Figure \ref{Comparaison}-(A-B) illustrates Z-component map 6 ms after excitation, when excited in “monophasic” mode and in “biphasic” mode respectively. Average displacement in the region of interest is equal to 3.3 \(\mu\)m in the first case and 0.2 \(\mu\)m in the second case: only “monophasic” mode is able to induce observable shear waves.

Figure \ref{Comparaison}-(C-D) illustrates Z-component map 6 ms after excitation in a 5% salt medium and in a 2% medium respectively (note that (E) and (A) are identical). Average displacement in the region of interest is equal to 3.3 \(\mu\)m in the first case and 1.4 \(\mu\)m in the second case: when electrical conductivity of the medium decreases, shear wave amplitude decreases roughly by a same factor.

Figure \ref{Comparaison}-(E-F) illustrates Z-component map 6 ms after excitation, when excited with a 100% and 50% amplitude in the coil respectively (note that (C) and (A) are identical). Average displacement in the region of interest is equal to 3.3 \(\mu\)m in the first case and 1.3 \(\mu\)m in the second case: shear wave amplitude is roughly divided by two when excitation amplitude is halved (according to the device panel).

Figure \ref{Comparaison}-(G-H) illustrates Z-component map 6 ms after excitation, when excited with a 100% and a -100% amplitude in the coil respectively, in the 2% salt medium (note that (G) and (D) are identical). Average displacement in the region of interest is equal to 1.3 \(\mu\)m in the first case and -1.4 \(\mu\)m in the second case: displacement amplitude is inverted when excitation is inverted.