Abstract
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.
Acknowledgements
We gratefully acknowledge the assistance from MED-EL Corporation on the manufacture of new floating piezoelectric microphone.
Disclosure statement
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
Funding information
This study was supported by National Natural Science Foundation of China (81271084 to F.C, 81170926 to H.K, 81500785 to N.G, 81000413 and 81370022 to D.R., 81200740 to J.Y, 81200738 to N.C, 81371093 to Z.H.), the Major State Basic Research Development Program of China (973 Program) (2011CB504500, 2011CB504506) to H.L and F.C, and Innovation Project of Shanghai Municipal Science and Technology Commission (11411952300) to F.C.