Now showing 1 - 8 of 8
  • Publication
    Camera-based instrument navigation in ENT-surgery
    ( 2018)
    Katanacho, Manuel
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    Algorithms for a camera-based surgical navigation system, with a localization based on the surface structure of the patients face, are developed and evaluated. The measurement technology is based on a single HD-camera that is integrated on a surgical instrument. Sophisticated and expensive state of the art systems are thus replaced by a software solution, which reduces the hardware costs and the space requirements in the operation room. A functional prototype is implemented and tested in a laboratory and an operating room. The challenge is to determine the camera's pose from a camera live stream with a feature based approach, without additional markers on the patient. The core software modules are mapping, registration and localization. The root-mean-square error of the system varies between 2.4 mm and 6.4 mm dependent on the lighting conditions. By removing a systematic error from the registration process, the accuracy is improved to 1.3 mm to 2.0 mm.
  • Publication
    Instrument calibration for a camera based surgical navigation system
    ( 2017)
    Katanacho, Manuel
    ;
    ; ;
    Melnik, Steffen
    In this abstract, we present a system for mounting a single-camera to arbitrary surgical instruments and calibrating its position relative to the instrument. The camera is used for surgical navigation and can be covered with sterile foil due to a connection mechanism to the mounting system with magnets. The calibration of the cameras' position relative to the instruments' tool center point is done by a checkerboard based calibration procedure and using defined pivot points.
  • Publication
    Accuracy of a single camera, marker based surgical navigation system - simulation and implementation
    ( 2017)
    Katanacho, Manuel
    ;
    ;
    Surgical navigation systems are used in many fields of surgery to support the surgeon with localization information during operation. Current systems are based on optical or electromagnetic tracking, both with its benefits and drawbacks. The presented approach is an alternative to the established measurement systems to simplify the use of surgical navigation in the operating room. This abstract aims at evaluating if the required accuracy for a surgical navigation application can be achieved by a single camera approach (see Fig. 1). The proposed system uses a single video camera mounted on an instrument and navigates relative to a flat marker mounted on the patient. The required transformation between camera and marker is computed by image processing methods.
  • Publication
    Region of interest detection with iterative colour clustering and a global weighting scheme
    ( 2017)
    Katanacho, Manuel
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    Hoffmann, Jonas
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    Many modern surgical systems utilize advanced computer vision and image processing techniques for a vast variety of tasks, such as object recognition, segmentation, classification and 3D reconstruction. In many cases, the extraction of a specific region of interest (ROI) in the image is performed prior to further processing steps. This increases the computation speed and may improve the quality of the system´s output because misleading elements in the image are masked out. We present a novel approach that considers global colour distributions to extract one (or more) ROIs in a camera image stream. Our method is both fast and robust against illumination discontinuities, irregularities in the texturing of surfaces and false areas with very similar colour. The method is used for the detection of human skin in an operating room environment for a camera based navigation system.
  • Publication
    Depth map based point cloud registration to CT patient data for surgical navigation
    ( 2017)
    Katanacho, Manuel
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    Lack, John-Certus
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    Hoffmann, Jonas
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  • Publication
    Camera pose estimation for a visual navigation system
    ( 2016)
    Katanacho, Manuel
    ;
    Hoffmann, Jonas
    A camera pose (position and orientation) estimation procedure is developed for application in navigated surgery. The procedure computes the camera's position and orientation relative to a surface model of the patient's face that is priorly acquired. Correspondences between tracked feature points in the camera video stream and three-dimensional points in the patient surface model allow constant computation of the camera's position and orientation. With this transformation the camera is used as a measurement tool in navigated surgery and represents one of the core components in a novel surgical navigation system called Visual Navigation, an alternative to conventional optical and electromagnetic tracking systems.
  • Publication
    Surgical navigation with QR codes
    ( 2016)
    Katanacho, Manuel
    ;
    Cadena, Wladimir de la
    ;
    Engel, Sebastian
    The presented work is an alternative to established measurement systems in surgical navigation. The system is based on camera based tracking of QR code markers. The application uses a single video camera, integrated in a surgical lamp, that captures the QR markers attached to surgical instruments and to the patient.
  • Publication
    3D human face reconstruction for surgical navigation
    ( 2016)
    Katanacho, Manuel
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    Hoffmann, Jonas
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    Engel, Sebastian