ResearchPast Projects
Innenohrmikrowandler zur Anregung der Perilymphe bei Schwerhörigkeit

Inner Ear Micro Transducer for the Stimulation of the Perilymph for the Hard of Hearing

Year:  2011
Funding:  German Research Foundation
Duration:  2008-2012
Is Finished:  yes

The goal of the DFG (German Research Foundation) project is to develop a microsystem that serves as an implantable hearing aid to improve hearing. For this purpose, an electromagnetic micro-converter is to excite the perilymph of the cochlea via the round window membrane by means of a plunger. The area of application is aimed at moderate sensorineural hearing loss, conductive hearing loss and combined hearing loss. The entire project covers two application periods. In the first application period of the project, fundamental work on the geometry of the microconverter, which is designed using simulations and temporal bone studies and manufacturing technologies and process parameters have been defined. The maximum dimensions of the system are determined by the available space on the round window membrane and were determined by a parameter study using dummy components, these dummy components being placed in human petrous bone (see Fig. 1).

In the area of simulations, mechanical, electromagnetic and thermal simulations were carried out and a geometry derived from the results. The complete system consists of an upper and a lower part, which are to be connected to each other. The upper part of the system contains the mechanical system, which consists of a boss and a silicon tappet and contains a Si3N4 membrane as well as the electromagnetic inference. The electromagnetic system is located in the lower part and consists of a two-layer copper coil and NiFe45/55 flux guides, the system in cross-section is shown in Fig. 2 and Fig. 3 and a general view in Fig. 4.

The main focus in the second application period is on the production and characterization of functional microcontrollers, the implantation in and load tests of these on human petrous bone and long-term studies on animal models (cats). After characterizing the transducer properties by means of a test procedure to be developed, the design of the microconverters is to be optimized and the optimized microconverters are to be manufactured. The results of the experimental investigations with regard to physiology and biocompatibility will be used to improve the first-generation transducer.

The project is being carried out in cooperation with the Hannover Medical School.