Preliminary Study of Optimization of Mri-compatible Ultrasonic Transducer Matching Layer Composites with Comsol

Abstract

Phase controlled high intensity focused ultrasound (p-hifu) is electronic phase controlled focusing.By adjusting the excitation voltage phase and amplitude of each array element, a variety of sound field modes, such as single-focus movement and multi-focus, can be generated. Magnetic resonance imaging (MRI) can reflect tissue details in nondestructive conditions and measure the temperature of tissue in vivo by analyzing the proton resonance frequency signals. The combination of p-hifu technology and MRI technology improves the accuracy and safety of treatment, but the combination of the two brings about non-negligible electromagnetic interference problems. Most EMC problems can be solved by electromagnetic shielding. Based on previous studies, this paper intends to study a novel electromagnetic shielding material Cu-Epoxy for ultrasonic transducers.The biggest innovation of this material is its dual functions- electromagnetic shielding and ultrasonic matching layer.We conduct preliminary simulation with Comsol software to verify its feasibility. Through the simulation of electromagnetic field and piezoelectric effect, we find that this material is feasible in theoretical design. The biggest advantage of this simulation model is that it can be used for theoretical design of composite materials and explore the optimization of their performance. In further research, we can develop the model from the simplest two-dimensional axisymmetric model to a three-dimensional model, making it closer to the real situation.