A transcutaneous power transfer interface based on a multicoil inductive link

This paper presents a transcutaneous power transfer link based on a multicoil structure. Multicoil inductive links using 4-coil or 3-coil topologies have shown significant improvement over conventional 2-coil structures for transferring power transcutaneously across larger distances and with higher efficiency. However, such performance comes at the cost of additional inductors and capacitor in the system, which is not convenient in implantable applications. This paper presents a transcutaneous power transfer interface that takes advantage on a 3-coils inductive topology to achieve wide separation distances and high power transfer efficiency without increasing the size of the implanted device compared to a conventional 2-coil structure. In the proposed link, a middle coil is placed outside the body to act as a repeater between an external transmitting coil and an implanted receiving coil. The proposed structure allows optimizing the link parameters after implantation by changing the characteristics of the repeater coil. Simulation with a multilayer model of the biological tissues and measured results are presented for the proposed link.