Novel multiple focal point technique for laser-induced shear wave generation in deep tissue: simulation insights

Purpose. Laser applications in biomedical imaging have several decades of history; however, some unexplored corners remain for study. While previous studies contain massive data on photoacoustic imaging, optical coherence imaging/elastography, and surface acoustic waves, the generation of shear waves in bulk by laser remained rarely investigated. Here, we study the applicability of multipoint laser exposure to generate deep tissue shear waves, which have potential applications in dynamic elastography.Method. Previous studies used single shots of laser to induce shear waves and create weak waves. Based on this, we suggest a multipoint approach to enhancing the amplitude of the shear wave in bulk. These approaches contain supersonic exposure, overlay Mach 1, and comb-push exposure in a finite element simulation environment.Result. Although the results showed a linear relationship between laser power and shear wave amplitude, the supersonic and overlay exposure increased the amplitude from 15 nm to over 60 nm and 230 nm, respectively.Conclusion. Our approaches showed a potentially successful increase in shear wave amplitude in the simulation environment. However, experimental data still need to be investigated before these techniques can be suggested for laser-induced shear wave elastography in the deep medium.