The effect of using two coils in a floating mass transducer for implantable middle ear hearing devices

The paper delves into the examination of energy transfer efficiency from a floating mass transducer, a crucial element of a middle ear implant, to the middle ear structure. The study compares two types of electromagnetic transducers: one employing cumulatively coupled coils and the other utilizing differentially coupled coils. Furthermore, it introduces a novel nonlinear model of electromechanical coupling, establishing a connection between a biomechanical representation of the middle ear and an electromechanical model of the transducer to elucidate the relative positioning of the coils to the magnet. Calculations are conducted using the Runge–Kutta method in Matlab to assess the induced vibrations of the stapes and the energetic efficiency of the implanted middle ear (middle ear with transducer). The simulation results highlight a significant dependence on the magnet and coils configuration, underscoring the necessity for optimization to ensure appropriate comfort for implant users. Lastly, the energetic efficiency of the transducer is compared across the frequency range of 0.2–8 kHz, leading to practical insights and conclusions.