Study of the Effect of Distance and Misalignment between Magnetically Coupled Coils for Wireless Power Transfer in Intraocular Pressure Measurement

An analysis of the effect of distance and alignment between two magnetically coupled coils for wireless power transfer in intraocular pressure measurement is presented. For measurement purposes, a system was fabricated consisting of an external device, which is a Maxwell-Wien bridge circuit variation, in charge of transferring energy to a biomedical implant and reading data from it. The biomedical implant is an RLC tank circuit, encapsulated by a polyimide coating. Power transfer was done by magnetic induction coupling method, by placing one of the inductors of the Maxwell-Wien bridge circuit and the inductor of the implant in close proximity. The Maxwell-Wien bridge circuit was biased with a 10 MHz sinusoidal signal. The analysis presented in this paper proves that wireless transmission of power for intraocular pressure measurement is feasible with the measurement system proposed. In order to have a proper inductive coupling link, special care must be taken when placing the two coils in proximity to avoid misalignment between them.

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Wireless power transfer system rigid to tissue characteristics using metamaterial inspired geometry for biomedical implant applications

Scientific Reports ◽

10.1038/s41598-021-84333-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ramesh K. Pokharel ◽

Adel Barakat ◽

Shimaa Alshhawy ◽

Kuniaki Yoshitomi ◽

Costas Sarris

Keyword(s):

Electromagnetic Waves ◽

Wireless Power Transfer ◽

Split Ring Resonator ◽

Input Power ◽

Power Transfer ◽

Wireless Power ◽

Biomedical Implant ◽

Safety Regulations ◽

Wireless Power Transfer System ◽

Tissue Characteristics

AbstractConventional resonant inductive coupling wireless power transfer (WPT) systems encounter performance degradation while energizing biomedical implants. This degradation results from the dielectric and conductive characteristics of the tissue, which cause increased radiation and conduction losses, respectively. Moreover, the proximity of a resonator to the high permittivity tissue causes a change in its operating frequency if misalignment occurs. In this report, we propose a metamaterial inspired geometry with near-zero permeability property to overcome these mentioned problems. This metamaterial inspired geometry is stacked split ring resonator metamaterial fed by a driving inductive loop and acts as a WPT transmitter for an in-tissue implanted WPT receiver. The presented demonstrations have confirmed that the proposed metamaterial inspired WPT system outperforms the conventional one. Also, the resonance frequency of the proposed metamaterial inspired TX is negligibly affected by the tissue characteristics, which is of great interest from the design and operation prospects. Furthermore, the proposed WPT system can be used with more than twice the input power of the conventional one while complying with the safety regulations of electromagnetic waves exposure.

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Resonance and EMI in vertical multi-coupled coils for wireless power transfer (WPT) system

2012 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications ◽

10.1109/imws.2012.6215772 ◽

2012 ◽

Cited By ~ 2

Author(s):

Sunkyu Kong ◽

Jonghoon J. Kim ◽

Joungho Kim

Keyword(s):

Wireless Power Transfer ◽

Power Transfer ◽

Wireless Power ◽

Coupled Coils

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Maximizing Wireless Power Transfer with Single-Turn Coreless Coupled Coils

2018 IEEE International Symposium on Circuits and Systems (ISCAS) ◽

10.1109/iscas.2018.8351209 ◽

2018 ◽

Cited By ~ 1

Author(s):

Y. Wanderoild ◽

A. Morel ◽

G. Pillonnet ◽

D. Bergogne ◽

Hubert Razik

Keyword(s):

Wireless Power Transfer ◽

Power Transfer ◽

Wireless Power ◽

Single Turn ◽

Coupled Coils

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Electrifying the disk: a modular rotating platform for wireless power and data transmission for Lab on a disk application

Lab on a Chip ◽

10.1039/c5lc00138b ◽

2015 ◽

Vol 15 (12) ◽

pp. 2584-2587 ◽

Cited By ~ 14

Author(s):

Jens Höfflin ◽

Saraí M. Torres Delgado ◽

Fralett Suárez Sandoval ◽

Jan G. Korvink ◽

Dario Mager

Keyword(s):

Data Transmission ◽

Wireless Power Transfer ◽

Power Transfer ◽

Wireless Power ◽

Rotating Platform ◽

Inductively Coupled ◽

Spinning Disk ◽

The Future ◽

Coupled Coils

We present a design for wireless power transfer, via inductively coupled coils, to a spinning disk. This is an important demonstration of what we believe will have numerous applications in the future.

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