A Free Plate Model Could Predict Ultrasonic Guided Waves Propagation in a 3D Printed Skull Phantom

Ultrasonic guided waves have been used to assess the quality of long cortical bone. Skull as a shell-structure, it may also support ultrasonic guided waves propagation. In this study, we used a free plate model to analyze the guided waves propagation in skull phantom and identified the guided modes. Simulation was performed using finite-difference time-domain (FDTD) method and the experiment was carried out on a 3D printed skull phantom and a plate phantom. The experimental dispersion trajectories were obtained using two-dimensional Fourier transform (2D-FT). No significant difference can be found between the results obtained from the plate and the skull phantoms, which illustrated that the Lamb theory used in long cortical bone could also be a proper model for analyzing guided modes in human skull.