33
ALIGNMENT RANKING SYSTEM
In Automatic Measurement Mode, the Scanmate Software uses a
pattern recognition algorithm to determine when the probe is
properly aligned. The alignment algorithm first looks for the proper
pattern of reflectance peaks from each expected interface. Then
the algorithm examines the retinal spike for particular signal
characteristics which are produced only by retinal interfaces.
Waveforms that meet the alignment criteria are ranked and put
into the measurement bank.
Alignment is ranked using a
“
star
”
system. As measurements enter
the measurement bank, they are given a 1
-
star, 2
-
star or 3
-
star
rank, with 3
-
star being the best. 3
-
star ranked measurements will
replace those in the bank with a lower ranking.
In order to meet the measurement criteria, eight measurements
must be obtained that meet the ranking (3
-
Star) and standard
deviation requirements. Standard deviation requirements can be
viewed and adjusted by selecting
Preferences > Doctor
.
Once the measurement bank is filled with 3
-
star measurements, and
all measurements are within the standard deviation parameters,
measurement will automatically stop. The entries in the bank are
used to calculate the measurement average.
If 3
-
star alignment is not achieved within the alignment timeout
period, a warning message will appear stating that alignment
accuracy requirements will be reduced. 1
-
star, 2
-
star and 3
-
star
measurements will be accepted for calculating the average.
If alignment continues to be undetected, a warning message will
appear stating that alignment accuracy requirements will be
disabled, placing the system in
“
Estimate Mode
”.
All measurements,
regardless of alignment, will be accepted for calculating the average.
If measurements are obtained that do not show signs of alignment,
they will be given an
“
EST
”
ranking.
NOTE:
Measurements with an
“
EST
”
ranking do not show signs of alignment. Star ranked
measurements should be given preference over
“
EST
”
ranked measurements when possible.
If eight valid measurements are not obtained prior to the video buffer expiring, the scan will
time out. Two long beeps will signal that the scan has timed out.
VIDEO BUFFER FULL
If 8 valid measurements have not been obtained before the video buffer is full, the scan will time
out as indicated by two long beeps. The default video duration is 1024 frames. This can be
adjusted in the
Preferences > System
menu.
