FDTD simulation study of ultrasonic wave propagation in human radius model generated from 3D HR-pQCT images

Abstract

A finite-difference time-domain (FDTD) technique was used to model the complex propagation of ultrasonic waves through the human radius. A three-dimensional model of the radius, including its uniaxial anisotropy and heterogeneity, was created using structural data obtained from high-resolution peripheral quantitative computed tomographic images. FDTD simulations were performed to achieve adequate wave convergence on the virtual fracture site in the mid shaft of a long cortical bone. The simulation comprised two steps. The first involved wave propagation from the virtual fracture site to two ring-shaped outside receiver arrays. In the second step, the receiver arrays functioned as transmitters, generating re-radiated waves based on the arrival times of the received waves. The re-radiated waves propagating from the transducer arrays were found to converge around the fracture site. Our findings will help to improve the propagation of ultrasonic irradiation through a cast to target a fracture site.