Abstract: A method for visualization includes receiving an input indicative of respective apparent coordinates of a plurality of points disposed along a length of a probe inside a body of a subject, and applying a model of known mechanical properties of the probe to the apparent coordinates so as to compute a cost function with respect to shapes that can be assumed by the probe in the body. A shape is chosen responsively to the cost function, and corrected coordinates of the points along the length of the probe are generated based on the shape. The representation of the probe using the corrected coordinates is then displayed.

Abstract: A method, including: receiving an input indicative of respective apparent locations of a plurality of points disposed along a length of a probe inside a body of a subject, and applying a model of known mechanical properties of the probe to the respective apparent locations so as to minimize a first cost function with respect to shapes that can be assumed by the probe in the body. The method further includes choosing a shape responsively to the minimized first cost function and determining preliminary coordinates of the apparent locations responsively to the shape, minimizing a second cost function with respect to differences between the apparent locations and the preliminary coordinates, and generating corrected coordinates of the points along the length of the probe based on the minimized second cost function.

Abstract: A method includes positioning body-electrodes in galvanic contact with a body of a patient and positioning a mapping-tool, having a mapping-electrode, in a plurality of regions in the body. The method further includes tracking the mapping-tool at different positions in each of the regions using a location-measuring system, and for each region, generating a respective set of calibration-currents between the body-electrodes and the mapping-electrode at the different positions in the region. A respective relation is derived for each region between the respective set of the calibration-currents and the different positions, and is used in determining the location of an investigation-tool in response to the different respective relations and investigation-tool-currents.

Abstract: Methods and systems method for sensing a position of an object in a body include positioning a probe in the body, making measurements of mapping electrical currents passing between at least a first electrode on the probe and a plurality of second electrodes on a surface of the body, calibrating the measurements so as to compensate for one or more non-ideal features of the measurements including effects of system-dependent electrical coupling to one or more devices other than the first electrode and the second electrodes, and computing the position of the probe in the body using the calibrated measurements.

Abstract: A method, including: receiving an input indicative of respective apparent locations of a plurality of points disposed along a length of a probe inside a body of a subject, and applying a model of known mechanical properties of the probe to the respective apparent locations so as to minimize a first cost function with respect to shapes that can be assumed by the probe in the body. The method further includes choosing a shape responsively to the minimized first cost function and determining preliminary coordinates of the apparent locations responsively to the shape, minimizing a second cost function with respect to differences between the apparent locations and the preliminary coordinates, and generating corrected coordinates of the points along the length of the probe based on the minimized second cost function.

Abstract: Apparatus and method for detecting metal disturbance during a medical procedure includes a probe having an insertion tube, a joint and a joint sensor, contained within the probe, for sensing a position of the insertion tube. The joint sensor has first and second subassemblies that are magnetic transducers. A processor is used for measuring force using the joint sensor, and has a threshold field value stored therein. The processor compares a sensed field value to the threshold field value and identifies a presence metal when the sensed field value is greater than the threshold field value.

Abstract: A method, consisting of modeling physical parameters representative of a probe in proximity to body tissue during an ablation procedure performed by the probe. The method also includes measuring a subgroup of the physical parameters during a non-ablation stage of the ablation procedure so as to generate measured non-ablative values of the subgroup, and measuring the subgroup of the physical parameters during an ablation stage of the ablation procedure so as to generate measured ablative values of the subgroup. In response to the modeling, the method includes generating calculated non-ablative values of the subgroup for the non-ablation stage, and generating calculated ablative values of the subgroup for the ablation stage. The method compares the measured non-ablative values with the calculated non-ablative values, and compares the measured ablative values with the calculated ablative values, so as generate optimal values of the physical parameters.

Abstract: Apparatus, consisting of a probe, configured to be inserted into a body cavity, and an electrode having an outer surface and an inner surface connected to the probe. The apparatus also includes a temperature sensor, protruding from the outer surface of the electrode, which is configured to measure a temperature of the body cavity.

Abstract: A method for calibrating impedance includes coupling at least first, second, and third electrodes at respective locations to a surface of a body of a subject. A first current passing through the body between the first and second body-surface electrodes is measured, and a second current passing through the body between the first and third body-surface electrodes is measured. From the first and second currents, a contact factor is derived that is indicative of the impedance between at least one of the body-surface electrodes and the surface of the body. Also described are methods for sensing the position of a probe and for detecting tissue contact based on a relation between currents from the probe to body-surface electrodes.

Abstract: A method for visualization includes receiving an input indicative of respective apparent coordinates of a plurality of points disposed along a length of a probe inside a body of a subject, and applying a model of known mechanical properties of the probe to the apparent coordinates so as to compute a cost function with respect to shapes that can be assumed by the probe in the body. A shape is chosen responsively to the cost function, and corrected coordinates of the points along the length of the probe are generated based on the shape. The representation of the probe using the corrected coordinates is then displayed.

Abstract: Methods and systems method for sensing a position of an object in a body include positioning a probe in the body, making measurements of mapping electrical currents passing between at least a first electrode on the probe and a plurality of second electrodes on a surface of the body, calibrating the measurements so as to compensate for one or more non-ideal features of the measurements including effects of system-dependent electrical coupling to one or more devices other than the first electrode and the second electrodes, and computing the position of the probe in the body using the calibrated measurements.

Abstract: A method includes positioning body-electrodes in galvanic contact with a body of a patient and positioning a mapping-tool, having a mapping-electrode, in a plurality of regions in the body. The method further includes tracking the mapping-tool at different positions in each of the regions using a location-measuring system, and for each region, generating a respective set of calibration-currents between the body-electrodes and the mapping-electrode at the different positions in the region. A respective relation is derived for each region between the respective set of the calibration-currents and the different positions, and is used in determining the location of an investigation-tool in response to the different respective relations and investigation-tool-currents.

Abstract: A method for calibrating impedance includes coupling at least first, second, and third electrodes at respective locations to a surface of a body of a subject. A first current passing through the body between the first and second body-surface electrodes is measured, and a second current passing through the body between the first and third body-surface electrodes is measured. From the first and second currents, a contact factor is derived that is indicative of the impedance between at least one of the body-surface electrodes and the surface of the body. Also described are methods for sensing the position of a probe and for detecting tissue contact based on a relation between currents from the probe to body-surface electrodes.

Abstract: A locating system for determining the location and orientation of an invasive medical instrument, for example a catheter or endoscope, relative to a reference frame, comprising: a plurality of field generators which generate known, distinguishable fields, preferably continuous AC magnetic fields, in response to drive signals; a plurality of sensors situated in the invasive medical instrument proximate distal end thereof which generate sensor signals in response to said fields; and a signal processor which has an input for a plurality of signals corresponding to said drive signals and said sensor signals and which produces the three location coordinates and three orientation coordinates of a point on the invasive medical instrument.

Abstract: A locating system for determining the location and orientation of an invasive medical instrument, for example a catheter (10) or endoscope, relative to a reference frame, comprising: a plurality of field generators (18, 20, 22) which generate known, distinguishable fields, preferably continuous AC magnetic fields, in response to drive signals; a plurality of sensors (30, 32, 34) situated in the invasive medical instrument (10) proximate the distal end thereof which generate sensor signals in response to said fields; and a signal processor (26) which has an input for a plurality of signals corresponding to said drive signals and said sensor signals and which produces the three location coordinates and three orientation coordinates of a point on the invasive medical instrument.

Abstract: A locating system for determining the location and orientation of an invasive medical instrument, for example a catheter (10) or endoscope, relative to a reference frame, comprising: a plurality of field generators (18, 20, 22) which generate known, distinguishable fields, preferably continuous AC magnetic fields, in response to drive signals; a plurality of sensors (30, 32, 34) situated in the invasive medical instrument (10) proximate the distal end thereof which generate sensor signals in response to said fields; and a signal processor (26) which has an input for a plurality of signals corresponding to said drive signals and said sensor signals and which produces the three location coordinates and three orientation coordinates of a point on the invasive medical instrument.

Abstract: A locating system for determining the location and orientation of an invasive medical instrument, for example a catheter (10) or endoscope, relative to a reference frame, comprising: a plurality of field generators (18, 20, 22) which generate known, distinguishable fields, preferably continuous AC magnetic fields, in response to drive signals; a plurality of sensors (30, 32, 34) situated in the invasive medical instrument (10) proximate the distal end thereof which generate sensor signals in response to said fields; and a signal processor (26) which has an input for a plurality of signals corresponding to said drive signals and said sensor signals and which produces the three location coordinates and three orientation coordinates of a point on the invasive medical instrument.

Abstract: A probe assembly (18) for connection to a console (34) including a problem (20) for insertion into the body of a subject and a cable (21) for connecting the problem (20) to the console (34), the problem (20) having distal (22) and proximal ends and including a microcircuit (90) which stores information relating to the probe (20), and the cable (21) including access circuitry for accessing the microcircuit in the probe.

Abstract: A method for calibrating a magnetic field generator, including fixing one or more magnetic field sensors to a probe in known positions and orientations and selecting one or more known locations in the vicinity of the magnetic field generator. The magnetic field generator is driven so as to generate a magnetic field. The probe is moved in a predetermined, known orientation to each of the one or more locations, and signals are received from the one or more sensors at each of the one or more locations. The signals are processed to measure the amplitude and direction of the magnetic field, at the respective positions of the one or more sensors and to determine calibration factors relating to the amplitude and direction of the magnetic field in the vicinity of the magnetic field generator.

Abstract: A probe (20) for insertion into the body of a subject, the probe (20) having distal (22) and proximal ends, and including an electronic microcircuit (90), which stores information relating to calibration of the probe (20). Preferably, the microcircuit (90) stores a calibration code, which is encrypted. Alternatively or additionally, the microcircuit (90) stores a usage code, which controls availability of the probe (20) to a user thereof. Preferably, the probe (20) includes access control circuitry (90) that allows the usage code to be changed so as to reduce the availability of the probe (20), but not to increase the availability thereof.