Coded Excitation of the Fundamental Flexural Guided Wave in Coated Bone Phantoms

There is an increasing interest of using ultrasonic guided waves to assess long cortical bones. In particular, a method of ultrasonic estimation of cortical thickness based on the fundamental flexural guided wave (FFGW), generally consistent with the A0 Lamb mode, has proven to be promising in vitro and modeling studies. Soft-tissue coating on top of the bone makes, however, the related in vivo application challenge. Visibility of FFGW on top of the soft tissue is not good due to the characteristic displacement profile of this mode, and due to its relatively high attenuation in the bone and surrounding tissue. Moreover, the soft tissue provides a direct propagation path for ultrasonic modes…