title: Stone Retropulsion with Ho: YAG and Tm: YAG Lasers: A Clinical Practice-Oriented Experimental Study.
abstract: To compare the retropulsion of stones with the use of holmium: yttrium aluminum garnet (Ho: YAG) laser and thulium: yttrium aluminum garnet (Tm: YAG) laser in settings that could be used in clinical practice.
  
  
  
  The experimental configuration included a glass tube set in a water bath filled with physiologic saline. Plaster of Paris stones were inserted in the tube. Tm: YAG and Ho: YAG laser systems were used along with a high-speed slow-motion camera. The lasers were activated with different settings. The displacement of the stone was measured according to a custom-made algorithm.
  
  
  
  Ho: YAG: the retropulsion of stones was the lowest with the energy setting of 0.5 J and the frequency of 20 Hz with long pulse duration. The highest retropulsion was observed in the case of 3 J, 5 Hz, and short pulse. Tm: YAG: the retropulsion of stones was the lowest with the energy setting of 1 J and the frequency of 10 Hz with either long or short pulse duration. Practically, there was no retropulsion at all. The highest retropulsion was observed in the case of 8 J, 5 Hz, and short pulse.
  
  
  
  Ho: YAG laser has a linear increase in stone retropulsion with increased pulse energy. On the other hand, the retropulsion rate was kept to the minimum with Tm: YAG as much as the energy level of 8 J. The activation of lasers with short pulse resulted in further displacement of the stone. Lower frequency with the same power setting seemed to result in further stone retropulsion. Higher power with the same frequency setting resulted in further displacement of the stone.
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Wissam
authors.initials: W
authors.lastname: Kamal
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kallidonis
authors.affiliation: 2 Electronics Laboratory, Department of Physics, University of Patras , Patras, Greece .
authors.forename: Georgia
authors.initials: G
authors.lastname: Koukiou
authors.affiliation: 3 Department of Chemical Engineering, University of Patras , Patras, Greece .
authors.forename: Lefteris
authors.initials: L
authors.lastname: Amanatides
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Vasileios
authors.initials: V
authors.lastname: Panagopoulos
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Pantelis
authors.initials: P
authors.lastname: Ntasiotis
authors.affiliation: 1 Department of Urology, University of Patras , Patras, Greece .
authors.forename: Evangelos
authors.initials: E
authors.lastname: Liatsikos
mesh_terms: D000465:Algorithms; D000535:Aluminum; D002137:Calculi / Q000628:therapy*; D004867:Equipment Design; D006695:Holmium; D006801:Humans; D007834:Lasers; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D017602:Lithotripsy, Laser / Q000295:instrumentation / Q000379:methods*; D013932:Thulium; D015019:Yttrium
chemical_list: C503779:yttrium-aluminum-garnet; D015019:Yttrium; D013932:Thulium; D000535:Aluminum; D006695:Holmium
keywords: Holmium; laser; retropulsion; thulium