@article{prince90,
  author = {M. R. Prince and G. M. La{M}uraglia and C. E. Seidlitz and S. A. Prahl and C. A. Athanasoulis and R. Birngruber},
  title = {Ball-Tipped Fibers for Laser Angioplasty with the Pulsed-Dye Laser},
  journal = {IEEE J. Quantum Electron.},
  year = {1990},
  volume = {26},
  pages = {2297--2304},
  abstract = {A method of introducing high-intensity laser radiation into arteries has been developed and tested in amputated human limbs. The device consists of a small-diameter, flexible, quartz optical fiber which tapers to a large-diameter, smooth, rounded-ball tip. The smooth-ball tip minimizes the chance of mechanical dissection or perforation of the vessel wall. The spot size can be varied over a large range by varying the fiber input coupling, taper length, and numerical aperture. With 480nm radiation, which is preferentially absorbed by atherosclerotic plaque and thrombus, at 8\,$\mu$s pulse durations, the device effectively recanalized occluded human peripheral arteries creating a 2--3mm diameter channel. The radiant exposure required to recanalize arteries (85 J/cm$^2$) was higher than the ablation threshold for plaque (56 J/cm$^2$) but well below the fluence required to ablate normal artery and perforate (226 J/cm$^2$). Time-delayed, flash photography shows the formation of a large vapor bubble with each ablative pulse, which suggests that laser recanalization can involve not only ablating plaque but also an expanding effect similar to balloon angioplasty. These data demonstrate that a tapered ball-tipped fiber can deliver the high-intensity 480nm radiation for selective ablation of plaque and that this device can effectively recanalize symptomatic peripheral artery occlusions.},
}