Sunday, May 18, 2025
5/18/2025
Advancement of an Implantable Microphone - Project Summary: In a prior NIDCD-funded project, we developed a prototype implantable microphone with the goal of enabling totally-implantable cochlear implants (TICI) that takes advantage of the outer-ear acoustic benefits. This microphone, called the UMic, senses the motion of the umbo (the distal tip of the manubrium) within the middle ear cavity. Due to its novel design and fabrication, the UMic's performance rivals that of a conventional external cochlear implant microphone in terms of sensitivity, bandwidth, linearity, dynamic range, signal-to-noise ratio, and ability to reject and shield from electrical noise (such as cochlear implant signals). The UMic was developed through iterations of analytical modeling, finite-element analysis, bench testing and implanted testing in human cadaveric ears. Its exceptional performance derives from its architecture: a triangular cantilever sensor comprised of two layers of piezoelectric polymer polyvinylidene fluoride (PVDF) providing a differential output. This sensor, composed of fully biocompatible materials, connects to a custom low-noise low-power differential amplifier. This proposal addresses the refinements needed to make the UMic ready for human use. The following four specific aims are planned. Aim-1 focuses on bench testing and refining the UMic for long-term durability and performance. Aim-2 focuses on finalizing the fixation hardware and tests the UMic in human cadaveric ears as refinements are made to the UMic system. Aim- 3 is a 2-month in vivo trial in sheep, to determine the effect of body noise on UMic performance and evaluate durability in vivo. Aim-4 is motivated by the fact that cochlear implant users experience sound signals differently than normal listeners. In Aim-4, cochlear implant users evaluate signals that were recorded by the UMic when it was implanted in human cadaveric ears and in live sheep. This allows UMic performance to be evaluated in Cl users without having to implant the UMic in live human subjects. Aims-3 and Aim-4 will provide feedback to guide Aim-1 and Aim-2 to further advance UMic performance and durability. Given the advanced state of our design and in preparation for the next translational steps, we have had meetings with the major Cl companies with plans to meet periodically, and have also met with FDA representatives to be followed with regular pre-submission meetings. With a functioning microphone in hand, and future work comprising carefully laid out steps, at the end of this grant period we plan to have a microphone ready for integration into a TICI which can then apply for FDA approval.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).