this is for holding javascript data
Pol Grasland-Mongrain edited Discussions.tex
about 8 years ago
Commit id: 3f3d3927b4e5a86645d1e84c1722d477c61b5af2
deletions | additions
diff --git a/Discussions.tex b/Discussions.tex
index 50f5f0f..cdea41e 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
less 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 \cite{Nightingale_2001}, \cite{Manduca_2001}. Interestingly, this is higher than the displacement we observed at 10 mJ (thermoelastic regime), but
long along the same order of magnitude of the displacement observed at 200 mJ (ablative regime). The minimum energy (10 mJ) of the laser beam used in our experiments is incidentally 2.5 times above the maximum permissible exposure for skin given by the Z136.1-2007 standard of the American National Standard Institute \cite{ANSIZ1361}.
In For practical applications to the human body, different strategies could be adopted to comply to ANSI standard:, including observation of the medium with a high resolution imaging technique that is able to track displacements of a few nanometers, such as high frequency
(100 (>100 MHz) ultrasound imaging or optical coherence tomography \cite{Li_2011}. Alternatively, the laser beam can be emitted onto a protective absorbing layer, such as a black sheet covering the patient's organs \cite{Li_2014}.
In conclusion, we have presented experimental observations of elastic shear waves generated by a laser beam in a soft medium. The involved phenomena were investigated, and revealed the existence of thermoelastic and ablative regimes. Furthermore, theoretical displacements were in good agreement with experimental measurements. Lastly, numerical studies showed displacement propagation patterns that were comparable to those generated experimentally.
The authors would like to thank Damien Garcia for lending the laser device, Simon Bernard for his help with Matlab coding, and Christine Tam for language corrections. Pol Grasland-Mongrain received a
CRSNG Natural Sciences and Engineering Research Council of Canada post-doctoral
grant. fellowship. The authors declare no conflict of interest in the work presented here.