deletions | additions       diff --git a/Discussions.tex b/Discussions.tex  index a803e6c..bf45519 100644  --- a/Discussions.tex  +++ b/Discussions.tex 
...
In a context of elastography measurements, shear wave elastography, the thermoelastic regime is a priori preferred to the ablative regime, as it is less destructive.  Muthupillai et al. assumed that a displacement of a few hundreds of nanometers should be sufficient to perform shear wave elastography \cite{7569924}. However, displacements of the order of the micrometer is usually required, required in ultrasound or MRI,  which is higher than the displacement observed at 10 mJ (thermoelastic regime) and about the same order of magnitude at 200 mJ (ablative regime). The minimum energy of our laser (532 nm, 10 ns, 10 mJ, 5 mm diameter) used in our experiments to get a shear wave is still incidentally  2.5 times above the maximum exposure permissible as for skin  given by the current Z136.1-2007 standard of the  American National Standard Institute (Z136.1-2000) for skin \cite{ANSIZ1361}, \cite{ANSIZ1361} -  a value which is also used in typical photoacoustic imaging experiments with 532 nm Q-switch Nd:YAG lasers \cite{Ku_2005}. This value is \cite{Ku_2005} but  also a few hundred times lower than the typical energy used for skin tatoo removal, which use same type of lasers tattoo removal  \cite{8352621}. In a practical application on human body, different strategies could be adopted to overcome this problem: emit the laser beam on a protective absorbing layer, for example a black sheet sticked to the patient organ; Or observe the medium with high resolution imaging technique, able to track displacements of a few nanometers, like very high frequency ultrasound (100 MHz) or Optical Coherence Tomography technique.  In summary, To sum up  this study article, we have  presented experimental  observation of elastic shear waves generated in soft tissues using a laser beam. The involved phenomenons were investigated and we distinguished thermoelastic and ablative regimes. Experiments in chicken breast sample showed the feasibility of the elastography method using a laser beam Theoretical displacements are close to experimental ones. Numerical studies show comparable displacement propagation patterns  as a shear wave source. in experiments.  The authors would like to thank Damien Garcia for lending the laser device and Simon Bernard for his help in Matlab coding. Pol Grasland-Mongrain received a CRSNG post-doctoral grant. The authors declare no conflict of interest in the work presented here.