Cochlear ImplantsABSTRACT: 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 EE 4611 Kevin Chan 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• 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 Cochlear Limited
Cochlear™ Nucleus® This is the timeline of their
implant components Advanced Bionics
Harmony™ processor HiRes 90K™ implant
Medical Electronics (MED-EL) MAESTRO™ 3.0 system
How the ear works• Outer
o Canalo Drum
• Middle (bones)o Malleus, Incus,
Stapes• Inner
o Cochleao Auditory Nerve
Types of Hearing Loss• Conductive
o Middle ear• Sensorineural
o Inner ear stereocilia• Cochlear Nerve
o Connection to brain
Components• External
o Microphoneo Speech processoro Transmitter
• Internalo Receiver/
Stimulatoro Electrode Array
MED-EL ElectrodeArray
Insertion of Electrode Array
Demonstrations of sound • Robotic-like• Fuzzy radio• Context helps understandinghttp://auditoryneuroscience.com/prosthetics/noise_vocoded_speech
Bio-friendly materials• Silicone (1,5)
o Used to case the electronic
• Ceramics (older models)o Weak and sensitive to external forces
• Titanium (2)o Replaced ceramic components
• Platinum (3)o Used for electrode contacts
Pros Cons
• 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
• 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• Completely internal• Water resistivity• Resolution• Battery Life• Manufacturing cost• Biomaterials
Laser-based cochlear implant
• 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
o This causes nerve cells to release neurotransmitters
Summary● How the ear works● Device structure● Potential Improvements● Infrared light stimulation
SourcesGeneral Informationhttp://www.medel.com/us/https://wiki.engr.illinois.edu/download/attachments/48137228/ECE+415+Cochlear+Implant+Final.pdfhttp://www.asu.edu/clas/shs/cilab/documents/publications/2004dormanwilson.pdfhttp://www.nlm.nih.gov/medlineplus/ency/article/007203.htmhttps://www.nidcd.nih.gov/health/hearing/pages/coch.aspxhttp://www.asha.org/public/hearing/Cochlear-Implant-Frequently-Asked-Questions/http://www.cdc.gov/ncbddd/hearingloss/types.htmlhttp://teamhearing.org/blogs/?tag=cochlear-implantsLaser based implanthttp://www.popsci.com/technology/article/2012-04/how-it-works-artificial-hearing-device-made-lasersBiomaterialshttp://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.
• 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.
