MI 24 Operating Instructions Feb 2010

Operating Instructions MI 24

1 Introduction... 3 2 Description ... 4 2.1 Purpose ... 4 2.1.1 PC-Interface: ... 4 2.1.2 Environmental conditions for the MI 24 ... 4 2.2 Tympanometry ... 4 2.3 Acoustic Reflex ... 5 3 Getting started ... 7 3.1 Unpacking ... 7 3.2 Preparing the MI 24 for use ... 7 3.2.1 Connect probe and accessories ... 7 3.3 Connect Mains Cable and Accessories ... 8 3.4 Switch the instrument on... 8 3.5 Getting familiar with the MI 24... 9 3.6 The display of the MI 24 ... 10 3.7 Calibrate the probe... 12 3.6 Getting familiar with the probe... 13 3.7 Choose an appropriate ear tip ... 14 4 How to create a Tympanogram ... 16 4.1 The basics of the impedance measurement ... 16 4.2 Training of the test person ... 17 4.3 Preparing the measurement ... 18 4.4 Measuring the Tympanogram ... 18 4.5 How to evaluate the Tympanogram display ... 20 4.6 How to print out the test result... 21 4.7 How to delete the test results ... 22 5. How to measure the Stapedius reflex ... 23 5.1 The basics of the Stapedius reflex measurement ... 23 5.2 Training the test person ... 24 6.3 Preparing the ipsilateral measurement ... 24 5.4 Doing the ipsilateral measurement ... 26 5.5 Preparing the contralateral measurement ... 27 5.6 How to interpret the reflex display ... 27 5.7 How to print out the test result... 29

Operating Instructions MI 24 6 Interpreting Test Results ... 30 6.1 Understanding the printout ... 30 6.2 Interpreting the tympanometric test result ... 30 6.3 Abnormal Values ... 31 7 How to test children ... 33 8 Recommended literature ... 34 9 Individual Setup of the MI 24 ... 35 9.1 The setup menu... 35 9.2 The Tympanogram Setup Menu ... 36 9.3 The Setup menu for Reflex Test ... 38 9.4 The Common Setup Menu... 39 9.5 Insert your personal printout data ... 40 10 Care and maintenance of the instrument ... 41 10.1 Cleaning of Probe Tip ... 41 11 How to change the printer paper ... 44 12 Warranty, Maintenance and Service ... 45 13 Safety Regulations ... 46 13.1 Electrical Safety:... 46 13.2 Measuring security:... 46 13.3 Device control:... 46 13.4 Operation: ... 46 13.5 Patient Safety: ... 46 14 Checklist for subjective device control ... 48 15 Technical Data and Accessories ... 49

Operating Instructions MI 24

1 Introduction Thank you very much for purchasing a quality product from the MAICO family. This automatic Tympanometer MAICO MI 24 is manufactured to meet all quality and safety requirements, and has been certified with the CE symbol according to Medical Directive 93/42/EEC. Please note: This medical instrument should only be operated by skilled personnel. In designing the MAICO MI 24 we placed particular importance in making it a user-friendly device, meaning its operation is simple and easy to understand. And because all functions are software controlled, upgrading later to new, extended measurement functions will be simple and inexpensive. That means that you have invested in a device that will adjust to your future needs. This user manual should make it as easy as possible for you to become familiar with the functions of the MAICO MI 24. Please open out the flap of illustrations on the last page. The description of the position (e.g. Ç) of controls, displays and connections, found again in the text, will make it easier for you to learn how to operate the MAICO MI 24. If you have problems or have ideas for further improvements, please get in touch with us. Simply call. Your MAICO-team

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Operating Instructions MI 24

2 Description 2.1 Purpose The MI 24 is an automatic instrument designed for tympanometric screening and diagnostic applications. The instrument performs automatic impedance tests along with multi-frequency, multi-level reflex screening. The MI 24 allows diagnostic testing of reflex decay and the Eustachian Tube. Eustachian Tube function tests may be determined on patients with intact or perforated eardrums. Test results are displayed on the front panel LCD screen and may be printed. 2.1.1 PC-Interface: An USB-interface for data transfer to a connected computer is built in. The MAICO MI 24 is laid out according to the EN of 60 601-1 „medically electrical devices “. In order to ensure this also with attached computer, the computer must correspond to the EN 60 601-1. If not, please look to chapter 13.5 Patient safety. 2.1.2 Environmental conditions for the MI 24 The MI 24 should be operated in a quiet room. The test room must be at normal temperature, usually 15 C / 59 F to 35 C / 95 F, and the instrument should be switched on about 10 minutes before the first measurement to musculus guarantee precise measuring hearing stapedius nerve results. If the device has been middle cooled down (e.g. during ear transport), please wait until it has bones warmed up to room temperature. ear canal ear drum

2.2 Tympanometry

middle ear

Tympanometry is the objective measurement of middle ear mobility (compliance) and pressure within the middle ear system. During the test, a low-pitched GEBAmi24e_10a.docx

cochle

eustachian tube

Figure 1 the middle ear

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Operating Instructions MI 24 probe tone (226 Hz) is presented to the ear canal by means of the handheld probe. This tone is used to measure the change in compliance in the middle ear system while the air pressure is varied automatically from a positive value (+200 daPa) to a negative value (-400 daPa max.). Maximum compliance of the middle ear system occurs when the pressure in the middle ear cavity is equal to the pressure in the external auditory canal. This is the highest peak of the curve as it is recorded on the chart. The position of the peak on the horizontal axis and on the vertical axis of the chart will provide diagnostic information regarding the function of the middle ear system. Examples of normal and abnormal tympanograms can be found in a later section of this manual. Gradient calculations are reported as the Tympanogram width at half of peak compliance expressed in daPa. A ”limits” box is available on both the display and printout to aid in diagnosis. Compliance is measured with respect to an equivalent volume of air, with the scientific quantity milliliter (ml). Air is measured in deca-Pascals (daPa). NOTE: 1.02 mmH2O = 1.0 daPa.

2.3 Acoustic Reflex An acoustic reflex, or contraction of the stapedial muscle, occurs under normal conditions when a sufficiently intense sound is presented to the auditory pathway. This contraction of the muscle causes a stiffening of the ossicular chain which changes the compliance of the middle ear system. As in Tympanometry, a probe tone is used to measure this change in compliance. When the stimulus presentation and measurement are made in the same ear by means of the probe, this acoustical reflex is referred to as an ipsilateral acoustic reflex. When the stimulus presentation and measurement are made in opposite ears, the reflex is referred to as a contra lateral acoustic reflex. For best results, this reflex measurement is automatically conducted at the air pressure value where the compliance peak occurred during the tympanometric test. Stimulus tones of varying intensities at 500, 1000, GEBAmi24e_10a.docx

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Operating Instructions MI 24 2000 or 4000 Hz are presented as short bursts. If a change in compliance greater than 0.05 ml is detected, a reflex is considered present. Because this is an extremely small compliance change, any movement of the probe during the test may produce an artifact (false response). The level at which a reflex occurs is recorded as a number, as PASS/FAIL and in graph form. If the tympanometric results display any abnormal findings, the results of the acoustic reflex testing may be inconclusive and should be interpreted with care. If a ”flat” tympanogram is observed, showing a non-mobile middle ear system, the MI 24 will not perform an acoustic reflex test. Theoretically, a compliance peak is necessary to observe a reflex at peak pressure.

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Operating Instructions MI 24

3 Getting started Your MI 24 was carefully inspected and packed for shipping. However, it is good practice to thoroughly inspect the outside of the shipping container for signs of damage. If any damage is noted, please notify the carrier immediately.

3.1 Unpacking Save all the original packing material and the shipping container so the instrument can be properly packaged if it needs to be returned for service or calibration. Please check that all accessories listed below are received in good condition. If any accessories are missing or damaged, immediately notify your MAICO Special Instrument Distributor. Accessories 1 Hand-held probe 24-count eartips kit: (4) yellow, 7 mm (4) green, 9 mm (4) white, 11 mm (4) yellow, 13 mm (4) green, 15 mm (4) blue, 18 mm Thermal printer paper (1 roll) Calibration test cavity Main cable

Part No. 802 172 705 069 705 056 705 057 705 058 705 059 705 060 705 061 705 078 896 075

3.2 Preparing the MI 24 for use 3.2.1 Connect probe and accessories Connect the probe cable to socket ­ on the rear of the instrument. Insert the plug into the socket and protect the connection by fastening the two screws of the connector.

Figure 2 The probe of the MI 24 GEBAmi24e_10a.docx

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¬¯­ ® « Figure 3 Connectors at the rear of the MI 24

Insert the pressure tube into the socket ¬♦and press it until it has a safe fit on the socket. Put the enclosed mains cable into the power connection socket « and its mains plug into a power socket. The instrument is now operational. «♣= mains connection socket ¬♦= probe tube connection ­ = probe connection socket ® = USB PC-interface ¯ = contra receiver socket

3.3 Connect Mains Cable and Accessories Put the enclosed mains cable into the power connection socket « and its mains plug into a power socket. The instrument is now operational. Your MI 24 is equipped with a contra receiver. Plug the cable in the contra receiver socket ¯.

3.4 Switch the instrument on Switch the mains switch Ð on. The LCD display Ç shows for a moment the instrument type and the software version. Then the basic measuring figure appears. The MI 24 should be switched on about 10 minutes before the first measurement to guarantee precise measuring results. If the device has been cooled down (e.g. during transport), please wait until it has warmed up to room temperature.

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Operating Instructions MI 24 3.5 Getting familiar with the MI 24

MENU MENU

14

PRINT PRINT

LL // R R

REFLEX REFLEX

1

2

3

ENTER ENTER

8 9 10 11 12 13 Figure 4 the controls of the MI 24

à = Print key Å = Reflex measurement off/ipsi/contra ipsi+contra/Setting of high probe tone Ë = Left (cursor control) Í = Right (cursor control) Ï = Enter

Ä = Right/left ear key Ê = Menu key Ì = Down (cursor control) Î = Up (cursor control) Ð = Power switch

The use of the extended functions is described in chapter 9 “Individual Setup of the MI 24".

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Operating Instructions MI 24

3.6 The display of the MI 24 The test result is shown during the measurement on the LCD display. The measurements are saved automatically and can be printed out in a fast and quiet way with the integrated printer. In figure 5 the initial empty Impedance Right Ipsi measurement screen is shown. The Status ml 3 READY measurement screen shows actual Ear Volume settings, test results and the 2 graphical display of the Compliance 1 tympanogram and reflexes. Pressure The top line shows from left to the 0 Gradient -600 -300 300 daPa right the type of test (in example figure 5 Impedance), the selected 1 2 3 4 test ear left or right and the 80 80 80 80 500 Hz I 1000 Hz I 2000 Hz I 4000 Hz I selected reflex test “ipsi”, “contra” AUTO dB or “Tympanogram” if no reflex test Figure 5 the measurement screen of the MI 24 is selected. At the left centre the graph of the tympanogram is shown. At the right five boxes show the status and test values. The upper box shows the actual status of the instrument: READY means that the instrument is ready for testing IN EAR shows that the probe is inserted in the ear TESTING means that the test is in progress BLOCKED means that probe is blocked in the ear LEAKING indicates that the air seal of the ear tip in the ear is not proper When the test is finished, the boxes below show the volume of the ear canal, the compliance, the pressure at maximum compliance and the gradient of the tympanogram. The four boxes below the tympanogram, marked 1 to 4, show the graphical reflex curves after the test. Below each box the test level and the test frequency are shown. After the frequency an “I” shows the ipsilateral testing is selected.

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Operating Instructions MI 24 At the bottom line in figure 5 the word “AUTO” and  dB Scale is shown. It means that the reflex test level increases automatically until a reflex was found or the maximum level is reached. With the cursor up button Î or down button Ì➉ the test level can be changed to a fixed level. The dB values below the boxes change accordingly. It is possible to have fixed levels from 70 dB to 100 dB and AUTO. The figures below each box mean: test level (80 dB in example figure 5), test frequency (500 Hz, ..), ipsilateral testing (I).

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3.7 Calibrate the probe With the calibration test cavity you can adjust your impedance with measuring instrument. Do the same when you change the probe (from screening probe to diagnostic probe and vice versa). The calibration is very easy and takes only 20 seconds. Main Menu Press the menu key Ê and the main menu (figure 6) appears on the LCD display Ç. Select the menu option Calibration with the Down button Ì. Press Enter Ï and follow the instructions on the LCD display Ç, as shown in Figure 7.

Tympanometrie : Caibration: Setup :

↑ ↓ Change item ENTER Select item

Put the probe tip È without ear tip into the hole of the test cavity labeled 0.5 ml and wait. When the text on the display Figure 6 Ç changes to the request for the 2 ml Display MI 24 Main Menu calibration put the probe tip È in the 2 ml cavity and proceed as described above. After the successful calibration of the 5 ml volume the MI 24 switches automatically to the tympanometry mode. The basic menu for the impedance measurement appears again and you are ready for measurements. If the error information Cavity calibration out of range appears during the calibration please control if the opening of the probe tip È is clean and try to recalibrate the probe. For more information about cleaning the probe also read Chapter: Cleaning the probe. If the error information appears again, the probe or the instrument is probably defect. Inform your service to get immediate help.

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Calibration Place the porbe in the .5 ml cavity

Figure 7 Display MI 24 Calibration

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Operating Instructions MI 24

3.6 Getting familiar with the probe The probe of the MI 24 is shown in figure 8. The probe head is X E R E ES adjustable in three steps (0°, 60° und 80°). It is adjusted by releasing the fixation screw (Figure 9 ¾) at the bottom of the probe a few turns, using a EP M E O E N E Q E coin or a screw driver. Adjust the Figure 8 MI 24 probe with additional screening probe head º by pulling it into probe tip  the required position until it rests. To do this hold the probe handle ¸ with the other hand. After it is set to the required position fasten the fixation screw ¾ again. ¾ Notice! To avoid damages on the sensitive measuring equipment, only bent the probe toward fixation screw! Figure 9

Transforming the Probe from Handheld to Clinical and Reverse: To exchange the probe insert press the release button ¹ of the probe with a tool or a pen. Remove the screening probe insert. Insert the diagnostic probe insert ¿ into the probe head º. Please recognize the right position of the connector of the diagnostic probe insert ¿. Press the diagnostic probe insert ¿ into the probe head º until it fastens. Note! The squared hole in the probe connection should face in the same direction as the push-button. Control lights and Display The probe button · can be used to select the required test ear. The colour of the control light ¹ changes accordingly to red (right ear) or blue (left ear). If selected in the setup menu pressing the probe button · during GEBAmi24e_10a.docx

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Operating Instructions MI 24 operation pauses also the test. The colour of the control light ¹ of the probe indicates in standby the selected ear and in operation the fitting of the probe in the auditory canal: A red control light ¹ indicates that the right ear is selected. The system is ready for measurements. As soon as you have put the probe into the auditory canal the control light ¹ lights green. Now the test runs off. Do not change the position of the probe any more until the green control light ¹ is going out indicating the end of the measurement. A blue control light ¹ indicates that the left ear is selected. The system is ready for measurements. As soon as you have put the probe into the auditory canal the control light ¹ lights green. Now the test runs off. Do not change the position of the probe any more until the green control light ¹ is going out indicating the end of the measurement. A yellow control light ¹ indicates an error. The kind of the error is indicated on the LCD-display Ç under status: LEAKING: The ear tip does not make the auditory canal airtight. Change the position of the probe until the control light ¹ lights green. If you are not successful use a bigger ear tip. BLOCKED: Indicates the seal of the probe opening. Change the position of the probe which points maybe at the side of the auditory canal until the control light ¹ lights green. If you are not successful please check if the probe is blocked with ear wax. The complete probe insert can be changed by pressing the release button » and removing the probe insert. If the probe tip ½ is clogged you can remove it by opening the fixation ring ¼. After cleaning of the probe tip ½ or selection of a new one, the tip must be fixed again by fastening the fixation ring ¼.

3.7 Choose an appropriate ear tip Choose an ear tip of the appropriate size from the ear tip set. Put the ear tip tightly on the probe tip. The probe tip should close up with the end of the ear tip. It should not disappear with more than about 1 mm in the ear tip or just out of the ear tip. GEBAmi24e_10a.docx

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Operating Instructions MI 24 By choosing an appropriate ear tip and placing it correctly on the probe you create the basic conditions for measurements without problems and mistakes. Now all preparations are concluded and you can start the impedance and reflex measurement. Please read the following chapters.

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Operating Instructions MI 24

4 How to create a Tympanogram In the following paragraph we will deal shortly with the principle and the background of the impedance measurement to create a better understanding. If you want to begin the measurements immediately just skip this paragraph and continue reading with 4.3 Preparing the measurements.

4.1 The basics of the impedance measurement The impedance measurement musculus serves the diagnosis of the stapedius hearing nerve condition of the middle ear and middle can therefore not be compared ear bones directly with other audiometrical tests such as sound or speech ear canal audiometry which serve the cochlea ear drum measurement of the hearing. middle ear Furthermore the impedance measurement is an objective eustachian tube measuring method which does not depend on the cooperation of the test person and can Figure 10 The middle ear therefore not be falsified by him. The two most important impedance measuring methods possible with your MI 24 are Tympanometry and the measurement of the Stapedius reflex which is treated in chapter 5. “How to measure the stapedius reflex”. The impedance measurement examines the acoustic resistance of the middle ear. If the eardrum is hit by a sound a part is absorbed and sent via the middle ear to the inner ear while the other part is reflected. The stiffer the eardrum is the more sound is reflected and the less sound reaches the inner ear. In the probe of the impedance measuring instrument a small loudspeaker is installed which emits a sound of low frequency via a GEBAmi24e_10a.docx

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Figure 11 – Principle of impedance measurement

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Operating Instructions MI 24 tube A (see Figure 11) into the auditory canal before the eardrum. Another tube B is connected with the microphone in the probe which receives the sound. Both tubes are lead together with tube C nearly to the eardrum and are made airtight against the outside pressure by the ear tip. A manometer and a pump which can produce both over- and under-pressure are connected with tube C. The less sound is reflected by the eardrum to the microphone the more stiff the eardrum is and with it the middle ear - the eardrum transmits the biggest part of the sound via the middle ear to the inner ear. The highest compliance is normally reached with an air pressure corresponding to the outside pressure. When performing Tympanometry during a measurement a continuous change of overand under-pressure is performed by the pump of the instrument in the outer auditory canal before the eardrum which is sealed by the ear tip in addition to the measurement with normal pressure. The compliance is measured simultaneously and shown in a diagram, the Tympanogram, Figure 12 – Tympnaogram (normal curve which illustrates the compliance in ml over area is hatched) the pressure in daPa. In figure 12 the area for normal Tympanogram curves is hatched. Here you can see that the highest compliance is reached with normal pressure. When you create over- or under-pressure the eardrum stiffens the compliance decreases. So you can draw conclusions on the condition of the middle ear from the form and the values of the Tympanogram.

4.2 Training of the test person Explain to the test person that the measurement is painless, that nothing gets into the auditory canal and that he does not have to answer when he hears the faint and deep test sound and the pressure in the auditory canal changes. In no case the test person should swallow, chew or move his head during the measurement. Figure 13

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Operating Instructions MI 24

4.3 Preparing the measurement Before you start a new Impedance Right Tympanogram measurement, delete former test results (see Status ml also chapter 4.7.) The 3 READY LCD display shows the Ear Volume 2 empty measurement Compliance screen for the right ear 1 and the control light Pressure of the probe lights red. 0 If you want to measure Gradient -600 -300 300 daPa the left ear change the side by pressing the L/R-key or the probe Figure 14 - Measurement screen (only Tympanogram) button. Then the selected test ear shown in the middle of the top of the LCD display will change from Right to Left and the control light of the probe lights blue. Switch off the reflex measurement by pressing the REFLEX-key. The word Tympanometry must appear at the right top of the display. Control if the auditory canal is free. Choose the right ear tip according to the size of the auditory canal and put it firmly onto the probe tip.

4.4 Measuring the Tympanogram Take hold of the top of the outer ear and pull it back. Insert the probe with the ear tip into the auditory canal until the control light ¹ of the probe is green. In order to start the test press the Enter button Ï and the control light in the probe is lighting permanently green. The status in the display changes to “Testing”. Do not move the probe until the green light goes out; the patient may not swallow or speak during the measurement. During the test you can watch on the LCD display how at first the Tympanogram is written on the left side and then how the values are put down on the right side. After about 4-5 seconds the test is completed, the green light turns off. Now you can remove the probe from the ear. If an error occurs during the measurement the test is stopped. If leakage occurs, the control light ¹ of the probe lights yellow and the display Ç under status “LEAKING" is reported. If the probe is blocked, the control light ¹ of the probe lights yellow and at the display Ç shows under status “BLOCKED". Please proceed as described in chapter 3.6 “Getting familiar GEBAmi24e_10a.docx

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Operating Instructions MI 24 with the probe”. If you want to measure the other ear, too, change the side by pressing the L/R-key Ä or the probe button · and repeat the measuring procedure described above with the other ear.

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