Welch Allyn TM286, Directions For Use Manual

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Directions for Use Operation 23
3. Place the black tubing of an ER-3A foam eartip (optional accessory) completely onto
the connector of the sound tube.
4. Roll the foam tip into the smallest diameter possible.
5. Insert the eartip well into the ear canal. Interauaral attenuation is improved with deep
insertion.
6. Allow foam to expand to acoustically seal ear canal.
7. Discard foam eartips after a single use.
Response handswitch (optional accessory)
If the optional handswitch is used, make sure that the handswitch connector is properly
inserted into the jack on the rear panel. (See
“Optional Accessories” on page 2). The
instrument will display an appropriate symbol whenever the handswitch is pressed.
Tympanometry/Reflex Test Sequence
Tympanometry only mode
1. Select the Tympanometry only mode by pressing on the front panel. The
display will immediately show the format for the tympanogram along with the
summary information headers ECV, cm
3
, daPa, and GR. The default scale for
compliance is 1.5 cm
3
. If a compliance peak greater than 1.5 cm
3
is measured, the
instrument automatically scales the compliance axis to 3.0 cm
3
so that more of the
tympanogram data can be seen.
2. Determine the test ear and select the appropriate ear ( R or L ) button so that the test
results will be labeled properly. It is not possible to change the test ear after the probe
is placed in the ear canal.
3. Examine the ear canal to determine the appropriate size eartip for the test and
position the eartip on the probe. Be certain that the eartip is pushed as far down the
probe tip as possible so that the eartip is flush with the tip of the probe.
4. Note that the green lamp is blinking, which indicates that the instrument is ready to
begin the test.
5. Place the probe up against the entrance of the ear canal so that its opening is
completely covered with the eartip and there are no visible leaks.
6. The 226 Hz test sequence begins when the instrument determines that a volume
between 0.2 cm
3
and 5.0 cm
3
is present. This is indicated by the green lamp
changing from blinking to steady. From this point on, hold the probe securely in this
same position without any movement. Monitor the probe and the individual's ear. At
the start of the test, the pressure system establishes a pressure of +200 daPa within
the ear canal. When this pressure is achieved, the instrument makes a measurement
of ear canal volume. This information is valuable as it indicates whether a good seal
has been established and helps to differentiate between two similar Tympanogram
types (i.e., a fluid-filled middle-ear system and a perforated tympanic membrane).
After the ear canal volume (ECV) is obtained, this compliance value is subtracted from
the remaining compliance measurements so that a direct reading of the
tympanogram compliance peak is possible.
Note
If using insert phones, ensure the appropriately sized foam tip is selected.