15
B.
Testing Procedure
Using a regular otoscope or the delivery head with air flow turned off,
examine the ear canal for the presence of cerumen and also to determine how
best to direct the NCA-200 airstream. The ear canal should be essentially
free of cerumen. If it is not, this must be removed prior to stimulating. After
selecting the proper temperature and the standard 60 second time for caloric
stimulation, start the flow of air and then place the speculum of the otoscopic
air delivery head directly into the ear and direct the flow of air onto the
tympanic membrane.
Momentarily depress the flow time activation trigger button on the delivery
head. If the NCA-200 is connected to the CHARTR 200 VNG/ENG or
CHARTR VNG/ENG system, subsequent depressions of the flow time
activation switch will center the tracing for VNG/ENG or start the video
recording for VNG. (If installed, the footswitch will also serve to start and
center tracings or start the video recording.) After the selected time interval
has elapsed, a beep indicates when the otoscopic air delivery head should be
removed. After stimulation, remove the speculum from the ear, dispose of
the speculum and carefully place the delivery head in a safe location. Be sure
to utilize alerting tasks as the eye movements are being recorded.
