Bone Abstracts

An orthogonally-anisotropic Biot-Johnson-Allard (BJA) model in which the dependences of tortuosity on porosity and angle are determined empirically from acoustic measurements on bone replicas has been developed. Phase velocities and attenuations of the fast and slow waves versus frequency, porosity and angle of propagation have been predicted by using BJA model. The attenuation of the fast wave is below 0.5 Np/m throughout the frequency and propagation angle range. The attenuation of the slow wave is around 1.7 Np/m throughout the frequency and propagation angle range. We also investigated the use of structural borne acoustic wave technique to diagnose the osteoporosis. When normal and osteoporotic bones are subjected to vibration, the resulting detected responses have different shapes, different natural frequencies, and amplitudes. Differences between normal and osteoporotic bones might be the sign of osteoporosis being diagnosed by structural vibration technique.