Strain estimation using the extended combined autocorrelation method

We previously proposed the combined autocorrelation (CA) method to estimate the strain distribution in tissue. This method is based on the conventional Doppler method but overcomes the problem of aliasing, which is a weakness of the Doppler method. The ability of the CA method has been demonstrated with phantom experiments and in vitro measurements. However, we have to maintain the tissue displacement in the axial direction because the CA method is based on 1-D processing, and this is difficult to perform with the conventional compression system. Therefore, in this paper, we propose an extended CA method that is robust against sideslip. We also demonstrate the ability of this method with computer simulations.