1552 IN-VITRO ASSESSMENT OF TIP DYNAMICS IN A NEW PORTABLE BALLISTIC LITHOTRIPTER

Abstract

You have accessJournal of UrologyStone Disease: New Technology/SWL, Ureteroscopic or Percutaneous Stone Removal1 Apr 20111552 IN-VITRO ASSESSMENT OF TIP DYNAMICS IN A NEW PORTABLE BALLISTIC LITHOTRIPTER Agnes J. Wang, Gavin McAlister, Jamie Gabriel, W. Neal Simmons, Michael E. Lipkin, Michael N. Ferrandino, Glenn M. Preminger, and Pei Zhong Agnes J. WangAgnes J. Wang Durham, NC More articles by this author , Gavin McAlisterGavin McAlister Durham, NC More articles by this author , Jamie GabrielJamie Gabriel Durham, NC More articles by this author , W. Neal SimmonsW. Neal Simmons Durham, NC More articles by this author , Michael E. LipkinMichael E. Lipkin Durham, NC More articles by this author , Michael N. FerrandinoMichael N. Ferrandino Durham, NC More articles by this author , Glenn M. PremingerGlenn M. Preminger Durham, NC More articles by this author , and Pei ZhongPei Zhong Durham, NC More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1560AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Intracorporeal lithotriptor technology is moving towards devices that do not need a separate unit as an energy source. The benefits are in cost reduction as well as the portability and the “wireless” nature of the device. One such pneumatic device, the LMA Stonebreaker™, is powered by sterile CO2 cartridges. A new device under development is a battery-operated electrokinetic ballistic lithotripter in which probe velocity and displacement can be modified to suit clinical applications by changing the hardness of the probe guide. An in vitro model was designed to compare the tip speed and displacement characteristics of this new electrokinetic ballistic device. METHODS To determine tip velocity and displacement, the probe tip was aligned to partially occlude an expanded laser beam that was aimed at a high bandwidth photo detector. Displacement and velocity were measured for 1mm (ureteroscopic) and 2mm (percutaneous) probes with both hard and soft probe guides. The probe position was correlated with the voltage measurement from the photo detector. A digital oscilloscope was used to capture the time/displacement characteristics of the probe tip. Twenty-five displacement profiles were measured for each probe and support combination. Means and standard deviations were computed for all groups. RESULTS The tip displacement was significantly increased when a soft probe guide was used. The mean probe tip displacement increased 37% (0.31 ± 0.04mm increase) and 52% (0.42 ± 0.10mm increase) for ureteroscopic and percutaneous probes, respectively. Soft probes guides also increased the mean tip velocity by 15% (0.9 ± 0.2 m/s increase) and 14% (0.5 ± 0.2 m/s increase) for ureteroscopic and percutaneous probes, respectively. CONCLUSIONS The elasticity of the probe guide has a large impact on tip velocity and displacement characteristics of electrokinetic ballistic lithotrites. The ability to change tip dynamics may provide optimum performance over a wide range of stone types. High velocity and smaller displacement tip characteristics are suited for hard stones such as calcium oxalate monohydrate while lower velocity and larger tip displacement may be more useful on softer stones. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e623 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Agnes J. Wang Durham, NC More articles by this author Gavin McAlister Durham, NC More articles by this author Jamie Gabriel Durham, NC More articles by this author W. Neal Simmons Durham, NC More articles by this author Michael E. Lipkin Durham, NC More articles by this author Michael N. Ferrandino Durham, NC More articles by this author Glenn M. Preminger Durham, NC More articles by this author Pei Zhong Durham, NC More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...