Transcript Cochlear Implants

Cochlear Implants
ABSTRACT: WHEN A PERSON LOSES HEARING, COCHLEAR IMPLANTS
MAKE IT POSSIBLE TO RESTORE THEIR ABILITY TO HEAR. THROUGH
SURGICAL PROCEDURE, A SYSTEM OF ELECTRONIC COMPONENTS IS
ABLE TO REPLACE A DAMAGED BIOLOGICAL SYSTEM. THE MOST
IMPORTANT PART OF THE SYSTEM IS THE ELECTRICAL TO BIOLOGICAL
CONNECTION MADE BY THE ELECTRODES.
Presented by: Connor Abens
Kevin Chan
EE 4611
May 2, 2014
Outline
● History of Cochlear Implant
● How the ear works
● Device structure
● Bio-friendly materials
● Pros/Cons
● Potential Improvements
● Future of Implant
History
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1800 Allesandro Volta stimulated inner ear with electricity
1956 Cochlear implant was designed
1978 First multi-channel cochlear implant
1980 FDA began regulation of cochlear implants
1984 First implant in an adult approved by FDA
1990 FDA approved implant for children above 2 years old
2000 FDA approved implant for infants above 12 months of age.
Development
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Cochlear Limited
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Cochlear™ Nucleus®
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This is the timeline of their implant
components
Advanced Bionics
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Harmony™ processor
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HiRes 90K™ implant
Medical Electronics (MED-EL)
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MAESTRO™ 3.0 system
How the ear works
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Outer
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Canal
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Drum
Middle (bones)
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Malleus, Incus, Stapes
Inner
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Cochlea
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Auditory Nerve
Types of Hearing Loss
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Conductive
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Middle ear
Sensorineural
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Inner ear stereocilia
Cochlear Nerve
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Connection to brain
Components
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External
o Microphone
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Speech processor
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Transmitter
Internal
o Receiver/Stimulator
o Electrode Array
MED-EL Electrode
Array
Insertion of Electrode Array
Demonstrations of sound
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Robotic-like
Fuzzy radio
Context helps understanding
http://auditoryneuroscience.com/prosthetics/noise_vocoded_speech
Bio-friendly materials
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Silicone (1,5)
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Used to case the electronic
Ceramics (older models)
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Weak and sensitive to external forces
Titanium (2)
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Replaced ceramic components
Platinum (3)
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Used for electrode contacts
Pros
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Hearing is possible
immediately after surgery
Sensitivity to a variety of
sounds
Eliminates the reliance upon
other people
Potentially enjoy music
Upgradable components
Speech understanding
without lip-reading
Cons
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Loss of natural hearing
Possible negative side effects
Must avoid water damage
Electromagnetic noise
Relative Volume isn’t
automatic
Static electricity damage
Costs $45,000 to $105,000
Potential Improvements
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Completely internal
Water resistivity
Resolution
Battery Life
Manufacturing cost
Biomaterials
Laser-based cochlear implant
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Electric stimulation isn’t precise
Modified cells react to light stimulation
Precision lasers instead of electrodes
Testing in rats and toadfish
Infrared light affects calcium ion flow
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This causes nerve cells to release neurotransmitters
Summary
● How the ear works
● Device structure
● Potential Improvements
● Infrared light stimulation
Sources
General Information
http://www.medel.com/us/
https://wiki.engr.illinois.edu/download/attachments/48137228/ECE+415+Cochlear+Implant+Final.pdf
http://www.asu.edu/clas/shs/cilab/documents/publications/2004dormanwilson.pdf
http://www.nlm.nih.gov/medlineplus/ency/article/007203.htm
https://www.nidcd.nih.gov/health/hearing/pages/coch.aspx
http://www.asha.org/public/hearing/Cochlear-Implant-Frequently-Asked-Questions/
http://www.cdc.gov/ncbddd/hearingloss/types.html
http://teamhearing.org/blogs/?tag=cochlear-implants
Laser based implant
http://www.popsci.com/technology/article/2012-04/how-it-works-artificial-hearing-device-made-lasers
Biomaterials
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199815/
5 Key Concepts
• Sounds travels through the ear canal then causes mechanical
vibration which creates waves in the cochlear fluid. Those waves
move the small hairs that stimulate the nerve cells.
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Cochlear implant directly stimulates nerve cells in the cochlea
Electronic Components consist of: microphone, processor,
transmitter, stimulator.
Silicone, ceramics, titanium and platinum are the materials used
and accepted by the body.
Electrode stimulation isn’t precise because electric current can
disperse into tissue. Laser stimulation is being studied to improve the
precision of implants.