The elaboration of excimer laser dosimetry for bone and meniscus cutting and drilling using optical fibers

Abstract

In order to optimize bone and cartilage ablation various excimer laser systems at 308 nm wavelength (pulse width 28 ns, 60 ns, 300 ns) and tapered fibers (core diameter 400 μm, 600 μm, 1000 μm) were combined. By variing the major parameters such as fluence, pulselength, repetition rate, fiber diameter, medium, manner of application (drilling, cutting) we analysed the interaction of the excimer laser beam with different organic material (meniscus, bone tissue). More than 300 cuts and drillings have been realized with different parameters. The ablation rate mainly depends on fluence, repetition rate and pulse duration. The achieved ablation rate was 3 μm/puls in bone. The drilling speed of the meniscus was 6 mm/s. The samples showed no carbonisation at all, when beeing cut or drilled in liquid medium. This might be a breakthrough in fiber guided excimer laser surgery. From these and further experiments we obtain the dosimetry, which will be the basis for the elaboration of necessary operation guidelines for accident surgery.