PHOTOGRAPHIC STUDIES OF LASER-INDUCED BUBBLE FORMATION IN ABSORBING LIQUIDS AND ON SUBMERGED TARGETS - IMPLICATIONS FOR DRUG-DELIVERY WITH MICROSECOND LASER-PULSES

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 cl ot). The hydrodynamic pressures following the bubble expansion and col lapse can also be used as a driving force to deliver clot-dissolving a gents into thrombus for enhancement of laser thrombolysis. Thus, the l aser-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 photograph y and high-speed photography. Potential applications in drug delivery using microsecond laser pulses are also discussed. (C) 1998 Society of Photo-Optical Instrumentation Engineers.