^{1}, G. Rus

^{1}, F. J. Suárez

^{1}, D. Arcoya

^{2}, N. Bochud

^{1}, J. Melchor

^{1}, L. Peralta

^{1},

J. Chiachío

^{1}and M. Chiachío

^{1}

^{1}Dpt. of Structural Mechanics, University of Granada, Spain.

^{2}Dpt. of Mathematical Analysis, University of Granada, Spain.

A shear torsion wave propagation model in a multilayered medium is formulated and implemented for solving the inverse problem of reconstructing its mechanical parameters from an ultrasonic torsional sensor. Shear stiffness properties of soft tissue are highly correlated with a number of pathologies like tumors, hepatic lesions and others. The importance of tissue shear mechanics is rooted in that, whereas compressibility is predominantly governed by the fluid phase of the tissue, the shear stiffness is highly dependent on the stroma micro-architecture, which is directly affected by those pathologies. However, diagnostic tools to quantify them are currently unsifficiently developed. A second contribution is an analytical estimate of the robust probability of detection, called RPOD, for use as optimality criteria for the sensor design. The RPOD is formulated probabilistically to maximize the probability of detecting the least possible pathology while minimizing the effect of measurement noise.