Introduction
The MI 24 and MI
26 are instruments used for tympanometric screenings.
In the tympanometric mode, it measures middle ear mobility and ipsilateral
acoustic reflex. Contralateral acoustic reflex is available as an
optional feature. Results are displayed on the front panel and also
can be printed.
The MI26
has the additional feature of performing audiometric pure tone screening.
This mode measures hearing response levels.
Product
Overview and Description
The Maico MI 24 & 26 perform automatic impedance tests and immediately
display the results on the front LCD screen or printout. Both instruments
offer programmable automated multi-frequency reflex tests with graphic
reflex display. Contralateral reflex testing is available as an
option. With the MI26 you can provide complete air conduction audiometric
testing and impedance screening in the school.
This unit
measures middle ear mobility and pressure within the middle ear
system. Using a hand-held probe, a low-pitched probe tone is presented
to the ear canal. The tone measures the change in compliance in
the middle ear system while the air pressure automatically moves
from a positive value to a negative value (+200-400 daPa max) or
vice versa.
When pressure
in the middle ear cavity equals pressure in the external auditory
canal maximum compliance occurs. This is also referred to as the
"highest peak" of the curve on the chart. The position
of the peak offers diagnostic information on the function of the
middle ear system.
The MI24/26
is ideal for testing because of the rapid speed with which it can
obtain both the tympanogram and reflex.
Product
Use and Procedure
 |
Set
Up |
| 1. |
Place
the instrument on a stable counter or table. |
| 2. |
Turn the
instrument so that the rear panel is in full view. |
| 3. |
Connect
the probe cord to the probe socket. |
| 4. |
On either
side of the socket you will see a spring clip. Fold the two
clips away from the socket. |
| 5. |
Insert the
plug into the socket on the rear panel. |
| 6. |
Secure the
connection by snapping each spring clip into place. |
| 7. |
Slip the
plastic tubing completely over the pressure tube connection. |
|
Head Set Installation-Audiometric
Pure Tone Screening (MI 26) |
| 1. |
Place
the instrument so the rear panel is in full view. |
| 2. |
Insert the
RED plug into the connection marked "R." |
| 3. |
Insert the
BLUE plug into the connection marked "L." |
|
Patient Response Switch-Audiometric
Pure Tone Screening |
| 1. |
Locate
the patient response connection on the rear panel. |
| 2. |
Insert the
plug. |
.
|
Contralateral Phone Cord Installation
|
| 1. |
Locate
the contralateral phone port on the rear panel. |
| 2. |
Insert the
plug. |
|
Power
Up |
| 1. |
Insert
the power plug into the back of the unit. |
| 2. |
Then into
the rear panel, insert the plug. |
The Maico
instrument has been designed to meet the most exacting electrical
safety requirements for patient care equipment. The hospital grade,
117 volt alternating current, three prong plug should be inserted
into a mating three prong hospital grade receptacle that is properly
grounded. This will ensure reliable and safe operation of this precision
instrument. The use of a three-prong to two-prong adapter should
be avoided.
Test
Procedures — Tympanometric Screening
Explain the test
to the patient; the soft-tipped probe will provide a seal and he/she
will hear a tone and feel gentle pressure. For the reflex test they
will hear a series of beeps. Ask them to be still as possible until
the probe is removed.
Hints
for Successful Screening
The
key to success is to make sure that you are at eye level with the
ear canal. Keep your hand steady and your eyes on the ear and probe
lights until the test is over. It's helpful to let the child become
familiar with you touching their ear before inserting the probe.
Audiometric
Pure Tone Screening MI26
Simply
tell the patient to press the response button whenever he/she hears a beep.
Tell them to listen very carefully because the beeps may be soft. Place
the earphones on the patient's head making sure the centers of the opening
of the phones do not slip. The red phone goes on the right ear and the blue
phone on the left ear. Tighten the headband so the phones do not slip off.
Do not let the patient adjust his/her own headset.
Audiometer
Function Procedures
|
1. |
Turn
the power Switch on the rear panel ON. |
| 2. |
Allow warm
up of 10 minutes. |
| 3. |
Press the
TY/AUD key to change from tympanogram to audiogram mode. |
Pass/Fail
Method:
The
initial setting on the LCD screen will indicate a frequency of 1KHz
and an intensity of 30 dB. Pressing the up and down arrow keys will
change the intensity levels. Holding down the side-to-side keys
will change the frequencies. Holding down these keys will let you
scroll through the selections. You can also choose pulse or steady
tones.
|
1. |
Set
the db level at a predetermined level for a Pass or Fail criteria. |
| 2. |
Present
the tone stimulus at 4 different frequencies. You will only
present one stimulus per frequency. Instruct the patient to
respond by pressing the response switch or raising their hand
when they hear a tone. A light will appear on the LCD screen
when the patient response switch is pressed. |
| 3. |
You may
present a tone 10dB higher if the patient fails at any frequency.
If a child fails 2 or more frequencies they can be referred
or rescheduled. |
This is a sample
situation. Please follow your state guidelines.
Hearing
Threshold Method
Modified Hughson-Westlake procedure is the most commonly used hearing
threshold.
|
1. |
Presenting
a signal for at least 1 second, start at 1000Hz with a 0dB
level. Increase another 10dB if no response. |
| 2. |
Continue
to increase 10 dB for a confirmation and orientation. If the patient
responds again, decrease the presentation in 10dB steps until the
patient no longer responds. |
| 3. |
Increase
5 dB until the patient responds. Once the patient responds,
descend 10dB until there is no response. Increase again in
the 5 dB steps. |
| 4. |
Repeat until
you have 2 out of 3 ascending responses at the same level.
Change the frequency and repeat the above procedure until
you have the thresholds for the number of frequencies you
wish to test. |
| 5. |
The hearing
threshold is defined as the lowest hearing level at which
the patient responds to two out of three ascending stimuli
at the same level. |
Features
and Benefits
 |
Daily
Calibrations: This
calibration allows the user to verify volume measurement accuracy
and the machine will make corrections to bring the tolerance within
+/- .1ml. This gives the user a higher degree of confidence in the
test reliability and this is a great tool when troubleshooting.
Real
Time Clock:
The automated recording of data and time provides the user
the assurance of accurately dating the test results for the
medical records.
5dB
Graphic Reflex Threshold Detection:
This provides more accurate results.
Fast
and Quieter Printer:
The printer is fast and quiet.
Programmable
Normal Box:
The normal tymp box can be adjusted to the customers needs.
This helps to reduce the number of false positives.
Detachable
Oto-scopic Probe: The ergonomic design of the probe
means easy positioning for easy seals.
Probe
Seal Pressure Reset:
It is not necessary to pull the probe back out of the ear
canal if there is a leak or a blockage. Just reposition the
probe until the test starts.
Easy
to Use:
Fewer keys are necessary because prompts are always available
on the button of the LCD display to lead the user through
test or function sequences.
Speed:
The average time per test is 3-4 seconds for tympanometry
and 10-12 seconds with reflexes.
LCD
display:
The LCD is at an appropriate angle for better viewing and
less glare. No struggling to view the display. A contrast
adjustment is available in the setup menu.
Audible
keypads:
The user has the choice of using volume levels or none when
the keypads are depressed. It provides the user with higher
comfort/confidence level.
Audiogram:
The MI26 records the audiogram using numeric results. This
is easier to read than a graphic display for most users. The
printout is also faster.
Clear
Probe Tip:
You can immediately see if there is debris, causing problems
without unscrewing the tip.
|
Frequently
Asked Questions
| Q: |
How
do you set the auto printer function? |
| A: |
Select the
method of printing ON prints every test, OFF prints only when
the Print key is pressed. LIM prints only when the test results
are out of the box.
|
| Q: |
How
do you turn off the reflex test? |
| A: |
NO REFLEX
means that the reflex test will not be performed. Pressing
the REFLEX key makes the selection.
|
| Q: |
How
do you change from ipsi to contra reflex testing or none at
all? |
| A: |
The REFLEX
button on the front panel control changes the reflex testing
mode from ISPI or Contra or no reflex.
|
| Q: |
How
do you do a daily calibration and what is unique about this
function? |
| A: |
At the start of
each day, select CALIBRATION to perform a brief calibration of the
probe. This function is unique because it allows the user to verify
volume measurement accuracy and the machine will make corrections
to bring the tolerance to within +/- .1ml.
|
| Q: |
Does
the audiometer function allow for a pulse tone? |
| A: |
Pulsed tone
ON is indicated with "on" displayed on both sides
of the stimulus box. When in pulse tone mode the STIMULUS
box will flash. In continuous mode the box will highlight
until the stimulus button is released.
|
| Q: |
How
do you change the normal tympanogram box? |
| A: |
Highlighting
TYMP and pressing the select item arrow key will enter the
TYMP setup screen. This is where you can decide whether or
not the limits box will be displayed. It's also where the
sweep speed, sweep direction and printing method are selected.
|
| Q: |
How
do you set the reflex levels? |
| A: |
Highlighting
REFLEX and pressing the Select Item arrow key will enter the
REFLEX setup screen. This is where you may select the number
of frequencies to test, the reflex dBhl starting level and
the pressure offset from peak compliance.
|
| Q: |
Can
you change the direction of the pressure? |
| A: |
You may
change the sweep direction to an either positive or negative
sweep under the tymp setup screen.
|
| Q: |
What
is in the "Miscellaneous Setup Screen?" |
| A: |
This
is where you may adjust the display contrast, enable/disable
the beep, and choose the screen language.
|
| Q: |
Can
the printout header be customized? |
| A: |
Under
the setup Menu Highlight PRINTOUT and press the select item
arrow. Two 20-character name/address lines can be entered
here. These will print out on top of the printout.
|
| Q: |
How
are the reflex levels shown on the display and printout? |
| A: |
The reflex
is shown in up to four tracings, with time on the horizontal
axis and a positive reflex or PASS (dotted line represents
.05ml) on the vertical axis.
|
| Q: |
How
do you clear the tests on the MI24/26? |
| A: |
Tests
will remain in memory until overwritten by another test. Pressing
and holding the L/R key for two seconds or by turning off
the instrument may erase tests. |
Technical
Specifications
| Tympanometry
Mode |
| Probe
Frequency: |
226Hz
+/- 2%, typical |
| Probe
Intensity: |
85
dB SPL into a 2cc cavity, AGC controlled |
| Pressure
Range: |
+200
to -400 daPa |
|
Volume Range: |
0.2ml
to 5.0 ml |
| Accuracy |
+-
10% or +- 10 daPa, whichever is greater |
| Rate
of Sweep: |
Variable
550 daPa/second max., 200 daPa second near peak |
| Test
Time: |
Less than 3 seconds typical |
| Compliance
Range: |
0-1.5ml or 0-3 ml (automatic selection) |
|
Reflex
Mode
|
|
IPSI Frequencies: |
500, 1000, 2000, 4000 Hz +/- 2% |
| IPSI
Intensities: |
70-105
dBhl (100dBhl is maximum when 4000 Hz is enabled. 105 dBhl
available only at 500, 1000 and 2000 Hz when 4000 Hz is disabled.)
On/Off ratio greater than 70dB, rise/fall time msec. Typical
500, 1000, 2000, 4000 Hz +/- 2%. |
| CONTRA
Frequencies: |
500,
1000, 2000, 4000 Hz +/- 2% |
| CONTRA
Intensities: |
70-110
dBhl (105dBhl is maximum when 4000Hz is enabled. 110dBhl available
only at 500, 1000, and 2000 Hz when 4000 Hz is disabled. |
|
Pressure:
|
Automatically
set to peak value on tympanometer
Contralateral reflex capabilities are an option.
|
| Display |
LCD
type graphically display shows graph of tympanogram, peak
pressure, canal volume, gradient, reflex, graph and conclusion |
| Printer |
| Print
Time: |
Approximately
27 seconds |
| Chart
Dimensions: |
2.5
inches wide by 6 inches long, thermal sensitive paper |
| Probe |
| Red
Light: |
Air
pressure leak |
|
Yellow
Light:
|
Occluded
probe tip
|
| Green
Light: |
Flashing:
ready to begin test
Steady: test in progress
|
| Dimension: |
15"W
x 4"H x13"D (38cm W x 10cm H x 33 cm D) |
| Weight: |
10lb/4.5
kg |
| Voltage: |
117/234
volts AC switchable |
|
Additional
Specifications for MI26
Pure Tone Screener:
Air conduction frequencies and HL ranges:
|
| Frequency |
Air
HL Range |
| 250Hz |
0-80
dBhl
|
| 500Hz |
0-90dBhl
|
| 1000Hz |
0-90dBhl |
|
2000Hz |
0-90dBhl |
| 3000Hz |
0-90dBhl
|
| 4000Hz |
0-90dBhl |
| 6000Hz |
0-90dBhl |
| 8000Hz |
0-90dBhl |
|
| Frequency
Accuracy: |
+/-
3% of indicated frequency |
| SPL
Calibration Accuracy: |
+/-
3 dB |
| Tone
Envelope: |
rise
time: 40 msec. typical
Fall time: 40 msec. typical
|
|
Calibrated
per ANSI S3.6 1996.
|
Articles / Manual
To read Steven D. Smith, Neuro-Audiologist's "Guide to Tympanometry
for Pediatricians" article click here.
Additional
Reading:
Hartford, Earl T. et al. Impedance Screening for Middle Ear Disease
for Children. New York: Grune & Strattin, 1978
Northern, Jerry L., ed Selected Readings in Impedance Audiometry.
Dobbs Ferry, New York: American Electromedics Corp. 1978.
Oeger, James, ed. Handbook of Clinical Impedance Audiometry. Dobbs
Ferry, New York: American Electromedics Corp. 1975.
Feldman, Alan S. and Wilbur, Laura Ann, eds. Acoustic Impedance
and Admittance- The Measurement of Middle Ear Function. Baltimore:Williams
and Wilkins, 1976
Popelka, Gerald R., ed. Hearing Assessment with the Acoustic Reflex.
New York:Grune and Stratton, 1981.
Cantekin, E., C. Bluestone, T. Fria, S. Stool, Q. Berry and D. Sabo,
1980. Identification of Otitis Media with Effusion in Children.
Ann. Otol. Rhinol. Laryngol. (suppl. 68)89, part 2 190-5.
Fiellau-Nikolajsen, Mogens. Tympanometry and Secretory Otitis Media.
Aahuus Stiftbogtrykkerie: Denmark, 1983.
Jack Katz, ed. Handbook of Clinical Audiology, Third Edition. Baltimore:
Williams and Wilkin, 1985.
To review the Maico Diagnostic web site click
here.
Sales
Brochure / Demo Disk
If you would like to receive a sales brochure please click
here.
Warranty
One year Limited Warranty: This warranty is extended to the original
purchaser of the instrument, by Maico, through the Distributor from
whom it was purchased. The warranty covers defects in material and
workmanship for a period of one year from the date of the delivery
of the instrument to the original purchaser. Accessories which are
purchased from Maico at the same time as the instruments are warranted
for one year from the date of purchase. For additional information
contact your Maico distributor.
Reimbursement
Reimbursement
for the use of the MI 24/26 for tympanometry is CPT code # 92567,
which pays an average of $20 per test. For acoustic reflex, CPT
#92568 usually pays $12. For Pure tone threshold the CPT code is
#92552, which is paid on average of $15. (Reimbursement differs
by state and insurance, the above are averages.)
Product
Ordering Information
| SH
Catalog # |
Product
Name |
| 51037 |
Tympanometer
/ Pure Tone Screener - MI 24 |
| 51038 |
Tympanometer
/ Pure Tone Screener - MI 26 with pure tone |
|
