I even thought this would become the stan-dard design for transducers in the future.”At Rion, this structure is now referred to as the “i transducer.” e “i” of course is the rst letter of Iwakura’s family name. He reects on how he managed to realize this structure.“e road was pretty rough, but I felt it ultimately depended on how the logic could be pieced together. I didn’t have the goal clearly in my sights yet, but I learned from my mistakes and listened to advice. I felt I was making progress, even if it was very slow progress. I am a later bloomer.” In 2013, the development of the cartilage conduction hearing aid was adopted as a commissioned project by the Ministry of Economy, Trade and Industry. ose of us at Rion got to work for three years in partnership with Nara Medical University (in charge of clinical evaluations) and the Chofu Electronics Engineering Co., Ltd. (in charge of mold production for the transducer parts). By that time, we had the manpower, the materials, and the funds to develop a real product.”In Search of an Ear Chipto Fit Any Ear ShapeIn 2013, Keisuke Watanuki joined the team to develop the cartilage conduction hearing aid. He took a course that diered from the course taken by Iwakura in the latter’s eorts to develop a transducer and found himself struggling to nd his way in the dark. Watanuki had experience in designing hearing aid housings. His role in developing the cartilage conduction hearing aid was to develop the ear chip (attachment part) for attaching the hearing aid to the ear.“When I rst laid eyes on the cartilage conduction hearing aid being developed with its large battery, I honestly had doubts it would ever become a product. But over time, working alongside Iwakura, I began to believe it would become a great product. My excitement kept growing as our goal came into sight.”What he found most challenging was nding a way to t the ear chip to the ear shape of potential users. e individual cases presented by potential users vary signicantly—some may have no external ear, others may only have a slight surgi-cally created indentation. In order to x the transducer properly onto the ear of any user, Watanuki had to nd a way to make customized attachment parts.“e heavier the ear chip, the lower the sensitivity in the high-frequency range, so I had to create a lightweight ear chip design. Another problem was the alignment of the direction of the vibration with the direc-tion of the user’s head. at’s necessary to maintain sensitivity. at’s why I decided to proceed with design work applying a custom-made hearing aid system with 3D printing technology, something that could create ear chips of complex shapes.”He collected molds of various ear shapes and did 3D scans and modeling before the 3D printing process. He repeated this process over and over. It was extremely challenging to create a lightweight ear chip that would t securely while maintaining the desired direction of vibration.“For ordinary hearing aids, an ear chip can be made once you have the ear mold. But the ear shapes of potential cartilage conduction hearing aid users are expected to be much more diverse. I also used photographs of each individual’s ear to determine the optimal ear chip shape. If the nished ear chip is heavy, auditory quality suers, and the risk of users drop-ping the hearing aid grows. So I had to shave o as much excess weight as possible. Initially, the person in charge of produc-tion told me it was impossible. But as we made more prototypes, we both slowly but surely gained experience and know-how. Although, even then, I have to say the goal still seemed a great way o.”Eventually, Watanuki succeeded in manu-alizing the ear chip production procedure with the cooperation of the person in charge of production. When asked about his satisfaction with his achievement, this was his reply.“I was present for the validation of the comfort of the cartilage conduction hear-ing aid performed at the Nara Medical University. A little child reluctantly put on the hearing aid while the mother stood by looking very worried. When the child’s face instantly lit up, I knew the child could hear. e mother began to weep with joy. I too shed tears in sympathy. I wouldn’t trade that moment for anything. at moment was truly a reward.”Opening a New Door to Hearing AidsYoko Fujishima, one of the frontline sta at the Rionet Center, oers hearing con-sultation services to her clients daily and provides them with optimal solutions. e emergence of cartilage conduction hearing aids, she says, has expanded the range of the solutions she can oer.“I can’t recommend air conduction hearing aids to those born without a properly-formed external auditory canal. In those cases, I have no choice but to recommend a bone conduction hearing aid. e cartilage conduction hearing aid changed all that. Now I can oer a wider range of solutions. e transducers on bone conduction hearing aids had to be xed tightly in place with pressure. Many users nd this physically distressing. e cartilage conduction hearing aid also has the advantages of being smaller and less noticeable.”It took almost 13 years to develop the cartilage conduction hearing aid aer the discovery of cartilage conduction by Professor Hosoi. e path wasn’t smooth and had many hurdles and obstacles. Growing numbers of medical facilities are currently prescribing them, and cartilage conduction hearing aids have found their way into the lives of many people. A new door to hearing aids had indeed been opened.Manufacturing the transducers, the key component of the cartilage conduction hearing aid.Yoko FujishimaCurrently works at the Rionet Center, a cer-tied shop specializing in hearing aids. She is a certied hearing aid technician, respon-sible for the sales and maintenance of hear-ing aids at the shop or medical facilities. To date, she has sold and adjusted cartilage conduction hearing aids to approximately 80 patients at clinics in Tokyo where they are available.5

元のページ  ../index.html#7