effect of electrode posion on electrophysiological and ... · effect of electrode posion on...
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EffectofElectrodePosi/ononElectrophysiologicalandPsychophysicalParametersinCIPa/entswith
LateralandPerimodiolarElectrodeArrays
ChantalDegen,MDpresentedat:CI2017
HannoverMedicalSchoolDepartmentofOtorhinolaryngology
Chairman:ThomasLenarzMD,Ph.D.
Disclosures
• FinancialSupportfromCochlearDeutschlandGmbH&Co.KG:– ConferenceFeeandTravelCosts
HighResolu/onCBCTImaging(Morita)
Slicethickness=125µm
Whythemedialwall?
MicroCTfromAvcietal.(2014)J.Comp.Neurol.
Cochlear Nucleus 522 „SRA“
Lateral artifacts
Cochlear Nucleus 532 „MRA“
Medial artifacts
Lateralwallvs.PerimodiolarArrays
CochleaMeasurementTool
CometProgram:Lexowetal.,2016.VisualizaTon,measurementandmodellingofthecochleausingrotaTngmidmodiolarsliceplanes.IntJComputAssistRadiolSurg.11(10):1855-69.doi:10.1007/s11548-016-1374-7.
Using3DReconstruc/ontoDeterminetheEMD
Electrodes
Perimodiolar Lateral wall
“MRA” 532
“Contour” 512 522
522
Preformed electrode array Straight electrode array
“SRA”
ElectrodePosi/on:Perimodiolarvs.LateralArraysNucleus 522
Nucleus 532
0.0
0.4
0.8
1.2
1.6
2.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
EMD [mm]
Electrode No.
Electrode Modiolus Distance in Perimodiolar vs. Lateral Arrays
532 522 512
0.0
0.4
0.8
1.2
1.6
2.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
EMD [mm]
Electrode No.
Electrode Modiolus Distance in Perimodiolar vs. Lateral Arrays
532 522 512
0.0
0.4
0.8
1.2
1.6
2.0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
EMD [mm]
Electrode No.
Electrode Modiolus Distance in Perimodiolar vs. Lateral Arrays
532 522 512
0.0
0.4
0.8
1.2
1.6
2.0
1 3 5 7 9 11 13 15 17 19 21
Electrode- Modiolus Distance
[mm]
Electrode number (basal to apical)
Nucleus 512
n= 10 per Group; Error bars: ± 1SD
Example:SpreadofExcita/onMeasurementCurveforElectrode15
0
20
40
60
80
100
120
140
160
180
200
10 11 12 13 14 15 16 18 19 20 21 22
ECAPAmplitudeatCurrentLevel200[µV]
MaskerElektrode
SOEWidthat½Amplitude
RecordingElectrodeProbeAcTveElectrode
Posi/veCorrela/onbetweenEMDandSpreadofExcita/onWidth
(Averages) Nucleus 532 (MRA: n=11) Nucleus 522 (SRA: n=10)
R²=0.41979
0.5
1.5
2.5
3.5
4.5
0.5 1 1.5
SOEWidth[mm]
Electrode-Modiolus-Distance[mm]
• TheSOEbecomeswiderwithincreasingdistancetothemodiolus.
R²=0.89128
1
2
3
4
0.5 1 1.5
SOEWidth[mm]
Electrode-Modiolus-Distance[mm]
R²=0.1311
3
3.5
4
4.5
5
5.5
6
0.5 0.6 0.7 0.8 0.9 1
T-Level[nC]
Electrode-Modiolus-Distance[mm]
Nucleus 532 (MRA) Nucleus 522 (SRA)
Posi/veCorrela/onbetweenEMDandT-Levels(Averages)
• PsychophysicalvaluesforMRA<PsychophysicalvaluesforSRA
R²=0.0383
3
3.5
4
4.5
5
5.5
6
0 0.5 1 1.5 2
T-Level[nC]
Electrode-Modiolus-Distance[mm]
Nucleus 532 (MRA)
Nucleus 522 (SRA)
Posi/veCorrela/onbetweenEMDandC-Levels(Averages)
R²=0.17254
8
8.5
9
9.5
10
10.5
11
11.5
12
12.5
13
0.5 0.8 1.1 1.4 1.7 2
C-Level[nC]
Electrode-Modiolus-Distance[mm]
• PsychophysicalvaluesforMRA<PsychophysicalvaluesforSRA
R²=0.33071
8
8.5
9
9.5
10
10.5
11
11.5
12
12.5
13
0.5 0.6 0.7 0.8 0.9 1
C-Level[nC]
Electrode-Modiolus-Distance[mm]
0.00
4.00
8.00
12.00
16.00
1 3 5 7 9 11 13 15 17 19 21
T-/C-Level (Q) [nC]
Electrode No.
Psychophysical Thresholds
522 C-Level 512 C-Level 532 C-Level 522 T-Level 512 T-Level 532 T-Level
R²=0.1365
6
8
10
12
14
16
18
0.5 0.7 0.9 1.1
t-NRT[nC]
AverageEMD
• TheECAPthresholdsbecomehigherwithincreasingdistancetothemodiolus.
Posi/veCorrela/onbetweenEMDandECAPThresholds(Averages)
Nucleus 532 (MRA) Nucleus 522 (SRA)
R²=0.07094
6
8
10
12
14
16
0.2 1 1.8
t-NRT[nC]
AverageEMD
SpeechPercep/onatthe1stFi]ng
0
10
20
30
40
50
60
70
80
90
100
Numbers Monosyllables HSM HSM+10dBnoise
[%]MRA(n=10)
Contour(n=10)
SRA(n=10)
No significant differences in speech perception in each test*.
*ANOVA
• NewCBCTresoluTonallowsformeasurementofsingleelectrodeEMDinpostoperaTveCBCTscans
• SOEWidthincreaseswithlargerdistancetothemodiolus
• T-Levels,C-LevelsandECAPthresholdsarelowerinperimodiolararrays
Summary
Thankyouforyoura_en/on.