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Full-Text Articles in Engineering
Photographic Studies Of Laser-Induced Bubble Formation In Absorbing Liquids And On Submerged Targets: Implications For Drug Delivery With Microsecond Laser Pulses, Hanqun Shangguan, Lee W. Casperson, Dennis L. Paisley, Scott A. Prahl
Photographic Studies Of Laser-Induced Bubble Formation In Absorbing Liquids And On Submerged Targets: Implications For Drug Delivery With Microsecond Laser Pulses, Hanqun Shangguan, Lee W. Casperson, Dennis L. Paisley, Scott A. Prahl
Electrical and Computer Engineering Faculty Publications and Presentations
Pulsed laser ablation of blood clots in a fluid-filled blood vessel is accompanied by an explosive evaporation process. The resulting vapor bubble rapidly expands and collapses to disrupt the thrombus (blood clot). The hydrodynamic pressures following the bubble expansion and collapse can also be used as a driving force to deliver clot-dissolving agents into thrombus for enhancement of laser thrombolysis. Thus, the laser-induced bubble formation plays an important role in the thrombus removal process. We investigate the effects of boundary configurations and materials on bubble formation with time-resolved flash photography and high-speed photography. Potential applications in drug delivery using microsecond …
Pressure Impulses During Microsecond Laser Ablation, Hanqun Shangguan, Lee W. Casperson, Scott A. Prahl
Pressure Impulses During Microsecond Laser Ablation, Hanqun Shangguan, Lee W. Casperson, Scott A. Prahl
Electrical and Computer Engineering Faculty Publications and Presentations
The collapse of laser-induced cavitation bubbles creates acoustic transients within the surrounding medium and also pressure impulses to the ablation target and light-delivery fiber during microsecond laser ablation. The impulses are investigated here with time-resolved flash photography, and they are found to occur whether or not the light-delivery fiber is in contact with the target. We demonstrate that the impulses depend primarily on the energy stored in the cavitation bubble. They are not directly dependent on the mode of light delivery (contact versus noncontact), and they are also not directly correlated to the other acoustic transients. The pressure impulses do …
Drug Delivery With Microsecond Laser Pulses Into Gelatin, Hanqun Shangguan, Lee W. Casperson, Alan Shearin, Kenton W. Gregory, Scott A. Prahl
Drug Delivery With Microsecond Laser Pulses Into Gelatin, Hanqun Shangguan, Lee W. Casperson, Alan Shearin, Kenton W. Gregory, Scott A. Prahl
Electrical and Computer Engineering Faculty Publications and Presentations
Photo acoustic drug delivery is a technique for localized drug delivery by laser-induced hydrodynamic pressure following cavitation bubble expansion and collapse. Photoacoustic drug delivery was investigated on gelatin-based thrombus models with planar and cylindrical geometries by use of one microsecond laser pulses. Solutions of a hydrophobic dye in mineral oil permitted monitoring of delivered colored oil into clear gelatin-based thrombus models. Cavitation bubble development and photoacoustic drug delivery were visualized with flash photography. This study demonstrated that cavitation is the governing mechanism for photoacoustic drug delivery, and the deepest penetration of colored oil in gels followed the bubble collapse. Spatial …