Design of a class‐E transcutaneous energy transmitter for an implantable system

Abstract

Purpose

The purpose of this paper is to develop a model of the inductive link for implantable systems. The model is suitable for a cochlear implant in which a lateral misalignment and distance coil can be up to 16 mm.

Design/methodology/approach

The description of the generation of implantable systems' high‐power, such as a cochlear implant, are powered by transcutaneous inductive power links formed by two coils: the first is a printed spiral coil used in the receiver device and the second is a solenoid coil used in the emitter device. Optimizing the power efficiency of the wireless link is imperative to minimize the size of the external energy source, heating dissipation in the tissue, and interference with other devices. The authors have outlined the theoretical foundation of optimal power transmission efficiency in an inductive link, and combined it with semi‐empirical models to predict parasitic components. The power amplifier itself is a class‐E amplifier optimized in both output voltage and efficiency, and bears an excellent tolerance to misalignments.

Findings

Two Spice‐based electrical models of the coils are achieved. The technique employed during the work is based on polynomial interpolation of the mutual inductance in which coil misalignments are considered as variables. On the other hand, a voltage regulator is studied and simulated by Cadence Analog Artist in the AMS 0.35 μm CMOS technology.

Originality/value

This paper provides a novel and useful method for transmitting power for an implantable system via an inductive link. The procedure of the authors' design is achieved at 10 MHz and the power transmission efficiency is 35 percent, whatever the longitudinal misalignment (up to 16 mm) between both coils.

Citation

Chaoui, M., Perdriau, R., Ghariani, H. and Lahiani, M. (2012), "Design of a class‐E transcutaneous energy transmitter for an implantable system", Microelectronics International, Vol. 29 No. 1, pp. 22-34. https://doi.org/10.1108/13565361211219130