Characterization of Acoustic and Mechanical Properties of Tissue-Mimicking Materials by Ultrasound

Abstract

Tissue-mimicking materials of biological tissues are essential in the field of Medical Imaging. These materials are known as phantoms or simulator objects. These phantoms are materials that simulate biological tissues in the interaction of ionizing and non-ionizing radiation. Thus, it is essential to know about the physical properties of these materials for use in new production and development of materials to employ as simulator objects. In this work, longitudinal ultrasonic waves were applied in a polymer material, looking for mechanical features and acoustic properties through pulse-echo ultrasound. The extraction of these attributes was obtained through a computational algorithm. Thus, an algorithm was developed to obtain the viscous and elastics modulus of the polymer. Were found through data processing: the attenuation coefficient, α = 0,152 dB/cm, and the longitudinal speed, c=1448,60 m/s, value of propagation in the sample. In this way, it was possible to estimate the modulus of storage elasticity and loss of the modulus of longitudinal elasticity, L' = 2,098 GPa e L" = 0,386 MPa and shear, G'= 0,424 GPa e G" = 0,068 MPa. The tangent delta, the volumetric modulus of elasticity, Young's modulus, and the Poisson's ratio were calculated from these. This study showed the possibility of obtaining essential information regarding the mechanical properties of polymers by pulse-echo ultrasound inspection. However, subsequent studies are necessary in order to carry out the validation of this method. For this, the results must be compared with those obtained using another standard technique, such as dynamic-mechanical analysis.