Abstract: A method for determining the best entry point for a percutaneous procedure, such as with a biopsy needle, comprises selecting first and second arbitrary entry points on a patient; determining the three dimensional (3-D) orientation of the needle at the first arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the first arbitrary entry point for pointing the needle at the secondary target; determining the 3-D dimensional orientation of the needle at the second arbitrary entry point for pointing the needle at the primary target; determining the 3-D orientation of the needle at the second arbitrary entry point for pointing the needle at the secondary target; determining a 3-D line representing the intersection of a first plane containing the first arbitrary entry point, the primary target point, and the secondary target point, and a second plane containing the second arbitrary entry point, the primary target, and the secondary target point, whereb

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images and direct them towards the camera. The images can then be combined by warping one onto the other.

Abstract: A method for computer assisted localization and navigation in a defined environment, comprises the steps of: obtaining a floor map of the defined environment; placing a set of identifiable markers on the floor in given locations; determining the position of a user with respect to ones of the markers; determining the global position of the user by utilizing the floor map and the given locations; and indexing a database for data associated with the global position.

Abstract: An external tracking system for use three dimensional (3D) reconstruction with X-ray C-arm systems comprises a set of marker or tool plates and a sensor system. It measures the 6D pose (position and orientation) of these tool plates relative to the sensor. The tool plate of such a tracking system is rigidly attached to the X-ray source frame of the C-arm system. In order to use an external tracking system for the recovery of projection geometry for 3D tomographic reconstruction, the relations of the external sensor coordinate systems to patient/world and X-ray coordinate systems have to be determined. Previously the transformation from tool plate to X-ray coordinate system has been determined based on CAD drawings and a calibration of the focal point of the X-ray system.

Abstract: The invention relates to a method and a device for generating a virtual installation model (2) as an image of a real installation (1). As a database therefor, digital picture data (4) representing pictures of a real installation (1) on the one hand and installation components (13) of a component library (6) on the other hand are used. The data of the installation components as well as the digital picture data (4) of the real installation (1) is evaluated by means of an image analysis (5). Based on this analysis, the identified installation components (13) are assigned to the virtually generated installation model (2). The virtual image of the real installation thus created serves to document the actual structure of the installation/facility, to simplify failure analysis, e.g., in areas that are difficult to access, and/or to operate and monitor the installation/facility. In addition to geometric data, functional data, etc. of the installation components are also stored.

Abstract: A computer-controlled method for automatically positioning a guide for a biopsy needle for its proper insertion into the body of a patient from a selected point on a surface of the body, so as to enter in a straight line passing through a designated target region within the body, in conjunction with an imaging system utilizing radiation from first and second source positions for deriving first and second radiographic images.

Abstract: Compensation can be provided for rotational and translational motion of a detector relative to the X-ray source in a C-arm X-ray device by warping the image on the detector plane to a virtual detector plane and then mapping the image into three-dimensional space. By using a virtual detector, the computations required to reconstruct the three-dimensional model are greatly simplified.

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images. Alignment of one camera with respect to the X-ray source may be achieved using images of reference points in space and their respective projections. Once the X-ray source and the video camera are positioned at the equivalent point in space, the resultant images can be superimposed through warping.

Abstract: Superimposed X-ray and video images can be obtained by acquiring the respective images from the optically equivalent points in space. One or more mirrors may be used to acquire the images. Alignment of one camera with respect to the X-ray source may be achieved using images of reference points in space. Once the X-ray source and the video camera are positioned at the equivalent point in space, the resultant images can be superimposed through warping.

Abstract: Apparatus for determining a proper insertion depth of a biopsy needle so that a sampling end of the needle just reaches to a designated target area within the body comprises at least one straight calibrated pointing device aligned to point through the selected point in a straight line passing through the designated target region. The pointing device exhibits first and second markers along its length such that respective images are formed on a first image plane by utilizing radiation from a radiation source, along with images corresponding to the selected point and the target area. The images are formed along a straight line in this order: (A) the first marker, (B) the second marker, (C) the selected point, and (D) the target region. The apparatus includes an arrangement for measuring distances on the image plane between images (A), (B), (C), and (D) and a calculator for calculating the cross ratio of the distances, whereby the proper insertion depth of the biopsy needle is determined.

Abstract: A method for detection and localization of a surgical device in a radiographic image of the surgical device, includes the steps of: generating a radiographic image, including an image of a surgical device and an anatomical background image; moving the device rotatably through a plurality of positions corresponding to steps of an alignment method; generating a plurality of radiographic images corresponding to the plurality of positions, respectively; subtracting each image of the plurality of images from preceding images so as to generate a plurality of difference images; deriving the mathematical intersection of all of the plurality of difference images; and thereby obtaining a resulting image containing only an image of the device on the radiographic image without the anatomical background image.

Abstract: A C-arm calibration method for 3D reconstruction in an imaging system comprising an imaging source and an imaging plane utilizes a planar transformation for relating voxels in a voxel space and pixels in the imaging plane, and comprises the steps of: defining a source coordinate system in reference to the imaging source; defining a normal plane in the voxel space, not including the origin of the source coordinate system and being substantially normal to an optical axis from the source to the imaging plane; defining a relationship between the source coordinate system and another coordinate system, herein referred to as a world coordinate system, by transformation parameters; identifying pixel location coordinates for a respective pixel corresponding to each voxel in the normal plane by utilizing a planar to planar transformation; storing a value of a filtered image at the respective pixel location; and accumulating contributions corresponding to a plurality of image projections so as to thereby reconstruct eac

Abstract: Apparatus for providing markers on an image, for use in conjunction with C-arm calibration apparatus for 3D reconstruction in an imaging system, comprises a plurality of radiation transparent planes intersecting at a line; and radiation opaque markers disposed on said transparent planes and arranged in respective patterns such that detection of coplanar markers on an image is possible without ambiguity even though said patterns be superimposed on a radiographic images.

Abstract: In an X-ray imaging system with a C-arm which exhibits mechanical instability and changes the radiation geometry, the image reconstruction ensues with a calculation of the coordinates of the individual voxels being forgone. A voxel-driven back projection ensues without the calculation of positional coordinates and physical focus position and detector position.

Abstract: A method for point reconstruction and metric measurement on radiographic images comprises the following steps: positioning a fluoroscope for producing a fluoroscopic image, in a position where an operator, such as a physician, can observe points inside a patient's body on which points at least one of reconstruction and metric measurement are to be carried out; positioning a positioning device on the patient's body at an arbitrarily selected point F visible in a radiographic image, designating target points T.sup.i, being points to be reconstructed, by the operator on the radiographic image; finding planes .pi..sup.i passing through the X-ray source and a line FT.sup.i as describe in the step I and II in the invention disclosure; rotating the fluoroscope to a new position and taking a new radiographic image from this new viewpoint, designating target points T.sup.i, being points to be reconstructed, by the operator the physician on the new radiographic image; computing first the orientation of vectors Ft.sup.

Abstract: A C-arm calibration method for 3D reconstruction in an imaging system comprising an imaging source and an imaging plane, utilizes a planar transformation for relating voxels in a voxel space and pixels in the imaging plane, and comprises the steps of defining a source coordinate system in reference to the imaging source; defining first and second normal planes in the voxel space, the planes being parallel to one another, neither including the origin of the source coordinate system and being substantially normal to an optical axis from the source to the imaging plane; defining a relationship between the source coordinate system and another coordinate system, herein referred to as a world coordinate system, by a rotation parameter, identifying pixel location coordinates for a respective pixel corresponding to each voxel in each of the first and second normal planes by utilizing the rotation parameter, storing a value of a filtered image at the respective pixel location; and accumulating contributions correspond

Abstract: Apparatus for C-arm calibration for 3D reconstruction in an imaging system comprising an imaging source and an imaging plane, and utilizing a planar transformation for relating voxels in a voxel space and pixels in the imaging plane, comprises data storage apparatus for storing a definition of a source coordinate system in reference to the imaging source; data storage apparatus for storing a definition of a normal plane in the voxel space, not including the origin of the source coordinate system and being substantially normal to an optical axis from the source to the imaging plane; data storage apparatus for storing a definition of a relationship between the source coordinate system and another coordinate system, herein referred to as a world coordinate system, by transformation parameters; apparatus for identifying pixel location coordinates for a respective pixel corresponding to each voxel in the normal plane by utilizing planar to planar transformation parameters; data storage apparatus for storing a valu

Abstract: A method for the detection and localization of a surgical tool in a radiographic image, including an image of a surgical device and an anatomical background image, includes the steps of generating a radiographic reference image, including an image of a surgical device and an anatomical background image and applying an oscillating movement to the device. The method further includes the steps of generating a number k of radiographic images during the oscillating movement; subtracting each image from the reference image, so as to generate a difference image; and deriving the mathematical intersection of all of the reference images, whereby a resulting image results including only the image of the device on the radiographic reference image and substantially without the anatomical background image.

Abstract: Apparatus for calibrating an intra-operative X-ray system having an X-ray source and a detector includes an optical camera associated with the X-ray source; an optical camera associated with the detector; an X-ray phantom placed within a field of view of the X-ray system during an off-line process; an optical phantom placed within a field of view of the optical cameras during the off-line process as well as the on-line process (called the patient run); and apparatus for computing a respective projection matrix from an image provided by any of the X-ray source and detector, and the optical cameras. A method to obtain the projection matrices characterizing the X-ray imaging geometry during the patient run, using the projection matrices associated to X-ray geometry as well as the optical cameras computed during an off-line process, and the projection matrices associated to the optical cameras during the patient run.

Abstract: Calibration apparatus for X-ray geometry, for use in conjunction with a portion of a patient's body to be X-rayed, an X-ray source, and imaging arrangement for forming an image, wherein the imaging arrangement is at a given orientation and distance from the portion of a patient's body, comprises a calibration ring adapted for being fastened to a portion of a patient's body, such as a patient's head. The ring exhibits a first degree of transparency to X-rays.