Investigation of Parameters and Improvement of MRT Compatibie Composite Magnet for Cochiear Implantation

The purpose of research to analyze and compare the designs and useful parameters of the models which can be used in cochlear implantation systems in order to select the optimal design.

Methods. The article describes the work carried out in improving the utility models RU 198574, RU 196686, RU 2727227 and creating an external composite magnet. The authors analyzed composite magnets with a different number of magnetic elements (q = 4, 6, 8, 10), as well as the implementation of an internal magnet with and without filling the empty space with ferrofluid.

Results. This article describes the carried work to improve the utility models RU 198574, RU 196686, RU 2727227 to create the improved external composite magnet. The authors provide a model of a modified design of the body of the implantable part of the composite magnet to improve its characteristics. Also was developed an external magnet with cylindrical corpus and seats for cylindrical compound magnets located around the circumference. This design of both composite magnets prevents angular rotations of the composite magnets. This makes it possible to take into account the relative position of the supply and output wires to the receiving and transmitting antennas developing the electrical part of the implant. The article presents the results of modeling the magnetic field of composite magnets with various sizes of housings and magnetic elements. Schemes of the magnetic field distribution during the interaction of both compound magnets are presented in this manuscript as well as the forces of the attracting of the external part and implanted have been calculated. The authors provide a formula for calculating the maximum force of attraction of compound magnets, due to the blood pressure in the capillaries.

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