Abstract: A method includes receiving (i) a plurality of electrocardiogram (ECG) signals acquired by a mapping catheter at a plurality of locations on a surface of a heart of a patient, (ii) a reference ECG signal from a reference catheter positioned at a nominal location in a coronary sinus (CS) of the patient, and (iii) position signals indicative of a position of the reference catheter in the CS. An electrophysiological (EP) map of at least part of the heart is calculated by time-referencing the ECG signals relative to the reference ECG signal. Based on the position signals, a displacement of the reference catheter from the nominal location in the CS, which distorts the time-referencing, is estimated. The distortion in the EP map is mitigated using the estimated displacement.

Abstract: The present system allows for the physician to change the relative height of the signal to allow for examination of details of the signals, while maintaining an ability to interpret signal voltage levels absolutely based on color or other secondary mechanism beyond signal height. The disclosed system and method provide for faster and more accurate analysis based upon the color of the signal. The signal height may change, such as to view, display, or examine details of the signal, while the colors of the display do not. The color scale of the signal provides an absolute scaling of the signal regardless of the displayed height.

Abstract: A catheter is responsive to external and internal magnetic field generators for generating position data of the catheter position and pressure data to determine pressured exerted on a distal end of the catheter when engaged with tissue, with a reduced number of sensing coils and reduced number of sensing coil leads for minimizing lead breakage and failure. The catheter includes a distal section adapted for engagement with patient tissue, where the distal section has a proximal portion, a distal portion and a flexible joint with a resilient member adapted to allow axial displacement and angular deflection between the proximal and distal portions of the distal section. The catheter may have three or less sensing coils with three or less leads, each transmitting signals between a respective sensing coil and the signal processor.

Abstract: A method is provided. The method includes receiving input intracardiac signals from a monitoring and processing apparatus. Each of the input intracardiac signals includes artifacts. The method includes encoding, by an autoencoder, the input intracardiac signals utilizing an intracardiac dataset to produce a latent representation. The method also includes decoding, by an autoencoder, the latent representation to produce output intracardiac signals. The output intracardiac signals include the input intracardiac signals reconstructed without the signal artifacts.

Abstract: A catheter adapted or high density mapping and/or ablation of tissue surface has a distal electrode matrix having a plurality of spines arranged in parallel configuration on which a multitude of electrodes are carried in a grid formation for providing uniformity and predictability in electrode placement on the tissue surface. The matrix can be dragged against the tissue surface upon deflection (and/or release of the deflection) of the catheter. The spines generally maintain their parallel configuration and the multitude of electrodes generally maintain their predetermined relative spacing in the grid formation as the matrix is dragged across the tissue surface in providing very high density mapping signals. The spines may have free distal ends, or distal ends that are joined to form loops for maintaining the spines in parallel configuration.

Abstract: Methods, apparatus, and systems for medical procedures are disclosed herein for receiving an input of a plurality of measured coordinates of a respective plurality of position transducers of a probe inside a body of a subject, receiving a measured voltage measurement output by the probe, determining a cost function based on a model of known mechanical properties of the probe compared to the measured coordinates with respect to shapes that can be assumed by the probe in the body and further based on an expected voltage value compared to the measured voltage measurement, selecting a shape based on the cost function, generating corrected coordinates of the points along the probe based on the shape and displaying a representation of the probe using the corrected coordinates.

Abstract: A method, including receiving a bipolar signal from a pair of electrodes in proximity to a myocardium of a human subject, and receiving a unipolar signal from a selected one of the pair of electrodes. The method further includes delineating a window of interest (WOI) for the unipolar and bipolar signals, within the WOI computing local unipolar minimum derivatives of the unipolar signal, and times of occurrence of the local unipolar minimum derivatives, and within the WOI computing bipolar derivatives of the bipolar signal at the times of occurrence. The method also includes evaluating ratios of the bipolar derivatives to the local unipolar minimum derivatives, and when the ratios are greater than a preset threshold ratio value, assigning the times of occurrence as times of activation of the myocardium, counting a number of the times of activation; and classifying the unipolar signal according to the number.

Abstract: A method including calculating, at multiple intra-cardiac locations, respective average atrial fibrillation cycle-length (AFCL) values. A determination is made as to whether the calculated average AFCL values are indicative of a regular atrial fibrillation (AF) activity. Gradients between pairs of the average AFCL values are calculated for a plurality of average AFCL values that are determined to be indicative of regular AF activity. The calculated AFCL gradients are presented to a user, overlaid on a map of at least a portion of the heart.

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: Described embodiments include a system that includes a current source generator and a processor. The processor is configured to drive the current source generator to supply, for application to tissue of a subject, an electric current having an amplitude that varies in accordance with a predefined function of time, such that the amplitude initially monotonically increases to a maximum value. Other embodiments are also described.

Abstract: A method, including receiving a unipolar ECG signal from the location in the heart from a selected one electrode of a pair of electrodes, computing a local unipolar minimum derivative of the unipolar signal at a plurality of times of occurrences of the local unipolar minimum derivative, identifying candidate time of occurrences of the plurality of times of occurrences of the local unipolar minimum derivative as candidate annotations of the time of activation of the myocardium, extracting features for each of the candidate annotations, assigning a confidence level based on a feature value for each of the candidate annotations, eliminating candidate annotations that have a confidence level below a threshold and generating a local activation time map using the remaining candidate annotations.

Abstract: A catheter has a mapping assembly having a plurality of splines mounted at its distal portion. The splines each have a proximal end disposed at the distal portion of the catheter body and a distal end and configured as a Fibonacci spiral arm that diverges outwardly from the proximal end. The splines have a support arm with shape memory, a non-conductive covering in surrounding relation to the support arm, at least one location sensor mounted at or near the distal end, a plurality of electrodes mounted in surrounding relation to the non-conductive covering, and a plurality of electrode lead wires extending within the non-conductive covering. Each electrode lead wire is attached to a corresponding one of the electrodes.

Abstract: The present system allows for the physician to change the relative height of the signal to allow for examination of details of the signals, while maintaining an ability to interpret signal voltage levels absolutely based on color or other secondary mechanism beyond signal height. The disclosed system and method provide for faster and more accurate analysis based upon the color of the signal. The signal height may change, such as to view, display, or examine details of the signal, while the colors of the display do not. The color scale of the signal provides an absolute scaling of the signal regardless of the displayed height.

Abstract: Cardiac ablation is carried out by placing two ablation electrodes on opposite sides of a wall of the heart to generally oppose one another. The effective current transmission area of one of the electrodes is then varied according to the distance between the two electrodes or the thickness of the wall. Sufficient electrical current is transmitted between the two electrodes to achieve transmural ablation.

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: A catheter adapted or high density mapping and/or ablation of tissue surface has a distal electrode matrix having a plurality of spines arranged in parallel configuration on which a multitude of electrodes are carried in a grid formation for providing uniformity and predictability in electrode placement on the tissue surface. The matrix can be dragged against the tissue surface upon deflection (and/or release of the deflection) of the catheter. The spines generally maintain their parallel configuration and the multitude of electrodes generally maintain their predetermined relative spacing in the grid formation as the matrix is dragged across the tissue surface in providing very high density mapping signals. The spines may have free distal ends, or distal ends that are joined to form loops for maintaining the spines in parallel configuration.

Abstract: A system and method of identifying focal sources is presented. The method can comprise detecting, via sensors, electro-cardiogram (ECG) signals over time, each ECG signal detected via one of the sensors having a location in a heart and indicating electrical activity of the heart, each signal comprising at least an R wave and an S wave; creating an R-S map comprising an R-to-S ratio for each of the ECG signals, the R-to-S ratio comprising a ratio of absolute magnitude of the R wave to absolute magnitude of the S wave; identifying, for each of the ECG signals, local activation times (LATs); and correlating the R-to-S ratios for the ECG signals on the R-S map and the identified LATs and using the correlation to identify the focal sources.

Abstract: A method, including receiving a bipolar ECG signal from a location in the heart from the pair of electrodes, receiving a unipolar ECG signal from the location in the heart from a selected one electrode of the pair of electrodes, computing a local unipolar minimum derivative of the unipolar signal at a plurality of times of occurrences of the local unipolar minimum derivative, computing a bipolar derivative of the bipolar signal, evaluating a ratio of the bipolar derivative to the local unipolar minimum derivative at the plurality of times of occurrences of the local unipolar minimum derivative, annotating each time of occurrence as a time of activation of the myocardium at the location in the heart when the ratio is greater than a preset threshold value, merging two annotations that arise from a single occurrence as a single annotation, evaluating features of the annotations and assigning a confidence level to each feature, eliminating annotations that have a confidence level below a threshold and generating

Abstract: Described embodiments include a system that includes a current source generator and a processor. The processor is configured to drive the current source generator to supply, for application to tissue of a subject, an electric current having an amplitude that varies in accordance with a predefined function of time, such that the amplitude initially monotonically increases to a maximum value. Other embodiments are also described.

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.