Cochlear implants are electronic devices that bypass damaged parts of the inner ear to provide a sense of sound to someone who is profoundly deaf or severely hard of hearing. They work by directly stimulating the auditory nerve with electrical signals. The first modern cochlear implant was developed in 1978 and provided multiple channels of stimulation, allowing for understanding of speech. Cochlear implants have since improved and are now commonly used worldwide to help many deaf individuals perceive sound and improve their ability to communicate.

3. What is cochlear implant?
 Cochlear Implant (Bionic Ear) is an
artificial electronic hearing device
designed to produce useful hearing
sensations by stimulating Cochlear
nerve inside the Inner Ear.

4.  It transforms the mechanical energy of
sound into electrical energy which
directly excites the remaining auditory
fibers.
 It is surgically implanted underneath the
skin behind patients ear

5. Purpose
 A cochlear implant bypass
nonfunctional parts of the ear and
directly stimulating the auditory
nerve.
 It does not merely amplify sound.
 It increases the amount of nervous
response to sound.
 It often improves sound detection
and increases speech understanding

7. “The more you know about the
past, the better prepared you
are for the future”
Theodore Roosevelt

8. Historical Background
* In 1751 Benjamin Franklin first suggested
that Electricity could produce hearing
sensation in the Deaf.
* Alessandro Volta (1800) placed metal rods
into both his Ears and connected them to a
source of Electricity. Before he lost
consciousness apparently he heard the
sound of bubbling water.

9.  *At the end of 19th century, Many famous
Otologists including Politzer, Ritter and
Gradenigo were interested by the finding
that passing an alternating current through
electrodes applied around the ear
produced sound.

10. 
In 1934, Andreed, Gersuni and Volkhov
published their report entitled,`Electrical
stimulation of the hearing organ` where an
electrode was placed near the round
window and described various hearing
sensations. Similar finding was reported by
Jones,Stevens and Lurie in 1940. William
F. House began thinking about & working
on possibility of CIs in 1956.

11.  1957-(French-Algerian surgeons Andre
Djourno and Charles Eyries) ; They were
the first who attempted to produce the first
cochlear implant.
It was single channel device.
The two subject claimed that the devices
helped them greatly with lip reading.
According to Zollner and Keidel(1963),the
Implants in Djurno’s patients were still
functioning 4-5 years later and the auditory
sensations remained unchanged.

12.  Due to some untoward effects noticed in
subjects implanted by House(1961) and
Simmons et al (1964) leading specialists
urged not to do further Implants until
much more basic animal research had
been completed. This effectively
stopped further clinical work for several
years although much work continued in
laboratory.

13.  1964- Blair Simmons at Stanford
University implanted some recipients
with a six-channel device.
 However, it was Dr. Michelson's patent
and ultimate device, which are thought
of as the first cochlear implants

14.  In 1969 human studies began again when
House implanted a further patient. It was a
bold move when House used a six-electrode
system designed by Jack Urban which were
Hardwired. The patient was tested extensively
for two years in the laboratory as, a wearable
external stimulator was not available until
1972. The Result was sufficiently encouraging
and then further 10 patients were Implanted in
1973 and finally despite much criticism the CI
was established as a means of alleviating
Total Deafness. Similar clinical works were
carried out in San Francisco (Merzenich-
1975), France (Chouard et al-1984),Germany
(Benfai et al-1984) and in Austria(Burian et al-
1984) during this period.

15.  William F. House produced 1st practical CI
in 1984 in conjunction with the House Ear
Inst. & the 3M corporation. With recent
Multichannel Devices it is expected that a
Deaf Child who can Hear with CI will have
the same educational outcome and
employment prospects as a Hearing Child.
 Prof.Graeme Clark of U M is creator &
developer of World’s first M-C Implant &
considered father of CI.

16.  More Recently, Multichannel Auditory Brain
Stem Implant (ABI) has been developed
based on CI technology. It is indicated in
patients having Bilateral Total Deafness not
suitable for CI (e.g;Bilateral Skull base
fracture, Ossified Cochleas). Here
Electrodes are placed in the entrance of
the 4th Ventricle to stimulate the Auditory
Pathway on the level of 2nd Neuron, the
Cochlear Nucleus Complex. Patients
having ABI have measurable benefits and
reported improvements of life quality.

17.  The first cochlear implant was invented by
Dr. William House, in 1961.[2] In 1964, Blair
Simmons and Robert J. White implanted a
six channel electrode in a patient's cochlea
at Stanford University.[3]
 The modern multichannel cochlear implant
was independently developed and
commercialized by Graeme Clark from
Australia and Ingeborg Hochmair and her
future husband, Erwin Hochmair, with the
Hochmairs' first implanted in a person in
December 1977 and Clark's in August 1978

18. Cochlear implant in Bangladesh
 On 13th December,2008 ,3rd time in Sir
Salimullah Medical College& Mitford
Hospital and 1st time in Dhaka Medical
College Hospital 5 Cochlear Implant was
done successfully.
 Now multiple hospitals provide CI
surgery in Bangladesh.

19. CI in Bangladesh

20. Parts of CI
 Cochlear implants
consist of internal and
external parts.
 The external parts
include a microphone,
a speech processor,
and a transmitter.
 The internal parts
include a receiver-
stimulator and an
electrode.

22. How does it work?

24. Selection criteria - children
 pre –lingually deaf children : On child
above 12months below 7 years.
At birth the cochlea is fully formed but the
auditory pathway is not. Auditory pathway is
dependent on stimulation for its maturation
and this stimulation is vital to acquisition of
speech and language skill as well as amount
of cognitive development.
 Post lingual deaf :no age limit

25.  degree of deafness- profound >90dB SNHL
with poor discrimination in both ears with
cochlear nerve.
 Respond to hearing aid- in those who do not
benefit from a hearing aid ,at least 3 to 6
months of use.
 Absence of contraindications- cochlear aplasia
or absent cochlear nerves are absolute
contraindications to cochlear implantation.

26. Selection criteria- adult
 Severe or profound hearing loss with
PTA of 70dB or greater heaing level
 Little or no benefit from hearing aids.
 Aided scores on open-set sentence test
of less than 50%.

27.  No evidence of central auditory lesions
or lack of an auditory nerve.
 No medical or radiological
contraindications for surgery

28. Pre-Operative Evaluation
 History
• genetic hearing loss
• auditory neuropathydyssynchrony
• Acquired deafness

29.  Physical examination-
 Audiological evaluation
 Electrophysiological test
 Auditory brainstem response (ABR)-
a)verify audiometric test result
b)identify patient with auditory
dyssynchrony
c)rule out possibility of functional
deafness

30.  Speech Perception Test
 Imaging
High resolution temporal bone
computed tomography
Magnetic resonance imaging

32. Cochlear Implant Surgery
 done by an implant team consisting of your
otology surgeon, a cochlear implant
audiologist, a radiologist, and, as needed,
a social worker, a psychologist or
psychiatrist
 Implant surgery is performed under general
anesthesia and lasts from two to three
hours. An incision is made behind the ear
to open the mastoid bone leading to the
middle ear. The procedure may be done as
an outpatient, or may (rarely) require an
overnight stay in the hospital

33. Post –operative Evaluation
 Device activation after 4-6 weeks
 Auditory rehabilitation after cochlear
implant
- Listening training
- Speech training
- Language training
- Delelopment of communication skills
- Involvement of family members

34. Rehabilitation
 With children, regular listening, speech
and language therapy would be
maintained for as long as appropriate,
which could be a number of years.
 The goal is to optimize patients’ hearing,
help developing listening and
communication skills, promote speech
and language acquisition and deal with
medical issues.

36. Complications
As with all operations, there are risks with
this surgery. These include:
 infection at the incision site
 bleeding
 complications related to anesthesia
 transient dizziness
 facial paralysis (rarely)
 temporary taste disturbances
 additional hearing loss
 device failure

37.  However, it should be noted that serious
surgical complications have been
observed at only one in 10,000
procedures of this type.
 Some long-term risks of the implant
include the unknown effects of
electrical stimulation on the nervous
system.
 It is also possible to damage the
implant's internal components by a
blow to the head, which will render the
device unworkable.

38.  A further consideration is that the use of(MRI)
for patients with cochlear resonance imaging
implants is not recommended because of the
magnets present in the devices.
 Several companies have developed implants
that do not use magnets or have altered the
receiver-stimulator make up to make it easier
to remove the magnets before testing.
 One fact that reduces the concern about MRI
testing is that for many medical indications,
MRI can be replaced with a computer assisted
tomography scan (CAT or CT scan), which is
not a problem for persons with cochlear
implants.

39.  Additionally, in July 2002, the Food and
Drug Administration (FDA) issued a
warning about a possible connection
between increased incidence of meningitis
and the presence of a cochlear implant.
 This warning included special vaccine
recommendations for those with implants,
as well as the voluntary removal from the
market of certain devices. Specifically,
those implants that included a positioner to
hold the electrodes in place in the cochlea
appear to be associated with an increased
risk of the disease

40. Prospect of Cochlear Implant
in Bangladesh
 A good number of patients really need Cochlear
Implant in our country (In USA 500000-700000
could get benefit from CI). In the past we were
not ready to accept the program in our country
due to lack of initiative and high price of the
program. Recently cost (Price of the device,
evaluation, surgery, rehabilitation) of the
program is getting down. Effort is going on for
development of an affordable effective Implant
for developing countries. Very soon we will get a
law-cost high-performance CI.

41.  We have already done more than 10 Cochlear
Implant Surgery in Dhaka Medical College and
Sir Salimullah Medical College in the
department of Otolaryngology in Bangladesh.
A Cochlear Implant team from India and Uk
help us to complete our dream project.
It is now true that deaf and dumb child will no
longer disable and able to speak again after
Surgery. This arrangement will help
transferring high-tech technology development
of manpower (ENT Surgeons) in Bangladesh

42. THANK YOU