{"200301":{"#nid":"200301","#data":{"type":"news","title":"Improved Hearing Anticipated for Implant Recipients","body":[{"value":"\u003Cp\u003EThe cochlear implant is widely considered to be the most successful neural prosthetic on the market. The implant, which helps deaf individuals perceive sound, translates auditory information into electrical signals that go directly to the brain, bypassing cells that don\u0027t serve this function as they should because they are damaged.\u003C\/p\u003E\u003Cp\u003EAccording to the National Institute on Deafness and Other Communication Disorders, approximately 188,000 people worldwide have received cochlear implants since these devices were introduced in the early 1980s, including roughly 41,500 adults and 25,500 children in the United States.\u003C\/p\u003E\u003Cp\u003EDespite their prevalence, cochlear implants have a long way to go before their performance is comparable to that of the intact human ear. Led by Pamela Bhatti, an assistant professor in the School of Electrical and Computer Engineering, a team of researchers at the Georgia Institute of Technology has developed a new type of interface between the device and the brain that could dramatically improve the sound quality of the next generation of implants.\u003C\/p\u003E\u003Cp\u003EA normal ear processes sound the way a Rube Goldberg machine flips a light switch \u2013 via a perfectly-timed chain reaction involving a number of pieces and parts. First, sound travels down the canal of the outer ear, striking the eardrum and causing it to vibrate. The vibration of the eardrum causes small bones in the middle ear to vibrate, which in turn, creates movement in the fluid of the inner ear, or cochlea. This causes movement in tiny structures called hair cells, which translate the movement into electrical signals that travel to the brain via the auditory nerve.\u003C\/p\u003E\u003Cp\u003EDysfunctional hair cells are the most common culprit in a type of hearing loss called sensorineural deafness, named for the resulting breakdown in communication between the ear and the brain. Sometimes the hair cells don\u0027t function properly from birth, but severe trauma or a bad infection can cause irreparable damage to these delicate structures as well.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EContemporary cochlear implants\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003ETraditional hearing aids, which work by amplifying sound, rely on the presence of some functioning hair cells. A cochlear implant, on the other hand, bypasses the hair cells completely. Rather than restoring function, it works by translating sound vibrations captured by a microphone outside the ear into electrical signals. These signals are transmitted to the brain by the auditory nerve, which interprets them as sound.\u003C\/p\u003E\u003Cp\u003ECochlear implants are only recommended for individuals with severe to profound sensorineural hearing loss, meaning those who aren\u0027t able to hear sounds below 70 decibels. (Conversational speech typically occurs between 20 and 60 decibels.)\u003C\/p\u003E\u003Cp\u003EThe device itself consists of an external component that attaches via a magnetic disk to an internal component, implanted under the skin behind the ear. The external component detects sounds and selectively amplifies speech. The internal component converts this information into electrical impulses, which are sent to a bundle of thin wire electrodes threaded through the cochlea.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EImproving the interface\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EAs an electrical engineer, Bhatti sees the current electrode configuration as a significant barrier to clear sound transmission in the current device.\u003C\/p\u003E\u003Cp\u003E\u0022In an intact ear, the hair cells are plentiful, and are in close contact with the nerves that transmit sound information to the brain,\u0022 says Bhatti. \u0022The challenge with the implant is getting efficient coupling between the electrodes and the nerves.\u0022\u003C\/p\u003E\u003Cp\u003EContemporary implants contain between 12 and 22 wire electrodes, each of which conveys a signal for a different pitch. The idea is the more electrodes, the clearer the message.\u003C\/p\u003E\u003Cp\u003ESo why not add more wire electrodes to the current design and call it a day?\u003C\/p\u003E\u003Cp\u003EMuch like house-hunting in New York City, the problem comes down to a serious lack of available real estate. At its widest, the cochlea is 2 millimeters in diameter, or about the thickness of a nickel. As it coils, it tapers down to a mere 200 micrometers, about the width of a human hair.\u003C\/p\u003E\u003Cp\u003E\u0022While we\u0027d like to be able to increase the number of electrodes, the space issue is a major challenge from an engineering perspective,\u0022 says Bhatti.\u003C\/p\u003E\u003Cp\u003EWith funding from the National Science Foundation, Bhatti and her team have developed a new, thin-film, electrode array that is up to three times more sensitive than traditional wire electrodes, without adding bulk.\u003C\/p\u003E\u003Cp\u003EUnlike wire electrodes, the new array is also flexible, meaning it can get closer to the inner wall of the cochlea. The researchers believe this will create better coupling between the array and the nervous system, leading to a crisper signal.\u003C\/p\u003E\u003Cp\u003EAccording to Bhatti, one of the biggest challenges is actually implanting the device into the spiral-shaped cochlea.\u003C\/p\u003E\u003Cp\u003E\u0022We could have created the best array in the world, but it wouldn\u0027t have mattered if the surgeon couldn\u0027t get it in the right spot,\u0022 says Bhatti.\u003C\/p\u003E\u003Cp\u003ETo combat this problem, the team has invented an insertion method that protects the array and serves as a guide for surgeons to ensure proper placement. The research is being done in collaboration with Georgia Regents University.\u003C\/p\u003E\u003Cp\u003EBefore it\u0027s approved for use in humans, it will need to undergo rigorous testing to ensure that it is both safe and effective; however, Bhatti is already thinking about what\u0027s next. She envisions that one day, the electrodes won\u0027t need to be attached to an array at all. Instead, they will be anchored directly to the cochlea with a biocompatible material that will allow them to more seamlessly integrate with the brain.\u003C\/p\u003E\u003Cp\u003EThe most important thing, according to Bhatti, is not to lose sight of the big picture.\u003C\/p\u003E\u003Cp\u003E\u0022We are always designing with the end-user in mind,\u0022 says Bhatti. \u0022The human component is the most important one to consider when we translate science into practice.\u0022\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThe research depicted in this article has been supported by the National Science Foundation, the federal agency charged with funding basic research and education across all fields of science and engineering. Any opinions, findings, and conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003E\u003Cem\u003E\u003Ca href=\u0022http:\/\/www.livescience.com\/27806-cochlear-implants-brain-awareness-bhatti-nsf.html\u0022\u003EThis Behind the Scenes article\u003C\/a\u003E was provided to LiveScience in partnership with the National Science Foundation.\u003C\/em\u003E\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThe writer is Valerie Thompson, Ph.D., AAAS Science and Technology Policy Fellow and National Science Foundation, Directorate for Engineering.\u003C\/em\u003E\u003Cbr \/\u003E\u003Cbr \/\u003E\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EA team of researchers at the Georgia Institute of Technology has developed a new type of interface between cochlear implant devices and the brain that could dramatically improve the sound quality of the next generation of implants. Cochlear implants help deaf individuals perceive sound.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Research aims at improving the performance of cochlear implants."}],"uid":"27303","created_gmt":"2013-03-18 15:52:05","changed_gmt":"2016-10-08 03:13:51","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2013-03-18T00:00:00-04:00","iso_date":"2013-03-18T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"200291":{"id":"200291","type":"image","title":"Pamela Bhatti  with cochlear implant","body":null,"created":"1449179934","gmt_created":"2015-12-03 21:58:54","changed":"1475894853","gmt_changed":"2016-10-08 02:47:33","alt":"Pamela Bhatti  with cochlear implant","file":{"fid":"196549","name":"bhatti-hearing.jpg","image_path":"\/sites\/default\/files\/images\/bhatti-hearing_0.jpg","image_full_path":"http:\/\/tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/bhatti-hearing_0.jpg","mime":"image\/jpeg","size":1126430,"path_740":"http:\/\/tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/bhatti-hearing_0.jpg?itok=6mky6JfK"}}},"media_ids":["200291"],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"145","name":"Engineering"},{"id":"146","name":"Life Sciences and Biology"}],"keywords":[{"id":"2651","name":"auditory"},{"id":"26471","name":"cochlear implant"},{"id":"61891","name":"hearing"},{"id":"12070","name":"Pamela Bhatti"},{"id":"7221","name":"prosthetic"},{"id":"166855","name":"School of Electrical and Computer Engineering"}],"core_research_areas":[{"id":"39441","name":"Bioengineering and Bioscience"},{"id":"39451","name":"Electronics and Nanotechnology"}],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJohn Toon\u003C\/p\u003E\u003Cp\u003EResearch News\u003C\/p\u003E\u003Cp\u003E\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E(404) 894-6986\u003C\/p\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}