otometrics Madsen ZODIAC 901, Руководство пользователя

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Softkey 5 ETF-P is included on the Tymp. intermediate menu. Press Tymp. to ob-
tain this menu, and then press Softkey 5 to access the ETF-P display
(Fig.4.11).
If the default settings have been altered using the ZODICON
TM
software,
the scale of the x -axis baseline may differ from the 45 s illustrated, and
the y -axis may be Pos. only or Neg. only, instead of Pos. and Neg. as
shown in Fig.4.11.
Softkey 4 Use Softkey 4 or Softkey 5 to decrease or increase the pump pressure,
respectively. The Status lamp will light while this is being done.
While using the pump, a scale at the top of the display indicates the cur-
rent pump position graphically, i.e., what proportion of the pump’s ca-
pacity is used to obtain the static pressure used for the measurement.
Rotary Knob Alternatively, turn the Rotary Knob . The pump position scale will ap-
pear temporarily at the top of the display to indicate the pump position
graphically.
Softkey 2 Press Softkey 2 (or the Start/Stop Button on the Probe) to start the test.
Y-Axis The screen displays the pressure in the ear canal over a 45-second time-
base. The patient should be instructed to swallow at regular intervals
during the measurement period, if necessary with the help of a glass of
water.
Softkey 1 Negative, positive or positive/negative y -axis may be selected by means
of Softkey 1 .
Ext. Range
Note that the pressure range of
±
200 daPa may be expanded to
±
400
daPa by pressing
Ext. Range.
“Staircase” Curve Each time the patient swallows, a perforated eardrum and a healthy
Eustachian Tube will result in a fall in pressure indicated on the display,
creating a so-called “staircase” curve after a number of swallows (illus-
trated in Fig.4.12). This is because the pressure in the ear canal is re-
lieved gradually, via the perforation and the Eustachian Tube. Neither a
blocked Eustachian Tube nor an intact eardrum allow relief from the
38 Operation Manual
MANUAL MODE Chap. 4 GN Otometrics
TYMPANOMETRY
4.1 ZODIAC 901 Middle-Ear Analyzer
Fig.4.11
Eustachian Tube Function,
Perforated Eardrum