Near Field Wireless Powering of Deep Medical Implants

Abstract

This study deals with the inductive-based wireless power transfer (WPT) technology applied to power a deep implant with no fixed position. The usage of a large primary coil is here proposed in order to obtain a nearly uniform magnetic field inside the human body at intermediate frequencies (IFs). A simple configuration of the primary coil, derived by the Helmholtz theory, is proposed. Then, a detailed analysis is carried out to assess the compliance with electromagnetic field (EMF) safety standards. General guidelines on the design of primary and secondary coils are provided for powering or charging a deep implant of cylindrical shape with or without metal housing. Finally, three different WPT coil demonstrators have been fabricated and tested. The obtained results have demonstrated the validity of the proposed technology.

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

“…Campi et al [24] executed WPT-based MRC in functional medical gadgets; the functioning frequency for the MRC technique was 4 MHz. The MRC technique included a coil in the transmitter, destination and load.…”

“…Other authors have used WPT with MRC to enhance power transfer and efficiency at different air-gap distances between coils to supply medical devices. In addition, studies [22][23][24][25] have used statistical analyses to calculate the accuracy of measuring biomedical parameters, such as temperature and heart rate. The contributions of this study are as follows.…”

Coil Design of a Wireless Power-Transfer Receiver Integrated into a Left Ventricular Assist Device

“…The coil coupling in a near-field WPT is based on the Faraday law of induction. A previous work [26] showed that the optimal frequency for a deep implant is around f = 4 MHz to obtain the maximal electromotive force for a small coil located well inside the human body within the limits of EMF safety. However, since 4 MHz is not in the unlicensed frequency band, the industrial, scientific, and medical To improve the performance of the system, the resonance condition is obtained by compensating the inductive reactance of primary and secondary coils by the capacitors.…”

“…The lumped parameters of the coils can be analytically calculated or, in the case of a complex configuration, can be numerically calculated at the frequency of interest solving magnetoquasistatic (MQS) field equations by the finite-element method (FEM) [25]. Then, parameters of compensation capacitors C 1 and C 2 are calculated as described in [26]. Analysis of the WPT equivalent circuit, performed by circuit simulators or MATLAB code, permits to calculate the electrical performance of the system in terms of efficiency η and transferred power P L to the load.…”

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

“…To eliminate these kinds of problems, wireless power transfer (WPT) systems have been developed for IMDs [9][10][11][12][13]. WPT technology utilizes a magnetic coupling method to transfer power wirelessly and recharge the IMDs.…”