An anisotropic bilayer model to gain insight into in-vivo guided wave measurements

The influence of soft-tissue on guided wave measurements for the assessment of cortical bone properties is not fully understood yet. To improve our understanding of the soft-tissue influence on the guided modes propagation characteristics, a series of assemblies of soft tissue- and bone-mimicking phantoms were ultrasonically investigated using the so-called axial transmission technique. For this purpose, an anisotropic bilayer model was developed and inserted in a model-based inverse problem procedure to infer the properties of both the solid and fluid layers. Finally, the potential of this modeling is evaluated on a few in-vivo measurements at the forearm.