Evaluations on the stability and bio-compatibility of a new piezoelectric microphone for the implantable middle ear microphone.

BACKGROUND

A new floating piezoelectric microphone (NFPM), driven by the acoustic vibration of the ossicles, has been manufactured in the lab.

OBJECTIVES

This study aimed at exploring the stability and bio-compatibility of this NFPM.

MATERIALS AND

METHODS

The NFPM was implanted into the cat tympanic cavity by clamping it to the handle of the malleus, and then a temporal bone computed tomography (CT) plain scan and three dimensional reconstruction were performed to observe its coupling with the handle of the malleus. After six months of implantation, cats' blood samples were taken for pro-inflammatory factor analysis. Then, the operative cavity was opened to check the NFPM, the auditory ossicular chain and some granulation tissue surrounding the NFPM.

RESULTS

The NFPM was firmly clamped to the handle of the malleus of the cats during the six months of implantation. Besides, there was no obvious systemic inflammatory response in the experimental animals. In addition, local proliferation of granulation tissue occurred in the tympanic cavity without hampering the movement of the auditory ossicle,or causing ischemia of the auditory ossicle.

CONCLUSION

The NFPM could be implanted in our experimental cats for a long period of time and had good bio-compatibility.