Effect of intracortical bone properties on the guided wave propagation using low-frequency axial transmission technique: Simulation study

Abstract

In this work, a semi-analytical finite-element method was on the propagation of acoustic guided wave. The simulations were performed with a realistic bone cross-sectional geometry by considering an axial transmission configuration. A point source excitation was applied using a toneburst centered at 35 kHz as the input signal. The propagating waves were monitored using out-of-plane displacement in the axial direction at 32 positions separated 4 mm apart. The properties of the endosteal region of cortical bone were varied from healthy to early osteoporotic conditions. The use of the two-dimensional Fourier transform (2DFFT) allowed the measurement of individual mode velocity, which was compared to the velocity typically measured using first arrival signal (FAS). The results have shown that variations in the velocity measured using 2DFFT were mainly associated to a low order flexural-like mode among the eight modes supported by the waveguide. Furthermore, the measured velocity decreased approximately 10/% du...