Abstract: Apparatus, consisting of a catheter that is configured to be inserted into a chamber of a heart and that has one or more electrodes configured to contact myocardial tissue at multiple locations in the chamber. The one or more electrodes receive electrical signals responsive to a conduction wave traveling through the tissue. The apparatus includes a display and a processor that is configured to receive the electrical signals from the catheter and to render to the display, responsively to the electrical signals, a map of the chamber including an indication of local times of occurrence of the conduction wave at the multiple locations. The processor is also configured to calculate, responsively to the local times of occurrence, a velocity of the conduction wave between the locations and to mark on the map one or more areas of the chamber in which the velocity is below a preset threshold.

Abstract: Apparatus, consisting of an envelope transparent to X-rays, and a fluid transparent to X-rays and contained within the envelope. Multiple charged particles, opaque to X-rays, are suspended within the fluid. There are at least two electrodes on opposite sides of the envelope, that are configured to apply a field to the multiple particles, so that, absent the field, the particles disperse throughout the fluid.

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, 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.

Abstract: A system includes an electrical interface for communicating with a probe, and a processor. The electrical interface is configured to be inserted into a heart of a patient. The processor is configured to (A) receive from the probe, via the electrical interface, (i) position-signals indicative of a position of a distal tip of the probe in the heart, (ii) a contact-force indication indicative of a contact force exerted on the distal tip, and (iii) an electrophysiological (EP) measurement acquired by the distal tip at the position, (B) calculate a contact-force vector based on the contact-force indication received from the distal tip, and (C) based on the position-signals and on the contact-force vector, estimate a location, on an electro-anatomical map of the heart, at which the distal tip touches tissue, and to update the electro-anatomical map with the EP measurement, associated with the estimated location.

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.

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: 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: 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 probe having a contact force sensor is inserted into a cardiac chamber and an image of the blood pool is generated. A portion of the blood pool is removed from the image to retain a remaining portion of the blood pool. A determination is made that the distal segment of the probe is within the remaining portion of the blood pool, and responsively to the determination the contact force sensor is manually zeroed.

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 probe having a contact force sensor is inserted into a cardiac chamber and an image of the blood pool is generated. A portion of the blood pool is removed from the image to retain a remaining portion of the blood pool. A determination is made that the distal segment of the probe is within the remaining portion of the blood pool, and responsively to the determination the contact force sensor is manually zeroed.

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: The present invention is directed to a method of ablation. The method includes the steps of inserting a probe having an ablation electrode into a body of a living subject and urging the ablation electrode into a contacting relationship with a target tissue. A measurement of at least one electroanatomic parameter is made between the ablation electrode and the target tissue, and the measurement is haptically communicated to an operator. Responsively to the communicated measurement, ablating the target tissue using the ablation electrode.

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: The present invention is directed to a method of ablation. The method includes the steps of inserting a probe having an ablation electrode into a body of a living subject and urging the ablation electrode into a contacting relationship with a target tissue. A measurement of a contact force is made between the ablation electrode and the target tissue, and the measurement is haptically communicated to an operator. The probe is adjusted responsively to the communicated measurement, to achieve a desired value of the contact force while ablating the target tissue using the ablation electrode.

Abstract: The present invention is directed to a method of ablation. The method includes the steps of inserting a probe having an ablation electrode into a body of a living subject and urging the ablation electrode into a contacting relationship with a target tissue. A measurement of at least one electroanatomic parameter is made between the ablation electrode and the target tissue, and the measurement is haptically communicated to an operator. Responsively to the communicated measurement, ablating the target tissue using the ablation electrode.