otometrics Madsen ZODIAC 901, Руководство пользователя

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AFAP
When AFAP is selected, the maximum rate of change of pressure varies
from 400 daPa/S before and after the peak to 200 daPa/S during the
peak. The sweep speed is reduced automatically when the measured pa-
rameter is changing rapidly with pressure, and speeded up automati-
cally when the measured parameter is not changing rapidly with
pressure. This advanced feature enables the ZODIAC 901 to complete
the measurement in the minimum time consistent with achieving the
specified accuracy.
NOTE
Note that when AFAP is selected, the measurement sweep stops as
soon as a tymp. is detected, thus further abbreviating the duration of
the measurement.
Using Setup to reduce the Pressure range can also be beneficial in mini-
mizing the measuring time by eliminating the flat, uninformative parts
of the healthy tympanogram.
4.1.3 ETF-I, INTACT EARDRUM
The Eustachian Tube connects the middle ear to the throat, but is nor-
mally sealed except during swallowing. Its purpose is to prevent a static
pressure differential from building up across the eardrum.
MEP Marker
(Version 4.x Only)
This test is similar to Tymp. Sweep, but provides for a second sweep to
be made without erasing the data from the first. The values of Ear Canal
Volume (ECV) and Middle Ear Pressure (MEP) from both tests are re-
corded, and after the second test the difference between the latter, MEPd
(= MEP2 minus MEP1), is also computed and displayed (please see
Fig.4.8). The MEP marker implemented in Version 4.x, enables the
marker for the second sweep to be moved in either direction displaying
computed values for MEP2 and MEPd.
The procedure for using the test is to get the patient to try to create an
over-pressure in the middle ear by closing the mouth, holding the nose,
blowing to create the over-pressure in the throat, and swallowing to
open the Eustachian Tube. The patient can then relax while the first
sweep is made. Then the patient drinks a glass of water, relieving the
over-pressure if the Eustachian Tube Function is normal. The second
sweep will then reveal a negative MEP (please see example in Fig.4.9).
36 Operation Manual
MANUAL MODE Chap. 4 GN Otometrics
TYMPANOMETRY
4.1 ZODIAC 901 Middle-Ear Analyzer
Fig.4.8
Intact Eardrum, Eustachian Tube
Function