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40 Troubleshooting
durations longer than a typical blink, the device generates the "pupil can no longer be
found" error. The device may not be able to locate the pupil for the following reasons.
Problem
The eyelids are closed.
An eyelid is obscuring all or part of the pupil.
The patient isn't looking at the red light.
If the device cannot find the patient's pupil, testing cannot
be performed.
After pressing the Start test button, I get an "Excessive ambient light" error
The flicker implicit time changes with illumination levels. External light that reaches the
eye under test can therefore affect results (making the timing faster). The eyecup is
designed to block external light from reaching the eye. If the RETeval-DR device senses
too much ambient light, an error message will display on the screen. After pressing
Restart to reduce the amount of ambient light reaching the eye, perform the following.
Problem
"Excessive ambient light" error
After pressing the Start test button, I get an "Unable to calibrate" error
The RETeval-DR device, after checking for ambient light, recalibrates the flash intensity
and color to match the factory-calibrated settings. The white interior sphere that the
Welch Allyn
Solution
Ask the patient to open their eyes.
•
Ensure that the patient is covering their other eye
with the palm of their hand.
•
Ask the patient to open their eyes wider. Drooping
eyelids that cover part of the pupil may require the
clinician to manually hold them open wider during the
test.
•
Use the eyecup to keep the eyelid open by using the
thumb and forefinger to simultaneously gently lift the
patient's eyebrow upwards and gently pull down on
the skin below the eye while securing the eyecup in
place.
The bright glint dot should be inside or near the pupil if the
patient is looking at the red light. Ask the patient to look at
the red light.
•
If you believe that the device should be able to find a
pupil, please run the Record Video option in Protocol.
•
Afterwards, dock the device to a computer or laptop,
browse to the Data directory on the device, and copy
the resulting .rff file to your computer or laptop
(named null_*_*.rff, where the *'s are numbers).
•
Contact Welch Allyn Technical Support:
www.welchallyn.com/service
to send Welch Allyn the file.
Solution
Rotate the RETeval-DR device so the eyecup better contacts
the skin around the eye.
Hold your hand near the patient's temple to block the light
with your hand
Move to a darker location or turn off any room lighting.
®
™
RETeval-DR
for instructions on how
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