Abstract: A system includes a display and a processor. The processor is configured to: (i) estimate, based on signals, multiple regions of tissue on a surface of an organ, which are affected by multiple respective electrodes positioned in the organ, (ii) calculate, for at least a subset of the electrodes, a unified region of the tissue affected by the subset, and (iii) display a mark indicative of the unified region on the display.

Abstract: An apparatus includes an interface and a processor. The interface is configured for exchanging signals with: (i) a probe, which is inserted into a body of a patient and includes a flexible distal-end assembly, wherein the distal-end assembly comprises a magnetic position sensor and two or more intra-body electrodes, and, (ii) multiple body-surface electrodes attached externally to the body of the patient. The processor is configured to estimate, based on the signals exchanged with the probe, a spatial displacement of the magnetic sensor between consecutive measurements, and to estimate a position of the distal-end assembly in the body based on (i) the signals exchanged with the intra-body electrodes and the body-surface electrodes, (ii) a-priori known spatial relationships between two or more of the intra-body electrodes of the probe and (iii) the estimated spatial displacement of the magnetic sensor.

Abstract: A system includes multiple electrically-conductive channels and a processor. The processor is configured to receive, over the electrically-conductive channels, (i) respective first electric currents from a probe, which is within a body of a patient, via a plurality of first electrodes, which are attached to skin of the patient at a region of the body, and (ii) a second electric current from the probe via a second electrode, which is attached to the skin and is connected to one of the channels. The processor is further configured to ascertain respective first electric-current values of the first electric currents and a second electric-current value of the second electric current, and to calculate a position of the probe between the region and the second electrode, based on the first electric-current values and the second electric-current value. Other embodiments are also described.

Abstract: A method uses multiple patches fixed to a surface of a body, the patches including respective electrodes in contact with the surface, and at least one of the patches configured to output a signal in response to a magnetic field applied to the body. Initially, the signal is processed to compute first magnetic and first electrical locations of the at least one of the patches. Subsequently, the signal is processed to compute second magnetic and second electrical locations of the at least one of the patches. A first relation is computed between the first magnetic and electrical locations, and a second relation is computed between the second magnetic and electrical locations. When there is a difference between the first and the second relations, a magnetic location correction is computed responsively to the difference, and the correction is applied in tracking a position of a magnetic tracking sensor inside the body.

Abstract: A system includes multiple electrically-conductive channels and a processor. The processor is configured to receive, over the electrically-conductive channels, (i) respective first electric currents from a probe, which is within a body of a patient, via a plurality of first electrodes, which are attached to skin of the patient at a region of the body, and (ii) a second electric current from the probe via a second electrode, which is attached to the skin and is connected to one of the channels. The processor is further configured to ascertain respective first electric-current values of the first electric currents and a second electric-current value of the second electric current, and to calculate a position of the probe between the region and the second electrode, based on the first electric-current values and the second electric-current value. Other embodiments are also described.

Abstract: An apparatus includes an interface and a processor. The interface is configured for exchanging signals with: (i) a probe, which is inserted into a body of a patient and includes a flexible distal-end assembly, wherein the distal-end assembly comprises a magnetic position sensor and two or more intra-body electrodes, and, (ii) multiple body-surface electrodes attached externally to the body of the patient. The processor is configured to estimate, based on the signals exchanged with the probe, a spatial displacement of the magnetic sensor between consecutive measurements, and to estimate a position of the distal-end assembly in the body based on (i) the signals exchanged with the intra-body electrodes and the body-surface electrodes, (ii) a-priori known spatial relationships between two or more of the intra-body electrodes of the probe and (iii) the estimated spatial displacement of the magnetic sensor.

Abstract: An apparatus includes a shaft, a flexible distal-end assembly, two or more sensing-electrodes, and a fiber-optic shape sensor. The shaft is configured for insertion into a body of a patient. The flexible distal-end assembly is fitted at a distal end of the shaft. The two or more sensing-electrodes are disposed over the distal-end assembly and are configured to generate signals indicative of positions of the sensing-electrodes in the body. The fiber-optic shape sensor is coupled to a portion of the distal-end assembly, wherein the two or more sensing-electrodes have a-priori known distances from a known location over the fiber-optic shape sensor, and wherein the fiber-optic shape sensor is configured to provide an indication of a spatial deformation of the flexible distal-end assembly.

Abstract: A method, including performing a first registration of a tracking system, which is configured to track a location of a probe within a human body organ, with a baseline coordinate system, and measuring first locations of the probe within the organ following the first registration. First indicators marking the first locations with a first visual effect are presented on an image of the organ, at positions on the image that are determined based on the first registration. After measuring the first locations, a second registration of the tracking system with the baseline coordinate system is performed, and second locations of the probe within the organ following the second registration are measured. Second indicators marking the second locations with a second effect, which is visually distinct from the first effect, are presented on the image of the organ, at positions on the image that are determined based on the second registration.

Abstract: A method, using multiple patches fixed to a surface of a body, the patches including respective electrodes in contact with the surface, and at least one of the patches configured to output a signal in response to a magnetic field applied to the body. Initially, the signal is processed to compute first magnetic and first electrical locations of the at least one of the patches. Subsequently, the signal is processed to compute second magnetic and second electrical locations of the at least one of the patches. A first relation is computed between the first magnetic and electrical locations, and a second relation is computed between the second magnetic and electrical locations. When there is a difference between the first and the second relations, a magnetic location correction is computed responsively to the difference, and the correction is applied in tracking a position of a magnetic tracking sensor inside the body.