Abstract: Described embodiments include a method that includes constructing a computerized electroanatomical model of a portion of a heart, the model including a mesh, which approximates the portion of the heart, and a plurality of points, at different respective locations on the mesh, having respective associated local activation times (LATs) that were ascertained from electrocardiographic signals acquired from the portion. The method further includes constructing a graph that interconnects the points and, based on the respective locations and LATs of the points, identifying, from a plurality of pathways, through the graph, from a first one of the points having a lowest one of the LATs to a second one of the points having a highest one of the LATs, both a shortest pathway and a longest pathway. The method further includes displaying the mesh, with the identified shortest pathway and longest pathway superimposed over the mesh. Other embodiments are also described.

Abstract: A 3-dimensional image is displayed in high resolution colors by generating a 3-dimensional model as a triangular mesh, converting the mesh into a grid of voxels, and assigning attribute values to a portion of the voxels. Laplacian interpolation based on the portion of the voxels is applied for iteratively calculating interpolated attribute values of other voxels. The voxels are rendered as a colored image according to the attribute values on a display.

Abstract: A method includes receiving a computerized tomography (CT) image comprising voxels of a body part of a subject, segmenting the image so as to identify a surface of a skin and a surface of a bone in the image, measuring respective minimum distances to the bone from a plurality of points on the surface of the skin, and rendering an image of the surface of the skin while visually coding the rendered image so as to indicate the respective minimum distances.

Abstract: A method for data display includes acquiring a three-dimensional (3D) map of a lumen inside a body of a subject, transforming the 3D map of the lumen into a two-dimensional (2D) image by projecting the 3D map onto an annulus, and presenting the 2D image on a display screen.

Abstract: A 3-dimensional image is displayed in high resolution colors by generating a 3-dimensional model as a triangular mesh, converting the mesh into a grid of voxels, and assigning attribute values to a portion of the voxels. Laplacian interpolation based on the portion of the voxels is applied for iteratively calculating interpolated attribute values of other voxels. The voxels are rendered as a colored image according to the attribute values on a display.

Abstract: Cardiac catheterization is carried out by inserting a multi-electrode probe into a heart of a living subject, preparing a current position map of the electrodes to define respective locations of the electrodes, and recording electrograms from the electrodes. Activation times are annotated at the respective locations by analysis of the electrograms and generating an activation map. A region of the activation map is selected and earliest ones of the activation times in the selected region identified. The earliest activation times are graphically indicated.

Abstract: Cardiac catheterization is carried out by inserting a multi-electrode probe into a heart, constructing a position map of the electrodes, and simulating a 3-dimensional surface of the heart. The method is further carried out by placing the position map in registration with an acquired image of the heart, constructing, based on the position map, a mesh that models the 3-dimensional surface of the heart, and adjusting positions of vertices of the mesh relative to mapped points in the position map to improve a registration of the mesh with the acquired image.

Abstract: A real-time three-dimensional (3D) cardiac imaging system and method is disclosed. Anatomical data of a cardiac structure may be acquired and a 3D model of the cardiac structure may be generated. Visual data relevant to a cardiac procedure may be generated, such as location and orientation of a catheter, tags, points, color-coded temperature information, and/or color-coded local activation times (LAT) for the cardiac structure. The visual data superimposed on the 3D model of the cardiac structure may be visually displayed on a visual display device. A glass state view may be generated by generating a modified set of the visual data that includes removing at least a portion of the visual data that obscures a view of an anatomical feature of interest and/or the catheter, and adding edge enhancement to the cardiac structure. The glass state view may be requested to be visually displayed on the visual display device.

Abstract: A method, consisting of presenting on a display screen a graphical image of a heart of a patient, including icons representing a catheter that is positioned within the heart and an electrode on the catheter, while the electrode is in contact with tissue at a location in the heart. The method further includes acquiring, using the electrode, electrical signals from the tissue at the location, and processing the acquired signals so as to detect an occurrence of a predefined signal feature in the acquired signals. The method also includes, upon detecting the occurrence of the predefined signal feature, modifying a visual feature of at least one of the icon representing the electrode and the icon representing the catheter on the display screen.

Abstract: Described embodiments include an apparatus that includes a display, including a screen, and a processor. The processor is configured to define a bounding region on the screen. The processor is further configured to render a quadric, which is defined in a parameter space, over a three-dimensional electroanatomical map of a surface of a heart that is displayed on the screen, by, for each pixel in the bounding region, transforming, to the parameter space, a virtual ray that passes through the pixel, and ascertaining whether a point of intersection between the transformed virtual ray and the quadric exists in the parameter space, and, for each pixel in the bounding region for which the point of intersection exists, rendering the pixel on the screen, based on properties of the point of intersection. Other embodiments are also described.

Abstract: A method for data display includes acquiring a three-dimensional (3D) map of a lumen inside a body of a subject, transforming the 3D map of the lumen into a two-dimensional (2D) image by projecting the 3D map onto an annulus, and presenting the 2D image on a display screen.

Abstract: Described embodiments include an apparatus that includes a display, including a screen, and a processor. The processor is configured to define a bounding region on the screen. The processor is further configured to render a quadric, which is defined in a parameter space, over a three-dimensional electroanatomical map of a surface of a heart that is displayed on the screen, by, for each pixel in the bounding region, transforming, to the parameter space, a virtual ray that passes through the pixel, ascertaining whether a point of intersection between the transformed virtual ray and the quadric exists in the parameter space, and, subsequently, provided the point of intersection exists, rendering the pixel on the screen, based on properties of the point of intersection. Other embodiments are also described.

Abstract: Values of a physiologic parameter at respective measured points in a heart are obtained. A 3-dimensional model of the heart is constructed, which includes first spatial elements that include the measured points and second spatial elements that do not include the measured points. The values of the parameter in the second spatial elements are interpolated and regional densities of the measured points in the model determined. The values of the parameter at the first spatial elements and the second spatial elements are displayed on a functional map of the heart, and a graphical characteristic of the map is modified responsively to the regional densities.

Abstract: A method for mapping a 3D surface that contains a volume in space, the method including: acquiring 3D vertices representing the surface, and defining in the space a first plane cutting the volume and a second parallel plane, external to the volume, thereby partitioning the vertices into a first set not between the two planes and a second set located between the two planes. The method further includes projecting the first set vertices onto the first plane so as to generate first projected points therein, and projecting the second set vertices onto the first plane while translating these vertices in respective directions parallel to the second plane by respective translations responsive to respective distances of the second vertices from the first plane, thereby generating second projected points in the first plane. The first and second projected points are displayed as a 2D representation of the surface on a screen.

Abstract: A method, including calculating locations of first sensors attached to a probe that has been inserted into a human patient, and calculating positions of second sensors attached to a sheath via which the probe is inserted. The method also includes calculating respective shapes of the probe and the sheath, to achieve a best fit to the calculated probe sensor locations and sheath sensor positions, while restricting the probe to pass through the sheath. The calculated respective shapes of the probe and the sheath are used to present an image of the sheath aligned with the probe.

Abstract: A method for 3D rendering, including receiving a group of 3D triangles defining a mesh of a surface, each 3D triangle in the group having 3D vertices with respective 3D coordinates, and transforming each 3D triangle into a 2D triangle having 2D vertices corresponding respectively to the 3D vertices, each 2D vertex having respective 2D pixel coordinates and a triplet of pixel attributes corresponding to the 3D coordinates of a corresponding 3D vertex. Each 2D triangle is passed to a graphics processor, which treats the triplet of pixel attributes of each 2D vertex as interpolatable values. The graphics processor computes respective triplets of interpolated pixel attributes for pixels within each 2D triangle by interpolation between the pixel attributes of the 2D vertices, and a 3D image of the surface is rendered by converting the interpolated pixel attributes computed by the graphics processor into voxel coordinates in the 3D image.

Abstract: A 3-dimensional image is displayed in high resolution colors by generating a 3-dimensional model as a triangular mesh, converting the mesh into a grid of voxels, and assigning attribute values to a portion of the voxels. Laplacian interpolation based on the portion of the voxels is applied for iteratively calculating interpolated attribute values of other voxels. The voxels are rendered as a colored image according to the attribute values on a display.

Abstract: A technique for controlling order of selecting elements from an ordered set of N elements, the technique provides applying to the ordered set a mathematical function P converting the order, in which the elements are preliminarily ordered in the set, into a desired order defined by the function P. The elements may further be selected from the set according to the new order defined by the function P. The elements in the set comprise at least one of the following: devices, items, parameters, values.

Abstract: A method for mapping a 3D surface that contains a volume in space, the method including: acquiring 3D vertices representing the surface, and defining in the space a first plane cutting the volume and a second parallel plane, external to the volume, thereby partitioning the vertices into a first set not between the two planes and a second set located between the two planes. The method further includes projecting the first set vertices onto the first plane so as to generate first projected points therein, and projecting the second set vertices onto the first plane while translating these vertices in respective directions parallel to the second plane by respective translations responsive to respective distances of the second vertices from the first plane, thereby generating second projected points in the first plane. The first and second projected points are displayed as a 2D representation of the surface on a screen.

Abstract: A method, consisting of acquiring signals, indicative of temperatures at respective locations in a biological tissue, from a plurality of thermal sensors mounted on a probe in contact with the tissue, interpolating between the temperatures so as to produce a temperature distribution map, and displaying the temperature distribution map on a screen. The method also includes determining that at least one of the thermal sensors is a malfunctioning thermal sensor, and that remaining thermal sensors of the plurality are correctly operating. The at least one malfunctioning thermal sensor is assigned a first arbitrary temperature and the correctly operating thermal sensors are assigned second arbitrary temperatures.