deletions | additions       diff --git a/Discussions.tex b/Discussions.tex  index 60067a8..7dd43de 100644  --- a/Discussions.tex  +++ b/Discussions.tex 
...
In the context of shear wave elastography, the thermoelastic regime is a priori preferred over the ablative regime, because it is not destructive. Even if first shear wave elastography experiments assumed that a displacement of a few hundred nanometers would be sufficient \cite{7569924}, displacements of the order of a few micrometers are usually required in practice for ultrasound or magnetic resonance elastography in biological tissues \cite{Nightingale_2001}, \cite{Manduca_2001}. This amplitude is higher than the displacement we observed at 10 mJ (thermoelastic regime), but along the same order of magnitude of the displacement observed at 200 mJ (ablative regime). For application in human body, the lowest fluence (500 J/m$^2$, corresponding to a 10 mJ, 5 mm-diameter laser beam) that was used in these experiments is incidentally 2.5 times above the maximum permissible exposure for skin (200 J/m$^2$) given by the Z136.1-2007 standard of the American National Standard Institute. To overcome this issue, different strategies could be adopted, including \textcolor{red}{using using  other types of laser, with higher maximum permissible exposure;} exposure;  emission of the laser beam onto a protective absorbing layer, such as a black sheet covering the patient's skin \cite{Li_2014}; or using a higher resolution imaging technique able to track smaller displacements, such as high frequency ($>$100 MHz) ultrasound imaging or optical coherence tomography \textcolor{red}{- -  in this last case however, low penetration depth may lead to the observation of surface acoustic waves instead of shear waves}. waves.  Combination with optical coherence tomography may even lead to a real-time, fully remote, small-scale laser-based technique to assess a soft solid \textcolor{red}{stiffness} stiffness  \cite{Li_2011}, \cite{Song_2016a}.