Abstract: A method for calculating conduction velocity of a cardiac activation wavefront from electrophysiological (“EP”) data points generated by a mapping system during a mapping procedure for a heart is provided. The method comprises for each EP data point comprising a local activation time, and position data defining a location within the heart corresponding to the local activation time: defining a neighborhood of EP points comprising the EP data point and a selection of neighboring EP data points; representing local activation time as a function f(x,y), where x and y our coordinates within a hyperplane defined to contain the neighborhood of EP data points based on the position data for each EP data point in the neighborhood; and calculating conduction velocity at the EP data point as a norm function of a gradient for the function f(x,y).

Abstract: A method and system for determining QRS onset in cardiac signals is described. The system and method comprise acquiring N ECG signals and each comprises a plurality of QRS complexes. The system and method further selecting one QRS complex to form the basis of a search for the QRS onset point and defining a starting location within the ECG signal that has the selected QRS complex for the search. Further, the method and system comprises searching backwards in time from said starting location for a first nadir in the signal associated with the selected QRS complex and setting the time of the first nadir as the time for the QRS onset point.

Abstract: Disclosed is a method for generating high resolution point cloud data for electro-anatomical mapping comprising receiving sparsely measured point cloud data having a plurality of data points. Surface mesh data comprising mesh points defining triangles on a myocardial surface is generated. The point cloud data is mapped to the surface mesh data. For each point of the surface mesh data that cannot be mapped to the point cloud data because there is a missing data point in point cloud data, an interpolation operation is performed based on the point cloud data within the neighbourhood of the point to generate a value for the missing data point. The interpolation operation is repeated N times. For every repetition, a difference between the value for the missing data point generated from the current iteration and the value for the missing data point generated from the immediately preceding iteration is compared, until the difference is below a threshold.

Abstract: Disclosed is a method for electro-anatomical mapping. In accordance with the method, surface mesh data is defined to represent the geometry of a myocardial surface. The mesh data comprises mesh points arranged to defined triangles on the myocardial surface and the mesh data is segmented into boundary areas. Point cloud data comprising a plurality of point cloud data points is received and each point cloud data point is assigned to a corresponding mesh point within a boundary area. The point cloud data point and its corresponding mesh point defines a mapping. For each mapping, a difference in a spatial location is determined between the points comprising the mapping. A warping function is selectively applied to spatially relocate the mesh point within each mapping based on the location of the corresponding point cloud data point within the mapping.

Abstract: A method for determining cardiac tissue health based on a depolarization wave within an EGM is disclosed. The method includes computing a first derivative with respect to time (DV/DT) of the EGM, determining extrema for the first derivative, establishing a value DV/DTMIN based on the extrema and mapping the value DV/DTMIN to cardiac tissue.

Abstract: A system for assessing a cardiac condition of a subject includes a sensor configured to record a plurality N of electrocardiographic signals from the subject to generate an ECG (electrocardiogram). The system further includes a processor configured to compute an RMS (root-mean-square) magnitude function from the recorded signals, and to measure from the RMS magnitude function an RMS variable that contains information about the cardiac condition of the subject. The ECG may be a standard 12-lead clinical ECG. The measured RMS variables may include RMS T-wave width, RMS RT recovery time, and RMS QT interval.

Abstract: A system for assessing a cardiac condition of a subject includes a sensor configured to record a plurality N of electrocardiographic signals from the subject to generate an ECG (electrocardiogram). The system further includes a processor configured to compute an RMS (root-mean-square) magnitude function from the recorded signals, and to measure from the RMS magnitude function an RMS variable that contains information about the cardiac condition of the subject. The ECG may be a standard 12-lead clinical ECG. The measured RMS variables may include RMS T-wave width, RMS RT recovery time, and RMS QT interval.

Abstract: A system for assessing a cardiac condition of a subject includes a sensor configured to record a plurality N of electrocardiographic signals from the subject to generate an ECG (electrocardiogram). The system further includes a processor configured to compute an RMS (root-mean-square) magnitude function from the recorded signals, and to measure from the RMS magnitude function an RMS variable that contains information about the cardiac condition of the subject. The ECG may be a standard 12-lead clinical ECG. The measured RMS variables may include RMS T-wave width, RMS RT recovery time, and RMS QT interval.

Abstract: Systems and methods are provided in the disclosure for estimating a risk of arrhythmia in a patient using electrocardiographic analysis. In certain aspects, a method of estimating a risk of arrhythmia in a patient is provided. The method comprises receiving electrocardiographic signals of the patient from a plurality of leads over a plurality of heart beats, averaging the electrocardiographic signals to produce an averaged electrocardiographic signal, and determining deflections in the averaged electrocardiographic signal, wherein each deflection has an amplitude and a duration. The method further comprises determining a significance of each deflection based on whether the amplitude of that deflection exceeds a threshold, and estimating a risk of arrhythmia in the patient based on at least one of a number, the amplitudes, and the durations of the significant deflections within a portion of the averaged electrocardiographic signal.

Abstract: Systems and methods are provided in the disclosure for estimating a risk of arrhythmia in a patient using electrocardiographic analysis. In certain aspects, a method of estimating a risk of arrhythmia in a patient is provided. The method comprises receiving electrocardiographic signals of the patient from a plurality of leads over a plurality of heart beats, averaging the electrocardiographic signals to produce an averaged electrocardiographic signal, and determining deflections in the averaged electrocardiographic signal, wherein each deflection has an amplitude and a duration. The method further comprises determining a significance of each deflection based on whether the amplitude of that deflection exceeds a threshold, and estimating a risk of arrhythmia in the patient based on at least one of a number, the amplitudes, and the durations of the significant deflections within a portion of the averaged electrocardiographic signal.

Abstract: A method for determining a physiological characteristic of a patient on which a medical device is applied is disclosed. Electric current data is obtained from the medical device. The electric current data is filtered to produce filtered data. The physiological characteristic is determined based on the filtered data.

Abstract: A system for assessing a cardiac condition of a subject includes a sensor configured to record a plurality N of electrocardiographic signals from the subject to generate an ECG (electrocardiogram). The system further includes a processor configured to compute an RMS (root-mean-square) magnitude function from the recorded signals, and to measure from the RMS magnitude function an RMS variable that contains information about the cardiac condition of the subject. The ECG may be a standard 12-lead clinical ECG. The measured RMS variables may include RMS T-wave width, RMS RT recovery time, and RMS QT interval.