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Auditory Brainstem Implant
Electrode array inside cochlea
Nucleus Array In Situ - showing 22 channels safely placed in speech frequency range
The Auditory Pathway
Diagram showing relative positions of a cochlear implant andan auditory brainstem implant
Medial geniculate body
Inferiorcolliculus
Lateral lemniscus
Superior&accessory olive areaDorsal cochlearnucleusVentralcochlearnucleus
(Adapted from"Neurotology",Jacklerand Brackmann)
Cochlear
Auditory cortex
VIIIthnerve
CochlearImplant
AuditoryBrainstemImplant
Nucleus 24 Auditory Brainstem Implant
CI24M receiver-stimulator
Monopolarreference electrodes
(ball & plate)
Microcoiled electrodewires
Electrode array(21 platinum disks0.7mm diameter)
T-shapedDacronmesh
Removeablemagnet
Position of ABI in the Brainstem
ICP
OLIVE
PB
LM
ABI
CEREBELLUM
VIII
VII IX
VIPons Medulla
FlocculusPC
V.
Tumour
WPS / BLN
Position of ABI in the Brainstem
PenetratingAuditory Brainstem Implant
PABI ElectrodeABI Electrode
8.5mm
Electrode diameter:: 0.7mm
2
3
4
5
6
7
8
9
10
11
12
14
13
15
16
17
18
19
20
21
22
Penetrating ABI Location
Rikke Pedersen 20 y
ABI 24 Advantages and Benefits
• Optimizes stimulation using 21 distinct sites.
• Potential to Confirm placement using NRT.
• Widest choice of Coding strategies.
MRI Considerations
MRIStatic
Magnetic Field(1.5T)
Magnetic SwitchedGradients (20 T/s)
Radio Frequency (RF)
Energy(2-16KW peak
@ 64 MHz)
FORCE in Magnetic components
CURRENT in conductingcomponents
HEAT
Removal of Nucleus 24 ABI Magnet
Tests to Ensure Reliability
Impact Test
Tests to Ensure Reliability
Impact TestCochlear routinely conducts tests to ensure the reliability of our products. For example, the CI24M implant has undergone extreme impact testing to verify ruggedness by simulating a blow to the head of a T-ball travelling at 65.0km/h (40.4mph).Test rig: impact hammer with T-ball with a mass of 3.6 kg (7.9lb), dropped through 450mm (17.7in).
Nucleus 24 Auditory Brainstem Implant
CI24M receiver-stimulator
Monopolarreference electrodes
(ball & plate)
Microcoiled electrodewires
Electrode array(21 platinum disks0.7mm diameter)
T-shapedDacronmesh
Removeablemagnet