Application systems for intracorporeal laser-induced shockwave lithotripsy using the Nd:YAG Q-switched laser.
For laser-induced shockwave lithotripsy, the electromagnetic energy of a laser light pulse is converted intracorporeally into the acoustic energy of a shockwave. The lithotriptor is based on a specially developed, Q-switched Nd:YAG laser whose high power light pulses (70 mJ, 25 nsec) are coupled into a flexible quartz fiber with a core diameter of 600 mum. Using focusing elements, energy densities higher than 6 x 10 5 J m -2 can be achieved, resulting in an optical breakdown in water followed by a shockwave. As a result of different absorption mechanisms, the breakdown threshold can be decreased by placing a metallic target into the laser beam. The different shockwave formations of such optomechanical transducers have been measured. First clinical applications have been performed.
Frank
F
F
MBB-Medizintechnik GmbH, Munich, West Germany.
Eichenlaub
M
M
Hessel
S
S
Wondrazek
F
F
D004867:Equipment Design; D006801:Humans; D053685:Laser Therapy; D008096:Lithotripsy / Q000295:instrumentation* / Q000379:methods; D017602:Lithotripsy, Laser; D055095:Optics and Photonics; D014159:Transducers; D014514:Ureteral Calculi / Q000628:therapy*