Transcript Cochlear Implants: Where We`ve Been, Where We`re Going

Cochlear Implants:
Where We’ve Been,
Where We’re Going
Amber M. Gardner, Ph.D., CCC-A
University of Virginia Health System
Early Attempts…

Alessandro Volta – early 1800s became the first
to stimulate the auditory system electrically
Two metal rods in his ears (approx. 50V)
 “a boom within the head” followed by a sound
similar to that of boiling thick soup

Early Attempts…


Realization made over the next 50-60 years that
since sound is more of an alternating signal,
stimulating with DC wasn’t going to produce an
adequate hearing sensation
Duchenne – 1885 – used an alternating current

“the beating of a fly’s wings between a pane of glass
and a curtain”

Improving, but not there yet…
Early Attempts…

Brenner – 1868 – published study that revealed
hearing sensation was better using negative
polarity. Also found that a reduction of
unpleasant side effects could be achieved with
correct placement of the electrodes
Early Attempts…


1930s – thermonic valve (vacuum tube) was
introduced and this allowed greater precision in
electrical stimulation
Wever & Bray (1930)– electrical response
recorded near the auditory nerve of a cat was
similar (freq. & amplitude) to sounds to which
the ear had been exposed
Early Attempts…

Gersuni & Volokhov (1936) First to
demonstrate that with electrical stimulation
hearing sensation still remained after removal of
tympanic membrane & ossicles – theorized the
cochlea was the site of stimulation
Early Attempts…

Stevens & Jones (1939) – Listed several
mechanisms that produced hearing when the
cochlea was stimulated electrically
Electrical energy could be converted into sound by a
direct effect on the basilar membrane that would
vibrate maximally at a point determined by the
frequency – these vibrations would stimulate the
hair cells
 Direct stimulation of the auditory nerve produced a
crude hearing sensation.

Early Attempts…

1940s & 1950s – Researchers began to realize
that if more precise hearing sensations were to
be produced stimulation of the auditory nerve
fibers must be more localized vs. widespread
current.
Early Attempts…


1950 – Lundberg stimulated the auditory nerve
during a neurosurgical operation. Used a
sinusoidal current - patient only heard noise.
1957 – Djourno & Eyries – placed a wire
directly on the auditory nerve (cholesteatoma
surgery). Initially pt. just heard “a roulette
wheel” & “a cricket” but was eventually able to
differentiate pitch and identify several words.
Getting Closer

Doyle et al (1964) inserted an electrode array (4
electrodes) into the cochlea of a deaf patient


Patient was able to repeat phrases
Simmons (1966) inserted an electrode array into
the cochlea with more precision (closer to the
modiolus)

Patient had ability to determine signal duration
length and tonality was achieved
Almost There


Early 1970s - Michelson and House - insertion
of electrode array through scala tymani driven
by implantable receiver stimulators.
1972 – speech processor developed to interface
with the House 3M single electrode implant &
was commercially marketed.

Single channel devices - very poor speech
understanding (especially in open set)
Multi-channel Cochlear Implant
Rod Saunders –
First multi-channel
CI patient (1978)
Courtesy: Cochlear
Increasing Channels - Speech

Channels will increase from 1 to 2, 2 to 4, 4 to 8
to 32 – note the improvement in quality.
Increasing Channels - Music

First you will hear the song with 4 channels,
then 8, then 16, then 32 – finally you will hear
the original.
Demo
Trends in Candidacy
1985
1990
1998
Today
Age of
Implantation
Adults age 18 or
older
Adults & Children age
2 years or older
Adults & Children age
18 months +
Adults & Children age 12
months +
Onset of Hearing
Loss
Postlinguistic
Postlinguistic Adults &
Pre/Postlinguistic
Children
Pre/Postlinguistic
Adults & Children
Pre/Postlinguistic
Adults & Children
Degree of
SNHL
Profound
Profound
Severe-to-Profound
Adults
Profound Children
Severe-to-Profound Adults,
Children > age 2
Profound children
< 2 years old
Adult Speech
Scores
(open–set)
0%
0%
40% or less sentences in
quiet
50% on sentences in quiet in
ear to be implanted, with 60%
or less in contralateral ear or
binaurally
Pediatric Speech
Scores
N/A
0%
Lack of auditory
progress,
Less than 20% pediatric
word tests
Lack of auditory progress,
30% or less on pediatric word
tests
3 FDA Approved CI Manufacturers



Cochlear – 1985
Advanced Bionics – 1996
MedEl – 2001 (1994 – European release)
Speech Processor (1978)
Courtesy: Cochlear
Speech Testing (1978)
Courtesy: Cochlear
Cochlear – Portable Speech
Processor
1980 – 2nd
Recipient
(George
Watson)
Courtesy: Cochlear
Nucleus 22 Device
Courtesy: Cochlear
Wearable Speech Processor (WSP)
1982
Courtesy: Cochlear
From WSP to Mini Speech Processor
(MSP) 1986
Courtesy: Cochlear
CI22M (Mini 22 Implant)



Courtesy: Cochlear
Magnet
Flexible receiver antenna
1988
MSP to Spectra

Courtesy: Cochlear
Introduced in 1988 to go
with the CI22M
CI24M





Courtesy: Cochlear
1997
Removable Magnet
Monopolar electrodes
Telemetry – can measure
impedances
Stimulation rates
increased
Spectra to Sprint



Courtesy: Cochlear
1997
Increased number of
program slots
More flexibility
Esprit


Courtesy: Cochlear
1998
First BTE processor
from Cochlear
Esprit 3G


Courtesy: Cochlear
2002 (24 users)
2004 (22 users)
Freedom


Courtesy: Cochlear
Courtesy: Cochlear

2005 - New internal &
external devices
Same processor for
BTE, bodyworn options
New “Smart Sound”
features
System 5



Courtesy: Cochlear
Courtesy: Cochlear
Courtesy: Cochlear
Launched Sept. 8, 2009
Internal device – thinner,
but same technology
platform
External – thinner, more
water resistant,
autophone, 2 way
remote control
Advanced Bionics History



Company started by Al Mann in 1993
1996 - received FDA approval for adults
1997 - received FDA approval for pediatrics
Advanced Bionics



Courtesy: Advanced Bionics
1.0 – 1994 (adults)
1.2 – 1996 (adults), 1997
(pediatrics)
CII ~ 2000
HiRes 90k



Courtesy: AB
2003
Titanium (vs. ceramic)
housing
Removable magnet
AB – Body Worn Processors
Courtesy: Advanced Bionics
1.0 - 1994
1.2 - 1996
S-Series
~ 1999
PSP~
2001
AB – BTE Speech Processors
Courtesy: Advanced Bionics
Platinum BTE
1998
CII BTE
2000
Auria & Harmony
2003 & 2006
MedEl History







1975 - Hochmairs begin development of
cochlear implant
1977 - Multi-channel CI implanted in Vienna
1989 - MedEl is founded
1991 - Industry first BTE speech processor
(trials)
1994 - European approval of MedEl system
2001 - FDA approval of MedEl system
2003 - FDA approval of MRI compatibility (.2
MedEl Internal Devices

Combi 40+
Introduced 1996
Pulsar CI
100 and



Sonata
Pulsar – September
2005 (Ceramic
Housing)
Sonata – September
2007 (Titanium
Housing)
Magnet fixed
Courtesy: MedEl
38
Tempo+ Speech Processor (1999)



Lightest BTE
Processor
Up to 9 Programs
One processor –
multiple wearing
options
Courtesy: MedEl
39
Opus 2 Speech Processor 2007



Courtesy: MedEl
Ergonomic switch
free design
Wireless FM
Fine Tuner – bilateral
support, volume,
sensitivity & telecoil
switches
Future Directions



Greater number of bilateral recipients
Hybrid/EAS cochlear implants
Totally implantable cochlear implants
Bilateral CI

Benefits
Improved localization
 Improved speech in noise performance


Insurance Coverage - class action law-suits
Hybrid/EAS


EAS - Electric-Acoustic Stimulation
Combination of CI & HA
High frequency information - shorter electrode
array
 Low frequency information - HA (typically mild to
moderate HL)


Still in clinical trials in US


MedEl
Duet
Approved in Europe (2007)
All 3 companies still in US trials
Courtesy: MedEl
43
Hybrid/EAS

European & trial data indicates patients are
performing significantly better with EAS than
CI alone or HA alone


Noted especially in music & speech in noise
Points to consider
Risk of damage to residual hearing acuity during
original insertion of electrode array
 What is the course of action if hearing acuity
changes and HA is no longer beneficial - additional
surgery with new/standard array?

Totally Implantable Cochlear
Implant (TICI/TIKI)

Internal Components
Rechargeable battery (lithium ion)
 Microphone (subcutaneous)
 Speech processor


External Hardware
Battery recharger
 On/Off
 Volume/Sensitivity

TIKI
Totally Implantable Cochlear
Implant (TICI/TIKI)

Benefits

No external parts
able to “hide deafness”
 no cables, mics... to break


Able to hear 24hrs a day (in shower, while
sleeping...)
Totally Implantable Cochlear
Implant (TICI/TIKI)

Disadvantages
Larger internal device - more surgical time/larger
incision
 Battery will have to be replaced (approx. 6yrs)



Replace only battery or entire device?
Hear “body noises” (breathing, swallowing). Some
people are unable to adjust to these.
TIKI Results



3 patients implanted Melbourne
Able to have “invisible hearing” or use 3G
processor
Hearing acuity
TIKI - Mild to moderate HL (improving to mild HL
after 6 months)
 3G - Hearing WNL


Speech discrimination - CNC Lists
TIKI - 33% (Improved as compared to pre-op)
 3G - 77%

Thank you