Experimental validation of displacement vector measurement based on two-dimensional modulation method with virtual hyperbolic scanning

We have proposed a new modulation method that can generate modulated RF signals with oscillation in two mutually orthogonal directions over a wide, deep area using a small-aperture probe. We had also shown the validity of the method by numerical simulations in a previous work. In this study, we applied the method to an experimental system and validated it by phantom experiments. In numerical simulation, point-source transmission has been performed, but in practical measurement, it does not acquire a sufficient signal-to-noise ratio (SNR) for estimating displacement because of its low output power. A spatially coded excitation, Hadamard spatial coding, was employed to increase SNR. An experiment on wire targets indicated that the proposed method can modulate the RF signal correctly, and an experiment on elasticity imaging suggested that it enables us to estimate displacement in axial and lateral directions with high precision.