You have accessJournal of UrologyStone Disease: SWL, Ureteroscopic or Percutaneous Stone Removal II1 Apr 20101586 NON-CONTACT INFRARED TEMPERATURE MEASUREMENT OF ULTRASONIC LITHOTRIPTERS – A COMPARISON OF COMMONLY USED LITHOTRIPSY DEVICES Christian Keil, Peter Olbert, Axel Hegele, Andres Jan Schrader, and Rainer Hofmann Christian KeilChristian Keil More articles by this author , Peter OlbertPeter Olbert More articles by this author , Axel HegeleAxel Hegele More articles by this author , Andres Jan SchraderAndres Jan Schrader More articles by this author , and Rainer HofmannRainer Hofmann More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1352AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Ultrasonic lithotripters are used during PCNL for the fragmentation and removal of renal calculi. This work presents a novel non contact, real time method to compare the temperatures of ultrasonic lithotripsy handpieces and probes during lithotripsy. METHODS In an in vitro setup 4 ultrasonic lithotripters (US3/EMS, Vario/EMS, LUS2/Olympus, Cyberwand/Gyrus/ACMI) were activated continuously for 15 minutes using an artificial stone and balanced irrigation/suction flow (200 ml/min). For demonstrating reproducibility 3 repetitions were performed with each device. Temperature of handpiece and probe was measured using an infrared thermo camera (Fluke Ti20) at 1, 2, 5, 10 and 15 minutes. Additionally, the development of temperatures over time was checked with interrupted suction. RESULTS A rise in handpiece temperature could be traced in both EMS devices. A plateau of constant temperatures was reached after 10 minutes. Maximum temperatures were 53 °C (US3) and 39 °C (Vario). No heating could be measured using the Olympus LUS2. The Cyberwand probe broke after 4 min. during the first testing at 50 °C. With interrupted suction temperature at the probe/handpiece-connection rose to more than 80 °C at Vario and US3 and to 40 °C at LUS2 within 2 minutes. Temperature distribution over the probe measured in air showed heating just at nodes of the standing longitudinal wave but not at antinodes including the tip of the probe. Radial contact with the probe led to substantial local heat-up. CONCLUSIONS In vitro testing showed different temperature increases for all devices. Repetitions of measurements showed good reproducibility of results. All devices tested are within the temperature range given by medical device safety standards (IEC 601). As temperature increase is a function of power input and device efficiency, fragmentation power for these devices varies, as confirmed e.g. by Ferrandino et al 2007. To avoid critical temperatures, continuous suction during ultrasonic lithotripsy is essential. Tissue safety of ultrasonic lithotripsy was confirmed by demonstrating that the distal probe end does not show an ultrasonic wave related temperature increase. Any radial contact with the probe must be avoided as this leads to rapid heating by local friction, caused by the high frequency axial motion of the probe. Due to the non-contact principle of infrared temperature measurement it was also possible to apply the testing in vivo. The trends found in the in vitro setup could be confirmed. Marburg, Germany© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e613 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Christian Keil More articles by this author Peter Olbert More articles by this author Axel Hegele More articles by this author Andres Jan Schrader More articles by this author Rainer Hofmann More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...