Evaluation of Optical Feedback for Preventing Tissue Damage in Dye Laser Lithotripsy
Microsecond laser pulses are beneficial for laser lithotripsy because they can be coupled into and transmitted through very thin caliber fibers (200 μim core diameter). The interaction between the laser pulse at the fiber tip and the target object is both thermal and mechanical and relies more on the power density than on the wavelength. If the fiber tip is in direct contact with a urinary stone, a plasma is initiated by the high energy density of the laser pulse (< 100 J/cm2). Oscillations of the plasma bubble result in mechanical shock waves that lead to stone disintegration. The quality of the distal fiber surface is uncritical in this process. For this reason highly flexible fiber application systems utilizing a 200 μm quartz fiber without accessory devices to facilitate plasma formation can be used with microsecond lasers for lasertripsy.
KeywordsOptical Feedback Laser Lithotripsy Plasma Bubble Calcium Oxalate Dihydrate Prevent Tissue Damage
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