\r\nis proposed to measure shear moduli in soft tissue with direct

\r\naccess availability, using shear wave elastography technique. The

\r\nmeasurement of shear moduli of tissues is a challenging problem,

\r\nmainly derived from a) the difficulty of isolating a pure shear wave,

\r\ngiven the interference of multiple waves of different types (P, S,

\r\neven guided) emitted by the transducers and reflected in geometric

\r\nboundaries, and b) the highly attenuating nature of soft tissular

\r\nmaterials. An immediate application, overcoming these drawbacks,

\r\nis the measurement of changes in cervix stiffness to estimate the

\r\ngestational age at delivery. The design has been optimized using

\r\na finite element model (FEM) and a semi-analytical estimator of

\r\nthe probability of detection (POD) to determine a suitable geometry,

\r\nmaterials and generated waves. The technique is based on the time

\r\nof flight measurement between emitter and receiver, to infer shear

\r\nwave velocity. Current research is centered in prototype testing and

\r\nvalidation. The geometric optimization of the transducer was able

\r\nto annihilate the compressional wave emission, generating a quite

\r\npure shear torsional wave. Currently, mechanical and electromagnetic

\r\ncoupling between emitter and receiver signals are being the research

\r\nfocus. Conclusions: the design overcomes the main described

\r\nproblems. The almost pure shear torsional wave along with the short

\r\ntime of flight avoids the possibility of multiple wave interference.

\r\nThis short propagation distance reduce the effect of attenuation, and

\r\nallow the emission of very low energies assuring a good biological

\r\nsecurity for human use.","references":null,"publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 111, 2016"}