title: Generation of Shear Waves by Laser in Soft Media in the Ablative and Thermoelastic Regimes.
abstract: This article describes the generation of elastic shear waves in a soft medium using a laser beam. Our experiments show two different regimes depending on laser energy. Physical modeling of the underlying phenomena reveals a thermoelastic regime caused by a local dilatation resulting from temperature increase, and an ablative regime caused by a partial vaporization of the medium by the laser. Computed theoretical displacements are close to experimental measurements. A numerical study based on the physical modeling gives propagation patterns comparable to those generated experimentally. These results provide a physical basis for the feasibility of a shear wave elastography technique (a technique which measures a soft solid stiffness from shear wave propagation) by using a laser beam.
authors.affiliation: Laboratory of Biorheology and Medical Ultrasonics, Montreal Hospital Research Center, Montreal (QC), H1X0A9, Canada.
authors.forename: Pol
authors.initials: P
authors.lastname: Grasland-Mongrain
authors.affiliation: Laboratory of Biorheology and Medical Ultrasonics, Montreal Hospital Research Center, Montreal (QC), H1X0A9, Canada; Departement of Electrical Engineering, École Polytechnique of Montreal, Montreal (QC), H3C3A7, Canada.
authors.forename: Yuankang
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Departement of Electrical Engineering, École Polytechnique of Montreal, Montreal (QC), H3C3A7, Canada; Institute of Biomedical Engineering, École Polytechnique and University of Montreal, Montreal (QC), H3T1J4, Canada.
authors.forename: Frederic
authors.initials: F
authors.lastname: Lesage
authors.affiliation: Laboratory of Therapeutic Applications of Ultrasound, Inserm u1032, Inserm, Lyon, F-69003, France.
authors.forename: Stefan
authors.initials: S
authors.lastname: Catheline
authors.affiliation: Laboratory of Biorheology and Medical Ultrasonics, Montreal Hospital Research Center, Montreal (QC), H1X0A9, Canada; Institute of Biomedical Engineering, École Polytechnique and University of Montreal, Montreal (QC), H3T1J4, Canada; Departement of Radiology, Radio-oncology and Nuclear Medicine, University of Montreal, Montreal (QC), H3C3J7, Canada.
authors.forename: Guy
authors.initials: G
authors.lastname: Cloutier