2109 IN VITRO RESPIRATORY MOTION MODEL FOR LITHOTRIPTER BEAM WIDTH ASSESSMENT (2010)

You have accessJournal of UrologyStone Disease: New Technology1 Apr 20102109 IN VITRO RESPIRATORY MOTION MODEL FOR LITHOTRIPTER BEAM WIDTH ASSESSMENT Michael Lipkin, Dorit Zilberman, John Mancini, Nathan Smith, Georgy Sanknin, Neal Simmons, Glenn Preminger, and Pei Zhong Michael LipkinMichael Lipkin More articles by this author , Dorit ZilbermanDorit Zilberman More articles by this author , John ManciniJohn Mancini More articles by this author , Nathan SmithNathan Smith More articles by this author , Georgy SankninGeorgy Sanknin More articles by this author , Neal SimmonsNeal Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Pei ZhongPei Zhong More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.2196AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Accurately representing in vivo renal stone distribution in vitro requires considerations for both stone spreading and respiration movement. From a rigorous in vitro model, shockwave lithotripter efficacy can be confidently assessed pre-animal study. Recent investigations have examined the adverse effects of respiration on fragmentation efficiency and offered stone targeting as a solution. This work shows improvement from in situ acoustic lens modification of an extracorporeal electromagnetic lithotripter for beam width enhancement and flattened acoustic energy density profile. METHODS Motor-controlled SI-mimicking motion of a membrane-capped cylindrical holder (ø14 mm) for 12.5 mm displacement range and 12 breath cycles/min was implemented with clinically relevant inhalation and exhalation pauses. Small (<0.2 mm/cycle) displacement randomization ensured no synchronization between motion and shocking. Two electromagnetic lithotripters of matched acoustic energies and varying focal plane beam widths were tested at 2000 shocks and 1 Hz pulse repetition frequency in degassed water using ø10 mm spherical BegoStone samples. RESULTS The electromagnetic source with 1.4 times wider beam width produced 92% comminution efficiency (<2.0 mm) compared to 83% for the more tightly focused lithotripter. Student's t-test gives a P-value less than 0.01. Static focal tests produced statistically similar comminution for the two sources. CONCLUSIONS Widening of an electromagnetic lithotripter's focal beam and flattening of its acoustic energy density profile can benefit stone comminution efficiency in vitro under conditions mimicking normal human respiratory motion. Integration of respiratory motion, both regular and irregular, with more geometrically complex stone holders may further our understanding of clinically relevant lithotripter parameters. Durham, NC© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e820 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Michael Lipkin More articles by this author Dorit Zilberman More articles by this author John Mancini More articles by this author Nathan Smith More articles by this author Georgy Sanknin More articles by this author Neal Simmons More articles by this author Glenn Preminger More articles by this author Pei Zhong More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...