Intracardiac unipolar far-field cancellation using a multielectrode catheter.

Abstract

The method is performed by a mapping engine executed by a processor. The method includes receiving electrical activity from electrodes of a catheter. The method includes performing a spatial electrode signal analysis of the electrical activity for each electrode of the catheter. The method includes scaling common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

Description

[Technical field]

[0001] (Incorporated by reference) This application claims priority to U.S. Provisional Patent Application No. 63 / 288,966, filed December 13, 2021, which is incorporated by reference in its entirety herein.

[0002] FIELD OF THEINVENTION The systems and methods herein relate generally to signal processing. [Background technology]

[0003] In general, conventional cardiac mapping is a computer-processed operation that generates a three-dimensional map of the heart that medical professionals can use to determine the precise source location of arrhythmias or when performing medical procedures such as cardiac ablation to treat atrial fibrillation (aFib).

[0004] By way of example, in conventional cardiac mapping, a three-dimensional map of the heart is created when a medical professional (e.g., a physician) guides a catheter through a patient's blood vessels until the catheter is positioned inside the heart. The catheter senses electrical activity, and computer processing operations analyze the electrical activity and generate a three-dimensional map of the heart.

[0005] A problem with conventional cardiac mapping is that far-field signals mask or interfere with local field signals in the electrical activity. Furthermore, conventional computer processing operations are not well suited to addressing far-field signals. For example, computer processing operations assume that all far-field signals are the same on all electrodes of the catheter. Summary of the Invention [Problem to be solved by the invention]

[0006] What is needed is a system and method for extracting and analyzing electrical activity from a catheter while reducing or eliminating interference from the far field. [Means for solving the problem]

[0007] In accordance with an exemplary embodiment, a method is provided. The method is performed by a mapping engine executed by one or more processors. The method includes receiving electrical activity from a plurality of electrodes of a catheter. The method includes performing a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes. The method includes scaling common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal. In accordance with one or more embodiments, the exemplary method embodiments described above may be implemented as an apparatus, a system, and / or a computer program product.

[0008] According to one or more embodiments, a system is provided. The system includes a memory that stores mapping engine software. The system includes one or more processors. The one or more processors execute the software to cause the mapping engine to receive electrical activity from a plurality of electrodes of a catheter, perform a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes, and scale common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal. According to one or more embodiments, the exemplary system embodiments described above may be implemented as an apparatus, a method, and / or a computer program product. [Brief description of the drawings]

[0009] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which like reference numbers indicate similar elements and in which: [Figure 1] 1 shows a diagram of an example system that may implement one or more features of the subject matter of this disclosure, in accordance with one or more embodiments. [Diagram 2]1 shows a diagram of a system according to one or more embodiments. [Figure 3A] 1 illustrates a method according to one or more embodiments. [Figure 3B] 1 illustrates a graph in accordance with one or more embodiments. [Figure 4] 1 illustrates a method according to one or more embodiments. [Diagram 5] 1 illustrates an exemplary catheter, according to one or more embodiments. [Figure 6] 1 illustrates an exemplary catheter, according to one or more embodiments. [Figure 7] 1 illustrates a plot according to one or more embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The systems and methods herein relate generally to signal processing. In accordance with one or more embodiments, the systems and methods described herein provide intracardiac unipolar far-field reduction or cancellation using a multiple electrode catheter. As an example, the systems and methods described herein are described with respect to a mapping engine.

[0011] The mapping engine may be implemented as processor executable code or software and is necessarily anchored in the process operations by the medical device device and the processing hardware of the medical device device. For ease of explanation, the mapping engine is described herein with respect to mapping the heart, but any anatomical structure, body part, organ, or portion thereof may be targeted for mapping by the mapping engine described herein. In accordance with one or more embodiments, the mapping engine obviates the traditional cardiac mapping assumption that all far-field signals are the same on all electrodes. In contrast to traditional cardiac mapping, the mapping engine intelligently satisfies the new assumption that the far-field signals are similar but not exactly the same. The mapping engine then weights the electrodes inversely proportional to their distance to identify common signal components between the electrodes. This common signal component is used by the mapping engine to precisely reduce or cancel far-field interference. Reducing or canceling far-field interference by the mapping engine produces cleaner near-field signals for improved cardiac mapping.

[0012] One or more advantages, technical effects, and / or benefits of the mapping engine may include filtering out far-field interference and estimating pure local activation (e.g., especially for highly complex mapping cases) from unipolar signals replacing the need for bipolar signals, which are well known for their shortcomings such as electrode distance and directional distortion. Thus, by utilizing and transforming specifically unipolar signals, the mapping engine doubles the number of electrodes analyzed to obtain or increase spatial behavior resolution. Note that in cases of slow activation, the mapping engine may also filter out persistent aFib near-far field signals to enhance aFib target detection.

[0013] 1 is a diagram of an example system (e.g., a medical device instrument) that may implement one or more features of the subject matter herein in accordance with one or more embodiments, shown as system 10. All or a portion of system 10 may be used to collect information (e.g., biometric data and / or a training data set) and / or may be used to implement a mapping engine 101 as described herein. The system 10 includes a recorder 11, a heart 12, a catheter 14, a model or anatomical map 20, an electrogram 21, a spline 22, a patient 23, a physician 24 (or medical professional or clinician), a location pad 25, an electrode 26, a display device 27, a distal tip 28, a sensor 29, a coil 32, a Patient Interface Unit (PIU) 30, an electrode skin patch 38, an ablation energy generator 50, and a workstation 55 (including at least one processor 61 and at least one memory 62 that stores a mapping engine 101), as shown. It should be noted that each element and / or item of the system 10 is representative of one or more of that element and / or item. The example system 10 shown in FIG. 1 may be modified to implement the embodiments disclosed herein. The embodiments of the present disclosure may be similarly applied using other system components and configurations. Additionally, system 10 may include additional components, such as elements for sensing electrical activity and / or physiological signals, wired or wireless connectors, processing devices, and display devices.

[0014] The system 10 includes multiple catheters 14 that are percutaneously inserted by a physician 24 through the vascular system of a patient 23 into a chamber or vasculature of the heart 12. Typically, a delivery sheath catheter (which is one example of a catheter 14) is inserted into the left or right atrium near a desired location in the heart 12. The multiple catheters 14 may then be inserted into the delivery sheath catheter to reach a desired location. The multiple catheters 14 may include catheters dedicated to sensing Intracardiac Electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. An exemplary catheter 14 configured to sense IEGMs is shown herein. The physician 24 brings a distal tip 28 of the catheter 14 into contact with the heart wall to sense a target site of the heart 12. For ablation, the physician 24 similarly brings a distal end of an ablation catheter to a target site for ablation.

[0015] Catheter 14 is an exemplary catheter that includes one, and preferably multiple, electrodes 26 at distal tip 28, optionally distributed across multiple splines 22, and configured to sense IEGM signals. Catheter 14 may further include a sensor 29 embedded in or near distal tip 28 for tracking the position and orientation of distal tip 28. Optionally and preferably, position sensor 29 is a magnetic-based position sensor including three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0016] The sensor 29 (e.g., a position-based or magnetic-based position sensor) may operate in conjunction with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the distal end 28 of the catheter 14 may be tracked based on the magnetic field generated by the location pad 25 and sensed by the sensor 29. Details of magnetic-based position sensing technology are described in U.S. Patent Nos. 5,5391,199; 5,443,489; 5,558,091; 6,172,499; 6,239,724; 6,332,089; 6,484,118; 6,618,612; 6,690,963; 6,788,967; and 6,892,091.

[0017] The system 10 includes one or more electrode patches 38 positioned on the patient 23 for skin contact to establish a positional reference for the location pads 25 and impedance-based tracking of the electrodes 26. For impedance-based tracking, a current may be directed to the electrodes 26 and sensed at the patches 38, thereby triangulating the location of each electrode via the patches 38. Details of impedance-based location tracking technology are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, each of which is incorporated herein by reference.

[0018] Recorder 11 displays electrograms 21 captured by electrodes 18 (e.g., surface electrocardiogram (ECG) electrodes) and IEGMs captured by electrodes 26 of catheter 14. Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0019] The system 10 may include an ablation energy generator 50 adapted to deliver ablation energy to one or more electrodes 26 at a distal tip 28 of the catheter 14 configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or Pulsed-Field Ablation (PFA) energy, including monopolar or bipolar high-voltage DC pulses, such as may be used to effect irreversible electroporation (IRE).

[0020] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheters, the electrophysiological equipment, a power source, and a workstation 55 that controls the operation of the system 10. The electrophysiological equipment of the system 10 may include, for example, a number of catheters 14, location pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for implementing real-time calculations of catheter positions and performing ECG calculations.

[0021] The workstation 55 includes a processor unit 61 having a memory 62, a memory 62 or storage device loaded with suitable operating software, and user interface functionality, as described further herein. The workstation 55 may optionally provide multiple functions, including: (1) modeling the endocardial anatomical structures in three dimensions (3D) and rendering a model or anatomical map 20 for display on the display device 27, (2) displaying activation sequences (or other data) compiled from recorded electrograms 21 with representative visual indicators or images superimposed on the rendered anatomical map 20 on the display device 27, (3) displaying real-time positions and orientations of multiple catheters within the heart chambers, and (5) displaying sites of interest, such as locations where ablation energy is applied, on the display device 27. One commercially available product embodying elements of system 10 is available as the CARTO® 3 system, commercially available from Biosense Webster, Inc., 31A Technology Drive, Irvine, Calif., 92618.

[0022] The system 10 may be utilized to detect, diagnose, and / or treat cardiac conditions (e.g., using the mapping engine 101). Cardiac diseases, such as cardiac arrhythmias, persist as common and dangerous medical disorders, especially in the geriatric population. For example, the system 10 may be part of a surgical system (e.g., a CARTO® system available from Biosense Webster, Inc.) configured to obtain biometric data (e.g., anatomical and electrical measurements of a patient's organs, such as the heart 12, as described herein) and perform cardiac ablation procedures. More specifically, the treatment of cardiac diseases, such as cardiac arrhythmias, often requires obtaining detailed mapping of cardiac tissue, chambers, veins, arteries, and / or electrical pathways. For example, as a prerequisite for successful catheter ablation (as described herein), the source of the cardiac arrhythmia may be precisely localized in the chambers of the heart 12. Such localization is performed by electrophysiological studies during which spatially resolved electrical potentials may be detected by a mapping catheter (e.g., catheter 14) introduced into the chambers of the heart 12. This electrophysiological study, also called electroanatomical mapping, provides 3D mapping data, which may be displayed on the display device 27. Often, mapping and therapy functions (e.g., ablation) are provided by a single catheter or a group of catheters, with the mapping catheter also simultaneously acting as the therapy (e.g., ablation) catheter. According to one or more embodiments, the mapping engine 101 may be stored and executed directly by the catheter 14.

[0023] According to one or more embodiments, the mapping engine 101 performs an electrocardiograph and / or intracardiac electrogram (ECG / intracardiac electrogram, ICEG). ECG / ICEG is a process of analyzing / interpreting / recording the electrical activity of the heart 12 over a period of time using physiological signals of multiple electrodes 18 and 26 (e.g., in ICEG, at least one of the electrodes 26 is inside the heart 12). That is, to assist the system 100 in detecting, diagnosing, and / or treating a cardiac condition, one or more catheters 14 may be guided by a physician 24 into the heart 12 of the patient 23. As a result, the multiple electrodes 18 and 26 detect and provide signals (also known as physiological signals) that the mapping engine 101 uses to identify small electrical changes resulting from the electrophysiological pattern of the heart muscle depolarizing during each heartbeat. The ECG / ICEG may be performed over a period of time, such as, for example, 10 seconds. Thereby, the entire magnitude and direction of the electrical depolarization in the heart 12 is captured at each instant throughout the cardiac cycle. ECG / ICEG may be recorded during diagnostic or therapeutic procedures, the duration of which may vary from tens of minutes to hours. During each therapeutic procedure, there are typically several dozen ablation sessions, each lasting, for example, from a few seconds up to about a minute.

[0024] According to one or more embodiments, the mapping engine 101 may include and execute one or more algorithms, such as algorithms implementing a mathematical multiple signal decomposition operation. Because the mapping engine 101 provides accurate near-field components, excitation times (e.g., using minimum derivatives), and voltage levels (e.g., max-min), the mapping engine 101 reduces the need for wavefront algorithms. Examples of the one or more algorithms include, but are not limited to, Singular Value Decomposition (SVD), Principal Component Analysis (PCA), and / or other matrix decompositions or factorizations.

[0025] In a patient (e.g., patient 23) having Normal Sinus Rhythm (NSR), the heart (e.g., heart 12), including the atria, ventricles, and excitable conduction tissue, is electrically excited and beats in a synchronous and patterned manner, which may be detected, for example, in intracardiac electrocardiogram (IC ECG) data.

[0026] According to one or more embodiments, in patients (e.g., patient 23) with cardiac arrhythmias (e.g., aFib), the abnormal regions of cardiac tissue do not follow the synchronous beating cycle associated with normal conductive tissue, in contrast to patients with NSR. In contrast, the abnormal regions of cardiac tissue conduct abnormally to adjacent tissue, which disrupts the cardiac cycle and results in an asynchronous cardiac rhythm. It should be noted that this asynchronous cardiac rhythm can also be detected as IC ECG data. Such abnormal conduction has previously been known to occur in various regions of the heart 12, such as, for example, in the region of the sino-atrial (SA) node along the conduction pathways of the atrioventricular (AV) node, or in the myocardial tissue that forms the walls of the ventricles and atria. Other conditions also exist, such as atrial flutter, in which abnormal conductive tissue patterns lead to reentry pathways, causing the heart chambers to beat in a regular pattern that can be multiples of the sinus rhythm.

[0027] As an example, to assist system 10 in detecting, diagnosing, and / or treating cardiac disease, physician 24 may guide catheter 14 into heart 12 of patient 23 lying in bed. For example, physician 24 may insert the shaft through the sheath while manipulating the distal end of the shaft with a manipulator near the proximal end of catheter 14 and / or a deflection from the sheath. According to one or more embodiments, catheter 14 may be attached to the distal end of the shaft. Catheter 14 may be inserted through the sheath in a collapsed state and then expanded within heart 12.

[0028] In general, electrical activity at a point within the heart 12 may be measured by advancing a catheter 14, typically containing an electrical sensor (e.g., sensor 29) at or near its distal tip (e.g., at least one electrode 26), to the point within the heart 12 to contact tissue with the electrical sensor and acquire data at the point. One difficulty with mapping a heart chamber using a catheter type containing only a single distal tip electrode is that a long period of time may be required to collect data for each point over the necessary number of points required for a detailed map of the heart chamber as a whole. Therefore, multi-electrode catheters (e.g., catheter 14) have been developed to simultaneously measure electrical activity at multiple points within the heart chamber.

[0029] The catheter 14, which may include at least one electrode 26 and a catheter needle coupled on its body, may be configured to obtain biometric data, such as electrical signals, of a body organ (e.g., the heart 12) and / or ablate a tissue region (e.g., a chamber of the heart 12). It is noted that the electrode 26 is representative of any similar element, such as a tracking coil, piezoelectric transducer, electrode, or combination of elements configured to ablate a tissue region or obtain biometric data. According to one or more embodiments, the catheter 14 may include one or more position sensors that are used to determine trajectory information. This trajectory information may be used to infer motion characteristics, such as tissue contractility.

[0030] The biometric data (e.g., patient biometrics, patient data, or patient biometric data) may include one or more of Local Activation Time (LAT), electrical activity, topology, bipolar mapping, baseline activity, ventricular activity, dominant frequency, impedance, and the like. LAT may be a time point of threshold activity corresponding to local activation calculated based on a normalized initial onset. Electrical activity may be any applicable electrical signal that may be measured based on one or more thresholds and may be sensed and / or enhanced based on signal-to-noise ratio and / or other filters. Topology may correspond to the physical structure of the body part or a portion of the body part and may correspond to changes in the physical structure for different parts of the body part or for different body parts. The dominant frequency may be a frequency or range of frequencies commonly found in a portion of the body part and may be different in different parts of the same body part. For example, the dominant frequency of the PV (Pulmonary Vein) of the heart may be different from the dominant frequency of the right atrium of the same heart. Impedance may be a resistance measurement in a particular region of the body part.

[0031] Examples of biometric data include, but are not limited to, patient identification data, IC ECG data, bipolar intracardiac reference signals, anatomical and electrical measurements, trajectory information, Body Surface (BS) ECG data, historical data, brain biometric measurements, blood pressure data, ultrasound signals, radio signals, audio signals, two-dimensional or three-dimensional (3D) image data, blood glucose data, or temperature data, or other electrical activity and / or physiological signals. Biometric data may generally be used to monitor, diagnose, and treat any number of different diseases, such as cardiovascular diseases (e.g., arrhythmias, cardiomyopathies, and coronary artery disease), and autoimmune diseases (e.g., diabetes mellitus type I and type II). It is noted that BS ECG data may include data and signals collected from electrodes on the surface of the patient, IC ECG data may include data and signals collected from electrodes inside the patient, and ablation data may include data and signals collected from ablated tissue. Additionally, the BS ECG data, IC ECG data, and ablation data, along with catheter electrode position data, may be derived from one or more procedure records.

[0032] For example, the catheter 14 may use the electrodes 26 to perform intravascular ultrasound and / or MRI (Magnetic Resonance Imaging) catheterization to image (e.g., acquire and process biometric data) the heart 12. The catheter 14 is shown in an enlarged view within a chamber of the heart 12. It will be understood that any shape that includes one or more electrodes 26 may be used to implement the embodiments disclosed herein.

[0033] Examples of catheter 14 include, but are not limited to, a straight catheter with multiple electrodes, a balloon catheter including electrodes distributed on multiple spines forming a balloon, a lasso, a catheter with multiple electrodes in a grid shape or a loop catheter with multiple electrodes, a high density catheter, or any other applicable shape or combination. The straight catheter may be fully or partially elastic so that it may twist, bend, and / or otherwise change its shape based on received signals and / or based on the action of an external force (e.g., cardiac tissue) on the straight catheter. The balloon catheter may be designed to hold its electrodes in intimate contact against the endocardial surface when deployed within the patient's body. As an example, the balloon catheter may be inserted into a lumen such as a pulmonary vein (PV). The balloon catheter may be inserted into the PV in a deflated state, such that the balloon catheter does not occupy its maximum volume while inserted into the PV. The balloon catheter may expand while inside the PV, such that the electrodes on the balloon catheter contact the entire circular portion of the PV. Such contact with the entire circular portion of the PV or any other lumen allows for efficient imaging and / or ablation. Other examples of catheters 14 include the PentaRay® catheter and the Constellation catheter. Examples of catheters 14 are also described with respect to Figures 5-6, as described in more detail below.

[0034] According to other embodiments, a body patch and / or body surface electrodes (e.g., one or more electrode patches 38) may be positioned on or adjacent to the body of the patient 23. A catheter 14 having one or more electrodes 26 may be positioned within the body (e.g., within the heart 12) whose position may be determined by the 100 system based on signals transmitted and received between the one or more electrodes 26 of the catheter 14 and the body patch and / or body surface electrodes. Additionally, the electrodes 26 may sense biometric data from within the body of the patient 23, such as within the heart 12 (e.g., the electrodes 26 sense tissue electrical potentials in real time). The biometric data may be associated with the determined position of the catheter 14, thereby displaying a rendering of the patient's body part (e.g., the heart 12) showing the biometric data superimposed on the shape of the body part.

[0035] As a further example, the catheter 14 and other items of the system 10 may be connected to a workstation 55. The workstation 55 may include any computing device that employs ML (Machine Learning) / AI (Artificial Intelligence) algorithms, which may be included in the mapping engine 101. According to an exemplary embodiment, the workstation 55 includes one or more processors 61 (any computing hardware) and memory 62 (any non-transitory tangible medium), where the one or more processors 61 execute computer instructions for the mapping engine 101 and the memory 62 stores these instructions for execution by the one or more processors 61. For example, the workstation 55 may be configured to receive and process biometric data to determine whether a particular tissue region conducts electricity. In some embodiments, the workstation 55 may be further programmed by the mapping engine 101 (in software) to perform functions of an ablation procedure guidance method. For example, an ablation procedure guidance method may include receiving input (e.g., including one or more images and a conduction velocity vector estimate), generating a digital twin of the anatomical structure using the images and the conduction velocity vector estimate, and presenting the digital twin to provide precise ablation guidance of the anatomical structure and to provide electrophysiology information of the anatomical structure.

[0036] According to one or more embodiments, the mapping engine 101 may be external to the workstation 55, e.g., located in the catheter 14, in an external device, in a mobile device, in a cloud-based device, or may be a stand-alone processor. In this regard, the mapping engine 101 may be transferable / downloadable in electronic form over a network.

[0037] As one example, the workstation 55 may be any computing device described herein including software (e.g., mapping engine 101) and / or hardware (e.g., processor 61 and memory 62), such as a general purpose computer, with front-end and interface circuitry suitable for transmitting and receiving signals to and from the catheter 14 and for controlling other components of the system 10. For example, the front-end and interface circuitry may include an input / output (I / O) communication interface that allows the workstation 55 to receive signals from and / or transmit signals to at least one electrode 26. The workstation 55 may include real-time noise reduction circuitry, typically configured as a Field Programmable Gate Array (FPGA), followed by an Analog-to-Digital (A / D) ECG or electrocardiogram / electromyogram (EMG) signal conversion integrated circuit. The workstation 55 may communicate signals from the A / D ECG or EMG circuitry to a separate processor and / or may be programmed to perform one or more of the functions disclosed herein.

[0038] A display device 27, which may be any electronic device for visually presenting biometric data, is connected to the workstation 55. According to an exemplary embodiment, during a procedure, the workstation 55 may facilitate the presentation of a rendering of the body part to the physician 24 on the display device 27 and store data representative of the rendering of the body part in memory 62. For example, a map indicative of motion characteristics may be rendered / constructed based on trajectory information sampled at a sufficient number of points within the heart 12. As an example, the display 27 may include a touch screen that may be configured to allow input from the physician 24 in addition to presenting the rendering of the body part.

[0039] In some embodiments, physician 24 may use one or more input devices, such as a touchpad, mouse, keyboard, gesture recognizer, etc., to manipulate the renderings of elements of system 10 and / or body parts. For example, the input devices may be used to change the position of catheter 14 so that the renderings are updated. Note that display device 27 may be located at the same location or at a remote location, such as another hospital or another healthcare provider network.

[0040] According to one or more embodiments, the system 10 may also acquire biometric data using ultrasound, computed tomography (CT), MRI, or other medical imaging techniques utilizing the catheter 14 or other medical equipment. For example, the system 10 may acquire ECG data and / or anatomical and electrical measurements (e.g., biometric data) of the heart 12 using one or more catheters 14 or other sensors. More specifically, the workstation 55 may be connected by a cable to BS electrodes including adhesive skin patches affixed to the patient 23. The BS electrodes acquire / generate biometric data in the form of BS ECG data. For example, the processor 61 determines the position coordinates of the catheter 14 within the body part (e.g., the heart 12) of the patient 23. The position coordinates are based on impedance or electromagnetic fields measured between the body surface electrodes and the electrodes 26 of the catheter 14 or other electromagnetic components. Additionally or alternatively, the location pads generating the magnetic fields used for steering may be located on the surface of the bed (or table) or may be separate from the bed. The biometric data may be transmitted to the workstation 55 and stored in memory 62. Alternatively, or additionally, the biometric data may be transmitted to a server, which may be local or remote, using a network as described further herein.

[0041] According to one or more embodiments, the catheter 14 may be configured to ablate a tissue region of a chamber of the heart 12. For example, the catheter 14 is shown in an expanded view within a chamber of the heart 12. Additionally, an ablation electrode, such as at least one electrode 26, is configured to provide energy to a tissue region of an internal organ (e.g., the heart 12). The energy may be thermal energy and may cause damage to the tissue region beginning at a surface of the tissue region and extending through a thickness of the tissue region. Biometric data related to the ablation procedure (e.g., ablated tissue, ablation location, etc.) may be considered ablation data.

[0042] According to one embodiment, with respect to acquiring biometric data, a multi-electrode catheter (e.g., catheter 14) is advanced into a chamber of heart 12. Anteroposterior (AP) and lateral fluoroscopic photographs may be acquired to establish the position and orientation of each of the electrodes. An ECG may be recorded from each of the electrodes 26 in contact with the cardiac surface with respect to a time reference, such as the occurrence of P waves in sinus rhythm from a BS ECG and / or a signal from an electrode 26 of catheter 14 positioned within the coronary sinus. The system further disclosed herein may distinguish between electrodes that record electrical activity and electrodes that do not record electrical activity due to their lack of proximity to the endocardial wall. After an initial ECG is recorded, the catheter may be repositioned and fluoroscopic photographs and ECG may be recorded again. An electrical map may then be constructed from an iteration of the above process (e.g., via cardiac mapping).

[0043] Cardiac mapping may be performed using one or more techniques. In general, mapping of cardiac regions, such as cardiac regions, tissues, veins, arteries, and / or electrical pathways of the heart 12 may lead to identification of problem areas, such as scar tissue, arrhythmia sources (e.g., electrical rotors), healthy regions, and the like. The cardiac regions are mapped such that a visual rendering of the mapped cardiac regions is provided using a display, as further disclosed herein. Additionally, cardiac mapping (which is an example of cardiac imaging) may include mapping based on one or more modalities, such as, but not limited to, LAT, regional activation rate, electrical activity, topology, bipolar mapping, dominant frequency, or impedance. Data (e.g., biometric data) corresponding to multiple modalities may be acquired using a catheter (e.g., catheter 14) inserted into the patient's body and provided for rendering simultaneously or at different times based on corresponding settings and / or physician 24 preferences.

[0044] As an example of the first technique, cardiac mapping may be performed by sensing electrical properties of cardiac tissue, e.g., LAT, as a function of precise location within the heart 12. Corresponding data (e.g., biometric data) may be acquired by one or more catheters (e.g., catheter 14) advanced into the heart 12 and having electrical and position sensors (e.g., electrodes 26) at their distal tips. As a specific example, location and electrical activity may be initially measured at about 10 to about 20 points on the inner surface of the heart 12. These data points may generally be sufficient to generate a preliminary reconstruction or map of the cardiac surface with satisfactory quality. The preliminary map may be combined with data measured at additional points to generate a more comprehensive map of the cardiac electrical activity. In clinical practice, it is not uncommon to collect data from 100 or more sites (e.g., several thousand) to generate a detailed comprehensive map of the electrical activity of the cardiac chambers. The detailed maps generated can then serve as a basis for making decisions about a course of therapeutic action, such as tissue ablation as described herein, to alter the propagation of the heart's electrical activity and restore normal heart rhythm.

[0045] Furthermore, cardiac mapping is generated based on the detection of intracardiac potential fields (e.g., one example of IC ECG data and / or bipolar intracardiac reference signals). Non-contact methods may be implemented to simultaneously obtain a large amount of cardiac electrical information. For example, a catheter type having a distal end portion may be provided with a series of sensor electrodes distributed over its surface and connected to insulated conductors for connection to signal sensing and processing means. The size and shape of the end portion may be such that the electrodes are spaced apart from the wall of the heart chamber. The intracardiac potential fields may be detected during one heartbeat. According to one embodiment, the sensor electrodes may be distributed on a series of circumferences located in spaced apart planes. These planes may be perpendicular to the long axis of the catheter end portion. At least two further electrodes may be disposed adjacent to both ends of the long axis of the end portion. As a more specific example, the catheter may include four circumferences with eight electrodes equiangularly spaced apart on each circumference. Thus, in this particular implementation, the catheter may include at least 34 electrodes (32 circumferential electrodes and 2 end electrodes). As another more specific example, the catheter may include 5 soft flexible branches, 8 radial splines, or other multi-spline catheters such as a turner-type with parallel splines (e.g., any of which may have a total of 42 electrodes).

[0046] As an example of electrical or cardiac mapping, electrophysiological cardiac mapping systems and techniques based on non-contact and non-expandable multi-electrode catheters (e.g., catheter 14) may be implemented. An ECG may be acquired using one or more catheters 14 with multiple electrodes (e.g., 42-122 electrodes, etc.). This implementation allows knowledge of the relative geometry of the probe and endocardium to be obtained by an independent imaging modality, such as transesophageal echocardiography. After independent imaging, cardiac surface potentials may be measured using non-contact electrodes, and a map may be constructed from the surface potentials (e.g., possibly using a bipolar intracardiac reference signal). The technique may include (after an independent imaging step): (a) measuring electrical potentials using a number of electrodes disposed on a probe placed within the heart 12; (b) determining a geometric relationship between the probe surface and the endocardial surface and / or other references; (c) generating a matrix of coefficients representing the geometric relationship between the probe surface and the endocardial surface; and (d) determining the endocardial electrical potentials based on the electrode potentials and the matrix of coefficients.

[0047] As another example of electrical or cardiac mapping, techniques and devices may be implemented for mapping the electrical potential distribution of a heart chamber. An intracardiac multi-electrode mapping catheter assembly is inserted into heart 12. The mapping catheter (e.g., catheter 14) assembly preferably includes a multi-electrode array or companion reference catheter having one or more integral reference electrodes (e.g., one or more electrodes 26).

[0048] According to one or more embodiments, the electrodes may be deployed in a generally spherical array that may be spatially referenced to points on the endocardial surface by a reference electrode or by a reference catheter that is brought into contact with the endocardial surface. A preferred electrode array catheter may have a large number of individual electrode sites (e.g., at least 24). It should be noted that the exemplary technique may be implemented by knowing the location of each of the electrode sites on the array and by knowing the geometry of the heart. These locations are preferably determined by impedance plethysmography.

[0049] From an electrical or cardiac mapping perspective, and according to another embodiment, the catheter 14 is a cardiac mapping catheter assembly that includes an electrode array that defines multiple electrode sites. The cardiac mapping catheter assembly also includes a lumen for receiving a reference catheter having a distal tip electrode assembly that is used to probe the heart wall. The cardiac mapping catheter assembly may include a braid of insulated wires (e.g., having 24-64 wires in the braid), each of which may be used to form an electrode site. The cardiac mapping catheter assembly is readily positionable within the heart 12 for use in obtaining electrical activity information from a first set of non-contact electrode sites and / or a second set of contact electrode sites.

[0050] Additionally, according to another embodiment, a catheter 14 capable of mapping electrophysiological activity within the heart includes a distal tip adapted to deliver stimulation pulses for pacing the heart or an ablation electrode for ablating tissue in contact with the tip, and may further include at least a pair of orthogonal electrodes for generating a differential signal indicative of local cardiac electrical activity in the vicinity of the orthogonal electrodes.

[0051] As described herein, system 10 is utilized to detect, diagnose, and / or treat cardiac conditions. In an exemplary operation, system 10 performs a process for measuring electrophysiological data within a heart chamber. The process includes, in part, positioning a set of active and passive electrodes within heart 12, supplying current to the active electrodes, thereby generating an electric field within the heart chamber, and measuring the electric field at the passive electrode sites. The passive electrodes are included in an array disposed on an inflatable balloon of a balloon catheter. In a preferred embodiment, the array is said to have between 60 and 64 electrodes.

[0052] As another exemplary operation, cardiac mapping is performed by the system 10 using one or more ultrasound transducers. The ultrasound transducers may be inserted into the patient's heart 12 and may collect multiple ultrasound slices (e.g., two-dimensional or three-dimensional slices) at various positions and orientations within the heart 12. The position and orientation of a given ultrasound transducer is known, and the collected ultrasound slices are stored so that they may be displayed at a later time. One or more ultrasound slices corresponding to the position of a catheter 14 (e.g., a treatment catheter) are later displayed, with the catheter 14 overlaid on the one or more ultrasound slices.

[0053] Considering the system 10, it is noted that cardiac arrhythmias, including atrial arrhythmias, can be of the multiwavelet reentrant type, characterized by multiple asynchronous loops of electrical impulses that scatter and often self-propagate around the atria (e.g., another example of IC ECG data). Alternatively or in addition to the multiwavelet reentrant type, cardiac arrhythmias can also have focal excitation sources, such as when isolated regions of atrial tissue are excited autonomously in a rapid and repetitive manner (e.g., another example of IC ECG data). Ventricular tachycardia (V-tach or VT) is a tachycardial or fast, heart rhythm that originates from one of the ventricles. It is a potentially fatal arrhythmia, as it can lead to ventricular fibrillation and sudden death.

[0054] For example, aFib occurs when the normal electrical impulses generated by the sinoatrial node (e.g., another example of IC ECG data) are overwhelmed by chaotic electrical impulses (e.g., signal interference) originating in the atrial veins and PVs, causing irregular impulses to be conducted to the ventricles. The result is an irregular heartbeat that may persist for minutes to weeks or even years. In many cases, aFib is a chronic condition that often carries a small increase in the risk of death from stroke. The treatment approach for aFib is medication to reduce the heart rate or restore the heart rhythm to normal. Furthermore, patients with aFib are often given anticoagulants to protect against the risk of stroke. The use of such anticoagulants carries its own risks of internal bleeding. In some patients, medication is not sufficient and the patient's aFib is determined to be drug refractory, i.e., untreatable by standard pharmacological interventions. Synchronized cardioversion may also be used to convert aFib to a normal heart rhythm. Alternatively, patients with aFib may be treated with catheter ablation.

[0055] Catheter ablation-based therapy may include mapping electrical properties of cardiac tissue, particularly the endocardium and cardiac volume, and selectively ablating cardiac tissue by application of energy. Electrical or cardiac mapping (e.g., performed by any of the electrophysiological cardiac mapping systems and techniques described herein) includes creating potential maps (e.g., voltage maps) of wave propagation along cardiac tissue, or maps of arrival times (e.g., LAT maps) to points located within various tissues. Electrical or cardiac mapping (e.g., cardiac maps) may be used to detect localized cardiac tissue dysfunction. Ablation, such as cardiac mapping-based ablation, may stop or change the propagation of unwanted electrical signals from one part of the heart 12 to another.

[0056] Ablation techniques disrupt unwanted electrical pathways by creating non-conductive lesions. Various energy delivery modalities have been disclosed to create lesions, including the use of microwave, laser, and more generally, radio frequency energy to create a conduction block along the cardiac tissue wall. Another example of an energy delivery technique is irreversible electroporation (IRE), which provides a high electric field that damages cell membranes. In a two-stage procedure (mapping followed by ablation), electrical activity at points within the heart 12 is typically sensed and measured by advancing a catheter 14 containing one or more electrical sensors (e.g., electrodes 26) into the heart 12 and acquiring / capturing data (e.g., generally as biometric data or specifically as ECG data) at multiple points. The ECG data is then used to select a target region of the endocardium where ablation will be performed.

[0057] Cardiac ablations and other cardiac electrophysiology procedures are becoming increasingly complex as physicians treat challenging conditions such as atrial fibrillation and ventricular tachycardia. Treatment of refractory arrhythmias may now rely on the use of 3D mapping systems to reconstruct the anatomy of the targeted heart chamber. In this regard, the mapping engine 101 used by the system 10 herein manipulates and evaluates biometric data, generally, or ECG data, specifically, to generate improved tissue data that allows for more accurate diagnosis, images, scans, and / or maps for treating abnormal heart rhythms or arrhythmias. For example, cardiologists rely on software such as the Complex Fractionated Atrial Electrograms (CFAE) module of the CARTO® 3 3D mapping system, manufactured by Biosense Webster, Inc. (Diamond Bar, Calif.), to generate and analyze ECG data. The mapping engine 101 of the system 10 enhances this software to generate and analyze improved biometric data, which further provides multiple pieces of information regarding the electrophysiological properties of the heart 12 (including scar tissue) that are representative of the cardiac substrate (anatomical and functional) of the aFib.

[0058] Thus, the system 10 implements a 3D mapping system, such as the CARTO® 3 3D mapping system, to locate potential arrhythmogenic substrates of cardiomyopathies in terms of abnormal ECG detection. These cardiac disease-related substrates have been associated with the presence of delayed ECG and fragmentation of the endocardial and / or epicardial layers of the ventricular chambers (right and left). For example, areas of low or medium voltage may indicate ECG fragmentation and delayed activity. Furthermore, areas of low or medium voltage during sinus rhythm may correspond to critical isthmuses identified in sustained coherent ventricular arrhythmias (e.g., in non-permissive ventricular tachycardia, as well as in the atria). In general, abnormal tissue is characterized by low voltage ECG. However, early clinical experience with endocardial-epicardial mapping has shown that areas of low voltage are not always present as the only arrhythmogenic mechanism in such patients. Indeed, areas of low or medium voltage may show ECG fragmentation and delayed activity during sinus rhythm, which corresponds to critical isthmus identified during sustained coherent ventricular arrhythmias (e.g., only applicable to non-permissive ventricular tachycardia). Moreover, in many cases, ECG fragmentation and delayed activity are observed in areas showing normal or near-normal voltage amplitudes (>1-1.5 mV). The latter areas may be evaluated according to voltage amplitudes, but are not considered normal according to the intracardiac signal and therefore represent true arrhythmogenic substrates. 3D mapping may identify the location of arrhythmogenic substrates on the endocardial and / or epicardial layers of the right / left ventricle, whose distribution may vary depending on the evolution of the primary disease.

[0059] As another exemplary operation, cardiac mapping may be performed by the system 10 using one or more multi-electrode catheters (e.g., catheter 14). The multi-electrode catheters are used to stimulate and map electrical activity within the heart 12 and to ablate sites of abnormal electrical activity. In use, the multi-electrode catheter is inserted into a major vein or artery, e.g., the femoral vein, and then guided into a chamber of the heart 12 of interest. A typical ablation procedure involves inserting the catheter 14 having at least one electrode 26 at its distal end into the heart chamber. A reference electrode is provided by taping to the patient's skin or by a second catheter placed in or near the heart, or by selecting from one or the other electrodes 26 of the catheter 14. Radio frequency (RF) current is applied to the tip electrode 26 of the ablation catheter 14, and current flows through the medium (i.e., blood and tissue) surrounding the tip electrode toward the reference electrode. The current distribution depends on the amount of electrode surface in contact with tissue compared to blood, which is more conductive than tissue. Heating of the tissue occurs due to its electrical resistance. If the tissue heats up sufficiently, cell destruction is induced in the cardiac tissue, resulting in the formation of electrically non-conductive lesions in the cardiac tissue. This process also heats the tip electrode 26 by conduction from the heated tissue to the electrode itself. If the temperature of the electrode becomes high enough, possibly exceeding 60° C., a thin, transparent film of dehydrated blood proteins may form on the surface of the electrode 26. As the temperature continues to increase, this dehydrated layer may gradually thicken, causing blood to coagulate on the electrode surface. Because dehydrated biological material has a higher electrical resistance than endocardial tissue, the impedance to the flow of electrical energy into the tissue also increases. If the impedance becomes high enough, an impedance rise occurs and the catheter 14 must be removed from the body and the tip electrode 26 must be cleaned.

[0060] 2, a diagram of a system 200 that may implement one or more features of the subject matter of the present disclosure, according to one or more exemplary embodiments, is shown. The system 200 includes an apparatus 204, a local computing device 206, a remote computing system 208, a first network 210, and a second network 211 for a patient 202 (e.g., an example of the patient 23 of FIG. 1). Additionally, the apparatus 204 includes a biometric sensor 221 (e.g., an example of the catheter 14 of FIG. 1), a processor 222, a user input (UI) sensor 223, a memory 224, and a transceiver 225. It should be noted that the mapping engine 101 of FIG. 1 is reused in FIG. 2 for ease of explanation and brevity.

[0061] According to one embodiment, the device 204 is an example of the system 100 of FIG. 1, where the device 204 may include both components internal to the patient 202 and components external to the patient 202. According to another embodiment, the device 204 is an external device to the patient 202, including an attachable patch (e.g., attached to the patient's skin). According to another embodiment, the device 204 may be internal to the body of the patient 202 (e.g., subcutaneously implantable), where the device 204 may be inserted into the body of the patient 202 by any applicable method, including oral infusion, surgical insertion via a vein or artery, endoscopic surgery, or laparoscopic surgery. According to one embodiment, although a single device 204 is shown in FIG. 2, an exemplary system may include multiple devices.

[0062] Thus, the apparatus 204, the local computing device 206, and / or the remote computing system 208 may be programmed to execute computer instructions for the mapping engine 101. As one example, the memory 223 stores these instructions for the processor 222 to execute such that the apparatus 204 may receive and process biometric data via the biometric sensor 201. In this manner, the processor 222 and the memory 223 are representative of the processor and memory of the local computing device 206 and / or the remote computing system 208.

[0063] The apparatus 204, the local computing device 206, and / or the remote computing system 208 may be any combination of software and / or hardware that individually or collectively stores, executes, and implements the mapping engine 101 and its functions. Furthermore, the apparatus 204, the local computing device 206, and / or the remote computing system 208 may be an electronic computer framework that includes and / or uses any number and combination of computing devices and networks utilizing various communication technologies, as described herein. The apparatus 204, the local computing device 206, and / or the remote computing system 208 are easily scalable, extensible, and modular, capable of being tailored for different services, or reconfigured with some functions independent of others.

[0064] Networks 210 and 211 may be wired networks, wireless networks, or may include one or more wired and wireless networks. According to one embodiment, network 210 is an example of a short-range network (e.g., a Local Area Network (LAN) or a Personal Area Network (PAN)). Information may be transmitted between apparatus 204 and local computing device 206 over short-range network 210 using any one of a variety of short-range wireless communication protocols, such as Bluetooth, Wi-Fi, Zigbee, Z-Wave, Near Field Communication (NFC), Ultraband, Zigbee, or infrared (IR). Further, network 211 is an example of one or more of an intranet, a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a direct connection or series of connections, a cellular telephone network, or any other network or medium capable of facilitating communication between local computing device 206 and remote computing system 208. Information may be transmitted over network 211 using any one of a variety of long-range wireless communication protocols (e.g., TCP / IP, HTTP, 3G, 4G / LTE, or 5G / New Radio). It is noted that the wired connections of networks 210 and 211 may be implemented using Ethernet, Universal Serial Bus (USB), RJ-11, or any other wired connection, and the wireless connections may be implemented using Wi-Fi, WiMAX, and Bluetooth, infrared, cellular networks, satellite communications, or any other wireless connection methodology.

[0065] In operation, the device 204 may continuously or periodically acquire, monitor, store, process, and communicate biometric data associated with the patient 202 via the network 210. Additionally, the device 204, the local computing device 206, and / or the remote computing system 208 communicate via the networks 210 and 211 (e.g., the local computing device 206 may be configured as a gateway between the device 204 and the remote computing system 208). For example, the device 204 may be an embodiment of the system 100 of FIG. 1 configured to communicate with the local computing device 206 via the network 210. The local computing device 206 may be, for example, a fixed / standalone device, a base station, a desktop / laptop computer, a smartphone, a smartwatch, a tablet, or any other device configured to communicate with other devices via the networks 211 and 210. A remote computing system 208, implemented as a physical server on or connected to the network 211, or as a virtual server within a public cloud computing provider of the network 211 (e.g., Amazon Web Services (AWS)®), may be configured to communicate with the local computing device 206 over the network 211. Thus, biometric data related to the patient 202 may be communicated throughout the system 200.

[0066] The elements of the device 204 are now described. The biometric sensor 221 may include, for example, one or more transducers configured to convert one or more environmental conditions into electrical signals so that different types of biometric data may be observed / obtained / obtained. For example, the biometric sensor 221 may include one or more of an electrode (e.g., electrodes 18 and 26 of FIG. 1), a temperature sensor (e.g., a thermocouple), a blood pressure sensor, a blood glucose sensor, a blood oxygen sensor, a pH sensor, an accelerometer, and a microphone.

[0067] In executing the mapping engine 101, the processor 222 may be configured to receive, process, and manage biometric data acquired by the biometric sensor 221, and communicate the biometric data to the memory 224 for storage and / or across the network 210 via the transceiver 225. Biometric data from one or more other devices 204 may also be received by the processor 222 via the transceiver 225. As described in more detail below, the processor 222 may also be configured to selectively respond to different tapping patterns (e.g., single tap or double tap) received from the UI sensor 223 such that different tasks of the patch (e.g., acquiring, storing, or transmitting data) are initiated based on the detected pattern. In some embodiments, the processor 222 may generate audible feedback regarding detection of the gesture.

[0068] The UI sensor 223 includes a piezoelectric or capacitive sensor configured to receive user input, such as, for example, a tap or touch. For example, the UI sensor 223 may be controlled to perform capacitive coupling in response to the patient 202 tapping or touching the surface of the device 204. Gesture recognition may be performed by any one of a variety of capacitive types, such as resistive capacitive, surface capacitive, projected capacitive, surface ultrasonic, piezoelectric, and infrared touch. The capacitive sensor may be positioned over a small area or length of the surface such that a tap or touch on the surface activates the monitoring device.

[0069] The memory 224 is any non-transitory, tangible medium, such as magnetic, optical, or electronic memory (e.g., any suitable volatile and / or non-volatile memory, such as a random access memory or a hard disk drive). The memory 224 stores computer instructions that are executed by the processor 222.

[0070] The transceiver 225 may include a separate transmitter and a separate receiver, or, alternatively, the transceiver 225 may include a transmitter and receiver integrated into a single device.

[0071] During operation, the device 204 utilizing the mapping engine 101 observes / acquires biometric data of the patient 202 via the biometric sensor 221, stores the biometric data in memory, and shares this biometric data throughout the system 200 via the transceiver 225. The mapping engine 101 may then utilize models, neural networks, machine learning, and / or artificial intelligence to provide intracardiac unipolar far-field reduction or cancellation using a multiple electrode catheter.

[0072] Referring now to FIG. 3A, a method 300 (e.g., performed by the mapping engine 101 of FIG. 1 and / or FIG. 2) is shown, according to one or more exemplary embodiments. The method 300 is one example of using a multiple electrode catheter (e.g., catheter 14) to provide intracardiac unipolar far-field reduction or cancellation. The method 300, in one example, performs atrial local activation detection (regardless of late local activation and annotation) as well as ventricular detection within the QRS. It is noted that using a multi-electrode catheter provides a spatial advantage, and the mapping engine 101 analyzes each electrode 18 and 26 and each corresponding intracardiac voltage signal based on surrounding spatial electrode information. In this regard, the mapping engine 101 reduces or eliminates far-field information from all electrodes while significantly emphasizing pure local unipolar signals. In addition to accurate activity annotation, the mapping engine 101 also provides scar detection based on local activation amplitude, since the mapping engine 101 outperforms known bipolar sensitivity to the disadvantages of spatial electrode orientation and distance.

[0073] The method 300 begins at block 310 where the mapping engine 101 performs spatial electrode signal analysis for each of a plurality of electrodes. The spatial electrode signal analysis takes into account far-field characteristics that depend on spatial location to determine common signal components that provide electrode weighting information and may be an estimate of the far-field information.

[0074] At least one particular electrode is selected for spatial electrode signal analysis. For each particular electrode, all other electrode information is considered and correlated with respect to that particular electrode. According to one or more embodiments, the spatial electrode signal analysis is repeated with each electrode being a particular electrode. According to one or more embodiments, for each multi-electrode catheter stable site sampling time window, all electrodes are analyzed one by one. Furthermore, for each particular electrode, all other electrode information is considered as further described herein.

[0075] According to one or more embodiments of spatial electrode signal analysis, electrodes surrounding a particular electrode are weighted inversely proportional to their distance from the particular electrode. For example, the catheter 14 includes three (3) electrodes in a row separated by a distance such as two (2) millimeters. The mapping engine 101 may analyze the first electrode and assign it a weighting function. An exemplary weighting function is 1-0.25 * The weighting vector includes w11, w21, w31, where D is the distance of another electrode from the first electrode. The mapping engine 101 then generates a weighting vector of [w11, w21, w31]=[1, 0.5, 0] and analyzes the first electrode based on multiplying the first electrode by w11=1, the second electrode by w21=0.5, and the third electrode by w31=0.

[0076] As the distance from the reference electrode for a particular electrode increases, the weight decreases (e.g., the further away, the smaller the weight). According to one or more embodiments, electrodes beyond a certain distance may be excluded (note that the distance is catheter dependent, and in some cases, 5 millimeters). The mapping engine 101 then analyzes the electrode weighting information using one or more algorithms (e.g., a mathematical multiple signal decomposition operation). Examples of the one or more algorithms include, but are not limited to, singular value decomposition (SVD), principal component analysis (PCA), and / or other matrix decompositions or factorizations. SCV may be a generalization of eigendecomposition with an orthonormal eigenbasis of a square normal matrix, factorizing a real or complex matrix (e.g., the electrode weight matrix W). By analyzing the electrode weighting information, the mapping engine 101 estimates the common signal component hidden within all the signals. The common signal component is estimated by the mapping engine 101 by taking the largest decomposed component / signal. Other examples of the common signal component include the maximum common signal component and far-field information estimation.

[0077] In block 320, the mapping engine 101 scales the common signal components (identified by the mapping engine 101 and / or spatial electrode signal analysis). According to one or more embodiments, the mapping engine 101 automatically scales the common signal components by applying an inverse decomposition formula using only the common signal components. The far-field signal is then estimated by taking the scaled common signal.

[0078] According to one or more embodiments, the mapping engine 101 scales the common signal components to best fit the analyzed electrode signals. For example, as shown in graph 325 of FIG. 3B, the scaling is shown by a scalar multiplication. Graph 325 includes a sample index x-axis and a milli-voltage y-axis. The graph shows the original signal 326, the common signal 327, the scaled common signal 328 (i.e., far field), and the residual local signal 329 (i.e., near field). Furthermore, the residual signal is determined; i.e., once scaled and fitted, the common signal components are subtracted leaving only the residual signal. The residual signal estimates pure local information. The local information may include, but is not limited to, local field signals within the electrical activity detected by the electrodes.

[0079] In block 340, the mapping engine 101 analyzes the pure local information to identify / generate / provide local unipolar activation. Local unipolar activation may include complex cases of erasable activation patterns. According to one or more embodiments, for LAT mapping, the mapping engine 101 utilizes the derivative of the minimal pure local information to detect the activation moment within the cardiac cycle. According to one or more embodiments, for voltage (V) mapping, the mapping engine 101 takes the peak to peak of the local activation within the cardiac cycle. For both maps, the mapping engine 101 averages the final local results over several cardiac cycles and adds spatial smoothing by combining all the different spatial local results.

[0080] At block 350, the mapping engine 101 displays the results. According to one or more embodiments, the mapping engine provides the local unipolar activations (e.g., all local activation patterns for each electrode) on a constant zero (0) background of the user interface of the display 165. The visual presentation by the display 165 of the local activation patterns may include a long duration for consistency analysis.

[0081] 4, a method 400 (e.g., performed by mapping engine 101 of FIG. 1 and / or FIG. 2) is shown in accordance with one or more exemplary embodiments. Method 400 is one example of estimating far-field information, as described with respect to block 310 of FIG. 3A.

[0082] The method 400 begins at block 410, where the mapping engine 101 receives an electrode signal s from a plurality of electrodes 18 and 26. According to one or more embodiments, the mapping engine 101 receives an electrode signal s from an electrode 26 of the catheter 14.

[0083] In block 420, the mapping engine 101 determines a reference electrode q of the plurality of electrodes 18 and 26. The reference electrode q may be selected from any of the electrodes 26 of the catheter 14. Further, more than one reference electrode q may be determined, performing the method 400 for each reference electrode q.

[0084] In block 430, the mapping engine 101 determines weights according to an electrode weight matrix W based on the reference electrode q. The electrode weight matrix W may be based on the structure of the catheter 14. Note that the electrode weight matrix W stores and manages weights of electrodes surrounding a particular electrode in inverse proportion to the distance from the particular electrode. Examples of high density mapping catheters may include, but are not limited to, the OCTARAY™ mapping catheter by Biosense Webster® and / or the PENTARAY® NAV ECO high density mapping catheter. FIGS. 5-6 show an exemplary catheter 14.

[0085] FIG. 5 illustrates a catheter 500 according to one or more embodiments. The catheter 500 may be a catheter having multiple electrodes 534, for example, at least twenty (20) electrodes. As shown, the multiple electrodes may include exactly forty-eight (48) electrodes located across or distributed on multiple spines 37. Using such a number of electrodes 534 spread over a large area by spines 537 allows for the capture of a large amount of electrical activity over a large area at one time. According to one or more embodiments, the multiple spines 537 may travel through a sheath in a collapsed state and be expanded once within the patient 23 of FIG. 1. Electrical activity at any focal point within the heart 12 may be measured, typically by advancing the catheter 500, contacting cardiac tissue with the catheter 500, and acquiring data related to electrical activity at that point. One or more of the electrodes 534 may be selected as a reference electrode q.

[0086] For example, electrode 560 is designated as the reference electrode q. Also, the weight decreases as one moves away from electrode 560. In this manner, electrode 562 will have a greater weight than electrode 564 because electrode 562 is closer to electrode 560 than electrode 564. Furthermore, electrode 566 will have a lesser weight than electrode 562 because electrode 566 is farther from electrode 560 than electrode 562. Note that the distance between each of the electrodes 534 may be measured with respect to three-dimensional space (i.e., using x, y, z coordinates). Then, electrodes 564 and 566 may or may not have the same weight.

[0087] FIG. 6 illustrates a catheter 500 according to one or more embodiments. The catheter 600 is a catheter having multiple electrodes 605 that provide one or more physiological signals. For example, the electrodes 605 can be at least three (3) in number arranged in any combination of groups. As shown in FIG. 6, a group of three electrodes 612, 614, and 612 is on the same spline 620 as a group of two electrodes 622 and 624. According to one or more embodiments, the catheter 600 includes at least five (5) and possibly eight (8) or more arms (as shown in FIG. 6), and the electrodes 205 can include twenty (20) or forty-eight (48) monopolar electrodes positioned one or two millimeters apart from one another, in pairs or combinations (e.g., higher density provides better performance).

[0088] Returning to method 400, in block 440, the mapping engine 101 determines a dot product of weights according to the electrode weight matrix W and the electrode signal s.

[0089] In block 450, the mapping engine 101 processes the dot products to generate orthogonal signals using one or more algorithms. In general, the one or more algorithms of the mapping engine 100 include a mathematical multi-signal decomposition operation. Examples of the one or more algorithms include, but are not limited to, singular value decomposition (SVD), principal component analysis (PCA), and / or other matrix decompositions or factorizations. SCV may be a generalization of eigendecomposition that factorizes a real or complex matrix (e.g., the electrode weight matrix W) with an orthonormal eigenbasis of square normal matrices.

[0090] In block 460, the mapping engine 101 selects the maximum signal of the orthogonal signals. In block 455, the mapping engine 101 performs a correlation of the maximum signal with the signal of the reference electrode q to provide a projection value. In block 470, the mapping engine 101 takes a tensor product of the maximum signal and the projection value to provide a far-field estimate (e.g., a common signal component of electrical activity estimated by spatial electrode signal analysis).

[0091] 7, a method 700 (e.g., performed by mapping engine 101 of FIG. 1 and / or FIG. 2) is shown in accordance with one or more exemplary embodiments. Method 700 is one example of cardiac cycle specific electrode signal analysis, as described with respect to block 310 of FIG. 3A.

[0092] At block 708, the mapping engine 101 receives a first input. The first input includes a global PxP weighting matrix. At block 709, the mapping engine 101 receives a second input. The second input includes a particular electrode index K.

[0093] At block 710, the mapping engine 101 performs a first peaking operation. The first peaking operation includes peaking on a matrix row vector K. At block 715, the mapping engine 101 converts the global PxP weighting matrix into a diagonal matrix. According to one or more embodiments, the mapping engine 101 outputs a particular PxP weighting matrix for electrode K, where Wkk=1.

[0094] At block 718, the mapping engine 101 receives a third input. The third input includes N time samples with P electrode information in an NxP matrix. At block 720, the mapping engine 101 performs a matrix multiplication. The matrix multiplication includes a multiplication between an NxP matrix and a diagonal matrix, outputting a weighted information NxP matrix. At block 725, the mapping engine 101 performs an orthogonal decomposition of the weighted information NxP matrix to generate an orthogonal component NxP matrix.

[0095] At block 730, the mapping engine 101 performs a second peaking operation. The second peaking operation examines the orthogonal component NxP matrix to find the maximum component. The largest component is the common component.

[0096] At block 735, the mapping engine 101 performs orthogonal combination of the common components. The mapping engine 101 may utilize the orthogonal component NxP matrix from the orthogonal decomposition of block 725. The mapping engine 101 provides the common components based on the constructed NxP matrix. At block 740, the mapping engine 101 selects a column K. At block 745, the mapping engine 101 provides an output. The output includes an estimated far-field signal for electrode K.

[0097] In block 755, the mapping engine 101 also selects column K to determine original information for electrode K. In block 760, the mapping engine 101 performs far-field subtraction on the original information using the output in block 745 to determine residual information. In block 765, the mapping engine 101 provides an output. The output includes estimated local information for each electrode.

[0098] According to one or more embodiments herein or any of the method embodiments herein, a method is provided. The method includes receiving, by a mapping engine executed by one or more processors, electrical activity from a plurality of electrodes of a catheter. The method includes performing, by the mapping engine, a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes. The method includes scaling, by the mapping engine, common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

[0099] According to one or more embodiments herein or any of the method embodiments herein, the spatial electrode signals provide electrode weighting information, taking into account far-field characteristics that are spatial position dependent.

[0100] According to any of the method embodiments herein, the residual signal estimates purely local information.

[0101] According to any of the embodiments of the methods herein, the catheter includes a high density mapping catheter.

[0102] According to any of the embodiments of the methods herein, the mapping engine analyzes the residual signal to identify local unipolar activation.

[0103] According to any of the method embodiments herein, the mapping engine displays results including local unipolar activation.

[0104] According to any of the embodiments of the methods herein, the mapping engine determines a reference electrode of the plurality of electrodes.

[0105] According to any of the embodiments of the methods herein, the mapping engine determines a weight for each of the plurality of electrodes according to an electrode weight matrix that is based on a reference electrode.

[0106] According to any of the embodiments of the methods herein, the mapping engine determines a dot product of the weights and the electrical activity.

[0107] According to any of the method embodiments herein, the mapping engine uses one or more algorithms to process the dot products to generate orthogonal signals.

[0108] According to any of the method embodiments herein, the one or more algorithms include singular value decomposition.

[0109] According to any of the method embodiments herein, the mapping engine selects the maximum signal of the orthogonal signals.

[0110] According to any of the method embodiments herein, the mapping engine performs a correlation between the reference electrode signal and the maximum signal to provide a projection value.

[0111] According to any of the method embodiments herein, the mapping engine determines a tensor product of the maximum signal and the projection value to provide the far-field estimate as the common signal component.

[0112] According to one or more embodiments, a system is provided. The system includes a memory that stores mapping engine software. The system includes one or more processors that execute the software to cause the mapping engine to receive electrical activity from a plurality of electrodes of a catheter, perform a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes, and scale common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

[0113] According to any of the system embodiments herein, the residual signal estimates purely local information and the catheter comprises a high density mapping catheter.

[0114] According to any of the embodiments of the system herein, the mapping engine determines a reference electrode of the plurality of electrodes and determines a weight for each of the plurality of electrodes according to an electrode weight matrix.

[0115] According to any of the system embodiments herein, ma spatial electrode signal analysis provides electrode weighting information, taking into account far-field characteristics that are spatial location dependent.

[0116] According to any of the embodiments of the system herein, the mapping engine analyzes the residual signal to identify local unipolar activation.

[0117] According to any of the system embodiments herein, the mapping engine displays results including local unipolar activation.

[0118] The flow diagrams and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flow diagrams or block diagrams may represent a module, segment, or portion of instructions that includes one or more executable instructions for implementing the depicted logical function. In some alternative implementations, the functions shown in the blocks may occur in an order other than that shown in the figures. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block of the block diagrams and / or flow diagrams, and combinations of blocks in the block diagrams and / or flow diagrams, may be implemented by a dedicated hardware-based system that performs the specified function or operation, or may operate or execute a combination of dedicated hardware and computer instructions.

[0119] Although the features and elements are described above in a particular combination, those skilled in the art will understand that each of the features or elements may be used alone or in combination with other features and elements. It should be noted that the methods described herein may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution on a computer or processor. A computer-readable medium as used herein should not be construed as being a signal that is itself ephemeral, such as an electric wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a wave guide or other transmission medium (e.g., a light pulse passing through a fiber optic cable), or an electrical signal transmitted through a flow line.

[0120] Examples of computer-readable media include electrical signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, optical media such as Compact Disks (CDs) and Digital Versatile Disks (DVDs), Random Access Memory (RAM), Read-Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM or Flash memory), Static Random Access Memory (SRAM), and memory sticks. The processor may be used with software to implement a radio frequency transceiver for use with a terminal, a base station, or any host computer.

[0121] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly indicates otherwise. It is further to be understood that the terms "comprise" and / or "comprising," as used herein, indicate the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or other features, integers, steps, operations, elements, components, and / or groups thereof.

[0122] The description of different embodiments herein is presented for illustrative purposes, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used in this specification are selected to best explain the principles, practical applications, or technical improvements of the embodiments compared to the art found in the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

[0123] [Embodiment] (1) A method comprising: receiving, by a mapping engine executed by one or more processors, electrical activity from a plurality of electrodes of the catheter; performing, by the mapping engine, a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes; scaling, by the mapping engine, common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal. (2) The method of embodiment 1, wherein the spatial electrode signal analysis provides electrode weighting information taking into account far-field characteristics that are spatial position dependent. (3) The method of claim 1, wherein the residual signal estimates pure local information. (4) The method of embodiment 1, wherein the catheter comprises a high-density mapping catheter. (5) The method of embodiment 1, wherein the mapping engine analyzes the residual signal to identify local unipolar activation.

[0124] (6) The method of embodiment 5, wherein the mapping engine displays results including the local unipolar activation. (7) The method of embodiment 1, wherein the mapping engine determines a reference electrode among the plurality of electrodes. (8) The method of embodiment 7, wherein the mapping engine determines a weight for each of the plurality of electrodes according to an electrode weight matrix based on the reference electrode. (9) The method of embodiment 8, wherein the mapping engine determines a dot product of the weights and the electrical activity. (10) The method of embodiment 9, wherein the mapping engine processes the dot product using one or more algorithms to generate an orthogonal signal.

[0125] (11) The method of embodiment 10, wherein the one or more algorithms include singular value decomposition. (12) The method of embodiment 10, wherein the mapping engine selects a maximum signal among the orthogonal signals. (13) The method of embodiment 12, wherein the mapping engine performs a correlation between the reference electrode signal and the maximum signal to provide a projection value. (14) The method of embodiment 13, wherein the mapping engine determines a tensor product of the maximum signal and the projection value to provide a far-field estimate as the common signal component. (15) A system comprising: a memory for storing mapping engine software; one or more processors, the one or more processors executing the software to cause the mapping engine to: receiving electrical activity from a plurality of electrodes of the catheter; performing a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes; and one or more processors configured to: scale common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

[0126] (16) The system of embodiment 15, wherein the residual signal estimates pure local information and the catheter comprises a high-density mapping catheter. (17) The system of embodiment 15, wherein the mapping engine determines a reference electrode among the plurality of electrodes and determines a weight for each of the plurality of electrodes according to an electrode weight matrix. (18) The system of embodiment 15, wherein the spatial electrode signal analysis provides electrode weighting information taking into account far-field characteristics that are spatial position dependent. (19) The system of embodiment 15, wherein the mapping engine analyzes the residual signal to identify local unipolar activation. (20) The system of embodiment 19, wherein the mapping engine displays results including the local unipolar activation.

Claims

1. 1. A system comprising: a memory for storing mapping engine software; one or more processors, the one or more processors executing the software to cause the mapping engine to: receiving electrical activity from a plurality of electrodes of the catheter; performing a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes; and one or more processors configured to: scale common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

2. The system of claim 1 , wherein the residual signal estimates pure local information, and the catheter comprises a high-density mapping catheter.

3. The system of claim 1 , wherein the mapping engine determines a reference electrode of the plurality of electrodes and determines a weight for each of the plurality of electrodes according to an electrode weight matrix.

4. The system of claim 1 , wherein the spatial electrode signal analysis takes into account far-field characteristics that are spatial position dependent to provide electrode weighting information.

5. The system of claim 1 , wherein the mapping engine analyzes the residual signal to identify local unipolar activation.

6. The system of claim 5 , wherein the mapping engine displays results including the local unipolar activation.

7. 1. A method comprising: receiving, by a mapping engine executed by one or more processors, electrical activity from a plurality of electrodes of the catheter; performing, by the mapping engine, a spatial electrode signal analysis of the electrical activity for each electrode of the plurality of electrodes; scaling, by the mapping engine, common signal components of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

8. The method of claim 7 , wherein the spatial electrode signal analysis takes into account far-field characteristics that are spatial position dependent to provide electrode weighting information.

9. The method of claim 7 , wherein the residual signal estimates pure local information.

10. The method of claim 7 , wherein the catheter comprises a high-density mapping catheter.

11. The method of claim 7 , wherein the mapping engine analyzes the residual signal to identify local unipolar activation.

12. The method of claim 11 , wherein the mapping engine displays results including the local unipolar activation.

13. The method of claim 7 , wherein the mapping engine determines a reference electrode of the plurality of electrodes.

14. The method of claim 13 , wherein the mapping engine determines a weight for each of the plurality of electrodes according to an electrode weight matrix that is based on the reference electrode.

15. The method of claim 14 , wherein the mapping engine determines a dot product of the weights and the electrical activity.

16. The method of claim 15 , wherein the mapping engine uses one or more algorithms to process the dot products to generate orthogonal signals.

17. The method of claim 16 , wherein the one or more algorithms include singular value decomposition.

18. The method of claim 16 , wherein the mapping engine selects a maximum one of the orthogonal signals.

19. The method of claim 18 , wherein the mapping engine performs a correlation between the reference electrode signal and the maximum signal to provide a projection value.

20. The method of claim 19 , wherein the mapping engine determines a tensor product of the maximum signal and the projection value to provide a far-field estimate as the common signal component.

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