Effect of bone degradation on axially transmitted low frequency (<500 kHz) ultrasonic guided waves

Abstract

The early diagnosis of osteoporosis through bone quality assessment has been extensively studied in the past few years. Research in axial transmission in long cortical bone using ultrasonic guided waves was shown to be sensitive to variations of the bone properties such as the geometry and the mechanical properties. The aim of this presentation is, therefore, to simulate a complex bone-like geometry using 3D finite elements (FE) in order to investigate the influence of the cortical thickness mechanical properties degradation. Three parameters were investigated: (1) the thickness of the periosteal region, (2) the degradation of the endosteal region, and (3) the position of the transition zone from periosteal to endosteal regions. Moreover, the influence of soft tissue was investigated on a plate-like structure using semi-analytical iso-geometric analysis method (SAIGA). Two cortical bone phantom plates with different mechanical properties covered with a soft tissue mimicking material were used to perform axial transmission measurement. The dispersion curves of the propagating modes were experimentally measured and then were compared to the solutions obtained with the SAIGA method. The results showed the possibility to retrieve the properties of the bone phantom plates through an inversion of the dispersion curves.