1961 A NEW ACOUSTIC LENS DESIGN FOR PRODUCING AN IDEALIZED PRESSURE WAVEFORM WITH LOW PEAK PRESSURE AND BROAD FOCAL WIDTH IN ELECTROMAGNETIC SHOCK WAVE LITHOTRIPTERS

Abstract

You have accessJournal of UrologyStone Disease: Basic Research1 Apr 20101961 A NEW ACOUSTIC LENS DESIGN FOR PRODUCING AN IDEALIZED PRESSURE WAVEFORM WITH LOW PEAK PRESSURE AND BROAD FOCAL WIDTH IN ELECTROMAGNETIC SHOCK WAVE LITHOTRIPTERS Pei Zhong, Walter Simmons, Nathan Smith, Georgy Sankin, John Mancini, and Glenn Preminger Pei ZhongPei Zhong More articles by this author , Walter SimmonsWalter Simmons More articles by this author , Nathan SmithNathan Smith More articles by this author , Georgy SankinGeorgy Sankin More articles by this author , John ManciniJohn Mancini More articles by this author , and Glenn PremingerGlenn Preminger More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1971AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES A new acoustic lens for the Siemens Modularis electromagnetic shock wave lithotripter has been developed to produce a more idealized pressure waveform with low peak pressure and broad focal width. In-vitro comminution tests have been performed to evaluate the effect of these changes. METHODS In situ pulse superposition principle was used to design a new acoustic lens for the Modularis to truncate the second compressive wave while enlarging simultaneously the focal width produced by the original acoustic lens. The acoustic fields associated with the original and new lenses were characterized using a FOPH-500. Stone comminution tests were performed using BegoStone phantoms in vitro in a 15-mm tube holder at the lithotripter focus as well as 10 mm off axis. A dose of 2000 shocks was delivered at a clinically relevant energy setting. RESULTS At acoustic pulse energy of 42 mJ, the Modularis with the new lens produces a peak positive pressure of 41 MPa, compared to 47 MPa by the original lens. In addition, using the new lens the second compressive peak in the pressure waveform is significantly reduced and the -6 dB focal width is enlarged by 43%. After 2000 shocks, in vitro stone comminution produced by the original and new lenses are 100% and 99% at the lithotripter focus, and 49.7±15.0% and 75.3±8.74% (p < 0.001) at 10 mm off axis. CONCLUSIONS Using the new acoustic lens design, the Modularis lithotripter can produce an acoustic field with lower peak pressure and broader focal width. These changes lead to significantly improved stone comminution. Durham, NC© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e762 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Pei Zhong More articles by this author Walter Simmons More articles by this author Nathan Smith More articles by this author Georgy Sankin More articles by this author John Mancini More articles by this author Glenn Preminger More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...