests on the chinrest.
Auto Pupil
When the Auto Pupil feature is set to ON in the setup menu, the gaze monitoring system
will determine the size of the patient's pupil to the nearest 0.5 mm at the beginning of each
test (during initialization of gaze tracking), and will automatically enter that information into
the Patient Data information screen, marked Auto (*).
Vertex Monitoring
The Vertex Monitoring feature is designed to lessen the appearance of a trial lens artifact
image when the patient's head moves backwards (away from) the trial lens holder. The
intent is to reduce the possibility of inducing an arc-like defect or ring scotoma in the
patient's field test results. Vertex Monitoring will alert the operator (via a double beep) if
the patient's eye moves more than 7 mm away from its original position for any one
measurement. (The sample rate is once every question.)
Vertex distance measurement is obtained during gaze initialization. During gaze
initialization, the two IR LEDs on the trial lens holder appear as two dots of light on the
corneal surface. (Refer to 1.7.2 Gaze Tracking for a complete description.) The distance
between these two dots will decrease as the head moves away from its original position. If
the distance exceeds the software limits, an alert will sound. The test continues, and a pop-
up window appears allowing the user to reinitialize, continue without reinitializing, or turn
off vertex monitoring.