title: OpenHELP (Heidelberg laparoscopy phantom): development of an open-source surgical evaluation and training tool.
abstract: BACKGROUND
  Apart from animal testing and clinical trials, surgical research and laparoscopic training mainly rely on phantoms. The aim of this project was to design a phantom with realistic anatomy and haptic characteristics, modular design and easy reproducibility. The phantom was named open-source Heidelberg laparoscopic phantom (OpenHELP) and serves as an open-source platform.
  
  
  METHODS
  The phantom was based on an anonymized CT scan of a male patient. The anatomical structures were segmented to obtain digital three-dimensional models of the torso and the organs. The digital models were materialized via rapid prototyping. One flexible, using an elastic abdominal wall, and one rigid method, using a plastic shell, to simulate pneumoperitoneum were developed. Artificial organ production was carried out sequentially starting from raw gypsum models to silicone molds to final silicone casts. The reproduction accuracy was exemplarily evaluated for ten silicone rectum models by comparing the digital 3D surface of the original rectum with CT scan by calculating the root mean square error of surface variations. Haptic realism was also evaluated to find the most realistic silicone compositions on a visual analog scale (VAS, 0-10).
  
  
  RESULTS
  The rigid and durable plastic torso and soft silicone organs of the abdominal cavity were successfully produced. A simulation of pneumoperitoneum could be created successfully by both methods. The reproduction accuracy of ten silicone rectum models showed an average root mean square error of 2.26 (0-11.48) mm. Haptic realism revealed an average value on a VAS of 7.25 (5.2-9.6) for the most realistic rectum.
  
  
  CONCLUSIONS
  The OpenHELP phantom proved to be feasible and accurate. The phantom was consecutively applied frequently in the field of computer-assisted surgery at our institutions and is accessible as an open-source project at www.open-cas.org for the academic community.
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors: H G
authors: HG
authors: Kenngott
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors: J J
authors: JJ
authors: Wünscher
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors: M
authors: M
authors: Wagner
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors: A
authors: A
authors: Preukschas
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors: A L
authors: AL
authors: Wekerle
authors: Division of Medical and Biological Informatics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors: P
authors: P
authors: Neher
authors: Institute for Anthropomatics, Karlsruhe Institute of Technology, Karlsruhe, Germany.
authors: S
authors: S
authors: Suwelack
authors: Institute for Anthropomatics, Karlsruhe Institute of Technology, Karlsruhe, Germany.
authors: S
authors: S
authors: Speidel
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors: F
authors: F
authors: Nickel
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
authors: D
authors: D
authors: Oladokun
authors: Ruprecht-Karls-University, Department of General Abdominal and Transplant Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany.
authors: Lorenzo
authors: L
authors: Albala
authors: Division of Medical and Biological Informatics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors: L
authors: L
authors: Maier-Hein
authors: Institute for Anthropomatics, Karlsruhe Institute of Technology, Karlsruhe, Germany.
authors: R
authors: R
authors: Dillmann
authors: Division of Medical and Biological Informatics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors: H P
authors: HP
authors: Meinzer
authors: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany. Beat.Mueller@med.uni-heidelberg.de.
authors: B P
authors: BP
authors: Müller-Stich
mesh_terms: D005858:Germany; D006801:Humans; D021621:Imaging, Three-Dimensional; D010535:Laparoscopy / Q000193:education*; D008297:Male; D008953:Models, Anatomic; D015203:Reproducibility of Results; D000066908:Simulation Training / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000193:education*; D014057:Tomography, X-Ray Computed
keywords: Computer-assisted surgery; Laparoscopy; Minimally invasive surgery; Operation phantom; Segmentation; Simulator