Operating Instructions MI 24
Contents
1. Operating Instructions MI 24 MAICO 6 Interpreting Test Results nsnnnnnnnnanae cusid nied dspainsamsganinenscasuuarcaitaes 30 6 1 Understanding the printout 2s ct cssccecterssestuaesievdedosaatelensieeceegsanedees 30 6 2 Interpreting the tympanometric test result eee 30 6 3 Abnormal Values os veces ves ceria natin nrdionnedaenouduaueme ious nw baadaneneedenseawecd 31 7 How to test children gaciessswerteeneatanaasiuttedemnadananad tai tevan taniensmuscutennatialenaa seeds 33 8 Recommended literature ccc ccecccccccccccceeseseeseeeeeeeeeeeeeeeseeseseneseseeeees 35 9 Individual Setup of the M24 cccccsecscccncescobsnocceccQodeessbaneensasBondeubeboocncsdude 36 9 1 The setup TCIM tcatoccersasanascacainntenhastseasicheeniaintsaintasvodsausneisidtinvietess 36 9 2 The Tympanogram Setup Men cence scinctsrrrccsases adanserindyeawescuessiniers 37 9 3 The Setup menu for Reflex Test ooeeeeeseeeeeeeeeeesesrererererererereree 39 9 4 The Common Setup MCG vcs ccctscicnnesncseceetntonpedantmancdaneaananeceaencendiay 40 9 5 Insert your personal printout data cc ccceeccccceeeeeeeeeeseaeeeee ees 41 10 Care and maintenance of the instrument ccccceeececeeeeeeeeeeesteeees 42 10 1 Cleaning of Probe Tip ari ciceeesse ssc ace scandent sot deuuts coteucsen nade sencductads dees 42 A AISI WAP SO Mai 2 2 esses aie eres cee EE Oo oars sees 45 12 How to change the printer Paper cccccecececcccceceeeeesesssseseneeeeeee2. 14 2 Measuring security To guarantee that the tympanometer works 14 3 Device control 14 4 Operation 14 5 Patient Safety GEBAmi24e_11a docx properly the instrument has to be checked and calibrated at least once a year The service and calibration must be performed by an authorized service centre In accordance with the regulations of the EU medical directive we will drop our liability if these checks are not done The use of non calibrated tympanometers is not allowed The user of the instrument should perform a subjective instrument check once a week This check can be done following the list for Subjective instrument check see next page For your own security you should copy the enclosed list fill it in once a week and store it in your files Only skilled personnel Audiologists ENT professionals or other with equivalent knowledge should operate the instrument Warning Do not take a test while charging the device via USB cable External equipment intended for connection to signal input signal output or other connector shall comply with relevant IEC 48 850 234 9 07 11 5 MAICO GEBAmi24e_11a docx Operating Instructions MI 24 Standard e g IEC 60950 for IT equipment and the IEC 60601 series for medical electrical equipment In addition all such combinations systems shall comply with the standard 60601 1 1 Safety requirements for medical electrical systems Equipment not c
3. ready for measurement at the right top of the display The sound stimuli for the reflex measurement are reproduced by the receiver integrated in the probe Set the desired volume level with the Down key respectively the Up key n the LCD display below the reflex boxes at the bottom the selected level in dB in example figure 20 80 dB appears The I indicates that an ipsilateral test is selected You can choose between the fixed levels 70 75 80 85 90 95 and 100 dBHL and AUTO with a starting level of 70 or 80 dBHL If you choose AUTO the MI 24 starts with the lowest level 70 dBHL or 80 dBHL and increases the level automatically until a reflex is registered or the maximum value is reached You can choose your individual starting GEBAmi24e_11a docx 24 850 234 9 07 11 N Operating Instructions MI 24 MAICO level and maximum level see 8 3 Reflex pre settings If you have chosen a fixed level the instrument measures only with this level 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 GEBAmi24e_11a docx 25 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 5 4 Doing the ipsilateral measurement Carry out the measurement as described in chapter 4 4 Impedance Right Ipsi Recording the Stapedius reflex is measured Ear Volume B E O a oem Tympanogram D
4. MAICO Diagnostic GmbH MAICO Operating Instructions MI 24 MAICO Diagnostic GmbH Salzufer 13 14 D 10587 BERLIN Tel 49 30 70714650 Fax 49 30 70714699 5 Operating Instructions MI 24 MAICO WIATOdUCON eei a aia a a a a E nen te eee 3 2 Descrip UON e eee nen Ree E E ae eee 4 Boll PUDO O a E E E E 4 2 1 TPE ternacE eee e e E E EEE 4 2 1 2 Environmental conditions for the MI 24 4 2 2 TyYMpanometry eee eee ee omen eae eee ee eee rrtt EEEE eSEE were ae ream erret 4 2 3 Acoustic CT ercecett crs se eles dee sete panacea ede ea ate acne iniiai 5 3 Getting started ernsten rE AE e EEEE EER E ERa 7 SeU PACKIN G iaese ts ccerceiaives acseeareessoneeee nee sete eee sce s ad 7 3 2 Preparing the MI 24 for USE tance ccsec cc cniesacaadatednteuct ceensadeehecaoaerdasnceeds 7 3 2 1 Connect probe and accessories 00 0 cece cece eeeeeeeeeceeeeeeeeeeseeeaaen ones 7 3 3 Connect Mains Cable and Accessories ssssessssesseseseseseserrrrrreee 8 3 4 Switch the instrument OD seceiiaiencsvmraanacacunisdied ehicecieneti kates anceaescbdin sh 8 3 5 Getting familiar with the MI 24 00 ceceeceeeeeeeeeeeeeeesetttsaeaes 9 3 6 The display of the MI 24 cc ctinsracesingesendndeteanteeaeshinletseendvesgasaadoaiterticescs 10 3 7 Calibrate the probe esssssnnininninnsusssssnrrririrrrrrerrrrrrrrirrrrerernrrrren 12 3 8 Getting familiar with the probe ccc ceceeceeeeeeeeeeeeeeeentstseaees 13 3 9 Choose an appropriate ear WD ictrci
5. N Operating Instructions MI 24 MAICO 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 GEBAmi24e_11a docx 6 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 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 Part No 1 Hand held probe 802 172 24 count eartips kit 705 069 4 yellow 7 mm 705 056
6. Probe tip and ear tip clean Are all controls easy to use Are the test signals clear and non distorted If significant differences or damages are found please inform the service Tested by Date GEBAmi24e_11a docx 50 850 234 9 07 11 5 MAICO Operating Instructions MI 24 16 Technical Data and Accessories The Impedance meter MI 24 is an active diagnostic medical product according to the class Ila of the EU medical 0123 directive 93 42 EEC Impedance measurement Type Tympanometer Test frequency Test level Pressure range Volume range Accuracy Compliance range Reflex measurement Test frequencies Test method Intensities ipsi Intensities contra Attack release time Pressure at test General Memory Probe LCD display Printer Printing time Reflex Power supply GEBAmi24e_11a docx Class 2 acc to IEC 645 5 EN 60645 5 226 Hz 1 85 dBspL in 2 cm3 200 to 400 daPa 0 1 to 6 0 ml 5 or 10 daPa 0 1 to 6 0 ml 500 Hz 1 kHz 2 kHz 4 kHz 2 ipsi lateral contra lateral 70 dBu 100 dBy 70 dBy 105 dBy with button contra phone for 4 kHz 100 dBu 70 dBy 110 dBy with TDH 39 contra phone typical 10 ms Pressure max compliance Storage of test results for both ears probe with diagnostic insert Graphical display of the Tympanograms and reflex curves numeric display of max compliance pressure at max compliance canal volum
7. The PE T Status LCD display Ghows the eae Peale empty measurement pS a screen for the right ear ge fee Se and the control light Q 1 ff aay of the probe lights red E i Pressure a aio 600 300 300 daPa ee side by pressing the L R key br the probe button Then the Figure 14 Measurement screen only Tympanogram selected test ear shown in the middle of the top of the LCD display Gwill 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 of the probe is green In order to start the test press the Enter button 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
8. 35 Figure 36 The cleaning tool Consisting of 3 parts cleaning hooks wire with brush and hand grip Figure 37 With the hook of the cleaning tool you can remove cerumen from the ear tips GEBAmi24e_11a docx 44 850 234 9 07 11 N Operating Instructions MI 24 MAICO 11 Disinfection It is recommended that parts which are in direct contact with the patient are subjected to standard disinfecting procedure between patients This includes physically cleaning and use of a recognized disinfectant Individual manufacturer s instruction should be followed for use of this disinfecting agent to provide an appropriated level of cleanliness To avoid person to person cross contamination of communicable diseases eartips should only be used one time GEBAmi24e_11a docx 45 850 234 9 07 11 M MAICO Operating Instructions MI 24 12 How to change the printer paper Open the printer at the right side of the housing by pulling up the printer cover king its finger mould in front Remove the printer cover Remove the empty paper roll Place the new paper roll in the paper compartment in such a way that the paper ascends from the lower part of the paper roll Pull the blue lever which is located on the right front of the printer into its forward position The paper must roll from the bottom because it is coated on one side only If it is inserted wrongly no printout is visible Gently inse
9. 4 green 9 mm 705 057 4 white 11 mm 705 058 4 yellow 13 mm 705 059 4 green 15 mm 705 060 4 blue 18 mm 705 061 Thermal printer paper 1 roll 705 078 Calibration test cavity 896 075 b Main cable 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 I connector J Figure 2 The probe of the MI 24 GEBAmi24e_11a docx 7 850 234 9 07 11 Operating Instructions MI 24 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 on The LCD display shows for a moment the instrument type and the software version Then the basic measuring figure appears The MI 2
10. 6 6 in only 12 seconds While the printer is working no key action is possible and the probe is inactive In addition to the printing text treated in chapter 4 6 the result of the reflex test is printed out The level value dB at which a reflex had been measured appears below the graph If no reflex had been registered FAIL is printed on the top of the graph behind the test frequency The printout supports you to evaluate the test results correctly The graphs of tympanogram and reflex are useful for interpretation The tympanogram displays the middle ear mobility The horizontal axis shows the pressure the vertical axis the compliance The reflex is displayed in four MAICO MI 24 Id No Name Remarks Tympanogram Ditari 600 300 300 daPa Ear Volume 0 94 ml Compliance 0 81 ml Pressure 37 daPa Gradient 32 daPa Right Reflex ml Ipsi 500Hz PASS 0 154 gt 100 dBHL ml Ipsi 1000Hz PASS 100 dBHL mi Ipsi 2000Hz PASS 100 mi Ipsi 4000Hz PASS 15 s 95 dBHL Date IEXAMING NS ssc NA E eee Figure 24 Printout of a Tympanogram with ipsilateral reflextests charts Here the x axis stands for time the y axis shows the changes of compliance GEBAmi24e_11a docx 29 850 234 9 07 11 M MAICO Operating Instructions MI 24 6 Interpreting Test Results MAICO MI 24 6 1 Understanding the printout a Date Name Examiner T
11. ences scaseccinrenncncadensidcdeoesinnncdsgutonee 14 4 How to create a TympanograM wevecesecatter esses casantceiaiiecanadetineinmiad mages 16 4 1 The basics of the impedance measurement uininiiiiiriiirin 16 4 2 Training of the test person s ccc saictacesasnaeeciadadecdssvexiivtexveeosaaverngelcaes 17 4 3 Preparing the M aSUrEMENt cccccccccecececceceeeeeeeeeeeeeeeeeeeeeeeeeeess 18 4 4 Measuring the Tympanogram cccccccceceeeceececeeeeeeeeeeeeeeeeeeeeeeess 18 4 5 How to evaluate the Tympanogram display ccccccceeceseeeeeees 20 4 6 How to print out the test PESUM ss necesdenedinnsavtaessiveetedinadaaardsnebionnted 21 4 7 How to delete the test results ccccccccccceceecceceeeeeeeeeeeeeeeeeeeeeeeeess 22 5 How to measure the Stapedius reflex n ninnnininirirrrrririrrrrrrrrrrrn 23 5 1 The basics of the Stapedius reflex measurement eee 23 5 2 Training the test person wares ses tnatencsieneeted hates cose cect yiatiencelsneused eaten 24 5 3 Preparing the ipsilateral MEASUrEMENT eee cece eeeeeeeeeeeeeaes 24 5 4 Doing the ipsilateral measurement cee eeeeeeeeeteeeeeeeeetteeteteeeetees 26 5 5 Preparing the contralateral measurement cceeeeeeeeeeeeeeeeteeeeees 27 5 6 How to interpret the reflex display ccccccceeeeeeeeeeeeeeeteeeeeeeeees 27 5 7 How to print out the test FASUM c2cccccsccccssasseacseenstarncndnasadeswadeanancdeead 29 M
12. invers displayed item with the cursor keys LEFT respectively RIGHT The following settings are possible Pump speed With this option you can set the measurement speed With Automatic the pump speed adjusts automatically to the test conditions It is possible to Tympanogram Setup Menu Display limits ON Press Limit hi 150 daPa Press Limit Lo 400 daPa Comp Limit hi 1 5 ml Comp Limitlo 0 1 daPa Seal sensitivity Medium Change item ENTER choose item MENU Escape Figure 28 Tympnanogram Setup Menu choose also Minimum Medium or Maximum Of course a lower pump speed creates a higher precision of the measurement but needs more test time Display limits With ON you switch on the field for normal curves surrounded by a broken line in the Tympanogram With OFF you switch it off Press Limit hi With this option you can set the right limit of the box for normal Tympanograms to a value between 0 daPa and 200 daPa in steps of 25 daPa Press Limit lo With this option you can set the left limit of the box for normal Tympanograms to a value between 400 daPa and 25 daPa in steps of 25 daPa Comp limit hi With this option you can set the upper limit of the box for normal Tympanograms to a value betweenO 1 ml and 3 ml in steps of 0 1 ml GEBAmi24e_11a docx 37 850 234 9 07 11 M MAICO Operating Instructions MI 24 Comp limit lo With this option
13. on Remote Switch L R With the setting Tymp ony Smcommman Son tympanometry is tested after power up Print after Test OFF With Tymp and Reflex tympanometry Language English and reflex is tested after power up epay anaa T Change item USB ENTER choose item MENU Escape This is only the reference to the USB interface Figure 30 MI 24 common Setup Menu Remote Switch With this option you can change the function of the probe button You can choose between L R where the test ear can be selected with the probe button Pause where the test can be paused and restarted with the probe button vO L R or Pause where the test ear can be selected and the test can be paused and restarted with the probe button GEBAmi24e_11a docx 40 850 234 9 07 11 M MAICO Operating Instructions MI 24 Subject Data Printout With this option you can switch ON and OFF the printout of the headline which allows you to enter the data of the patient Clinic Data Printout If you entered your clinic data the printout of the entered data can be switched ON and OFF with this option Print after test With this option you enable an automatic printout after you finished a test by setting it ON With the setting OFF the printout will be only done after you press the PRINT button Language You can choose one of the languages German Deutsch French Francais English and Spanish Espanol for the
14. 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 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 GEBAmi24e_11a docx 3 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 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 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 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 The MAICO MI 24 is laid out according to the EN of 60 601 1 2 1 2 Environmental conditions for the MI 24 The MI 24 should be operated in a quiet room The test room must be a
15. the top of the LCD display he word Right or Left indicates the ear chosen at the moment Tympanogram at the right top indicates that the reflex measurement has been switched off In the boxes at the right the determined measurements are displayed Ear Volume indicates the volume of the section of the auditory canal between the ear tip and the eardrum in ml in the example 0 94 ml Compliance indicates the maximum value of the compliance from the Tympanogram in ml in the example 0 81 ml Pressure indicates the pressure with the highest measured Compliance in the example 37 daPa Gradient calculations are reported as the Tympanogram width at half of peak compliance expressed in daPa in the example 32 daPa GEBAmi24e_11a docx 20 850 234 9 07 11 5 MAICO Operating Instructions MI 24 4 6 How to print out the test result After the end of a test you can print out the results for your records by pressing the PRINT button The quiet thermal printer prints out the example Id No ee Date ee r i Name used in the previous paragraph 4 5 Eraminer While the printer is working no Tympanogram MAICO MI 24 key action is possible and the probe is inactive Figure 16 shows 3m the printout Id No Here you can put down the patients social Id number 1 Date Here the actual test date can be stated Name Here you can put down the patients name is eimi Examiner State here the Salen anders refer
16. tips yellow 12 5 mm Part No 70 50 59 set of 10 Ear tips green 15 mm Part No 70 50 60 set of 10 Ear tips blue 18 mm Part No 70 50 61 _ _ a M M GEBAmi24e_11a docx 53 850 234 9 07 11 5 Operating Instructions MI 24 MAICO Specifications are subject to change MAICO Diagnostic GmbH NA Salzufer 13 14 D 10587 Berlin Telephone 49 30 70 71 46 50 Telefax 49 30 70 71 46 99 MAICO internet www maico biz e mail export maico biz GEBAmi24e_11a docx 54 850 234 9 07 11
17. you can set the lower limit of the box for normal Tympanograms to a value between 0 1 ml and 1ml in steps of 0 1 ml Seal sensitivity Minimum This gives reproducible results Requires quiet probe handling Medium Quicker seal detection and less sensitive than the above selection Maximum Quick seal detection AGC on the probe tone is disabled To leave the Tympanometry Setup Menu press the MENU button GEBAmi24e_11a docx 38 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 9 3 The Setup menu for Reflex Test Select the menu option Reflex Test Setup Menu from the main setup menu as described before for the Tympanometry setup menu and the reflex setup menu will appear on the LCD display The reflex setup menu offers the following options Reflex Test Setup Menu Auto start dB Auto start dB 80 With this option you can choose the Auto maximum dB 105 acoustic pressure level the MI 24 starts the Reflex Sensitivity Sensitive reflex level measurement with if the vrint graphic a ips 500 Hz ON automatic identification of the reflex J000 H2 ON threshold is switched on You can choose 2000 Hz ON the acoustic pressure levels from 70 dBHL 4000 Hz on till 100 dBHL in steps of 5 dB Change item ENTER choose item MENU Escape Auto maximum dB With this option you can choose the Figure 29 maximal acoustic pressure level the MI 24 MI 24 Reflex setup Menu uses if the autom
18. 4 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 GEBAmi24e_11a docx 8 850 234 9 07 11 Operating Instructions MI 24 3 5 Getting familiar with the MI 24 Figure 4 the controls of the MI 24 Print key Right left ear key Reflex measurement off ipsi contra Menu key ipsi contra Setting of high probe tone Down cursor control Left cursor control Up cursor control Right cursor control Power switch Enter The use of the extended functions is described in chapter 9 Individual Setup of the MI 24 GEBAmi24e_11a docx 9 850 234 9 07 11 5 MAICO 3 6 The display of the MI 24 Operating Instructions 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 measurement screen is shown The measurement screen shows actual settings test results and the graphical display of the tympanogram and reflexes The top line shows from left to the right the type of test in example figure 5 Impedance the selected test ear left or right and the selected reflex test ipsi contra or Tympanogram if no reflex test is selecte
19. The practice of the impedance measurement is difficult especially with small children You could have problems with the child being restless or afraid of the examination or reacting sensitively to the change of pressure and the loud test sound but also with different conditions of the eardrum and the middle ear which do not appear in ears of adults During the measurement the minimum compliance must come to 0 08 ml if it is less a straight line runs over the zero line It is difficult to reach a probe seal with restless children If the child yawns or cries it is impossible for the instrument to create a stable pressure in the outer auditory canal In addition speaking causes stapedius muscle reflexes which lead to a permanent change of the compliance of the eardrum So the child should be made familiar with the surroundings and the ear being touched by the probe in order to carry out a successful impedance measurement This could be done by getting in touch with the child and by touching the ear in a playing way with the probe If you can touch the ear without problems the child will normally accept the probe being inserted If the child has accepted the surroundings and the touch of the ear it is important to distract the child s mind from the measurement Here you can succeed in diverting the child by many different methods Your phantasy is nearly unlimited you just have to avoid loud sound In case you measure very small children and hav
20. ance by illuminating the red light or a flat tympanogram will be recorded since no movement will occur with a change in air pressure Without a peak compliance of at least 0 1 ml the reflex test will not initiate An extremely flaccid tympanic membrane or an ossicular chain discontinuity will yield a very high peak compliance in the presence of normal middle ear oressure Ear canal volume will be normal and the reflex will be absent A fixation of the ossicular chain as in otosclerosis will produce a tympanogram with very low compliance in the presence of normal middle ear air pressure Ear canal volume is normal and the reflex is absent Middle ear fluid such as serious otitis media will yield a very flat tympanogram with no definite peak and negative air pressure A resolving case or beginning case may produce a reduced peak in the presence of GEBAmi24e_11a docx 31 850 234 9 07 11 M MAICO Operating Instructions MI 24 severe negative middle ear pressure The ear canal volume is normal and the reflex is either absent or at an elevated level Eustachian tube disfunction in the absence of fluid will show a normal compliance curve but it will be displayed to the negative side of the tympanogram Ear canal volume will be normal and the reflex may be present depending on the degree of involvement GEBAmi24e_11a docx 32 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 7 How to test children
21. atic identification of the reflex threshold is switched on You can choose the maximum acoustic pressure levels from 70 dB till 110 dBy in steps of 5 dB Reflex sensitivity With this option you select the sensitivity of the stapedius reflex detection With the setting Sensitive small changes of the compliance will achieve PASS as test results With the setting Robust a larger compliance change is needed to detect a PASS The setting Normal is the default setting Print graphic With this option you can switch ON and OFF the printout of the graphic reflex display for documentation 500 Hz With this option you can switch ON and OFF the stapedius reflex test for 500 Hz GEBAmi24e_11a docx 39 850 234 9 07 11 M MAICO Operating Instructions MI 24 1000 Hz With this option you can switch ON and OFF the stapedius reflex test for 1000 Hz 2000 Hz With this option you can switch ON and OFF the stapedius reflex test for 2000 Hz 4000 Hz With this option you can switch ON and OFF the stapedius reflex test for 4000 Hz 9 4 The Common Setup Menu Select the menu option Common Setup Menu from the main setup menu as described before and the common setup menu will appear on the LCD display The common setup menu offers the following options Common Setup Menu _ Power up f f Power up Tymp With this option you can choose the test USB mode of the MI 24 after switching
22. come more familiar with the normal ranges when you use the instrument GEBAmi24e_11a docx 30 850 234 9 07 11 5 Operating Instructions MI 24 MAICO The normal range for compliance is 0 2 ml to approximately 1 8 ml A compliance peak within the range indicates normal mobility of the middle ear system A peak found outside of these limits may be indicative for one of several pathologies Middle ear pressure should be equivalent to ambient air pressure O daPa on an air pressure scale Minor shifts of the peak compliance to the negative may occur with congestion and are rarely to the positive side Establish criteria for abnormal negative pressure when you become more familiar with using the equipment It is generally accepted that negative pressure of greater than 150 daPa indicates a referral for medical evaluation 6 3 Abnormal Values It is the purpose of this section to provide samples of tympanograms which reflect abnormal states of the middle ear mechanism It is not the intention of this section to provide you with a complete guide to interpreting results Complete information regarding pathologies and abnormal impedance testing can be found in the literature referenced A perforation in the tympanic membrane will cause a high ear canal volume measurement because the instrument will measure the volume of the entire middle ear space The MI 24 may refuse to run the test with the probe indicating a volume out of toler
23. culations 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 mmH20 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 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 GEBAmi24e_11a docx 5 850 234 9 07 11
24. d Impedance Right Ipsi 300 daPa Gradient Status READY Ear Volume Compliance Pressure a B 80 500 Hz 80 1000 Hz AUTO 80 80 2000 Hz 4000 Hz tydB Figure 5 the measurement screen of the MI 24 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 testing is selected GEBAmi24e_11a docx ae shows the ipsilateral 850 234 9 07 11 M MAICO Operating Instructions MI 24 At the bottom line in figure 5 the word AUTO and f4 dB Scale is shown It means that the reflex test level increases automatically until a reflex was found or the maximum l
25. e gradient and reflex thresholds Thermal printer paper roll width 110 mm 4 s one Tympanogram to 12 s Tympanogram and for both ears Mains 100 240 V 50 60 Hz 51 850 234 9 07 11 Operating Instructions MI 24 Power consumption app 25 VA BOO O Figure 43 Connectors on the rear Connection plugs Connection Specification Mains connection socket left right power 100 240 V 50 Hz Probe tube connection Probe connection socket PC interface 2 TX 3 RX 5 GND USB Contra receiver socket sleeve GND tip out ZA 10 Q UA 8 Veff Warm up time less than 10 min after power on Environment Conditions 15 435C 59 95 F operation 5 450C 41 122 F storage Maximum humidity 90 storage and operation Dimensions WxDxH 39x29x 11cm Weight app 2 6 kg GEBAmi24e_11a docx 52 850 234 9 07 11 M MAICO Operating Instructions MI 24 Standard accessories 1 hand held probe 1 mains cable 1 set of ear tips 1 calibration cavity cavities 5ml 2ml 0 5ml with probe holder 1 printer paper roll for app 350 printouts Optional accessories TDH 39 contra phone Part No 46 82 Carrying case Part No 70 50 14 Soft side carrying case Part No 1035 3002 Consumables roll printer paper Part No 70 50 78 set of 10 Ear tips yellow 7 4 mm Part No 70 50 56 set of 10 Ear tips green 9 mm Part No 70 50 57 set of 10 Ear tips white 11 mm Part No 70 50 58 set of 10 Ear
26. e 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 which illustrates the compliance in ml over 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 300 200 100 0 100 Pressure daPa Compliance ml Figure 12 Tympnaogram normal curve area is hatched 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 GEBAmi24e_11a docx 17 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 4 3 Preparing the measurement Before you start a new measurement delete Impedance Right TE former test results see also chapter 4 7
27. e to calm them with e g a dummy or a tea bottle the result might be slightly falsified maybe by a slightly irregular line of the Tympanogram Measurement with Hightone optional MI 24 In addition to the standard 226 Hz probe tone tympanometry the MI 24 has a high frequency probe tone of 1000 Hz that can be selected by the user A tympanogram recorded using the high probe tone is generally better suited for screening newborns and provides more accurate results for those subjects To select high probe tone frequency GEBAmi24e_11a docx 33 850 234 9 07 11 M MAICO Operating Instructions MI 24 When the instrument is switched on it automatically powers up in the standard tympanometry mode In order to choose tympanometry with high probe tone hold down the Reflex key for two seconds The screen for high probe tone tympanometry looks very similar to the normal tympanometry mode however the following differences will appear on the screen e The scaling is now measured in mmho e The pre selected frequency 1000 Hz is displayed in the upper left hand side of the screen e The tympanometry test with high probe tones is performed in the exact same way as a normal tympanometry test It is possible to perform normal tympanometry and high probe tone tympanometry in one test session and print the results for comparison When the first tympanometry curve has been drawn press the Reflex key for two seconds to switch to high prob
28. e tone tympanometry Now the next curve will be drawn automatically Press Print and a printout presenting both curves will appear Note It is not possible to perform reflex tests on the basis of a high probe tone tympanogram GEBAmi24e_11a docx 34 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 8 Recommended literature Auditory Disorders A Manual for Clinical Evaluation Jerger Susan and James Jerger Boston College Hill Press 1981 Handbook of Clinical Audiology Katz Jack Baltimore William amp Wilkins 1994 s Audiology Desk Reference Roeser Ross J New York Stuttgart Thieme 1996 Auditory Diagnosis Silam Shlomo and Carol A Silvermann San Diego London Singular Publishing Group 1997 GEBAmi24e_11a docx 35 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 9 Individual Setup of the MI 24 While getting familiar with the MI 24 in the TE previous chapters you had the chance to find out how easy the instrument is to P control You can carry out all normal ITE measurements and print them out too Tympanogram In addition the MI 24 offers many hidden chances for the experienced user j ic indivi NChange Item to adapt the instrument to his individual PSAT as Henu Escape demands Figure 26 Main M Set tivated In the following all the setup options are A naen ae treated precisely The settings shown in the figures are the standard
29. ease in compliance in the probe ear which Figure 19 Contra lateral test indicates a Stapedius reflex at the actual test GEBAmi24e_11a docx 23 850 234 9 07 11 M MAICO Operating Instructions MI 24 frequency and the test level The test level which was set when the reflex occurred is called reflex threshold and is shown in dBHL dB hearing loss 5 2 Training the test person In addition to the general introduction described in chapter 4 2 you should explain to the test person that loud test sounds will occur during the reflex measurement It is very important that the patient does not move his head at all because a reflex can be registered already with a change of compliance of 0 05 ml 5 3 Preparing the ipsilateral measurement The LCD display shows the empty Tympanogram for the right ear and the control light of the probe lights red If you want to measure the left Pedence ai H ear change the side by pressing 7 Status the L R key or the probe Oe ae en We test ear shown in the middle of cece the top of the LCD display ee sia ane ill change from Right to ie Left and the control light of se ar eee eel the probe lights blue 2 B z Switch the reflex measurement soo 1 100 2000 he 1 aood 1 on by pressing the REFLEX key o The word Ipsi must appear Figure 20 Display Tympanogram Reflex
30. ees 46 13 Warranty Maintenance and Service cccccecececcccccceeeeesesseseeeeeeeeeeeees 47 14 Safety Regulations osccier axcveduiniatstennngsodech neh Showa avnatt mcreseuchabontenes name aisor 48 14 1 Electrical Safety ates career t hraqtcetandwoceapcasactnnee ass thwieleeutetesans aahoetiawieds 48 14 2 Measuring Security cet cteuctaeusntetenteseadaniersanietriee uoiiwer eet atemetnende an 48 COINS Faces va oaceacnnagesnncatadeesouaacnatendedeqse Sadesaeaead oc csegeeeteaducs 48 14 4 Operation ee eee eee ree nee nee ene eae en eet 48 14 5 Patient Safetyi resucita a a docedeeeed 48 15 Checklist for subjective device control sssssssssessssssrerererererererereses 50 16 Technical Data and Accessories ccccccccccsccccesccecececscccecsecceccesesees 51 5 Operating Instructions MI 24 MAICO 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
31. ence for the test person Remarks Additional information about the test or patient can be Stated here 600 300 300 daPa Ear Volume 0 94 ml Figure 16 Printout of Tympanogram All other values and the Tympanogram correspond to those you have seen on the LCD display and which were explained on the previous page under 4 5 The intelligent printer control helps you to save paper It will only print out what has really been measured So the printout of the reflex frequencies misses in the example above because only the Tympanogram was measured If you have saved two Tympanograms for example for both the left and the right ear both are printed out side by side You can produce as many printouts as you want by pressing several times the PRINT button GEBAmi24e_11a docx 21 850 234 9 07 11 M MAICO Operating Instructions MI 24 4 7 How to delete the test results By pressing the R L key nger the measurement memory will be deleted On the LCD display the message Delete all Data occurs Press the ENTER button delete all patient data Then the LCD display shows an empty measurement screen If you press the MENU button bu return to the measurement screen without deleting the measurement data GEBAmi24e_11a docx 22 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 5 How to measure the Stapedius reflex 5 1 The basics of the Stapedius re
32. eustachian tube 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 er the middle ear to the inner ear while sae the other part is reflected The stiffer i TF the eardrum is the more sound is i reflected and the less sound reaches the inner ear In the probe of the me impedance measuring instrument a small loudspeaker is installed which a ___ manometer amits a sound of low frequency uaa Figure 11 Principle of impedance measurement loudspeaker GEBAmi24e_11a docx 16 850 234 9 07 11 M MAICO 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 over and under pressure is performed by th
33. evel is reached With the cursor up button or down button 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 l GEBAmi24e_11a docx 11 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 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 Hamnen Press the menu key and the main caibration menu figure 6 appears on the LCD core display Select the menu option Calibration with the Down button Press Enter and follow the instructions on the LCD display as shown in Figure 7 T 4 Change item ENTER Select item Put the probe tip without ear tip into the hole of the test cavity labeled 0 5 ml and wait When the text on the display Figure 6 changes to the request for the 2 ml Display MI 24 Main Menu calibration put the probe tip 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 appea
34. flex measurement While the Tympanometry method measures the change of the compliance caused by changing pressure in the outer auditory canal the Stapedius reflex measurement works with a changing compliance caused by contraction of the Stapedius muscle in the middle ear The contraction called Stapedius reflex causes a decrease in compliance and is caused by loud acoustic stimuli Regardless whether the acoustic stimulus is active on the left or on the right or on both sides the Stapedius reflex is always binaural i e it occurs in both ears at the same time The Stapedius reflex is caused in ears of adults with normal hearing by sine sounds with sound pressure levels between 70 Figure 17 The middle ear and 105 dB musculus stapedius hearing middle ear eustachian tube The reflex method measures continuously in one ear the probe ear the compliance with the pressure which caused before the highest compliance Simultaneously the stimulus ear is irritated by the sound which causes the contraction of the Stapedius muscle The ipsilateral reflex measurement uses the same ear for the probe and the stimulus The contra lateral measurement uses different ears for the Figure 18 Ipsilateral test probe and the stimulus The acoustic stimulus is offered to the ear opposite to the probe ear If the offered stimulus causes a reflex the m E impedance measuring instrument registers a decr
35. he Diagnostic Probe System The two different probe systems can be seen in the below picture Figure 31 To clean the small acoustic and air pressure channels of the probe tip unscrew the small ribbed plastic nut that holds the probe tip Figure 32 GEBAmi24e_11a docx 42 850 234 9 07 11 Operating Instructions MI 24 AIC After unscrewing the small ribbed plastic nut it is possible to detach the small probe tip with the small acoustic and air pressure channels from the transducer house Figure 33 Ribbed Plastic Nut Transducer House Transparent Sealing Probe Tip with the small acoustic and air pressure channels The cleaning of the acoustic and air pressure channels of the probe tip must be performed by means of the cleaning wire which can be found in the Ear tips Assortment provided with the MI 24 When cleaning the acoustic and air pressure channels of the probe tip the cleaning wire must be inserted from the back of the probe tip according to Figure 34 Figure 34 Besides cleaning the holes ensure also a proper surface cleaning of the transparent sealing After cleaning all the acoustic and air pressure channels of the probe tip it can be reassembled Make sure that the Probe Tip is connected correctly GEBAmi24e_11a docx 43 850 234 9 07 11 Operating Instructions MI 24 onto the Transducer Housing a small flange will ensure correct positioning before the plastic nut is gently tightened Figure
36. he printout contains the following Remarks information Ear volume Compliance Pressure Gradient Reflex Test Results Right PASS FAIL and IPSI CONTRA or iss pa z Tympanogram depending on the test e ce you have done This information provides Lees the data you need to interpret the test oo Tympanogram results oe ee A graph of the Tympanogram is provided aaa e Figure 32 to assist you in visual o 2 i sor es interpretation of the test This graph is a on rd representation of the relative mobility of aanp PH 1000 He PASS the middle ear system The horizontal axis wm T shows the changes in air pressure and the pg P CT S resulting mobility of the system The a ee compliance is recorded on the vertical is axis This mobility is expressed as a ia et change in the volume of the ear canal in ml Figure 25 Printout of a Tympanogram with ipsilateral reflextests The reflex is shown in up to four graphics with time on the horizontal axis and the change of the compliance on the vertical axis 6 2 Interpreting the tympanometric test result As a general rule values for ear canal volume should be between 0 2 and 2 0 ml children and adults A variance will be seen within this range depending on the age and ear structure of the person For example a 2 0 ml or larger reading in a small child could indicate a perforation in the tympanic membrane while it may be a normal reading in an adult You will be
37. ntrol light lights green Now the test runs off Do not change the position of the probe any more until the green control light is going out indicating the end of the measurement A yellow control light indicates an error The kind of the error is indicated on the LCD display under status LEAKING The ear tip does not make the auditory canal airtight Change the position of the probe until the control light 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 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 is clogged you can remove it by opening the fixation ring After cleaning of the probe tip or selection of a new one the tip must be fixed again by fastening the fixation ring 3 9 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_11a docx 14 850 234 9 07 11 M MAICO Operating Instructions MI 24 By choosing an app
38. omplying with IEC 60601 shall be kept outside patient environment as defined in the standard at least 1 5 m from the patient Any person who connects external equipment to signal input signal output or other connectors has created a system and is therefore responsible for the system complying with the requirements of IEC 60601 1 1 If in doubt contact your service technician or local representative for help The cradle connection provides power for the thermal printer In order to maintain a high level of safety it is necessary to have the instrument and its power supply checked according to the medical electrical safety standard IEC 60601 1 on a yearly basis by a qualified service technician 49 850 234 9 07 11 M MAICO Operating Instructions MI 24 15 Checklist for subjective device control According to the manufacturer requirement the user should control the instrument once a week to find errors immediately and to avoid wrong test results He should test Tympanogram and Reflex with an otologic normal person and compare the results with earlier measurements The printout should be filed together with the subjective test protocol to the documents of the instrument The test person should be healthy no otitis etc and should by at least 12 hours not exposed to loud noise Instrument type Serial No Test person Connectors and cables OK Instrument and probe Is the green light of the probe blinking
39. r should be checked and calibrated at least once a year This check has to be carried out by your dealer When returning the instrument for repairs it is essential to also send the probe and all other accessories Send the device to your dealer or to a service centre authorized by your dealer Please also include a detailed description of the faults In order to prevent damage in transit please use the original packing if possible when returning the instrument NOTE Within the European Union it is illegal to dispose electric and electronic waste as unsorted municipal waste According to this all MAICO products sold after August 13 2005 are marked with a crossed out wheeled bin Within the limits of Article 9 of DIRECTIVE 2002 96 EC on waste of electrical and electronic equipment WEEE MAICO has changed their sales policy To avoid additional distribution costs we assign the responsibility for the proper collection a and treatment according to legal regulations to our customers GEBAmi24e_11a docx 47 850 234 9 07 11 5 MAICO Operating Instructions MI 24 14 Safety Regulations 14 1 Electrical Safety The MI 24 tympanometer is constructed to comply with protection class Type BF of the international standard IEC 601 1 EN 60601 1 Protection from an electric shock is ensured even without the system earth connection The instruments are not intended for operation in areas with an explosion hazard
40. release button O f the probe with a tool or a pen Remove the screening probe insert Insert the diagnostic probe insert O to the probe head Please recognize the right position of the connector of the diagnostic probe insert Press the diagnostic probe insert into the probe head 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 changes accordingly to red right ear or blue left ear If selected in the setup menu pressing the probe button during GEBAmi24e_11a docx 13 850 234 9 07 11 M MAICO Operating Instructions MI 24 operation pauses also the test The colour of the control light 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 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 lights green Now the test runs off Do not change the position of the probe any more until the green control light is going out indicating the end of the measurement A blue control light 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 co
41. ropriate 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 GEBAmi24e_11a docx 15 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 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 serves the diagnosis of the condition of the middle ear and can therefore not be compared directly with other audiometrical tests such as sound or speech audiometry which serve the measurement of the hearing Furthermore the impedance measurement is an objective measuring method which does not depend on the cooperation of the test person and can Figure 10 The middie sar 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 musculus stapedius hearing middle ear canal D middle ear
42. rs again and you are ready for measurements If the error information Cavity Calibration calibration out of range appears Place the porbe in the 5 ml cavity during the calibration please control if the opening of the probe tip 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 niguiey the probe or the instrument is probably Display MI 24 Calibration defect Inform your service to get immediate help GEBAmi24e_11a docx 12 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 3 8 Getting familiar with the probe The probe of the MI 24 is shown in figure 8 The probe head is Q adjustable in three steps 0 60 L und 80 It is adjusted by releasing the fixation screw Figure 9 at the bottom of m the probe a few turns using a coin or a screw driver Adjust the probe head by pulling it into 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 again Figure 8 MI 24 probe with additional screening probe tip a Notice To avoid damages on the sensitive measuring m 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
43. rt the paper end between the rubber roll and the black plastic part at the rear of the printer Transport the printer paper until it appears from the upper part of the rubber roll Pull then the paper end app 10 to 15 cm Push the blue lever into its backward position Guide the paper end through the paper slot of the printer cover Close the printer cover y putting the two guide rails at the end of the printer cover to the appropriate slot of the paper compartment of the housing of MI 24 Press the front of the printer cover down until it fastens The instrument is now ready to print GEBAmi24e_11a docx 46 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 13 Warranty Maintenance and Service The MI 24 Tympanometer is guaranteed for 1 year This warranty is extended to the original purchaser of the instrument by MAICO through the Distributor from whom it was purchased and covers defects in material and workmanship for a period of one year from date of delivery of the instrument to the original purchaser The tympanometer may be repaired only by your dealer or by a service centre recommended by your dealer We urgently advise you against attempting to rectify any faults yourself or commissioning non experts to do so In the event of repair during the guarantee period please enclose evidence of purchase with the instrument In order to ensure that your instrument works properly the tympanomete
44. s MI 24 5 5 Preparing the contralateral measurement Switch on the contralateral reflex measurement by pressing again the red REFLEX key The word CONTRA must appear on the right top of the LCD display Here the highest fixed level is 110 dBHL with optional TDH 39 contra phone only The contra lateral measurement produces more reliable results because the receiver emitting the test signal and the probe measuring the compliance are separated If you are using an insert phone for contalateral measurement put an appropriate ear tip on the insert Impedance Right Contra E TEN Status i Ear Volume a Compliance 1 Pressure 600 300 300 daPa Ee 2 3B 4 N Z o i S oo oo 100 3 500 Hz C 1000 Hz C 2000 Hz C 4000 Hz C PASS PASS PASS PASS AUTO tydB Scale Figure 22 Example of a normal Tympanogram with contra lateral reflex results phone and insert it in the contalateral ear Continue now as described previously for the ipsilateral measurement 5 6 How to interpret the reflex display After having carried out a measurement you can read the recorded values on the LCD display In addition to the Tympanogram shown on the left side and the values shown on the right now you can see the results of the reflex measurement in the lower part of the display In four boxes marked 1 to 4 the stapedius response is shown graphically Belo
45. settings If you have altered a value by accident you just have to return to the standard setting shown here and the instrument will work as before By pressing the menu key you can return from every sub menu to the main menu and after all to the Tympanometry mode You can change the menu options with the cursor keys Up Left Down and Right The menu option actually selected is marked inverse on the LCD display GYSETUP in the example Figure 26 You select the chosen menu option by pressing Enter 9 1 The setup menu Select the menu option SETUP as Setup Menu illustrated in Figure 27 and the main ee setup menu will appear on the LCD Common Setup Menu display You can make different Clinical Setup Menu settings for the measurement of the tympanogram and the stapedius reflex for instrument setup for example the T Change Item contrast of the LCD display All your ENTER Select item Nishi Escapa settings are saved permanently until you ae re will change them again The settings also Sidi equ aad switched off GEBAmi24e_11a docx 36 850 234 9 07 11 5 MAICO 9 2 The Tympanogram Setup Menu Operating Instructions MI 24 Select the menu option Tympanogram Setup Menu as illustrated in Figure 35 and the Tympanogram setup menu will appear on the LCD display You change the menu options with the cursor keys DOWN respectively UP You can change the
46. t 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 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 musculus stapedius hearing ear canal 2 2 Tympanometry Tympanometry is the objective measurement of middle ear mobility compliance and pressure within the middle ear system During the test a low pitched Figure 1 the middle ear probe tone 226 Hz is presented to the ear canal by means of the hand held probe This tone is used to measure the change in compliance in the middle ear system while the air middle ear eustachian tube GEBAmi24e_11a docx 4 850 234 9 07 11 M MAICO Operating Instructions MI 24 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 cal
47. text on the LCD display and the printout After selection all the texts appear in the chosen language Display adjust The contrast of the LCD display can be changed with this option 9 5 Insert your personal printout data Select the menu option Clinic Setup Menu from the main setup menu to enter all required data of your clinic These data will be printed out later together with the test result and the patient data This screen is self explaining GEBAmi24e_11a docx 41 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 10 Care and maintenance of the instrument Disconnect the power plug before cleaning To clean the instrument probe contralateral receiver and other accessories use a soft cloth dampened with a little warm soapy water or washing up liquid no alcohol or spirits should be used During cleaning please ensure that no liquid runs into the switches level control or probe openings Please use a new eartip for each patient Always use eartips from MAICO or Sanibel Each eartip should only be used one time 10 1 Cleaning of Probe Tip In order to secure correct impedance measurements it is important to make sure that the probe system is kept clean at all times Therefore please follow the below illustrated instruction on how to remove e g cerumen from the small acoustic and air pressure channels of the probe tip For the MI 24 two different probe systems exist the Screening Probe System and t
48. uring the ae ee ae ee POs m measurement of the 7 Fe Pressure Stapedius reflex the change a ae Gradient of the compliance is 600 300 300 daPa represented in real time on i 5 3 7 the LCD display When the e Lem Le test is finished the curves for 500 Ne 1000 He 2000 Hz PASS PASS PASS the changes of compliance AUTO NdB Scale for 500 Hz 1000 Hz 2000 Hz and 4000 Hz are shown in four separate graphs at the bottom of the measurement screen see Figure 21 Below each curve you see the test level where a Stapedius reflex was registered automatically This is indicated by a PASS below the frequency If no reflex was detected a FAIL is reported and the maximum level is shown Figure 21 Example of a normal Tympanogram with ipsilateral reflex results You can judge watching the real time graph if you have a real Stapedius reflex or only disturbance and artifacts The lower dotted zero line of a graph indicates the measured compliance without a test sound All the positive or negative changes of compliance are shown as deviation from the zero line If a Stapedius reflex occurs the compliance decreases and the curve rises The box which occurs during the test symbolizes the threshold at which the MI 24 accepts a change of compliance as valid Stapedius reflex GEBAmi24e_11a docx 26 850 234 9 07 11 5 MAICO Operating Instruction
49. w each box the test level the test frequency the type of the test l ipsi C contra lateral are shown Also the test result is shown as PASS or FAIL In the example in Figure 23 for 500 Hz a stapedius reflex was registered at 100 dBHL and for 4 GEBAmi24e_11a docx 27 Impedance Right Ipsi aa Gute ah oh ane READY Ear Volume 0 94 ml roe are Pressure i POES 37 daPa Gradient 300 daPa 32 daPa 1 2 3 4 100 100 100 1000 Hz 2000 Hz 4000 Hz PASS PASS PAS AUTO N dB Scale Figure 23 Example of a normal Tympanogram with 850 234 9 07 11 N Operating Instructions MI 24 MAICO kHz at 95 dBHL If no reflex threshold was registered the information FAIL appears below the frequency A correct interpretation of the measuring results can only follow in connection with the Tympanogram the graphic reflex display and other actual data But in principle you can say that a Stapedius reflex indicates that the patient hears on the stimulus ear and that the sound lead on the probe ear functions GEBAmi24e_11a docx 28 850 234 9 07 11 5 MAICO Operating Instructions MI 24 5 7 How to print out the test result After a test you can print out the result for your documents by pressing the PRINTER button The quiet thermal printer prints out the example used in the previous paragraph
50. 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 of the probe lights yellow and the display nder status LEAKING is reported If the probe is blocked the control light of the probe lights yellow and at the display Ghows under status BLOCKED Please proceed as described in chapter 3 6 Getting familiar GEBAmi24e_11a docx 18 850 234 9 07 11 M MAICO 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 y the probe button and repeat the measuring procedure described above with the other ear GEBAmi24e_11a docx 19 850 234 9 07 11 5 Operating Instructions MI 24 MAICO 4 5 How to evaluate the Tympanogram display After having carried out a measurement you can Tymp 1000 Hz Right Tympanogram see the results on the LCD display 7a sats On the left side of the oe eae eal ee display you see the E EEE te EE ee Tympanogram The 2 Kompliance area surrounded by the rec ose oe nett EA o O8tml box is valid for wee Gee ane normal es se Tympanograms You 600 300 3 Gradient can change the area or switch it off For details see chapter 12 Individual Setup of Figure 15 Display of a 1000 Hz Tympanogram the MI 24 In the middle of
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