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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 AbensEE 4611 Kevin ChanMay 2, 2014 Slide 2 Outline History of Cochlear Implant How the ear works Device structure Bio-friendly materials Pros/Cons Potential Improvements Future of Implant Slide 3 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. Slide 4 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 Slide 5 How the ear works Outer o Canal o Drum Middle (bones) o Malleus, Incus, Stapes Inner o Cochlea o Auditory Nerve Slide 6 Types of Hearing Loss Conductive o Middle ear Sensorineural o Inner ear stereocilia Cochlear Nerve o Connection to brain Slide 7 Components External o Microphone o Speech processor o Transmitter Internal o Receiver/Stimulator o Electrode Array Slide 8 MED-EL Electrode Array Slide 9 Insertion of Electrode Array Slide 10 Demonstrations of sound Robotic-like Fuzzy radio Context helps understanding http://auditoryneuroscience.com/prosthetics/noise_vocoded_speech Slide 11 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 Slide 12 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 isnt automatic Static electricity damage Costs $45,000 to $105,000 Slide 13 Potential Improvements Completely internal Water resistivity Resolution Battery Life Manufacturing cost Biomaterials Slide 14 Laser-based cochlear implant Electric stimulation isnt 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 Slide 15 Summary How the ear works Device structure Potential Improvements Infrared light stimulation Slide 16 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/ Slide 17 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 isnt precise because electric current can disperse into tissue. Laser stimulation is being studied to improve the precision of implants.