CN118382394A

CN118382394A - Intracardiac monopolar far field cancellation using a multi-electrode catheter

Info

Publication number: CN118382394A
Application number: CN202280081835.7A
Authority: CN
Inventors: H·罗德里格斯
Original assignee: Biosense Webster Israel Ltd
Current assignee: Biosense Webster Israel Ltd
Priority date: 2021-12-13
Filing date: 2022-12-11
Publication date: 2024-07-23

Abstract

A method is implemented by a mapping engine executed by a processor. The method includes receiving electrical activity from an electrode of a catheter. The method includes performing spatial electrode signal analysis on the electrical activity of each electrode of the catheter. The method includes scaling the common signal component of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

Description

Intracardiac monopolar far field cancellation using a multi-electrode catheter

Incorporated by reference

The present application claims priority from U.S. provisional application No. 63/288,966 filed on 12 months 13 of 2021, which is incorporated herein by reference in its entirety.

Technical Field

The systems and methods herein relate generally to signal processing.

Background

Generally, conventional cardiac mapping is a computer processing operation that generates a three-dimensional map of the heart. The three-dimensional map may be used by a medical professional to determine the precise source location of the arrhythmia, or when performing a medical procedure, such as cardiac ablation, to treat atrial fibrillation (aFib).

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

A problem with conventional cardiac mapping is that the far-field signal masks or interferes with local field signals within the electrical activity. Furthermore, conventional computer processing operations are not suitable for addressing far field signals. For example, the computer processing operation assumes that all far field signals are the same on all electrodes of the catheter. 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.

Disclosure of Invention

According to one exemplary embodiment, a method is provided. The method is implemented 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 spatial electrode signal analysis on electrical activity of each of a plurality of electrodes. The method includes scaling the common signal component of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal. In accordance with one or more embodiments, the above-described exemplary method embodiments may be implemented as an apparatus, system, and/or computer program product.

In accordance with one or more embodiments, a system is provided. The system includes a memory storing software of the mapping engine. The system includes one or more processors. The one or more processors execute software to cause the mapping engine to receive electrical activity from the plurality of electrodes of the catheter; performing spatial electrode signal analysis on the electrical activity of each electrode of the plurality of electrodes; and scaling the common signal component of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal. In accordance with one or more embodiments, the above-described exemplary system embodiments may be implemented as an apparatus, method, and/or computer program product.

Drawings

A more detailed understanding of the following detailed description is provided in connection with the accompanying drawings in which like reference numerals refer to like elements and in which:

FIG. 1 shows a diagram of an example system that may implement one or more features of the presently disclosed subject matter in accordance with one or more embodiments;

FIG. 2 shows a diagram of a system in accordance with one or more embodiments;

FIG. 3A illustrates a method in accordance with one or more embodiments;

FIG. 3B illustrates a graph in accordance with one or more embodiments;

FIG. 4 illustrates a method in accordance with one or more embodiments;

FIG. 5 illustrates an exemplary catheter in accordance with one or more embodiments;

FIG. 6 illustrates an exemplary catheter in accordance with one or more embodiments; and

FIG. 7 illustrates a method in accordance with one or more embodiments.

Detailed Description

The systems and methods herein relate generally to signal processing. In accordance with one or more embodiments, the systems and methods herein use multiple electrode catheters to provide intracardiac monopolar far field reduction or elimination. As an example, the systems and methods herein are described with respect to a mapping engine.

The mapping engine may be implemented as processor executable code or software that must be rooted in the process operations performed by the medical device equipment as well as in the processing hardware of the medical device equipment. For ease of explanation, the mapping engine is described herein with respect to mapping a heart; however, any anatomical structure, body part, organ, or portion thereof may be the target for mapping by the mapping engine described herein. In accordance with one or more embodiments, the mapping engine omits the conventional cardiac mapping assumption that all far-field signals are the same on all electrodes. In contrast to conventional cardiac mapping, the mapping engine intelligently implements new assumptions that far-field signals are similar but not exactly the same. In turn, the mapping engine weights the electrodes in an inverse proportion to the distance to identify a common signal component across the electrodes. The common signal component is used by the mapping engine to accurately reduce or eliminate far field interference. Reducing or eliminating far field interference by the mapping engine produces cleaner near field signals for improved cardiac mapping.

One or more advantages, technical effects, and/or benefits of the mapping engine may include filtering far-field interference and estimating pure local activity from unipolar signals (e.g., particularly in the case of very complex mapping), which replace the need for bipolar signals that are known for their drawbacks (such as electrode distance and directional distortion). Thus, by specifically utilizing and transforming unipolar signals, the mapping engine doubles the number of electrodes analyzed to obtain or increase spatial behavior resolution. Additionally, in the case of late activation, the mapping engine may also remove the sustained aFib near-far field signal to enhance aFib target detection.

Fig. 1 is a diagram of an example system (e.g., medical device equipment and/or catheter-based electrophysiology mapping and ablation) shown as a system 10, wherein one or more features of the subject matter herein can be implemented in accordance with one or more embodiments. All or portions of the system 10 may be used to collect information (e.g., biometric data and/or training data sets) and/or to implement the mapping engine 101, as described herein. As shown, 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 in which the mapping engine 101 is stored). It is noted that each element and/or item of system 10 represents one or more of the element and/or item. The example of the system 10 shown in fig. 1 may be modified to implement the embodiments disclosed herein. The disclosed embodiments of the invention may be similarly applied using other system components and arrangements. In addition, the system 10 may include additional components, such as elements for sensing electrical activity and/or physiological signals, wired or wireless connectors, processing and display devices, and the like.

The system 10 includes a plurality of catheters 14 that are percutaneously inserted by a physician 24 into a chamber or vascular structure of the heart 12 through the vascular system of a patient 23. Typically, a delivery sheath catheter (which is one example of catheter 14) is inserted into the left atrium or right atrium near the desired location in heart 12. A plurality of catheters 14 may then be inserted into the delivery sheath catheter in order to reach the desired location. The plurality of 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 example catheter 14 configured for sensing IEGM is shown herein. The physician 24 brings the distal tip 28 of the catheter 14 into contact with the heart wall for sensing a target site in the heart 12. For ablation, the physician 24 would similarly bring the distal end of the ablation catheter to the target site for ablation.

The catheter 14 is an exemplary catheter comprising an electrode(s) 26 optionally distributed over a plurality of splines 22 at a distal tip 28 and configured to sense IEGM signals. In addition, catheter 14 may also include a sensor 29 embedded in or near distal tip 28 for tracking the location and orientation of distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based positioning sensor comprising three magnetic coils for sensing three-dimensional (3D) position and orientation.

The sensor 29 (e.g., a location or magnetic based sensor) may operate with a position pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predefined workspace. The real-time positioning of the distal tip 28 of the catheter 14 may be tracked based on the magnetic field generated with the position pad 25 and sensed by the sensor 29. Details of magnetic-based orientation sensing techniques are described in U.S. Pat. nos. 5,5391,199,443,489, 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.

The system 10 includes one or more electrode patches 38 positioned in contact with the skin of the patient 23 to establish a positional reference for impedance-based tracking of the position pad 25 and the electrode 26. For impedance-based tracking, current is directed toward the electrodes 26 and sensed at the patches 38 (e.g., electrode skin patches) so that the position of each electrode can be triangulated via the patches 38. Details of impedance-based position tracking techniques are described in U.S. patent nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, which are incorporated herein by reference.

The recorder 11 displays an electrogram 21 captured with electrodes 18 (e.g., body surface Electrocardiogram (ECG) electrodes) and IEGM captured with electrodes 26 of the catheter 14. Recorder 11 may include pacing capabilities for pacing the heart rhythm and/or may be electrically connected to a separate pacemaker.

The system 10 may include an ablation energy generator 50 adapted to conduct ablation energy to one or more of the electrodes 26 at the distal tip 28 of the catheter 14 configured for ablation. The energy generated by ablation energy generator 50 may include, but is not limited to, radio Frequency (RF) energy or Pulsed Field Ablation (PFA) energy, including monopolar or bipolar high voltage DC pulses that may be used to achieve irreversible electroporation (IRE), or a combination thereof.

The PIU30 is an interface configured to establish electrical communication between a catheter, electrophysiological equipment, a power source, and a workstation 55 for controlling operation of the system 10. The electrophysiology equipment of system 10 can include, for example, a plurality 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 PIU30 additionally includes processing power for enabling real-time calculation of the position of the catheter and for performing ECG calculations.

The workstation 55 includes a memory 62, a processor unit 61 having the memory 62 or a storage device with appropriate operating software loaded therein, and user interface capabilities, as further described herein. Workstation 55 may provide a number of functions, including optionally: (1) Three-dimensional (3D) modeling of endocardial anatomy and rendering of the model or anatomical map 20 for display on display device 27; (2) Displaying the activation sequence (or other data) compiled from the recorded electrogram 21 on a display device 27 with a representative visual marker or image superimposed on the rendered anatomic map 20; (3) Displaying real-time positions and orientations of a plurality of catheters within a heart chamber; and (5) displaying the site of interest (such as where ablation energy has been applied) on a display device 27. An article of commerce embodying elements of system 10 mayThe 3 system was purchased from Biosense Webster, inc.

The system 10 may be used to detect, diagnose, and/or treat cardiac conditions (e.g., using the mapping engine 101). Cardiac disorders such as cardiac arrhythmias are always common and dangerous medical conditions, particularly in elderly people. For example, the system 10 may be a surgical system (e.g., sold by Biosense WebsterA system) configured to obtain biometric data (e.g., anatomical measurements and electrical measurements of a patient organ such as heart 12, and as described herein) and perform a cardiac ablation procedure. More specifically, treatment of cardiac conditions such as arrhythmias generally requires obtaining detailed mapping of cardiac tissue, chambers, veins, arteries, and/or electrical pathways. For example, a prerequisite for successful performance of catheter ablation (as described herein) is that the cause of the arrhythmia is accurately located in the chamber of the heart 12. Such localization may be accomplished via an electrophysiology study during which electrical potentials are detected spatially resolved with a mapping catheter (e.g., catheter 14) introduced into a chamber of heart 12. The electrophysiology study (so-called electroanatomical mapping) thus provides 3D mapping data that can be displayed on the display device 27. In many cases, the mapping function and the therapeutic function (e.g., ablation) are provided by a single catheter or a group of catheters, such that the mapping catheter also operates as a therapeutic (e.g., ablation) catheter at the same time. According to one or more embodiments, the mapping engine 101 may be stored and executed directly by the catheter 14.

According to one or more embodiments, mapping engine 101 performs an electrocardiogram and/or an intracardiac electrogram (ECG/ICEG). ECG/ICEG is a process of decomposing/analyzing/recording electrical activity of heart 12 over a period of time using physiological signals of multiple electrodes 18 and 26 (e.g., with ICEG, at least one of electrodes 26 being within heart 12). That is, to support the system 100 in detecting, diagnosing, and/or treating a cardiac disorder, one or more catheters 14 may be navigated by the physician 24 into the heart 12 of the patient 23. In turn, the plurality of electrodes 18 and 26 detect and provide signals (also referred to as physiological signals) that the mapping engine 101 uses to identify small electrical changes caused by the electrophysiological pattern of depolarization of the myocardium during each heartbeat. For example, the ECG/ICEG may be performed over a period of time, such as ten (10) seconds. In this way, the overall magnitude and direction of electrical depolarization at the heart 12 is captured at each instant of the entire cardiac cycle. The ECG/ICEG may be recorded during a diagnostic or therapeutic procedure. The duration of the process may vary from tens of minutes to several hours. During each treatment protocol, there are typically several tens of ablation periods (ablation sessions), e.g., each ablation period lasting from a few seconds up to about 1 minute.

In accordance with one or more embodiments, the mapping engine 101 may include and execute one or more algorithms, such as algorithms implementing mathematical multi-signal decomposition operations. The mapping engine 101 reduces the need for wavefront algorithms because the mapping engine 101 provides accurate near field components, activation time (e.g., using minimum derivatives), and voltage level (e.g., max-min). Examples of one or more algorithms include, but are not limited to, singular Value Decomposition (SVD), principal Component Analysis (PCA), and/or other matrix decomposition or factorization.

In a patient with Normal Sinus Rhythm (NSR) (e.g., patient 23), a heart (e.g., heart 12) including atrial, ventricular and excitatory conductive tissue is electrically stimulated to beat in a synchronized patterned manner. Note that the electrical stimulus may be detected as intra-cardiac electrocardiogram (ICECG) data or the like.

According to one or more embodiments, in a patient (e.g., patient 23) suffering from an arrhythmia (e.g., aFib), the abnormal region of cardiac tissue does not follow the synchronized beating cycle associated with normal conducting tissue, in contrast to a patient suffering from NSR. In contrast, abnormal areas of heart tissue abnormally conduct to adjacent tissue, disrupting the cardiac cycle into an unsynchronized rhythm. Note that the asynchronous heart rhythm may also be detected as ICECG data. Such abnormal conduction is previously known to occur at various areas of the heart 12, such as in the Sinus (SA) junction region, along the conduction pathways of the Atrioventricular (AV) junction, or in myocardial tissue forming the walls of the ventricular and atrial heart chambers. Other conditions exist (such as tremors) in which the pattern of abnormal conductive tissue causes a reentrant pathway such that the chamber beats in a regular pattern, which may be multiple times the sinus rhythm.

By way of example, to support the system 10 in detecting, diagnosing, and/or treating a cardiac disorder, the catheter 14 may be navigated by the physician 24 into the heart 12 of the patient 23 lying in bed. For example, the physician 24 may insert the shaft through the sheath while manipulating the distal end of the shaft using a manipulator near the proximal end of the catheter 14 and/or deflection from the sheath. According to one or more embodiments, the catheter 14 may be fitted at the distal end of the shaft. The catheter 14 may be inserted through the sheath in the collapsed state and may then be deployed within the heart 12.

Generally, a catheter 14 containing an electrical sensor (e.g., sensor 29) at or near its distal tip (e.g., at least one electrode 26) may be advanced to a point in the heart 12 where the sensor contacts tissue and acquires data at that point in such a way that electrical activity at that point in the heart 12 is measured. One disadvantage of mapping a heart chamber using one type of catheter containing only a single distal tip electrode is the long time required to accumulate data point-by-point over the necessary number of points required for a detailed map of the chamber population. Accordingly, multi-electrode catheters (e.g., catheter 14) have been developed to measure electrical activity at multiple points in the heart chamber simultaneously.

Catheter 14, which may include at least one electrode 26 and a catheter needle coupled to its body, may be configured to obtain biometric data, such as electrical signals of an internal organ (e.g., heart 12) and/or ablate a tissue region thereof (e.g., a heart chamber of heart 12). It should be noted that electrode 26 represents any similar element, such as a tracking coil, a piezoelectric transducer, an electrode, or a combination of elements configured to ablate a tissue region or obtain biometric data. In accordance with one or more embodiments, catheter 14 may include one or more positioning sensors for determining trajectory information. The trajectory information may be used to infer motion characteristics, such as contractility of tissue.

Biometric data (e.g., patient biometric, patient data, or patient biometric data) may include one or more of Local Activation Time (LAT), electrical activity, topology, bipolar mapping, reference activity, ventricular activity, dominant frequency, impedance, etc. The LAT may be a point in time of a threshold activity corresponding to local activation calculated based on a normalized initial starting point. The electrical activity may be any suitable electrical signal that may be measured based on one or more thresholds and may be sensed and/or enhanced based on a signal-to-noise ratio and/or other filters. The topology may correspond to a physical structure of the body part or a portion of the body part, and may correspond to a change in the physical structure relative to different portions of the body part or relative to different body parts. The dominant frequency may be a frequency or range of frequencies that are prevalent at a portion of a body part and may be different in different portions of the same body part. For example, the dominant frequency of the PV of the heart may be different from the dominant frequency of the right atrium of the same heart. The impedance may be a resistance measurement at a given region of the body part.

Examples of biometric data include, but are not limited to, patient identification data, ICECG data, bipolar endocardial reference signals, anatomical and electrical measurements, trajectory information, body Surface (BS) ECG data, historical data, brain biometrics, blood pressure data, ultrasound signals, radio signals, audio signals, two-or three-dimensional (3D) image data, blood glucose data, and temperature data, or other electrical activity and/or physiological signals. Biometric data is generally used to monitor, diagnose, and treat any number of various diseases, such as cardiovascular diseases (e.g., arrhythmias, cardiomyopathy, and coronary artery disease) and autoimmune diseases (e.g., type I and type II diabetes). Note that BSECG data may include data and signals collected from electrodes on the surface of the patient, ICECG data may include data and signals collected from electrodes within the patient, and ablation data may include data and signals collected from tissue that has been ablated. In addition, BSECG data, ICECG data, and ablation data along with catheter-electrode positioning data may be derived from one or more protocol records.

For example, the catheter 14 may use the electrodes 26 to enable intravascular ultrasound and/or MRI catheterization to image the heart 12 (e.g., obtain and process biometric data). The catheter 14 is shown in an enlarged view inside the heart chamber of the heart 12. It should be appreciated that any shape including one or more electrodes 26 may be used to implement the embodiments disclosed herein.

Examples of catheter 14 include, but are not limited to, a linear catheter having multiple electrodes, a balloon catheter including electrodes dispersed over multiple ridges that shape the balloon, a lasso (lasso), a catheter having a mesh-shaped electrode or an annular catheter having multiple electrodes, a high density catheter, or any other suitable shape or complexity. The linear catheter may be fully or partially elastic such that it may twist, bend, and/or otherwise change its shape based on the received signal and/or based on an external force (e.g., cardiac tissue) being exerted on the linear catheter. The balloon catheter may be designed such that its electrodes may remain in intimate contact against the endocardial surface when deployed into a patient. For example, a 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 contracted state such that the balloon catheter does not occupy its maximum volume when inserted into the PV. The balloon catheter may be inflated inside the PV such that those electrodes on the balloon catheter are in contact with the entire circular segment of the PV. Such contact with the entire circular segment of the PV or any other lumen may enable effective imaging and/or ablation. Other examples of the catheter 14 includeCatheters and catheter catheters. Examples of the catheter 14 are also described with reference to fig. 5-6, as will be described in more detail below.

According to other examples, the body patches and/or body surface electrodes (e.g., one or more electrode patches 38) may also be positioned on or near the body of the patient 23. The catheter 14 having one or more electrodes 26 may be positioned within a body (e.g., within the heart 12), and the positioning of the catheter 14 may be determined by the system 100 based on signals transmitted and received between the one or more electrodes 26 of the catheter 14 and the body patches and/or body surface electrodes. Additionally, the electrodes 26 may sense biometric data from within the patient 23 (such as within the heart 12) (e.g., the electrodes 26 sense the electrical potential of tissue in real time). The biometric data may be associated with the determined location of the catheter 14 such that a rendering of a body part (e.g., heart 12) of the patient may be displayed and the biometric data overlaid on the shape of the body part may be displayed.

By way of another 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 employing an ML/AI algorithm (which may be included in the mapping engine 101). According to an exemplary embodiment, workstation 55 includes one or more processors 61 (any computing hardware) and memory 62 (any non-transitory tangible medium), wherein the one or more processors 61 execute computer instructions with respect to mapping engine 101, and memory 62 stores these instructions for execution by the one or more processors 61. For example, workstation 55 may be configured to receive and process biometric data and determine whether a given tissue region is electrically conductive. In some embodiments, workstation 55 may be further programmed (in software) by mapping engine 101 to perform the functions of the ablation procedure guidance method. For example, an ablation procedure guidance method may include receiving an input (e.g., including one or more images and a conduction velocity vector estimate), generating digital twinning of the anatomical structure using the images and the conduction velocity vector estimate, and presenting the digital twinning to provide accurate ablation guidance of the anatomical structure and to provide electrophysiological information of the anatomical structure.

According to one or more embodiments, the mapping engine 101 may be located external to the workstation 55, and may be located, for example, 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 transmitted/downloaded in electronic form over a network.

In one example, workstation 55 may be any computing device as described herein (such as a general purpose computer) including software (e.g., mapping engine 101) and/or hardware (e.g., processor 61 and memory 62) having suitable front-end and interface circuitry for transmitting signals to and receiving signals from catheter 14, as well as for controlling other components of system 10. For example, the front-end and interface circuitry includes an input/output (I/O) communication interface that enables the workstation 55 to receive signals from and/or transmit signals to the 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 analog-to-digital (a/D) ECG or electrocardiograph or Electromyography (EMG) signal conversion integrated circuits. Workstation 55 may pass signals from the a/DECG or EMG circuitry to another processor and/or may be programmed to perform one or more of the functions disclosed herein.

Connected to the workstation 55 is a display device 27, which may be any electronic device for visual presentation of biometric data. According to an exemplary embodiment, during a procedure, workstation 55 may facilitate presentation of body part renderings to physician 24 on display device 27 and storage of data representing the body part renderings in memory 62. For example, a map depicting motion characteristics may be rendered/constructed based on trajectory information sampled at a sufficient number of points in the heart 12. As an example, the display device 27 may include a touch screen that may be configured to accept input from the physician 24 in addition to presenting the body part rendering.

In some embodiments, physician 24 may use one or more input devices (such as a touchpad, mouse, keyboard, gesture recognition device, etc.) to manipulate elements of system 10 and/or body part rendering. For example, an input device may be used to change the positioning of the catheter 14 so that the rendering is updated. It is noted that the display device 27 may be located at the same location or at a remote location, such as in a separate hospital or in a separate healthcare provider network.

In accordance with one or more embodiments, the system 10 may also use ultrasound, computed Tomography (CT), MRI, or other medical imaging techniques utilizing the catheter 14 or other medical equipment to obtain biometric data. For example, the system 10 may use one or more catheters 14 or other sensors to obtain ECG data and/or anatomical and electrical measurements (e.g., biometric data) of the heart 12. More specifically, workstation 55 may be connected by a cable to a BS electrode comprising an adhesive skin patch attached to patient 23. The BS electrode obtains/generates biometric data in the form of BSECG data. For example, the processor 61 determines the location coordinates of the catheter 14 within a body part (e.g., heart 12) of the patient 23. These positioning coordinates are based on impedance or electromagnetic fields measured between the body surface electrodes and the electrodes 26 or other electromagnetic components of the catheter 14. Additionally or alternatively, the location pad generating the magnetic field for navigation may be located on the surface of the bed (or table) and may be separate from the bed. The biometric data may be transmitted to workstation 55 and stored in memory 62. Alternatively or in addition, the biometric data is transmitted to a server, which may be local or remote, using a network as further described herein.

According to one or more embodiments, the catheter 14 may be configured to ablate a tissue region of a heart chamber of the heart 12. For example, a catheter 14 within a heart chamber of the heart 12 is shown in an enlarged view. Furthermore, an ablation electrode, such as at least one electrode 26, is configured to provide energy to a tissue region of an internal body organ (e.g., heart 12). The energy may be thermal energy and may begin at the surface of the tissue region and extend into the thickness of the tissue region to cause damage to the tissue region. Biometric data relative to an ablation procedure (e.g., ablating tissue, ablation location, etc.) may be considered ablation data.

According to one example, a multi-electrode catheter (e.g., catheter 14) is advanced into a chamber of heart 12 relative to obtaining biometric data. Front-to-back (AP) and side-to-side (side) fluoroscopes may be obtained to establish the positioning and orientation of each electrode. The ECG may be recorded from each of the electrodes 26 in contact with the heart surface relative to a time reference, such as the onset of a P-wave from the sinus rhythm of BSECG and/or a signal from the electrode 26 of the catheter 14 placed in the coronary sinus. As further disclosed herein, the system can distinguish between those electrodes that record electrical activity and those electrodes that do not record electrical activity due to the lack of close proximity to the endocardial wall. After the initial ECG is recorded, the catheter is repositioned and the fluoroscopic map and ECG may be recorded again. An electrical map may then be constructed (e.g., via cardiac mapping) according to iterations of the process described above.

Cardiac mapping may be implemented using one or more techniques. In general, mapping of cardiac regions (such as cardiac regions, tissue, veins, arteries, and/or electrical pathways of the heart 12) may enable identification of problematic regions (such as scar tissue), sources of arrhythmia (e.g., electrical rotors), healthy regions, and the like. The cardiac region is mapped such that a display is used to provide a visual rendering of the mapped cardiac region, 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, local activation speed, electrical activity, topology, bipolar mapping, dominant frequency, or impedance. Data (e.g., biometric data) corresponding to multiple modalities may be captured using a catheter (e.g., catheter 14) inserted into the patient and may be provided for rendering simultaneously or at different times based on corresponding settings and/or preferences of physician 24.

As an example of the first technique, cardiac mapping may be accomplished by sensing electrical characteristics (e.g., LAT) of cardiac tissue from a precise location within the heart 12. Corresponding data (e.g., biometric data) may be acquired through one or more catheters (e.g., catheter 14) advanced into heart 12 and having electrical sensors and position sensors (e.g., electrodes 26) in their distal tips. As a specific example, the location and electrical activity may initially be measured at about 10 to about 20 points on the interior surface of the heart 12. These data points may generally be sufficient to generate a preliminary reconstruction or map of the heart surface of satisfactory quality. The preliminary map may be combined with data taken at additional points to produce a more comprehensive map of cardiac electrical activity. In a clinical setting, it is not uncommon to accumulate data at 100 or more sites (e.g., thousands) to generate detailed and comprehensive maps of heart chamber electrical activity. The generated detailed map may then be used as a basis for deciding on the course of therapeutic action, such as tissue ablation as described herein, to alter the propagation of cardiac electrical activity and restore normal heart rhythm.

Furthermore, a cardiac map is generated based on the detection of an intracardiac potential field (e.g., which is an example of ICECG data and/or a bipolar intracardiac reference signal). A non-contact technique for simultaneously acquiring a large amount of cardiac electrical information can be realized. For example, a catheter of the type having a distal end portion may be provided with a series of sensor electrodes distributed over its surface and connected to insulated electrical conductors for connection to signal sensing and processing means. The end portion may be sized and shaped such that the electrode is substantially spaced apart from the wall of the heart chamber. The intracardiac potential field may be detected during a single heartbeat. According to one example, the sensor electrodes may be distributed over a series of circumferences lying in planes spaced apart from each other. These planes may be perpendicular to the long axis of the end portion of the catheter. At least two additional electrodes may be provided adjacently at the ends of the long axis of the ends. As a more specific example, the catheter may include four circumferences, with eight electrodes equiangularly spaced apart on each circumference. Thus, in this 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 other multi-spline catheters, such as five soft flexible branches, eight radial splines, or a parallel spline turner type (e.g., any of which may have a total of 42 electrodes).

As an example of electrical or cardiac mapping, electrophysiology cardiac mapping systems and techniques based on non-contact and non-expanding multi-electrode catheters (e.g., catheter 14) may be implemented. ECG may be obtained with one or more catheters 14 having multiple electrodes (e.g., such as between 42 and 122 electrodes). Depending on the implementation, knowledge of the relative geometry of the probe and endocardium may be obtained by a separate imaging modality, such as transesophageal echocardiography. After independent imaging, the non-contact electrodes may be used to measure cardiac surface potentials and construct maps therefrom (e.g., in some cases, using bipolar endocardial reference signals). The technique may include the following steps (after the independent imaging step): (a) Measuring the electrical potential with a plurality of electrodes disposed on a probe positioned in the heart 12; (b) Determining a geometric relationship of the probe surface and endocardial surface and/or other references; (c) Generating a coefficient matrix representing the geometric relationship of the probe surface and endocardial surface; and (d) determining the endocardial potential based on the electrode potential and the coefficient matrix.

According to another example of electrical mapping or cardiac mapping, techniques and apparatus for mapping the electrical potential distribution of a cardiac chamber may be implemented. An intracardiac multi-electrode mapping catheter assembly is inserted into the 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).

According to one or more embodiments, the electrodes may be deployed in a substantially spherical array, which may be spatially referenced to a point on the endocardial surface by a reference electrode or by a reference catheter in contact with the endocardial surface. A preferred electrode array catheter may carry a plurality of individual electrode sites (e.g., at least 24). In addition, this example technique can be implemented by knowing the location of each of the electrode sites on the array and knowing the heart geometry. These positions are preferably determined by impedance plethysmography techniques.

In view of electrical mapping or cardiac mapping and according to another example, catheter 14 is a cardiac mapping catheter assembly that includes an electrode array defining a plurality of electrode sites. The cardiac mapping catheter assembly also includes a lumen to receive a reference catheter having a distal tip electrode assembly for probing a wall of the heart. The cardiac mapping catheter assembly includes a braid of insulated wires (e.g., 24 to 64 wires in the braid), and each wire may be used to form an electrode site. The cardiac mapping catheter assembly is readily positionable in the heart 12 for acquiring electrical activity information from the first set of non-contact electrode sites and/or the second set of contact electrode sites.

Further, according to another example, catheter 14, which may implement 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. The catheter 14 may also include at least one pair of orthogonal electrodes to generate a difference signal indicative of local cardiac electrical activity adjacent the orthogonal electrodes.

As described herein, the system 10 is used to detect, diagnose, and/or treat cardiac disorders. In an example operation, a process for measuring electrophysiological data in a heart chamber is implemented by the system 10. The process includes, in part, positioning a set of active and passive electrodes into the heart 12, supplying current to the active electrodes, thereby generating an electric field in the heart chamber, and measuring the electric field at the passive electrode sites. The passive electrodes are contained in an array positioned on an inflatable balloon of a balloon catheter. In a preferred embodiment, the array is said to have from 60 to 64 electrodes.

As another example operation, cardiac mapping is implemented by the system 10 using one or more ultrasound transducers. The ultrasound transducer may be inserted into the heart 12 of the patient, and a plurality of ultrasound slices (e.g., two-dimensional or 3D slices) may be collected at various locations 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 can be displayed at a later time. One or more ultrasound slices corresponding to the positioning of the catheter 14 (e.g., a treatment catheter) over a period of time are displayed, and the catheter 14 is overlaid onto the one or more ultrasound slices.

In view of the system 10, it is noted that arrhythmias, including atrial arrhythmias, may be of the multiple wavelet reentrant type, characterized by multiple asynchronous loops of electrical pulses (e.g., another example of ICECG data) that are dispersed around the atrial chamber and that are generally self-propagating. Alternatively, or in addition to the multiple wavelet foldback, an arrhythmia may also have a focal source (e.g., another example of ICECG data), such as when isolated tissue regions within the atrium spontaneously beat in a rapid repeating manner. Ventricular tachycardia (V-tach or VT) is a tachycardia or tachycardia derived from one of the ventricles. This is a potentially life threatening arrhythmia, as it can lead to ventricular fibrillation and sudden death.

For example, aFib may occur when a normal electrical pulse (e.g., another example of ICECG data) generated by the sinus node is submerged by a turbulent electrical pulse originating in the atrial vein and PV that causes irregular pulses to be transmitted to the ventricles. Irregular heartbeats develop and may last from minutes to weeks, or even years. aFib is a chronic condition that typically results in a small increase in the risk of mortality due to stroke. aFib's line therapy is a medication that slows down or normalizes heart rate. In addition, persons suffering from aFib are often given anticoagulants to prevent them from risk of stroke. The use of such anticoagulants is accompanied by its own risk of internal bleeding. For some patients, drug treatment is inadequate and their aFib is considered drug refractory, i.e., not curable with standard drug intervention. Synchronous electrical cardioversion may also be used to transition aFib to a normal heart rhythm. Alternatively, the patient is treated aFib by catheter ablation.

Catheter-based ablation therapy may include mapping electrical characteristics of heart tissue (particularly endocardium and heart volume), and selectively ablating heart tissue by applying energy. Electrical or cardiac mapping (e.g., implemented by any of the electrophysiology cardiac mapping systems and techniques described herein) includes creating a map of electrical potentials (e.g., voltage maps) traveling along the cardiac tissue or arrival times to various tissue localization points (e.g., LAT maps). Electrical mapping or cardiac mapping (e.g., cardiac mapping) may be used to detect local cardiac tissue dysfunction. Ablation, such as ablation based on cardiac mapping, may stop or alter unwanted electrical signals from propagating from one portion of the heart 12 to another.

The ablation process damages unwanted electrical pathways by forming non-conductive ablation foci. A variety of energy delivery forms for forming ablation foci have been disclosed and include the use of microwaves, lasers, and more commonly radio frequency energy to form conduction blocks along the heart tissue wall. Another example of an energy delivery technique includes irreversible electroporation (IRE), which provides a high electric field that damages the cell membrane. In a two-step procedure (e.g., mapping and then ablation), electrical activity at various points within the heart 12 is typically sensed and measured by advancing a catheter 14 containing one or more electrical sensors (or electrodes 26) into the heart 12 and obtaining/acquiring data at various points (e.g., as biometric data in general, or ECG data in particular). The ECG data is then used to select the endocardial target area where ablation is to be performed.

As clinicians treat increasingly challenging conditions such as atrial fibrillation and ventricular tachycardia, cardiac ablation and other cardiac electrophysiology protocols become increasingly complex. Treatment of complex arrhythmias may rely solely on the use of a 3D mapping system in order to reconstruct the anatomy of the heart chamber of interest. In this regard, the mapping engine 101 employed by the system 10 herein manipulates and evaluates the biometric data in general or the ECG data in particular to produce improved tissue data that enables more accurate diagnosis, images, scanning, and/or mapping for treating abnormal heartbeats or arrhythmias. For example, cardiologists rely on software such as that produced by Biosense Webster, inc. (Diamond Bar, calif.)A complex fractionated electrocardiography (CFAE) module of the 3d mapping system to generate and analyze ECG data. The mapping engine 101 of the system 10 augments this software to generate and analyze improved biometric data, which further provides a plurality of pieces of information about the electrophysiological properties of the heart 12 (including scar tissue), which represent the cardiac stroma (anatomy and function) aFib.

Thus, system 10 implements a 3D mapping system, such asA 33D mapping system to locate potentially arrhythmogenic substrates for cardiomyopathy in terms of abnormal ECG detection. The matrix associated with these cardiac conditions is associated with the presence of disintegrated and prolonged ECG in the endocardial and/or epicardial layers of the ventricular chambers (right and left). For example, areas of low or medium voltage may exhibit ECG fragmentation and prolonged activity. Furthermore, during sinus rhythms, areas of low or medium voltage may correspond to critical isthmuses identified during sustained and organized ventricular arrhythmias (e.g., applicable to intolerant ventricular tachycardia, and in the atrium). In general, abnormal tissue is characterized by a low voltage ECG. However, initial clinical experience in endocardial-epicardial mapping indicates that low voltage regions are not always present as the sole arrhythmogenic mechanism in such patients. In fact, areas of low or medium voltage may exhibit ECG fragmentation and prolonged activity during sinus rhythms that correspond to the critical isthmus identified during sustained and tissue ventricular arrhythmias, e.g., only for intolerant ventricular tachycardia. Furthermore, in many cases, ECG fragmentation and prolonged activity are observed in areas exhibiting normal or near normal voltage amplitudes (> 1mV-1.5 mV). While the latter regions can be evaluated based on voltage amplitude, they cannot be considered normal based on intracardiac signals, thus representing a true arrhythmogenic matrix. The 3D mapping is capable of locating the arrhythmogenic matrix on the endocardial and/or epicardial layers of the right/left ventricle, which may vary in distribution according to the spread of the underlying disease.

As another example operation, cardiac mapping may be implemented by the system 10 using one or more multi-electrode catheters (e.g., catheter 14). The multi-electrode catheter is used to stimulate and map electrical activity in the heart 12 and to ablate sites of abnormal electrical activity. In use, the multi-electrode catheter is inserted into a main vein or artery (e.g., femoral vein) and then directed into the chamber of the heart 12 of interest. A typical ablation procedure involves inserting a catheter 14 having at least one electrode 26 at its distal end into a heart chamber. The reference electrode is provided glued to the skin of the patient, or is provided by a second catheter positioned in or near the heart or selected from one or other electrodes 26 of catheter 14. Radio Frequency (RF) current is applied to tip electrode 26 of ablation catheter 14 and the current flows to the reference electrode through the medium (e.g., blood and tissue) surrounding the tip electrode. The distribution of the current depends on the amount of electrode surface in contact with the tissue compared to blood, which has a higher conductivity than the tissue. Heating of the tissue occurs due to the electrical resistance of the tissue. The tissue is heated sufficiently to cause cell destruction in the heart tissue, resulting in the formation of non-conductive ablation sites within the heart tissue. During this process, heating of the tip electrode 26 also occurs due to conduction from the heated tissue to the electrode itself. If the electrode temperature becomes sufficiently high (possibly above 60℃.), a thin transparent coating of dehydrated blood proteins may form on the surface of the electrode 26. If the temperature continues to rise, the dehydrated layer may become thicker, resulting in blood clotting 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 increases sufficiently, an impedance rise occurs and the catheter 14 must be removed from the body and the tip electrode 26 cleaned.

Turning now to fig. 2, a diagram of a system 200 in which one or more features of the disclosed subject matter may be implemented is shown in accordance with one or more exemplary embodiments. With respect to patient 202 (e.g., an example of patient 23 of fig. 1), 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. Further, the device 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.

According to one embodiment, the device 204 is an example of the system 100 of fig. 1, wherein 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 a device external to the patient 202 that includes an attachable patch (e.g., attached to the patient's skin). According to another embodiment, the device 204 may be inside the body of the patient 202 (e.g., subcutaneously implanted), wherein the device 204 may be inserted into the patient 202 via any suitable means, including oral injection, surgical insertion via a vein or artery, endoscopic procedure, or laparoscopic procedure. Although a single device 204 is shown in fig. 2, an example system may include multiple devices, according to one embodiment.

Accordingly, the apparatus 204, the local computing device 206, and/or the remote computing system 208 may be programmed to execute computer instructions with respect to the mapping engine 101. For example, the memory 223 stores such instructions for execution by the processor 222 so that the device 204 can receive and process biometric data via the biometric sensor 201. As such, processor 222 and memory 223 represent processors and memory of local computing device 206 and/or remote computing system 208.

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 store, execute, and implement the mapping engine 101 and its functionality. Additionally, the apparatus 204, the local computing device 206, and/or the remote computing system 208 may be an electronic computer framework, including and/or employing any number and combination of computing devices and networks utilizing various communication techniques, as described herein. The apparatus 204, local computing device 206, and/or remote computing system 208 are readily scaled, expanded, and modularized, with the ability to change to a different service or reconfigure some features independently of other features.

Networks 210 and 211 may be wired networks, wireless networks, or 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 sent between the apparatus 204 and the local computing device 206 via the network 210 using any of a variety of short-range wireless communication protocols, such as bluetooth, wi-Fi, zigbee, Z-Wave, near Field Communication (NFC), ultra-band, zigbee, or Infrared (IR). In addition, network 211 is an example of one or more of the following: an intranet, a Local Area Network (LAN), a Wide Area Network (WAN), a Metropolitan Area Network (MAN), a direct connection or a series of connections, a cellular telephone network, or any other network or medium capable of facilitating communications between the local computing device 206 and the remote computing system 208. The information may be sent via the network 211 using any of a variety of remote wireless communication protocols (e.g., TCP/IP, HTTP, 3G, 4G/LTE, or 5G/new radio). Note that for either of networks 210 and 211, the wired connection may be implemented using ethernet, universal Serial Bus (USB), RJ-11, or any other wired connection and wireless connection may be implemented using Wi-Fi, wiMAX, and bluetooth, infrared, cellular network, satellite, or any other wireless connection method.

In operation, the device 204 may continuously or periodically obtain, monitor, store, process, and communicate biometric data associated with the patient 202 via the network 210. In addition, the apparatus 204, the local computing device 206, and/or the remote computing system 208 communicate over networks 210 and 211 (e.g., the local computing device 206 may be configured as a gateway between the apparatus 204 and the remote computing system 208). For example, the apparatus 204 may be an example 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/stand alone device, a base station, a desktop/laptop computer, a smart phone, a smartwatch, a tablet, or other device configured to communicate with other devices via networks 211 and 210. Is implemented as a physical server on or connected to network 211 or a public cloud computing provider of network 211 (e.g., amazonWebServices) The remote computing system 208 of the virtual server in (a) may be configured to communicate with the local computing device 206 via the network 211. Thus, biometric data associated with the patient 202 may be transmitted throughout the system 200.

The elements of 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 such that different types of biometric data are observed/obtained/acquired. For example, the biometric sensor 221 includes one or more of the following: electrodes (e.g., electrodes 18 and 26 of fig. 1), temperature sensors (e.g., thermocouples), blood pressure sensors, blood glucose sensors, blood oxygen sensors, pH sensors, accelerometers, and microphones.

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 to communicate the biometric data to the memory 224 via the transceiver 225 for storage and/or across the network 210. Biometric data from one or more other devices 204 may also be received by the processor 222 through the transceiver 225. As described in more detail below, the processor 222 may be configured to selectively respond to different tap patterns (e.g., single or double taps) received from the UI sensor 223 such that different tasks (e.g., acquisition, storage, or transmission of data) of the patch may be activated based on the detected patterns. In some implementations, the processor 222 may generate audible feedback regarding the detected gesture.

The UI sensor 223 includes, for example, a piezoelectric sensor or a capacitive sensor configured to receive user input such as a tap or touch. For example, in response to the patient 202 tapping or contacting the surface of the device 204, the UI sensor 223 may be controlled to achieve capacitive coupling. Gesture recognition may be implemented via any of a variety of capacitance types, such as resistive capacitance, surface capacitance, projected capacitance, surface acoustic wave, piezoelectric, and infrared touch. The capacitive sensor may be disposed at a small area or over the length of the surface such that a tap or touch on the surface activates the monitoring device.

Memory 224 is any non-transitory tangible medium such as magnetic memory, optical memory, or electronic memory (e.g., any suitable volatile memory and/or non-volatile memory such as random access memory or hard disk drive). Memory 224 stores computer instructions for execution by processor 222.

Transceiver 225 may include a separate transmitter and a separate receiver. Alternatively, transceiver 225 may comprise a transmitter and a receiver integrated into a single device.

In operation, the device 204 observes/obtains biometric data of the patient 202 via the biometric sensor 221 with the mapping engine 101, stores the biometric data in memory, and shares the biometric data across 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 elimination using multiple electrode catheters.

Turning now to fig. 3A, a method 300 (e.g., performed by the mapping engine 101 of fig. 1 and/or 2) is shown in accordance with one or more example embodiments. Method 300 is an example of using multiple electrode catheters (e.g., catheter 14) to provide intracardiac monopolar far field reduction or elimination. In one example, method 300 performs atrial local activation detection as well as ventricular detection within the QRS (regardless of late local activation and annotation). It is noted that the use of a multi-electrode catheter provides a spatial advantage in that the mapping engine 101 analyzes each electrode 18 and 26 and each corresponding intra-cardiac voltage signal based on ambient spatial electrode information. In this regard, the mapping engine 101 reduces or eliminates far field information from all electrodes while significantly enhancing the purely local unipolar signal. In addition to accurate activation annotations, the mapping engine 101 also provides scar detection based on local activation amplitudes because the mapping engine 101 outperforms the known bipolar sensitivity to spatial electrode direction and distance drawbacks.

The method 300 begins at block 310, where the mapping engine 101 performs spatial electrode signal analysis on each of a plurality of electrodes. Spatial electrode signal analysis considers the far field characteristics of spatial location correlations to provide electrode weighting information and to determine a common signal component, which may be an estimate of far field information.

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

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

As the distance of a particular electrode from a reference electrode increases, the weight decreases (e.g., the farther away the weight is, the less the weight is). According to one or more embodiments, electrodes beyond a certain distance (note that this distance is catheter-dependent and in some cases 5 millimeters) may be eliminated. The mapping engine 101 then analyzes the electrode weighting information using one or more algorithms (e.g., mathematical multi-signal decomposition operations). Examples of one or more algorithms include, but are not limited to, singular Value Decomposition (SVD), principal Component Analysis (PCA), and/or other matrix decomposition or factorization. The SCV may be a factorization of a real matrix or complex matrix (e.g., electrode weight matrix W) to generalize the eigen-decomposition of a square orthonormal matrix with orthogonal eigen-bases. By analyzing the electrode weighting information, the mapping engine 101 estimates common signal components that are hidden within all signals. The common signal component is estimated by the mapping engine 101 by taking the largest decomposition component/signal. Other examples of common signal components include an estimate of the maximum common signal component and far field information.

At block 320, the mapping engine 101 scales the common signal component (identified by mapping engine 101 and/or spatial electrode signal analysis). In accordance with 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 using the scaled common signal.

In accordance with one or more embodiments, mapping engine 101 scales the common signal component to best fit the analyzed electrode signal. Scaling is demonstrated by scalar multiplication, for example, as shown in graph 325 of fig. 3B. Graph 325 includes a sample index x-axis and millivoltage y-axis. The graph shows an initial signal 326, a common signal 327, a scaled common signal 328 (i.e., far field), and a residual local signal 329 (i.e., near field). Furthermore, a residual signal is determined. That is, once scaled and fit, the common signal component is subtracted to leave 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.

At block 340, the mapping engine 101 analyzes the pure local information to identify/generate/provide local monopolar activation. Local monopolar activation may include complications of a dual activation mode. In accordance with one or more embodiments, for LAT mapping, the mapping engine 101 utilizes the least pure local information derivative to detect activation times within the cardiac cycle. According to one or more embodiments, for voltage (V) mapping, the mapping engine 101 takes local activation peak-to-peak over a 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.

At block 350, the mapping engine 101 displays the results. According to one or more embodiments, the mapping engine provides localized monopolar activation (e.g., all localized activation modes for each electrode) above a constant zero background of the user interface of the display 165. The visual presentation of the display 165 in the locally activated mode may include a large duration for consistency analysis.

Turning now to fig. 4, a method 400 (e.g., performed by the mapping engine 101 of fig. 1 and/or 2) is shown in accordance with one or more exemplary embodiments. Method 400 is an example of an estimation of far-field information, such as described with respect to block 310 of fig. 3A.

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

At 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. Furthermore, more than one reference electrode q may be determined such that the method 400 is performed for each reference electrode q.

At block 430, the mapping engine 101 determines weights from 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 the weights of the electrodes around a specific electrode, which are inversely proportional to the distance from the specific electrode. Examples of high density mapping catheters may include, but are not limited to, biosenseOctaray ^TM mapping catheter and/orNavEco high-density mapping catheters. Fig. 5-6 illustrate an example catheter 14.

Fig. 5 illustrates a catheter 500 in accordance with one or more embodiments. Catheter 500 may be a catheter having a plurality of electrodes 534, such as at least twenty (20) electrodes. As shown, the plurality of electrodes may include exactly forty-eight (48) electrodes located on or dispersed across the plurality of ridges 37. Using such a number of electrodes 534 distributed over a broad area by ridges 537 allows a large amount of electrical activity to be captured over a large area at a time. According to one or more embodiments, the plurality of ridges 537 move through the sheath in a collapsed state and are expandable once within the body of the access patient 23 of fig. 1. Electrical activity at any focal point in heart 12 can generally be measured by: catheter 500 is advanced, cardiac tissue is brought into contact with catheter 500, and data relating to electrical activity at that point is acquired. One or more of the electrodes 534 may be selected as reference electrode q.

For example, electrode 560 is designated as reference electrode q. Further, as the distance from the electrode 560 increases, the weight decreases. In this way, because electrode 562 is closer to electrode 560 than electrode 564, electrode 562 will have a higher weight than electrode 564. In addition, because electrode 566 is farther from electrode 560 than electrode 562, electrode 566 will have a lower weight than electrode 562. Note that the distance between each of the electrodes 534 may be measured relative to three dimensions (i.e., using x, y, z coordinates). In turn, the electrodes 564 and 566 may or may not have the same weight.

Fig. 6 illustrates a catheter 500 in accordance with one or more embodiments. Catheter 600 is a catheter having a plurality of electrodes 605 that provide one or more physiological signals. For example, the number of electrodes 605 may be at least three (3) arranged in any combination group. As shown in fig. 6, a set of three electrodes 612, 614 and 612 are located on the same spline 620 as a set of two electrodes 622 and 624. According to one or more embodiments, catheter 600 includes at least five (5) arms (as shown in fig. 6), and in some cases, eight (8) or more arms, and electrode 205 may include twenty (20) or forty-eight (48) monopolar electrodes positioned in pairs or coupled 1 millimeter or 2 millimeters apart from each other (e.g., higher density improving performance).

Returning to the method 400, at block 440, the mapping engine 101 determines dot products of weights from the electrode weight matrix W and the electrode signals s.

At block 450, the mapping engine 101 processes the dot product using one or more algorithms to generate a quadrature signal. In general, one or more algorithms of the mapping engine 100 include mathematical multi-signal decomposition operations. Examples of one or more algorithms include, but are not limited to, singular Value Decomposition (SVD), principal Component Analysis (PCA), and/or other matrix decomposition or factorization. The SCV may be a factorization of a real matrix or complex matrix (e.g., electrode weight matrix W) to generalize the eigen-decomposition of a square orthonormal matrix with orthogonal eigen-bases.

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

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

At block 708, the mapping engine 101 receives a first input. The first input includes a global PxP weight matrix. At block 709, a second input is received. The second input includes a specific electrode index K.

At block 710, the mapping engine 101 performs a first peeping operation. The first peeping operation includes peeping the matrix row vector K. At block 715, the mapping engine 101 converts the global PxP weight matrix into a diagonal matrix. According to one or more embodiments, mapping engine 101 outputs a specific PxP weight matrix for electrode K, where Wkk =1.

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

At block 730, the mapping engine 101 performs a second peeping operation. The second peeping operation looks at the orthogonal component NxP matrix to find the largest component. The largest component is the common component.

At block 735, the mapping engine 101 performs orthogonal synthesis of the common components. The mapping engine 101 may utilize the orthogonal component NxP matrix from the orthogonal decomposition of block 725. Mapping engine 101 provides common components based on the synthesized NxP matrix. At block 740, the mapping engine 101 selects column K. At block 745, the mapping engine 101 provides an output. The output comprises an estimated far field signal of electrode K.

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

According to one or more of the method embodiments herein, or any one of them, 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 a mapping engine, spatial electrode signal analysis on electrical activity of each of a 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.

According to one or more of any of the method embodiments herein, the spatial electrode signal considers the spatial location dependent far field characteristics to provide electrode weighting information.

According to any of the method embodiments herein, the residual signal estimates pure local information.

According to any of the method embodiments herein, the catheter comprises a high density mapping catheter.

According to any of the method embodiments herein, the mapping engine analyzes the residual signal to identify local monopolar activation.

According to any of the method embodiments herein, the mapping engine displays results including localized monopolar activation.

According to any of the method embodiments herein, the mapping engine determines a reference electrode of the plurality of electrodes.

According to any of the method embodiments herein, the mapping engine determines the weight of each electrode of the plurality of electrodes from an electrode weight matrix based on the reference electrode.

According to any of the method embodiments herein, the mapping engine determines a dot product of the weight and the electrical activity.

According to any of the method embodiments herein, the mapping engine processes the dot product using one or more algorithms to generate the quadrature signal.

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

According to any of the method implementations herein, the mapping engine selects the largest signal of the orthogonal signals.

According to any of the method embodiments herein, the mapping engine performs a correlation analysis of the maximum signal and the signal of the reference electrode to provide projection values.

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

In accordance with one or more embodiments, a system is provided. The system includes a memory storing software of the mapping engine. The system includes one or more processors. The one or more processors execute software to cause the mapping engine to receive electrical activity from the plurality of electrodes of the catheter; performing spatial electrode signal analysis on the electrical activity of each electrode of the plurality of electrodes; and scaling the common signal component of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

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

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

According to any of the system embodiments herein, the spatial electrode signal analysis considers spatial location dependent far field characteristics to provide electrode weighting information.

According to any of the system implementations herein, the mapping engine analyzes the residual signal to identify local monopolar activation.

According to any of the system embodiments herein, the mapping engine displays results that include localized monopolar activation.

The flowcharts 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 flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Although features and elements are specifically described above, one of ordinary skill in the art will recognize that each feature or element may be used alone or in any combination with other features and elements. Furthermore, the methods described herein may be implemented in a computer program, software or firmware incorporated in a computer readable medium for execution by a computer or processor. As used herein, a computer-readable medium should not be construed as a transitory signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a pulse of light passing through a fiber optic cable), or an electrical signal transmitted through an electrical wire.

Examples of computer readable media include electronic signals (transmitted over a wired or wireless connection) 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 Discs (CDs) and Digital Versatile Discs (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. A processor associated with the software may be used to implement a radio frequency transceiver for use in a terminal, a base station, or any host computer.

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" include plural referents unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.

The description of the various embodiments herein is presented for purposes of illustration and is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the embodiments. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application or technical improvement over the technology existing in the market, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method, comprising:

receiving, by a mapping engine executed by one or more processors, electrical activity from a plurality of electrodes of a catheter;

performing, by the mapping engine, spatial electrode signal analysis on the electrical activity for each of the plurality of electrodes; and

Common signal components of the electrical activity identified by the spatial electrode signal analysis are scaled by the mapping engine to determine a residual signal.

2. The method of claim 1, wherein the spatial electrode signal analysis considers spatial location dependent far field characteristics to provide electrode weighting information.

3. The method of claim 1, wherein the residual signal estimates pure local information.

4. The method of claim 1, wherein the catheter comprises a high density mapping catheter.

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

6. The method of claim 5, wherein the mapping engine displays results comprising the local monopolar activation.

7. The method of claim 1, wherein the mapping engine determines a reference electrode of the plurality of electrodes.

8. The method of claim 7, wherein the mapping engine determines the weight of each electrode of the plurality of electrodes from an electrode weight matrix based on the reference electrode.

9. The method of claim 8, wherein the mapping engine determines a dot product of the weights and the electrical activity.

10. The method of claim 9, wherein the mapping engine processes the dot product using one or more algorithms to generate quadrature signals.

11. The method of claim 10, wherein the one or more algorithms comprise singular value decomposition.

12. The method of claim 10, wherein the mapping engine selects a largest signal of the orthogonal signals.

13. The method of claim 12, wherein the mapping engine performs a correlation of the maximum signal with a signal of the reference electrode to provide projection values.

14. The method of claim 13, wherein the mapping engine determines a tensor product of the maximum signal and the projection values to provide a far field estimate as the common signal component.

15. A system, comprising:

a memory storing software of a mapping engine; and

One or more processors executing the software to cause the mapping engine to:

Receiving electrical activity from a plurality of electrodes of a catheter;

performing spatial electrode signal analysis on the electrical activity for each electrode of the plurality of electrodes; and

Scaling the common signal component of the electrical activity identified by the spatial electrode signal analysis to determine a residual signal.

16. The system of claim 15, wherein the residual signal estimates pure local information and the catheter comprises a high-density mapping catheter.

17. The system of claim 15, wherein the mapping engine determines a reference electrode of the plurality of electrodes and determines a weight for each electrode of the plurality of electrodes according to an electrode weight matrix.

18. The system of claim 15, wherein the spatial electrode signal analysis considers spatial location dependent far field characteristics to provide electrode weighting information.

19. The system of claim 15, wherein the mapping engine analyzes the residual signal to identify local monopolar activation.

20. The system of claim 19, wherein the mapping engine displays results comprising the local monopolar activation.