NarvisLab

Chair for Computer Aided Medical Procedures & Augmented Reality
Lehrstuhl für Informatikanwendungen in der Medizin & Augmented Reality

Chirurgische Klinik und Poliklinik Innenstadt The NARVIS lab is our research laboratory at Chirurgischen Klinik und Poliklinik - Innenstadt, LMU München providing an interdisciplinary platform for our research activities. Since 2004, a strong collaboration between surgeons and computer scientists has been established and resulted in a large number of international publications and various research projects. Main topic of projects running at NARVIS lab addresses medical applications for Augmented Reality Technologies. The two main research interests at NARVIS lab are the Camera Augmented Mobile C-arm and different projects for in-situ visualization using a stereo video see-through head mounted display.

Getting There

LMUKlinikumInnenstadt_small.PNG

Ludwig-Maximilians-Universität München
Chirurgische Klinik und Poliklinik - Innenstadt, AG CAS
Nussbaumstr. 20
80336 München
Room: C2.06
Tel.: +49 89 5160-3615
Tel.: +49 89 5160-3635
Tel.: +49 89 5160-3632
Fax: +49 89 5160-3630

There is very limited payed parking available and no free parking at all. Therefore, it is strongly recommended to use public transport.

Getting There By Train (from Hauptbahnhof by foot)

If you come to Munich by train, you do not even need to use public transport. The hospital is within walking distance (10min) from the central station:
  • When reaching the end of tracks, head right to the south exit of the station.
  • After leaving the station, cross Bayerstr. and continue southwards on Goethestr.
  • After approx. 500m, turn left on Nussbaumstr.
  • Cross Schillerstr. and continue on Nussbaumstr.
  • After approx. 100m you will reach the main entrance of Chirurgische Klinik on the left side. There is also a heliport close to the entrance.
  • After entering the building use the staircase on the left side. At the staircase you will find signs leading you to the lab.
  • Inside the building look for Station 3, which is in the second floor. In the same floor you'll find our room C2.06.

By Public Transport / from the airport

  • Use subway lines U1, U2, U3, or U6 to Sendlinger Tor.
  • When you come from the airport you can change to U1/U2 at Central Station or to U3/U6 at Marienplatz
  • Exit the station to Nussbaumstr.
  • Walk along Nussbaumstr.
  • After approx. 500m you will reach the main entrance of Chirurgische Klinik on the right side. There is also a heliport close to the entrance.
  • After entering the building use the staircase on the left side. At the staircase you will find signs leading you to the lab.
  • Inside the building look for Station 3, which is in the second floor. In the same floor you'll find our room C2.06.

After you entered the building, turn left, and go towards the staircase at the end of the entrance hall. From here, the way to the Narvis lab is marked by signs. You can also ask the desk officer at the entrance desk ("Pforte") at Chirurgische Klinik, Nussbaumstr. 20 to call us (3615). We will then pick you up there.


Größere Kartenansicht

Photos


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Downloads

Internal Website

If you are working at NARVIS Lab and if you need access to the infrastructure such as internet, keys, phone numbers here is the place to get information.

Publications about Research Activities at NARVIS lab

2012
L. Wang, P. Fallavollita, R. Zou, X. Chen, S. Weidert, N. Navab
Closed-form inverse kinematics for interventional C-arm X-ray imaging with six degrees of freedom: modeling and application
IEEE Transactions on Medical Imaging (to appear). (bib)
2011
M. Wieczorek, A. Aichert, P. Fallavollita, O. Kutter, A. Ahmadi, L. Wang, N. Navab
Interactive 3D visualization of a single-view X-Ray image
Proceedings of Medical Image Computing and Computer-Assisted Intervention (MICCAI 2011), Toronto, Canada, September 2011. (bib)
S. Weidert, L. Wang, P. Thaller, J. Landes, A. Brand, N. Navab, E. Euler
X-ray Stitching for Intra-operative Mechanical Axis Determination of the Lower Extremity
the 11th Annual Meeting of the International Society for Computer Assisted Orthopaedic Surgery, London, UK, June 15-19 2011 (bib)
L. Wang, R. Zou, S. Weidert, J. Landes, E. Euler, D. Burschka, N. Navab
Closed-form inverse kinematics for intra-operative mobile C-arm positioning with six degrees of freedom
SPIE Medical Imaging, Lake Buena Vista (Orlando), Florida, USA, February 2011 (bib)
2010
C. Bichlmeier
Immersive, Interactive and Contextual In-Situ Visualization for Medical Applications
Dissertation an der Fakultät für Informatik, Technische Universität München, 2010 ( online version available here) (bib)
L. Wang, M. Springer, H. Heibel, N. Navab
Floyd-Warshall All-Pair Shortest Path for Accurate Multi-Marker Calibration
The 9th IEEE and ACM International Symposium on Mixed and Augmented Reality, Seoul, Korea, Oct. 13 - 16, 2010. (bib)
T. Blum, M. Wieczorek, A. Aichert, R. Tibrewal, N. Navab
The effect of out-of-focus blur on visual discomfort when using stereo displays
The 9th IEEE and ACM International Symposium on Mixed and Augmented Reality, Seoul, Korea, Oct. 13 - 16, 2010. The original publication is available online at ieee.org. (bib)
C. Bichlmeier, E. Euler, T. Blum, N. Navab
Evaluation of the Virtual Mirror as a Navigational Aid for Augmented Reality Driven Minimally Invasive Procedures
The 9th IEEE and ACM International Symposium on Mixed and Augmented Reality, Seoul, Korea, Oct. 13 - 16, 2010. The original publication is available online at ieee.org. (bib)
L. Wang, R. Zou, S. Weidert, J. Landes, E. Euler, D. Burschka, N. Navab
Modeling Kinematics of Mobile C-arm and Operating Table as an Integrated Six Degrees of Freedom Imaging System
The 5th International Workshop on Medical Imaging and Augmented Reality, MIAR 2010, Beijing, China, September 19-20, 2010 (bib)
A. Ahmadi, F. Pisana, E. DeMomi?, N. Navab, G. Ferrigno
User friendly graphical user interface for workflow management during navigated robotic-assisted keyhole neurosurgery
Computer Assisted Radiology (CARS), 24th International Congress and Exhibition, Geneva, CH, June 2010 (bib)
L. Wang, J. Traub, S. Weidert, S.M. Heining, E. Euler, N. Navab
Parallax-Free Intra-Operative X-ray Image Stitching
the MICCAI 2009 special issue of the Journal Medical Image Analysis (bib)
L. Wang, J. Landes, S. Weidert, T. Blum, A. von der Heide, E. Euler, N. Navab
First Animal Cadaver Study for Interlocking of Intramedullary Nails under Camera Augmented Mobile C-arm A Surgical Workflow Based Preclinical Evaluation
the 1st International Conference on Information Processing in Computer-Assisted Interventions (IPCAI), Switzerland, June 23 2010. The original publication is available online at www.springerlink.com. (bib)
S. Weidert, L. Wang, J. Landes, A. von der Heide, N. Navab, E. Euler
First Surgical Procedures under Camera-Augmented Mobile C-arm (CamC) guidance
The 3rd Hamlyn Symposium for Medical Robotics ,London, UK, May 25 2010 (bib)
A. Plate, A. Ahmadi, T. Klein, N. Navab, J. Weiße, J. Mehrkens, K. Bötzel
Towards a More Objective Visualization of the Midbrain and its Surroundings Using 3D Transcranial Ultrasound
54. Jahrestagung der Deutschen Gesellschaft für Klinische Neurophysiologie und Funktionelle Bildgebung (DGKN), Halle, GER, March 2010 (bib)
P. Wucherer, C. Bichlmeier, M. Eder, L. Kovacs, N. Navab
Multimodal Medical Consultation for Improved Patient Education
Proceedings of Bildverarbeitung fuer die Medizin (BVM 2010), Aachen, Germany, March 2010 (bib)
M. Wieczorek, A. Aichert, O. Kutter, C. Bichlmeier, J. Landes, S.M. Heining, E. Euler, N. Navab
GPU-accelerated Rendering for Medical Augmented Reality in Minimally-Invasive Procedures
Proceedings of Bildverarbeitung fuer die Medizin (BVM 2010), Aachen, Germany, March 14-16 2010 (bib)
P. Dressel, L. Wang, O. Kutter, J. Traub, S.M. Heining, N. Navab
Intraoperative positioning of mobile C-arms using artificial fluoroscopy
SPIE Medical Imaging, San Diego, California, USA, February 2010 (bib)
2009
C. Bichlmeier, S.M. Heining, L. Omary, P. Stefan, B. Ockert, E. Euler, N. Navab
MeTaTop: A Multi-Sensory and Multi-User Interface for Collaborative Analysis of Medical Imaging Data
Interactive Demo (ITS 2009), Banff, Canada, November 2009 (bib)
C. Bichlmeier, S. Holdstock, S.M. Heining, S. Weidert, E. Euler, O. Kutter, N. Navab
Contextual In-Situ Visualization for Port Placement in Keyhole Surgery: Evaluation of Three Target Applications by Two Surgeons and Eighteen Medical Trainees
The 8th IEEE and ACM International Symposium on Mixed and Augmented Reality, Orlando, US, Oct. 19 - 22, 2009. (bib)
C. Bichlmeier, M. Kipot, S. Holdstock, S.M. Heining, E. Euler, N. Navab
A Practical Approach for Intraoperative Contextual In-Situ Visualization
International Workshop on Augmented environments for Medical Imaging including Augmented Reality in Computer-aided Surgery (AMI-ARCS 2009), London, UK, September 2009 (bib)
C. Bichlmeier, S.M. Heining, M. Feuerstein, N. Navab
The Virtual Mirror: A New Interaction Paradigm for Augmented Reality Environments
IEEE Trans. Med. Imag., vol. 28, no. 9, pp. 1498-1510, September 2009 (bib)
L. Wang, J. Traub, S. Weidert, S.M. Heining, E. Euler, N. Navab
Parallax-free Long Bone X-ray Image Stitching
Medical Image Computing and Computer-Assisted Intervention (MICCAI), London, UK, September 20-24 2009 (bib)
A. Ahmadi, T. Klein, N. Navab
Advanced Planning and Ultrasound Guidance for Keyhole Neurosurgery in ROBOCAST
Russian Bavarian Conference (RBC), Munich, GER, July 2009 (bib)
A. Ahmadi, T. Klein, N. Navab, R. Roth, R.R. Shamir, L. Joskowicz, E. DeMomi?, G. Ferrigno, L. Antiga, R.I. Foroni
Advanced Planning and Intra-operative Validation for Robot-Assisted Keyhole Neurosurgery In ROBOCAST
International Conference on Advanced Robotics (ICAR), Munich, GER, June 2009 (bib)
B. Ockert, C. Bichlmeier, S.M. Heining, O. Kutter, N. Navab, E. Euler
Development of an Augmented Reality (AR) training environment for orthopedic surgery procedures
Proceedings of The 9th Computer Assisted Orthopaedic Surgery (CAOS 2009), Boston, USA, June, 2009 (bib)
N. Navab, S.M. Heining, J. Traub
Camera Augmented Mobile C-arm (CAMC): Calibration, Accuracy Study and Clinical Applications
IEEE Trans. Med. Imag., to appear (bib)
L. Wang, J. Traub, S.M. Heining, S. Benhimane, R. Graumann, E. Euler, N. Navab
Long Bone X-ray Image Stitching using C-arm Motion Estimation
Proceedings of Bildverarbeitung fuer die Medizin (BVM 2009), Heidelberg, Germany, March 22-24 2009 (bib)
L. Wang, S. Weidert, J. Traub, S.M. Heining, C. Riquarts, E. Euler, N. Navab
Camera Augmented Mobile C-arm: Towards Real Patient Study
Proceedings of Bildverarbeitung fuer die Medizin (BVM 2009), Heidelberg, Germany, March 22-24 2009 (bib)
2008
C. Bichlmeier, B. Ockert, S.M. Heining, A. Ahmadi, N. Navab
Stepping into the Operating Theater: ARAV - Augmented Reality Aided Vertebroplasty
The 7th IEEE and ACM International Symposium on Mixed and Augmented Reality, Cambridge, UK, Sept. 15 - 18, 2008. (bib)
J. Traub
New Concepts for Design and Workflow Driven Evaluation of Computer Assisted Surgery Solutions
Dissertation an der Fakultät für Informatik, Technische Universität München, 2008 ( online version available here) (bib)
O. Kutter, A. Aichert, C. Bichlmeier, J. Traub, S.M. Heining, B. Ockert, E. Euler, N. Navab
Real-time Volume Rendering for High Quality Visualization in Augmented Reality
International Workshop on Augmented environments for Medical Imaging including Augmented Reality in Computer-aided Surgery (AMI-ARCS 2008), USA, New York, September 2008 (bib)
C. Bichlmeier, B. Ockert, O. Kutter, M. Rustaee, S.M. Heining, N. Navab
The Visible Korean Human Phantom: Realistic Test & Development Environments for Medical Augmented Reality
International Workshop on Augmented environments for Medical Imaging including Augmented Reality in Computer-aided Surgery (AMI-ARCS 2008), USA, New York, September 2008 (bib)
J. Traub, A. Ahmadi, N. Padoy, L. Wang, S.M. Heining, E. Euler, P. Jannin, N. Navab
Workflow Based Assessment of the Camera Augmented Mobile C-arm System
International Workshop on Augmented Reality environments for Medical Imaging and Computer-aided Surgery (AMI-ARCS 2008), New York, NY, USA, September 2008 (bib)
L. Wang, J. Traub, S.M. Heining, S. Benhimane, R. Graumann, E. Euler, N. Navab
Long Bone X-ray Image Stitching Using Camera Augmented Mobile C-arm
Medical Image Computing and Computer-Assisted Intervention, MICCAI, 2008, New York, USA, September 6-10 2008 (bib)
F. Wimmer, C. Bichlmeier, S.M. Heining, N. Navab
Creating a Vision Channel for Observing Deep-Seated Anatomy in Medical Augmented Reality
Proceedings of Bildverarbeitung fuer die Medizin (BVM 2008), Munich, Germany, April 2008 (bib)
J. Traub, S.M. Heining, E. Euler, N. Navab
Two camera augmented mobile C-arm – System setup and first experiments
Proceedings of The 8th Computer Assisted Orthopaedic Surgery (CAOS 2008), Hong Kong, China, June, 2008 (bib)
S.M. Heining, C. Bichlmeier, E. Euler, N. Navab
Smart Device: Virtually Extended Surgical Drill
Proceedings of The 8th Computer Assisted Orthopaedic Surgery (CAOS 2008), Hong Kong, China, June, 2008 (bib)
T. Sielhorst
New Methods for Medical Augmented Reality
Dissertation an der Fakultät für Informatik, Technische Universität München, 2008 ( online version available here) (bib)
2007
C. Bichlmeier, S.M. Heining, M. Rustaee, N. Navab
Laparoscopic Virtual Mirror for Understanding Vessel Structure: Evaluation Study by Twelve Surgeons
The Sixth IEEE and ACM International Symposium on Mixed and Augmented Reality, Nara, Japan, Nov. 13 - 16, 2007. (bib)
C. Bichlmeier, F. Wimmer, S.M. Heining, N. Navab
Contextual Anatomic Mimesis: Hybrid In-Situ Visualization Method for Improving Multi-Sensory Depth Perception in Medical Augmented Reality
The Sixth IEEE and ACM International Symposium on Mixed and Augmented Reality, Nara, Japan, Nov. 13 - 16, 2007. (bib)
T. Sielhorst, Wu Sa, A. Khamene, F. Sauer, N. Navab
Measurement of absolute latency for video see through augmented reality
Sixth IEEE and ACM International Symposium on Mixed and Augmented Reality (ISMAR'07), Nara, Japan, November 2007 (bib)
T. Sielhorst, M. Bauer, O. Wenisch, G. Klinker, N. Navab
Online Estimation of the Target Registration Error for n-ocular Optical Tracking Systems
to appear Proceedings of Medical Image Computing and Computer-Assisted Intervention (MICCAI 2007), Brisbane, Australia, October 2007 (bib)
P. Stefan, J. Traub, S.M. Heining, C. Riquarts, T. Sielhorst, E. Euler, N. Navab
Hybrid navigation interface: a comparative study
Proceedings of Bildverarbeitung fuer die Medizin (BVM 2007), Munich, Germany, March 2007, pp. 81-86 (bib)
C. Bichlmeier, T. Sielhorst, S.M. Heining, N. Navab
Improving Depth Perception in Medical AR: A Virtual Vision Panel to the Inside of the Patient
Proceedings of Bildverarbeitung fuer die Medizin (BVM 2007), Munich, Germany, March 2007 (bib)
2006
C. Bichlmeier, N. Navab
Virtual Window for Improved Depth Perception in Medical AR
International Workshop on Augmented Reality environments for Medical Imaging and Computer-aided Surgery (AMI-ARCS 2006), Copenhagen, Denmark, October 2006 (bib)
J. Traub, P. Stefan, S.M. Heining, T. Sielhorst, C. Riquarts, E. Euler, N. Navab
Hybrid navigation interface for orthopedic and trauma surgery
Proceedings of Medical Image Computing and Computer-Assisted Intervention (MICCAI 2006), Copenhagen, Denmark, October 2006, pp. 373-380 (bib)
T. Sielhorst, C. Bichlmeier, S.M. Heining, N. Navab
Depth perception a major issue in medical AR: Evaluation study by twenty surgeons
Proceedings of Medical Image Computing and Computer-Assisted Intervention (MICCAI 2006), Copenhagen, Denmark, October 2006, pp. 364-372
The original publication is available online at www.springerlink.com
(bib)
J. Traub, P. Stefan, S.M. Heining, T. Sielhorst, C. Riquarts, E. Euler, N. Navab
Towards a Hybrid Navigation Interface: Comparison of a Slice Based Navigation System with In-situ Visualization
Proceedings of International Workshop on Medical Imaging and Augmented Reality (MIAR 2006), Shanghai, China, August, 2006, pp.179-186 (bib)
S.M. Heining, P. Stefan, L. Omary, S. Wiesner, T. Sielhorst, N. Navab, F. Sauer, E. Euler, W. Mutschler, J. Traub
Evaluation of an in-situ visualization system for navigated trauma surgery
Journal of Biomechanics 2006; Vol. 39 Suppl. 1, page 209 (bib)
J. Traub, P. Stefan, S.M. Heining, T. Sielhorst, C. Riquarts, E. Euler, N. Navab
Stereoscopic augmented reality navigation for trauma surgery: cadaver experiment and usability study
International Journal of Computer Assisted Radiology and Surgery, 2006; Vol. 1 Suppl. 1, page 30 - 31. The original publication is available online at www.springerlink.com (bib)
T. Sielhorst, M. Feuerstein, J. Traub, O. Kutter, N. Navab
CAMPAR: A software framework guaranteeing quality for medical augmented reality
International Journal of Computer Assisted Radiology and Surgery, 2006; Vol. 1 Suppl. 1, page 29 - 30.
The original publication is available online at www.springerlink.com
(bib)
S.M. Heining, P. Stefan, F. Sauer, E. Euler, N. Navab, J. Traub
Evaluation of an in-situ visualization system for navigated trauma surgery
Proceedings of The 6th Computer Assisted Orthopaedic Surgery (CAOS 2006), Montreal, Canada, June, 2006 (bib)

CAMP Research Projects @ NARVIS

NARVIS - navigated augmented reality visualization system

NARVIS - navigated augmented reality visualization system

Advanced visualization is getting increasingly important for the operation room of the future. The increasing number of available medical images must be presented to surgery team in new ways in order to support them rather than overloading with more information. In our project NARVIS we integrate an HMD-based (head mounted display) AR system into the operation room for 3D in situ visualization of computed tomography (CT) images. The final system aims at spinal surgery. The work is in close collaboration with our project partners “Klinikum für Unfallchirgie” at LMU, A.R.T. Weilheim, and Siemens Corporate Research in Princeton. The project is funded by Bayerische Forschungsstiftung.
Augmented Reality Magic Mirror using the Kinect

Augmented Reality Magic Mirror using the Kinect

The Kinect allows tracking of users without additional markers. We develop a magic mirror that generated an overlay of a video image with volume visualization from a CT volume. Such a system could be used for education of anatomy.
ARAV Augmented Reality Aided Vertebroplasty

ARAV Augmented Reality Aided Vertebroplasty

In today’s ORs more and more operations are performed employing minimally invasive procedures. Surgical instruments are inserted through a tiny cut on the patient’s skin, the port to the inside of the patient. In some cases endoscope cameras record video images of the operation site that are presented on a monitor. As a consequence of this technique, the surgeon’s field of view is divided into several work spaces, the monitor, the patient and information of medical imaging data presented on a third station. The missing direct view on the workspace complicates intuitive control of surgical tools. In contrast to open surgery the physician has to collect information from several fields of view at the same time and fuse information mentally to create a complete model of his working space, the operation site. The minimally invasive intervention vertebroplasty was determined as a suitable medical application to bring an Head Mounted Display (HMD) into the OR for augmentation of surgical instruments and medical imaging data. In-situ visualization with an HMD presents all available imaging data and navigational information in one field of view. The objective of vertebroplasty is the insertion of cement into weak and brittle vertebrae through a trocar for stabilization. In this case the view on the inside of the patient is not provided by an endoscope camera. However, since the operation is performed under a CT scanner, imaging data is permanently updated to check position of the trocar and amount of inserted cement. Imaging data is presented on a monitor and has to be mapped mentally by the surgeon on the real operation site.
Virtual Mirror: Interaction Paradigm for Augmented Reality Applications

Virtual Mirror: Interaction Paradigm for Augmented Reality Applications

Augmented Reality offers a higher degree of freedom for the programmer than classical visualization of volume data on a screen. The existing paradigms for interaction with 3D objects are not satisfactory for particular applications since the majority of them rotate and move the object of interest. The classic manipulation of virtual objects cannot be used while keeping real and virtual spaces in alignment within an AR environment. This project introduces a simple and efficient interaction paradigm allowing the users to interact with 3D objects and visualize them from arbitrary viewpoints without disturbing the in-situ visualization, or requiring the user to change the viewpoint. We present a virtual, tangible mirror as a new paradigm for interaction with 3D models. The concept borrows its visualization paradigm in some sense from methodology used by dentists to examine the oral cavity without constantly changing their own viewpoint or moving the patients head. The virtual mirror improves the understanding of complex structures, enables completely new concepts to support navigational aid for different tasks and provides the user with intuitive views on physically restricted areas.
Improving Depth Perception and Perception of Layout for In-Situ Visualization in Medical Augmented Reality

Improving Depth Perception and Perception of Layout for In-Situ Visualization in Medical Augmented Reality

In-situ visualization in medical augmented reality (AR) using for instance a video see-through head mounted display (HMD) and an optical tracking system enables the stereoscopic view on visualized CT data registered with the real anatomy of a patient. Data can aligned with the required accuracy and the surgeons do not have to analyze data on an external monitor or images attached to the wall somewhere in the operating room. Thanks to a medical AR system like mentioned before, surgeons get a direct view onto and also ”into” the patient. Mental registration of medical imagery with the operation site is not necessary anymore. In addition surgical instruments can be augmented inside the human body. Bringing medical imagery and surgical instruments in the same field of action provides the most intuitive way to understand the patient’s anatomy within the region of interest and allows for the development of completely new generations of surgical navigation systems.
Unfortunately, this method of presenting medical data suffers from a serious lack. Virtual imagery, such as a volume rendered spinal column, can only be displayed superimposed on real objects. If virtual entities of the scene are expected behind real ones, like the virtual spinal column beneath the real skin surface, this problem implicates incorrect perception of the viewed objects respective their distance to the observer. The strong visual depth cue interposition is responsible for misleading depth perception. This project aims at the development and evaluation of methods to improve depth perception for in-situ visualization in medical AR. Its intention is to provide an extended view onto the human body that allows an intuitive localization of visualized bones and tissue.
Surgical Workflow Analysis in Laparoscopy for Monitoring and Documentation

Surgical Workflow Analysis in Laparoscopy for Monitoring and Documentation

Surgical workflow recovery is a crucial step towards the development of intelligent support systems in surgical environments. The objective of the project is to create a system which is able to recognize automatically the current steps of a surgical laparoscopic procedure using a set of signals recorded from the OR. The project adresses several issues such as the simultaneous recordings of various signals within the OR, the design of methods and algorithms for processing and interpreting the information, and finally the development of a convenient user interface to display context sensitive information inside the OR. The current clinical focus is on laparoscopic cholecystectomies but the concepts developed in the project also apply to laparoscopic surgeries of other kinds.
Reconstruction and Registration of Histology and Phase Contrast Images for Clinical Validation of Imaging Modalities

Reconstruction and Registration of Histology and Phase Contrast Images for Clinical Validation of Imaging Modalities

Before its introduction into the hospital, a new imaging modality has to be validated. In other words, appearing structures need to be correlated to the imaged tissues. Such a cross validation is only meaningful when performed against the gold standard which is histology. Currently, cross validation is performed by qualitative comparison of 3D datasets to 2D histology slices. Since the acquisition of a consistent 3D histology volume is a challenging task, its comparison to the corresponding dataset always remained qualitative.

The classic histology procedure can be divided in four steps: pre processing, cutting, post processing and imaging of the tissues. In the first step, the sample is chemically processed to preserve the tissues and is then embedded in a paraffin block. By using a microtome, it is cut in very thin slices, and put on a glass slide. During post processing the sample is stained to enhance the structures of interest. The imaging is performed with a camera mounted in a microscope, or with a dedicated scanner. Several difficulties inherent to this process can have a dramatic influence on the quality of the reconstructed histology volume. For instance, since the cutting process is done manually, problems like flipping, bending or ripping of the slides may happen. If the knife starts to wear off, some banding will appear over the slices. Moreover, a few slices could be missing. Finally since the staining color is time dependent, variation in the color of the slices can occur.

In this project, we propose to improve the histology procedure and to develop methods towards a consistent reconstruction of 3D histology volumes.
Assessment of Fluid Tissue Interaction Using Multi-Modal Image Fusion for Characterization and Progression of Coronary Atherosclerosis

Assessment of Fluid Tissue Interaction Using Multi-Modal Image Fusion for Characterization and Progression of Coronary Atherosclerosis

Coronary artery diseases such as atherosclerosis are the leading cause of death in the industrialized world. In this project, we develop computational tools for segmentation and registration problems on intravascular images including IVUS (Intravascular Ultrasound) and OCT (Optical Coherence Tomography). One sample component of this project is Automatic Stent Implant Follow-up from Intravascular OCT Pullbacks. The stents are automatically detected and their distribution is analyzed for monitoring of the stents: their malpositioning and/or tissue growth over stent struts.
MeTaTop A Multi Sensory Table Top System for Medical Procedures

MeTaTop A Multi Sensory Table Top System for Medical Procedures

A tabletop system in medical environments can be used for interactive and collaborative analysis of patient data but also as a multimedia user interface within sterile space. For preoperative planning physicians in charge with a particular patient meet to discuss the medical case and plan further steps for therapy. For this reason, they could collaboratively view and browse through all kind of available medical imaging data with the tabletop system. Alternatively such a system could be a central interaction device for all kind of equippment within the OR requiring user input, however, can not be operated by the sterile surgeon. We believe that the projection of all kind of user and information interfaces on a sterile glass plane would facilitate the clinical workflow.
This project is strongly related to the Tangible Interaction Surface for Collaboration between Humans project.
Motion Compensation for Catheterizations

Motion Compensation for Catheterizations

In many minimally-invasive interventions, catheters are inserted into the body and guided to a region of interest with the help of fluoroscopic imaging (low-dose X-ray image sequences). Due to patient motion, the navigation can be disturbed, and the physician needs a longer time for treatment. This is hazardous in terms of radiation for both, physician and patient. In order to overcome these problems, suitable image-based compensation methods to resolve (non-) rigid motion can be applied. In this project, patient motion is analyzed and suitable compensation algorithms are developed.
Endovascular Stenting of Aortic Aneurysms

Endovascular Stenting of Aortic Aneurysms

Endovascular stenting is a minimally invasive treatment technique for aortic aneurysms or dissections. Thereby, a certain aortic prosthesis (stent graft) is placed inside the aortic aneurysm in order to prevent a life-threatening rupture of the aortic wall. Prior to the intervention, a computed tomography angiography (CTA) is acquired on which the surgical staff can measure the parameter of the desired stent graft and finalize the intervention workflow. The entire interventional catheter navigation is done under 2D angiography imaging where the physician is missing the important 3D information. The purpose of our project is two-fold:
1. In the planning phase, a modified graph cuts algorithm automatically segments the aorta and aneurysm, so the surgical staff can choose an appropriate type of stent to match the segmented location, length, and diameter of the aneurysm and aorta. By visualizing the defined stent graft next to the three-dimensionally reconstructed aneurysm, mismeasurements can be detected in an early stage. Our main goal is the creation of an interactive simulation system that predicts the behaviour of the aortic wall and the movement of the implanted stent graft.
2. During implantation of the stent graft, after an intensity based registration of CTA and angiography data, the current navigation can be visualized in the 3D CT data set at any time. This includes solutions for electro-magnetic tracking of catheters as well as guide wires and stent grafts. Eventually, Our main goal is the creation of solutions that enable the surgeon to enhance the accuracy of the navigation and positioning, along with a minimum use of angiography, leading to less radiation exposure and less contrast agent injection.
Simulated Ultrasound

Simulated Ultrasound

We are simulating Ultrasound images from CT volumes by assuming a correlation between Hounsfield units and acoustic impedance. Rays are cast trough the CT volume to simulate the US image formation. Simulated Ultrasound from CT can be used for CT/Ultrasound registration by comparing a real US image to simulated ones. Another application of simulated US is training.
Camera Augmented Mobile C-arm

Camera Augmented Mobile C-arm

Mobile C-arms are an everyday tool to acquire X-ray images in the operating room during surgery. The Camera Augmented Mobile C-arm (CamC) system augments a regular mobile C-arm by a video camera for X-ray and video image overlay. Thanks to the mirror construction and one time calibration of the device, the acquired X-ray images are co-registered with the video images without any further calibration or registration during the intervention. The CamC system can support a wide range of potential clinical applications, such as needle guidance, interlocking of intramedullary nails, and pedicle screw placement.
3D user interfaces for medical interventions

3D user interfaces for medical interventions

This work group aims at practical user interfaces for 3D imaging data in surgery and medical interventions. The usual monitor based visualization and mouse based interaction with 3D data will not present acceptable solutions. Here we study the use of head mounted displays and advanced interaction techniques as alternative solutions. Different issues such as depth perception in augmented reality environment and optimal data representation for a smooth and efficient integration into the surgical workflow are the focus of our research activities. Furthermore appropriate ways of interaction within the surgical environment are investigated.
Laparoscope Augmentation for Minimally Invasive Liver Resection

Laparoscope Augmentation for Minimally Invasive Liver Resection

In recent years, an increasing number of liver tumor indications were treated by minimally invasive laparoscopic resection. Besides the restricted view, a major issue in laparoscopic liver resection is the precise localization of the vessels to be divided. To navigate the surgeon to these vessels, pre-operative imaging data can hardly be used due to intra-operative organ deformations caused by appliance of carbon dioxide pneumoperitoneum and respiratory motion.

Therefore, we propose to use an optically tracked mobile C-arm providing cone-beam computed tomography imaging capability intra-operatively. After patient positioning, port placement, and carbon dioxide insufflation, the liver vessels are contrasted and a 3D volume is reconstructed during patient exhalation. Without any further need for patient registration, the volume can be directly augmented on the live laparoscope video. This augmentation provides the surgeon with essential aid in the localization of veins, arteries, and bile ducts to be divided or sealed.

Current research focuses on the intra-operative use and tracking of mobile C-arms as well as laparoscopic ultrasound, augmented visualization on the laparoscope's view, and methods to synchronize respiratory motion.
Port Placement in Minimally Invasive Endoscopic Surgery

Port Placement in Minimally Invasive Endoscopic Surgery

Optimal port placement is a delicate issue in minimally invasive endoscopic surgery. A good choice of the instruments' and endoscope's ports can avoid time-consuming consecutive new port placement. We present a novel method to intuitively and precisely plan the port placement. The patient is registered to its pre-operative CT by just moving the endoscope around fiducials, which are attached to the patient's thorax and are visible in its CT. Their 3D positions are automatically reconstructed. Without prior time-consuming segmentation, the pre-operative CT volume is directly rendered with respect to the endoscope or instruments. This enables the simulation of a camera flight through the patient's interior along the instruments' axes to easily validate possible ports.
Discovery and Detection of Surgical Activity in Percutaneous Vertebroplasties

Discovery and Detection of Surgical Activity in Percutaneous Vertebroplasties

In this project, we aim at discovering automatically the workflow of percutaneous vertebroplasty. The medical framework is quite different from a parallel project , where we analyze laparoscopic surgeries. Contrary to cholecystectomies where much information is provided by the surgical tools and by the endoscopic video, in vertebroplasties and kyphoplasties, we believe that the body and hand movement of the surgeon give a key insight into the surgical activity. Surgical movements like hammering of the trocar into the vertebra or the stirring of cement compounds are indicative of the current workflow phase. The objectives of this project are to acquire the workflow related signals using accelerometers, processing the raw signals and detecting recurrent patterns in order to objectively identify the low-level and high-level workflow of the procedure.



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