Experimental approach of the diffraction effect with random phase transducers

Abstract

The authors have evaluated on a foam phantom the continuous evolution of the estimated attenuation with respect to the distance between the probe and the sample. Results show large changes rapidely occuring because of the diffraction effect. Random phase transducer (RPT) are then introduced for attenuation estimation. RTP can be partially or totally incoherent. New diffraction calibration curves show that no diffraction occurs with the RPT, all the more as they are totally incoherent. As a consequence, the attenuation is very stable as a function of the probesample distance . All these observations will be confirmed through in vitro measurements on human placentae.