Abstract: Methods and systems for position determination are described for using an intrabody probe having a plurality of electrodes to generate a plurality of different electrical fields, and to also measure, using the plurality of electrodes, a measurement set (a Ve-e measurement set) comprising a plurality of measurements of the plurality of different electrical fields while the probe remains in one position. From the Ve-e measurement set, spatial position coordinates for the intrabody probe are estimated within an intrabody coordinate system, using an established mapping between previously observed Ve-e measurement sets and positions in the intrabody coordinate system. Systems and methods for generating and selecting such mappings are also described.

Abstract: Methods and systems of computing parameter values of one or more model parameters are described. The model models structural and dielectric properties of a structure in a human or an animal body. An exemplary method includes: accessing voltage measurements made at different places in the vicinity of the structure by one or more in-body field sensing electrodes in response to currents applied to one or more field supplying electrodes; and computing the parameter values by adjusting the parameter values to fit predicted voltage values to the accessed voltage measurements, wherein the predicted voltage values are predicted from the model for the currents applied to the field supplying in-body electrodes.

Abstract: Electrical field-guided positioning of a second device within a body cavity, using electrical field mapping information generated from electrical field measurements by electrodes of a first device. The first device, in some embodiments, is a catheter electrode probe, and the second device is an internally implantable and/or operated medical device. An exposed, electrically conductive portion of the second device is optionally configured to be used as an electrical field measuring electrode. A rule is applied to measurements made by this electrode to estimate its position within a body cavity. The rule is generated, in some embodiments, using measurements made by the first device.

Abstract: A method of computing a dielectric map is disclosed comprising exciting at least one pair of electrodes according to an excitation scheme, the at least one pair of electrodes comprising at least one pair of in-body electrodes (also referred herein below intra-body electrode) located inside of the examined living body, measuring and recording voltages developing on the in-body electrodes during the excitation according to the excitation scheme, solving an inverse problem to derive a 3D dielectric map from the recorded voltages and optionally providing a 3D image of the body tissues based on the 3D dielectric map. Methods are also disclosed that combine intrabody electrodes and surface electrodes secured to the body or use only surface electrodes. Embodiments encompass the use of constraints in deriving the 3D dielectric map and combining measurements made at different locations inside the body with moving intrabody electrodes.

Abstract: A method of generating a combined image of a body part from a sequence of partially overlapping source images of the body part, each of the partially overlapping source images showing the body part at one of a plurality of different times, the source images being ordered in the sequence according to the different times, the method including defining a temporally coherent sequence of transformations, for registering the partially overlapping source images in the sequence with each other, registering the source images to each other using the defined temporally coherent sequence of transformations, to obtain co-registered images, and combining at least some of the co-registered images into a combined image. Related apparatus and methods are also described.

Abstract: A method of estimating a spatial relationship between at least a part of a patient esophagus and a heart chamber, including: measuring at least one electric parameter at one or more positions within the heart chamber to obtain measured values; and estimating the spatial relationship based on the measured values.

Abstract: In some embodiments, a body cavity shape of a subject is reconstructed based on intrabody measurements of voltages by an intrabody probe (for example, a catheter probe) moving within a plurality of differently-oriented electromagnetic fields crossing the body cavity. In some embodiments, the method uses distances between electrodes as a spatially calibrated ruler. Positions of measurements made with the intrabody probe in different positions are optionally related by using spatial coherence of the measured electromagnetic fields as a constraint. Optionally, reconstruction is performed without using a detailed reference (image or simulation) describing the body cavity shape. Optionally, reconstruction uses further information to refine and/or constrain the reconstruction; for example: images, simulations, additional electromagnetic fields, and/or measurements characteristic of body cavity landmarks. Optionally, reconstruction accounts for time-dependent cavity shape changes, for example, phasic changes (e.g.

Abstract: Methods and systems are provided for estimating velocity of blood, flowing along a blood vessel at a blood flow direction, based on measurements made using a medical implement that resided in a portion of the blood vessel and comprised a first electrode and a second electrode. One of the disclosed methods include: accessing voltage measurements measured at the first and second electrodes when a bolus of a fluid went through the portion of the blood vessel at the blood flow direction; wherein the voltage measurements were made at the first and the second electrodes; estimating a time that took the bolus to go from the first electrode to the second electrode based on the accessed voltage measurements; and estimating the velocity of the blood based on the estimated time and a distance known to exist along the medical implement between the first and second electrodes.

Abstract: In some embodiments, data sensed and/or operational parameters used during a catheterization procedure are used in the motion frame-rate updating and visual rendering of a simulated organ geometry. In some embodiments, measurements of and/or effects on tissue by sensed and/or commanded probe-tissue interactions are converted into adjustments to the simulated organ geometry, allowing dynamic visual simulation of intra-body states and/or events based on optionally partial and/or non-visual input data. Adjustments to geometry are optionally to 3-D positions of simulated data and/or to simulated surface properties affecting geometrical appearances (e.g., normal mapping). Optionally, the organ geometry is rendered as a virtual material using a software environment (preferably a graphical game engine) which applies simulated optical laws to material appearance parameters affecting the virtual material's visual appearance.

Abstract: There is provided a method of displaying a pre-acquired three dimensional (3D) image of at least a portion of an organ of a patient, the method comprising: receiving a plurality of electrical readings, each from a different electrode mounted on a catheter inside the portion of the organ of the patient, wherein the electrodes are mounted on the catheter at known distances from each other, transforming the plurality of electrical readings to a corresponding plurality of image points using a mapping transformation that transforms each electrical reading of the catheter from inside the portion of the organ of the patient to an anatomically corresponding image point in the 3D image based on the known distances, and displaying the 3D image with a marking of at least one of the plurality of image points.

Abstract: Registration of catheter-sensed intrabody voltage field measurements obtained along one or more tracks of catheter advance of withdrawal is made, in some embodiments, to reference voltage field measurements lying along predetermined tracks. Tracks optionally comprise the course of a blood vessel such as the superior or inferior vena cava, a path defined and/or limited by encounters with a wall of a heart chamber and/or apertures thereof, and/or another track of catheter motion. In some embodiments, transform parameters are propagated to regions away from the track, potentially allowing more rapid acquisition of targets.

Abstract: Methods for creation and use (e.g., for navigation) of displays of flattened (e.g., curvature-straightened) 3-D reconstructions of tissue surfaces, optionally including reconstructions of the interior surfaces of hollow organs. In some embodiments, data comprising a 3-D representation of a tissue surface (for example an interior heart chamber surface) are subject to a geometrical transformation allowing the tissue surface to be presented substantially within a single view of a flattened reconstruction. In some embodiments, a catheter probe in use near the tissue surface is shown in positions that correspond to positions in 3-D space sufficiently to permit navigation; e.g., the probe is shown in flattened reconstruction views nearby view regions corresponding to regions it actually approaches. In some embodiments, automatic and/or easily triggered manual view switching between flattened reconstruction and source reconstruction views is implemented.

Abstract: A method of generating a combined image of a body part from a sequence of partially overlapping source images of the body part, each of the partially overlapping source images showing the body part at one of a plurality of different times, the source images being ordered in the sequence according to the different times, the method including defining a temporally coherent sequence of transformations, for registering the partially overlapping source images in the sequence with each other, registering the source images to each other using the defined temporally coherent sequence of transformations, to obtain co-registered images, and combining at least some of the co-registered images into a combined image. Related apparatus and methods are also described.

Abstract: A method of estimating a spatial relationship between at least a part of a patient esophagus and a heart chamber, including: measuring at least one electric parameter at one or more positions within the heart chamber to obtain measured values; and estimating the spatial relationship based on the measured values.

Abstract: In some embodiments, a body cavity shape of a subject is reconstructed based on intrabody measurements of voltages by an intrabody probe (for example, a catheter probe) moving within a plurality of differently-oriented electromagnetic fields crossing the body cavity. In some embodiments, the method uses distances between electrodes as a spatially calibrated ruler. Positions of measurements made with the intrabody probe in different positions are optionally related by using spatial coherence of the measured electromagnetic fields as a constraint. Optionally, reconstruction is performed without using a detailed reference (image or simulation) describing the body cavity shape. Optionally, reconstruction uses further information to refine and/or constrain the reconstruction; for example: images, simulations, additional electromagnetic fields, and/or measurements characteristic of body cavity landmarks. Optionally, reconstruction accounts for time-dependent cavity shape changes, for example, phasic changes (e.g.

Abstract: In some embodiments, data sensed and/or operational parameters used during a catheterization procedure are used in the motion frame-rate updating and visual rendering of a simulated organ geometry. In some embodiments, measurements of and/or effects on tissue by sensed and/or commanded probe-tissue interactions are converted into adjustments to the simulated organ geometry, allowing dynamic visual simulation of intra-body states and/or events based on optionally partial and/or non-visual input data. Adjustments to geometry are optionally to 3-D positions of simulated data and/or to simulated surface properties affecting geometrical appearances (e.g., normal mapping). Optionally, the organ geometry is rendered as a virtual material using a software environment (preferably a graphical game engine) which applies simulated optical laws to material appearance parameters affecting the virtual material's visual appearance.

Abstract: Methods for creation and use (e.g., for navigation) of displays of flattened (e.g., curvature-straightened) 3-D reconstructions of tissue surfaces, optionally including reconstructions of the interior surfaces of hollow organs. In some embodiments, data comprising a 3-D representation of a tissue surface (for example an interior heart chamber surface) are subject to a geometrical transformation allowing the tissue surface to be presented substantially within a single view of a flattened reconstruction. In some embodiments, a catheter probe in use near the tissue surface is shown in positions that correspond to positions in 3-D space sufficiently to permit navigation; e.g., the probe is shown in flattened reconstruction views nearby view regions corresponding to regions it actually approaches. In some embodiments, automatic and/or easily triggered manual view switching between flattened reconstruction and source reconstruction views is implemented.

Abstract: There is provided a method of displaying a pre-acquired three dimensional (3D) image of at least a portion of an organ of a patient, the method comprising: receiving a plurality of electrical readings, each from a different electrode mounted on a catheter inside the portion of the organ of the patient, wherein the electrodes are mounted on the catheter at known distances from each other, transforming the plurality of electrical readings to a corresponding plurality of image points using a mapping transformation that transforms each electrical reading of the catheter from inside the portion of the organ of the patient to an anatomically corresponding image point in the 3D image based on the known distances, and displaying the 3D image with a marking of at least one of the plurality of image points.