Transcript Dias nummer 1

Auditory Brainstem Implant
Electrode array inside
cochlea
Nucleus Array In Situ showing 22 channels safely placed in speech frequency range
Auditory cortex
Medial geniculate body
Inferior colliculus
The Auditory
Pathway
Lateral lemniscus
Superior & accessory olive area
Dorsal cochlear nucleus
Ventral cochlear nucleus
VIIIth nerve
Cochlear
Auditory
Brainstem
Implant
(Adapted from "Neurotology",Jackler and Brackmann)
Cochlear
Implant
Diagram showing
relative positions
of a cochlear
implant and
an auditory
brainstem
implant
Nucleus 24 Auditory Brainstem
Implant
Electrode array
(21 platinum disks
0.7mm diameter)
Monopolar
reference electrodes
(ball & plate)
T-shaped
Dacron
mesh
Microcoiled electrode
wires
CI24M receiver-stimulator
Removeable
magnet
Position of ABI in the Brainstem
CEREBELLUM
ICP
LM
PB
ABI
OLIVE
Position of ABI in the Brainstem
PC
Tumour
VIII
V.
VII
Pons
WPS / BLN
VI
Flocculus
IX
Medulla
Penetrating
Auditory Brainstem Implant
ABI Electrode
20
17
16
19
22
21
14
18
11
10
13
15
8
12
4
7
9
2
5
6
85
.mm
Ee
l c trode d a
im e e
t r::0 7
.mm
3
PABI Electrode
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
MRI
Static
Magnetic
Field
(1.5T)
Magnetic
Switched
Gradients
(20 T/s)
Radio
Frequency (RF)
Energy
(2-16KW peak
@ 64 MHz)
FORCE
in Magnetic
components
CURRENT
in conducting
components
HEAT
Removal of Nucleus 24 ABI Magnet
Tests to Ensure
Reliability
Impact
Test
Cochlear 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
Electrode array
(21 platinum disks
0.7mm diameter)
Monopolar
reference electrodes
(ball & plate)
T-shaped
Dacron
mesh
Microcoiled electrode
wires
CI24M receiver-stimulator
Removeable
magnet