Energy harvesting coil for circularly polarized fields in magnetic resonance imaging

TL;DR

This paper introduces a novel compact coil design for energy harvesting in MRI scanners, enabling wireless power without degrading image quality and doubling harvested voltage compared to linear polarization methods.

Contribution

It presents a new coil design combining loop and butterfly coils for efficient energy harvesting of circularly polarized MRI fields, validated through simulations and experiments.

Findings

The proposed coil is safe and does not affect MRI image quality.

It achieves twice the voltage harvesting compared to linear polarization setups.

The design is compatible with standard 1.5 Tesla MRI scanners.

Abstract

Specialized radio-frequency coils and sensors placed inside the magnetic resonance imaging (MRI) scanner considerably extend its functionality. However, since cable connected in-bore devices have several disadvantages compared to wireless ones, the latter currently undergo active development. One of the promising concepts in wireless MRI coils is energy harvesting that relies on converting the energy carried by the radio-frequency MRI field without the need for additional transmitters as in common wireless power transfer realizations. In this Article, we propose a compact harvesting coil design based on the combination of the loop and butterfly coils that allows energy harvesting of a circularly polarized field. By performing numerical simulations and experiments with commonly used Siemens Espree and Avanto 1.5 Tesla MRI scanners, we demonstrate that the proposed approach is safe, efficient, does not decrease the quality of MRI images, and allows doubling the harvested voltage compared to linearly polarized setups.