Improvement of power efficiency of inductive links for implantable devices

This paper presents the analysis of inductive links for remote powering of implantable devices and a method to improve the power link efficiency by modifying the geometrical parameters of planar spiral inductors. The analysis of the inductive links includes a model for the inductors, which is more accurate for larger bandwidths. The corresponding equations for the power and voltage transfer functions in the inductive links are solved by using MATLAB's Symbolic Math Toolbox. These equations are verified in Agilent ADS, and the results perfectly match. Besides the analysis, a method to improve the power efficiency by changing the geometrical parameters of the spiral inductors is proposed. © 2008 IEEE.