Comparison of Series Compensation Topologies for Inductive Chargers of Biomedical Implantable Devices

Abstract

Modern biomedical implantable devices provide an increasingly popular solution for health monitoring and medical issues. Their level of development in the coming years will depend on their reliability and endurance. Their powering and recharging capabilities are key factors for their dominance. In this work, series compensation topologies for use in inductive chargers of biomedical implantable devices are investigated with regard to their performance. The goal is to assess the possibility of reducing the component count of the implantable device and thus, increase its reliability and patient safety. Comparison is performed between the commonly used series-series compensation topology with a topology which incorporates no capacitors in the secondary side but only series compensation in the primary. Extensive investigation of the operation of the two topologies is made through mathematical analysis, simulations, and experimental evaluation, for the most popular schemes of operation, with regard to frequency selection. A prototype inductive charger, including a custom-made inductive link, was designed and built for the experimental evaluation of the system. Insights on the operation of both topologies are provided and the results show that primary-side series compensation can be a strong alternative to series-series compensation, in biomedical applications.

Design and Implementation of a Wireless Charging-Based Cardiac Monitoring System Focused on Temperature Reduction and Robust Power Transfer Efficiency

“…The WPT system has four main compensating topologies, which are distinguished by their inductance and capacitance connection type; series-series, series-parallel, parallel-series and parallel-parallel [25][26][27][28]. These topologies can be modified or selected depending on their application's characteristics.…”

Differential-Evolution-Assisted Optimization of Classical Compensation Topologies for 1 W Current-Fed IMD Wireless Charging Systems

“…Topologies with series compensation on the primary have the great advantage of being able to operate from a voltage source at the input, avoiding the need for other stages, which could compromise the overall performance of the system. On the other hand, with parallel compensation in the primary, the circuit must be powered by a current source, which, in a way, makes the execution of the project difficult and can compromise the overall performance if an intermediate stage is necessary [18]. However, although parallel compensation in the primary brings with it the mentioned disadvantage, other technical advantages may justify the application of this topology.…”

Design of Powering Wireless Medical Sensor Based on Spiral-Spider Coils

“…Most research on IC-WPT uses it to enhance power transfer and efficiency at different air-gap distances between coils [12][13][14][15]. One study used MRC-WPT to improve the Transfer efficiency for small household appliances and implanted devices [16].…”