A new floating piezoelectric microphone for the implantable middle ear microphone in experimental studies.

CONCLUSIONS: The new floating piezoelectric microphone is feasible for use as an implantable middle ear microphone in a totally implantable cochlear implant.

OBJECTIVES: A piezoelectric sensor that is driven by the acoustic vibration of the ossicles is one possible design for a microphone for a totally implantable cochlear implant. Such a new floating piezoelectric microphone has been manufactured in the lab. The purpose of this article was to study the frequency response of the new floating piezoelectric microphone in the intact ossicular chain and to identify whether it is usable and implantable.

METHODS: The frequency response of the new floating piezoelectric microphone was analyzed using in vitro testing of fresh cadaveric heads. The microphone, which was designed with an integrated unibody structure to ensure good biocompatibility and capsulation, was attached to the long process of the incus by a titanium clip, or placed in the tympanic cavity and stimulated with pure tones of different frequencies.

RESULTS: The new floating piezoelectric microphone can pick up the vibration of the long process of the incus and convert it into electrical signals sensitively and flatly.