Inhoud
Inleiding fysiologische tests van het auditieve systeem ......................................................................... 8
Inleiding fysiologische tests van het auditieve systeem ......................................................................... 8
Eigenschappen van het auditieve systeem ......................................................................................... 8
Meetbare responsen in het auditieve systeem .............................................................................. 8
Meetbare responsen in het auditieve systeem: ............................................................................. 9
→ klik aanbieden → evaluatie van het gehoor → stel: vlakke lijn = doofheid ......................... 9
→ dmv elektrodes hersenactiviteit meten ..................................................................................... 9
Meetmethodes ................................................................................................................................... 9
Algemene principes stimulatie ........................................................................................................... 9
Lopende golf basilair membraan ...................................................................................................... 11
Niet-lineariteit .................................................................................................................................. 12
Soorten responsen ........................................................................................................................... 12
Definitie fysiologische responsen ................................................................................................. 12
- Steady state: auditieve cortex volgt auditief signaal in respons, volgen van amplitude-
modulaties → Indien geen modulatie: enkel transiënte on- en offset, geen steady-state respons
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- Transiënte respons bv. click: want geen FM aanwezig ......................................................... 13
o Clicks snel achter elkaar: afhankelijk tijdschalen → auditieve systeem volgt snel
opeenvolgende clicks, afhankelijk van: ........................................................................................ 13
1) Rate van stimulatie ............................................................................................................... 13
2) Plaats op auditieve pad ........................................................................................................ 13
Responsopname ........................................................................................................................... 13
Responsdetectie ........................................................................................................................... 16
Stimulatiefrequentie en analysevenster ....................................................................................... 16
Otoakoestische emissies (OAE) ............................................................................................................ 17
Inleiding............................................................................................................................................ 17
Inleiding fysiologische tests van het auditieve systeem ....................................................................... 17
Oorsprong van OAE .......................................................................................................................... 17
Lopende golf basilair membraan .................................................................................................. 18
Beweging van de haarcellen ......................................................................................................... 18
Cochleaire versterker ................................................................................................................... 19
Contributie IHC en OHC op frequentieselectiviteit ....................................................................... 19
Samenvattend .............................................................................................................................. 20
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,Soorten ottoakoestische emissies .................................................................................................... 20
Spontane otoakoestische emissies (SOAE) ................................................................................... 20
Transient evoked otoakoestische emissies (TEOAE) ..................................................................... 21
Meten van OAE’s (Algemeen)........................................................................................................... 23
Meetprocedure ................................................................................................................................ 23
Algemeen: .................................................................................................................................... 23
Correcte plaatsing probe: ............................................................................................................. 23
Calibratie ...................................................................................................................................... 24
Stoorgeluid onderdrukken bij TEOAE ........................................................................................... 24
Opnamesysteem voor TEOAE overlopen .......................................................................................... 25
Stimulusweergave ........................................................................................................................ 25
Stimulusniveau ............................................................................................................................. 25
Stimulusstabiliteit ......................................................................................................................... 26
Responsweergave ........................................................................................................................ 26
Responsweergave van het frequentiedomein .............................................................................. 26
Belang van verwijderen (= niet includeren) van stimulus ............................................................. 27
Artefactrejectie en aantal middelingen ............................................................................................ 27
Interpretatie in de grafiek ............................................................................................................ 28
Analyse nadat we weten dat we goede OAE’s hebben .................................................................... 28
Vergelijking golfvormen ............................................................................................................... 28
Vergelijking spectrum (%) ............................................................................................................. 29
Oefening: TEOAE – toneburst ........................................................................................................... 29
TEOAE als functie van SPL ................................................................................................................ 30
TEOAE en gehoorverlies ................................................................................................................... 30
TEOAE in kinderen ............................................................................................................................ 31
DPOAE (= distortion product OAE) ................................................................................................... 31
Oorsprong distortietonen bij niet-lineaire systemen ....................................................................... 31
Herhaling niet-lineariteit .............................................................................................................. 31
Niet-lineariteit in de cochlea ........................................................................................................ 32
DPOAE .............................................................................................................................................. 33
Hoe meten? .................................................................................................................................. 33
Effect van frequenties bij het meten van OAE’s ........................................................................... 34
Efect van level .............................................................................................................................. 34
DPOAE aangroei ........................................................................................................................... 35
DP(OAE)-gram .............................................................................................................................. 35
DPOAE amplitudes ....................................................................................................................... 35
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, DPOAE en gehoorverlies ............................................................................................................... 35
DPOAE als functie van leeftijd ...................................................................................................... 36
OAE en status middenoor............................................................................................................. 36
OAE als screening ......................................................................................................................... 36
Auditory evoked potentials (AEP)......................................................................................................... 37
Transiënt evoked AEPs ..................................................................................................................... 37
Hoe op te meten? ......................................................................................................................... 37
Differentiaalversterker ..................................................................................................................... 37
AEPs in de cochlea: elektrocochleography (ECoG) ........................................................................... 38
Hoe meten? .................................................................................................................................. 38
AEPs in de cochlea (responscomponenten geregistreerd met EcochG) ....................................... 38
Effect van elektrodeplaatsing ....................................................................................................... 39
Effect van stimuluspolariteit......................................................................................................... 39
CAP effect van intensiteit op amplitude en latentie ..................................................................... 39
Window en inter-stimulus interval ............................................................................................... 39
Meetinstellingen voor ECoG ......................................................................................................... 39
ECoG en Cochleaire implantaten .................................................................................................. 40
Electrically-evoked action potential (ECAP) ...................................................................................... 41
ECAP effect van prestimulus (Masker) ......................................................................................... 41
CAP en cochleaire implantaten (Artefacten) ................................................................................ 41
ECAP en gehoordrempels ............................................................................................................. 41
Auditory brainstem response (ABR) ..................................................................................................... 42
Generatoren ..................................................................................................................................... 42
Elektrodeplaatsing: 10-20 systeem EEG ........................................................................................... 42
Scalp potential .................................................................................................................................. 43
Elektrodeplaatsing en dipolen die in de klinische ABR gebruikt worden ...................................... 43
Stimulus............................................................................................................................................ 44
Polariteit ....................................................................................................................................... 44
CM component meten ................................................................................................................. 44
Auditieve neuropathie...................................................................................................................... 45
Filterinstellingen ........................................................................................................................... 45
Middelen ...................................................................................................................................... 45
Analyse ABR...................................................................................................................................... 45
Normale variabiliteit..................................................................................................................... 46
Effect van intensiteit .................................................................................................................... 46
Latentie ........................................................................................................................................ 46
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, CM component vs. latentie als functie van intensiteit ................................................................. 47
Effect van gehoorverlies op ABR morfologie ................................................................................ 47
Effect van gehoorverlies op piek V latentie .................................................................................. 48
Effect van rate op ABR componenten .......................................................................................... 48
ABR retrocochleaire problematiek ............................................................................................... 48
Verschillende gehoorverliezen en de effecten (KENNEN!!!) ............................................................ 49
Normal hearing............................................................................................................................. 49
Hoogfrequent sensorisch gehoorverlies ....................................................................................... 49
Laagfrequent sensorisch gehoorverlies ........................................................................................ 50
Retrocochleair gehoorverlies ....................................................................................................... 50
Ernstig hoogfrequent gehoorverlies ............................................................................................. 50
Ernstig tot diepgannd gehoorverlies ............................................................................................ 51
Herhaling .......................................................................................................................................... 51
Verbetering van SNR ........................................................................................................................ 52
Test protocol ................................................................................................................................ 52
Klik – ABR ......................................................................................................................................... 53
Parameters ................................................................................................................................... 53
Drempelbepaling .......................................................................................................................... 53
Voordelen en nadelen .................................................................................................................. 54
DUS: Meer frequentiespecifiek met een ABR gaan meten ........................................................... 54
Manier om meer frequentiespecifiek te gaan: tone burst ABR .................................................... 54
Klik ABR ........................................................................................................................................ 56
Noise masking .............................................................................................................................. 57
Corticale transiënte responsen ............................................................................................................ 58
Verschillende transiënte responsen ................................................................................................. 58
Definitie epoch ................................................................................................................................. 59
Generatoren vs. het gemeten potentiaal ......................................................................................... 59
Effect elektrodeplaatsing ............................................................................................................. 59
Belang van middelen voor het meten van een respons ............................................................... 60
Het belang van middelen als functie van de responsamplitude ................................................... 60
CAEP – hoe te meten .................................................................................................................... 60
Verschillende transiënte corticale responsen .................................................................................. 61
Transiënte ‘onset’ response (TOR) ............................................................................................... 61
Auditory change complex (ACC) ................................................................................................... 64
Mismatch negativity (MMN) ........................................................................................................ 66
P300 ............................................................................................................................................. 66
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