You have accessJournal of UrologyStone Disease: New Technology/SWL, Ureteroscopic or Percutaneous Stone Removal II1 Apr 20121701 IPAD-ASSISTED PERCUTANEOUS ACCESS TO THE KIDNEY - INITIAL EXPERIENCE Jens Rassweiler, Michael Müller, Markus Fangerau, Jan Klein, Hans-Peter Meinzer, and Dogu Teber Jens RassweilerJens Rassweiler Heilbronn, Germany More articles by this author , Michael MüllerMichael Müller Heidelberg, Germany More articles by this author , Markus FangerauMarkus Fangerau Heidelberg, Germany More articles by this author , Jan KleinJan Klein Heilbronn, Grenada More articles by this author , Hans-Peter MeinzerHans-Peter Meinzer Heidelberg, Germany More articles by this author , and Dogu TeberDogu Teber Heidelberg, Germany More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1638AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Percutaneous access to the kidney is the most important factor to minimize complications and maximize success of percutaneous nephrolithotomy (PCNL). Based on previous experience with marker-based tracking (inside-out), we created a new system for augmented reality navigation using an iPad during percutaneous puncture of the kidney based on computer tomography (CT). METHODS One day before surgery, the patient underwent a thin-sliced CT in prone position (similar to PCNL) with coloured radiodense spherical markers fixed around the percutaneous access area. The CT-data are segmented to visualize all important anatomical structures (ie. ribs, collecting system, stones, renal parenchyma, colon, spleen. liver) in 3D. Before surgery, the markers are re-attached exactly on the skin of the patient in prone position. During the intervention, an iPad is used as camera to locate the markers and simultaneously as display device to show the enhanced virtual reality of patient‘s situs. The backfacing camera of the iPad captures images of the access site, compresses and transmits them via WiFi to a server located in a room nearby. The server in turn runs the algorithms to analyze the position of the markers and to compute a correct registration of the video image and the CT. Finally, the server creates the augmented reality enhanced image and sends it back to the iPad. This creates a virtual insight into the patient. During percutanoeus puncturing of the kidney. The augmented reality visualization enables the surgeon to adjust puncture site and angle of the needle on to the virtual calix. The access into the collecting system is then monitored by digital fluoroscopy. RESULTS We used this novel navigation system in patients with complicated nephrolithiasis. The segmented imaging enabled us to select the optimal puncture site and angle without any use of ultrasound or fluoroscopy. Particularly the knowledge of the location of adjacent organs (bowel, spleen, ribs) was helpful. This resulted in a one step direct puncturing of the collecting system. Moreover, the augmented reality overlay provided additional information (ie stone localization) during endoscopic stone manipulation reducing the need of fluoroscopy. CONCLUSIONS The use of marker-based tracking proved to be easy and safe to handle. The use of the iPad was advantageous providing good imaging quality of the virtual reality and space enough for the surgeon to perform the puncture. It may obviate the use of ultrasound for percutaneous access and reduces the need of fluoroscopy. Future work will focus on the tracking of the needle and the use stereoscopic tablets. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e686 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jens Rassweiler Heilbronn, Germany More articles by this author Michael Müller Heidelberg, Germany More articles by this author Markus Fangerau Heidelberg, Germany More articles by this author Jan Klein Heilbronn, Grenada More articles by this author Hans-Peter Meinzer Heidelberg, Germany More articles by this author Dogu Teber Heidelberg, Germany More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...