Lejing Wang

Name: Lejing Wang Email: wangle@in.tum.de Phone: +49 (89) 289-17079 Room: MI 03.13.041

Research Projects

Camera Augmented Mobile C-arm The problem of positioning mobile C-arms, e.g. for down the beam techniques, as well as repositioning during surgical procedures currently requires time, skill and additional radiation. The Camera-Augmented Mobile C-arm (CAMC) is able to speed up the procedure, simplify its execution and reduce the necessary radiation. The C-arm is extended by a CCD camera. The CCD camera is attached to the C-arm such that it is virtually at the same location than the x-ray source. This is done by a double mirror construction. A two step calibration routine has be done only once at the moment the camera is attached. Extensions for a lightwight, but complete navigation system for pedile screw placement or implant positioning is currently under investigation.

Videos

Magic X-ray Stitching (Mosaicing)

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Theses, SEPs, and IDPs under my (Co-)Supervision

Available:

• C-arm Motion Estimation without Radiation (DA/MA/BA)
  C-arm (X-ray source) motion estimation is a crucial step for many (computer aided) clinical applications, like X-ray image stitching, C-arm placement and so on. Most approaches are based on using X-ray images, and thus introduce additional radiation. Our Camera Augmented Mobile C-arm system is capable of acquiring the X-ray and optical image overlay, so the pose or motion of C-arm X-ray source can be computed using the information from optical images. This will definitely save a lot of radiation. Our current method for pose/motion estimation is using a planar marker pattern. The shortcomings are the difficulty of integrating this planar pattern into the clinical procedure and the limited viewed field to the camera. Therefore, using a flexible distribution of markers, in which markers can located in any 3D positions without any constraint, makes integration much easier and can provide an unlimited viewed field. However, using such a flexible distribution of markers will lose the 3D positions of each marker and thus the estimated translation is up to a scaling factor. We developed a novel method to recover this scaling factor. The main goal of this student project is to implement, evaluate and integrate the method.

Current:

Finished:

Publications

2009
	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 2009 (to be published) (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 2009 (to be published) (bib)
2008
	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)