While not technically a prosthesis, a hearing aid does replace something that a person is missing, one of their senses. Because each and every one of us has minor variations in the way our ear canals are shaped, a one-size-fits-all model for hearing aids doesn’t really deliver the performance that it could achieve if it were tailor made for an individual.
Three scientists at the Danish hearing aid firm Widex were recently awarded the European Inventor Award for their pioneering work on CAMISHA (Computer-Aided Manufacturing for Individual Shells for Hearing Aids). The process that Jan Tøpholm, Søren Westermann, and Svend Vitting Andersen created uses 3D scanning and 3D printing to create a bespoke “in the ear” (ITE) hearing-aid that delivers top of the line performance.
As you can imagine the process begins by injecting a patient’s ear canal with liquid silicone to form a perfect impression of his ear canal’s shape. Once solidified, the mold is removed and scanned so that it can be converted into a 3D model. The 3D representation of the mold is then imported into a CAD software package where it is stitched together and then sent to a 3D printer (stereolithography) for manufacturing. Once the hearing aids have been printed, the micro-circuitry that processes and amplifies sound is packed into the custom shell and, well, there you have it – the world’s most accurately produced, customized hearing aid.
According to CNN, the CAMISHA technique for creating hearing aids is so effective that 95 percent of the world’s custom made ITE hearing aids use this method of production.
Images and Video Courtesy of Widex and CNN
[Editors note: Widex has been using 3D printing to make ITE shells since 2003. While it does not manufacture 95% of ITE hearing aids, CAMISHA has been patented and is used by many hearing aid manufacturers, making the 95% claim an accurate statement.]