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Future
developments
Cochlear Ltd will be focussing on:
- lower
power consumption
- biocompatability
- miniaturisation
- manufacturing
automation.
A
new development of the Nucleus® 24 implant system
is the neural response telemetry tool.
Neural
response telemetry (NRT)
The NRT tool provides a simple way to directly record
neural responses. Information from Nucleus NRT gives
the audiologist or surgeon confirmation that the cochlear
implant is effectively stimulating the hearing nerve
fibres in the inner ear and all conveniently measured
within minutes. This non-invasive, objective test is
quicker and easier than other standard methods and does
not require sedation or the use of external recording
electrodes.
NRT
measurements assist clinicians in selecting and optimising
initial programming parameters — speeding and simplifying
the programming of young children. NRT is unique to
the Nucleus® 24 implant system and provides an objective
measure of auditory nerve function.
During
NRT testing, an electrical signal is sent to the implant
electrode and the activity of the hearing nerve fibres
is recorded. All of the 22 electrodes of the Nucleus
cochlear implant can be measured if required. NRT can
be performed during the cochlear implant surgery and
at the follow-up appointments any time after surgery.
NRT testing (Cochlear Pty Ltd)
| 1. |
The
test can be performed at any time by connecting
a speech processor to a programming system running
the Nucleus NRT software on a computer |
| 2. |
A
pulse is delivered from one electrode to the hearing
nerve fibres in the inner ear. |
| 3. |
The
hearing nerve fibres respond to the pulse. |
| 4. |
The
implant system sends the response back to the computer
which collects the information. |
The
steps are repeated to build a profile of the responsiveness
of the hearing nerve fibres at different sites on the
electrode array.
Improving the implant
Australian researchers are continually looking to improve
the Cochlear implant. The pre-curved electrode has demonstrated
better sound discrimination when tested against previous
implants. Another area they will be focussing on is
the possibility of making the whole device invisible.
To do this the speech processor and microphone could
also be implanted inside the body. Sound vibrations
in the skin could be detected using a piezo-electric
microphone, or the vibrations of the middle ear ossicles
could be sensed and transmitted to the brain.
Another
important area for research is the use of nerve growth
factors to protect the hearing nerve from dieback and
also regenerate the nerve. This could be used in combination
with the Cochlear implant to improve effectiveness or
could provide a complete pharmacological cure for sensori-neural
hearing loss.
Growth
of the cochlear implant industry is backed by research
and development conducted in Australia and overseas.
In Australia, the Cooperative
Research Centre for Cochlear Implant, Speech and
Hearing Research, the Bionic Ear Institute, the University
of Melbourne Department of Otolaryngology and the
Human Communication Research Centre are all involved
in cochlear implant research. Ongoing research aims
to:
- improve
the cochlear implant by increasing understanding of
how electrical stimulation by the cochlear implant
is perceived by the users, and how best to present
speech information to them
- minimise
the impact of noise on the clarity of the speech signal
provided by the cochlear implant
- maximise
the benefit that young children gain from the cochlear
implant
- improve
the understanding of how the auditory nerve fibres
and brain respond to the electrical stimulation of
the cochlear implant, including the testing of newer
modes of electrical stimulation
- develop
new speech processing strategies through computer
simulations of the response of the auditory system
to acoustic and electrical stimulation
- improve
the design of the cochlear implant electrodes
- improve
pre- and post-operative clinical management
- improve
surgical procedures
- develop
a technique for direct electrical stimulation of the
brainstem for deaf people who are unable to use the
cochlear implant - particularly those with few residual
auditory nerve fibres
- make
the cochlear implant suitable for people who still
have some hearing
- combine
cochlear implant and hearing aid strategies, so that
people — particularly those with some hearing
— can continue to benefit from a hearing-aid
once they have a cochlear implant
- investigate
the use of two microphones — one behind each
ear — to improve the perception of speech in
noisy environments
- develop
a cochlear implant or hearing aid that resides entirely
under the skin. The first stage of this research is
the development of a microphone system that can be
completely implanted
- and
develop ways of initiating auditory nerve regeneration
to enhance the effectiveness of existing cochlear
implant systems. http://www.science.org.au/nova/029/029box03.htm
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