Broadband Vibration-Isolating Metamaterial for MRI-Induced Vibrations

Abstract

Magnetic resonance imaging (MRI) is an important diagnostic tool in the medical field. Vibrations originating from the gradient coils of an MRI system lead to loud operational noise. This study explores a numerical investigation of elastic metamaterial designed for the attenuation of MRI-induced vibrations that could radiate as sound at the air-structure interface. Elastic metamaterials with embedded resonators can significantly attenuate wave propagation by opening a local resonance bandgap. In this study, the wave propagation properties of two elastic metamaterial models are analysed. The resulting dispersion diagrams are studied using a parametric analysis to investigate the influence of different geometric features on bandgap generation. The metamaterial models are analysed using finite element analysis (FEA) to investigate their wave attenuation performance. A frequency analysis of the multicellular model shows a high transmission loss corresponding to the bandgaps in the calculated dispersion diagrams. The results reveal that the optimised metamaterial model shows an overlap of 72.3 % with the vibration frequency range of the MRI scanner, while the frequency analysis of the multicellular arrangement reports a transmission loss of up to 115.7 dB. These results demonstrate the potential of such elastic metamaterials for targeted vibro-acoustic control and provide a framework for designing structures for wave attenuation in sensitive acoustic environments.