Method and system for analyzing and presenting connections between ablation points

Abstract

A method, apparatus and computer program product, the method comprising: obtaining coordinates of a location in a body part of a patient; determining at least one trajectory comprising at least a portion of the location; determining whether a connection between at least two locations connected along the at least one trajectory exceeds a threshold; providing a visual representation of the body part, the visual representation comprising visual indications of at least some of the locations and connections between the locations; and providing a visual indication of the connection weight if the connection exceeds the threshold.

Description

Technical Field

[0001] The present disclosure relates generally to medical applications, and in particular to evaluating and representing connections between ablation points. Background Art

[0002] Arrhythmias can be caused by problems with the electrical activity in the heart's electrical conduction system and, in particular, in one or more points or zones on the walls of the heart chambers. Atrial fibrillation is a type of arrhythmia characterized by chaotic signals that cause the atria (left and / or right) to squeeze very quickly and in an asynchronous rhythm.

[0003] A common treatment for atrial fibrillation (also known as A-fib) is ablation, which uses energy to create scars on one or more active areas on the heart wall in order to block the erroneous electrical signals that contribute to the disorder and restore a normal heartbeat. Ablation can use one or more types of energy to create the scars, such as, but not limited to, radiofrequency (RF), pulsed field (sometimes called PFA or irreversible electroporation (IRE)), focused laser, ultrasound, heat, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The present disclosure will be more fully understood through the following detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings, in which:

[0005] Figure 1 is a schematic illustration of a catheter-based electrophysiological (EP) mapping and ablation system according to some exemplary embodiments of the present disclosure;

[0006] Figure 2A is a schematic diagram of a heart undergoing ablation according to some exemplary embodiments of the present disclosure;

[0007] Figure 2B is a schematic diagram of a user examining a heart having a plurality of locations to which ablation has been applied according to some exemplary embodiments of the present disclosure;

[0008] Figure 3A and Figure 3B It shows how larger distances in three-dimensional space appear shorter when projected onto a two-dimensional plane;

[0009] Figure 3C According to some embodiments of the present disclosure, Figure 3B points in which there are complementary connecting lines;

[0010] Figure 4 is a flow chart of steps in a method for determining and displaying ablation sites and connections therebetween according to some exemplary embodiments of the present disclosure;

[0011] Figure 5A and Figure 5B An example of a line segment connecting ablation locations, as created by a conventional solution, is shown;

[0012] FIG. 5C to FIG. 5F Examples of connected line segments created by existing solutions and some exemplary embodiments of the present disclosure are shown;

[0013] Figure 6 shows an image of a heart displayed on a display device with ablation points and with estimated trajectories according to some embodiments of the present disclosure; and

[0014] Figure 7 is a schematic block diagram of a computing platform for determining and indicating connections between ablation points exceeding a predetermined threshold according to some exemplary embodiments of the present disclosure. DETAILED DESCRIPTION

[0015] In the following description, numerous specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In other cases, well-known circuits, control logic components, and details of computer program instructions for conventional algorithms and processes are not shown in detail to avoid unnecessarily obscuring the present invention.

[0016] Software programming code embodying aspects of the present invention is typically stored in a permanent storage device such as a computer-readable medium. In a client-server environment, such software programming code may be stored on a client or a server. The software programming code may be contained in any of a variety of known media used with a data processing system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, tapes, compact disks (CDs), digital video disks (DVDs), and computer instruction signals contained in a transmission medium with or without a carrier wave modulating the signal. For example, the transmission medium may include a communication network such as the Internet. In addition, although the present invention may be embodied in computer software, the functionality required to implement the present invention may alternatively be embodied in part or in whole using hardware components, such as application specific integrated circuits or other hardware, or some combination of hardware components and software.

[0017] Overview

[0018] It is known that atrial fibrillation can be triggered by abnormal conduction pathways originating from muscle bundles extending from the atria to the pulmonary veins.

[0019] Cardiac ablation is a procedure that locally heats and ablates cardiac tissue on the inner surface of the heart chambers in order to alleviate cardiac dysfunction, such as atrial fibrillation. For example, ablation can produce electrical isolation of the pulmonary veins, thereby restoring sinus rhythm.

[0020] When a physician (usually a cardiologist) performs ablation therapy, the physician typically forms an ablation lesion by applying energy to the cardiac tissue using an ablation electrode positioned at the distal end of a catheter. The ablation electrode contacts the tissue in the cardiac chamber at a plurality of discrete ablation sites along a predetermined trajectory. Depending on the ablation area and the desired result, the defined trajectory can be open, i.e., a line with a start and end point, or form a closed loop.

[0021] The cardiologist can monitor the procedure by observing the position of the catheter tip in the heart image on a display. For example, the catheter tip position can be detected by a catheter position tracking system or an imaging system.

[0022] If adjacent ablation lesions created by the cardiologist are too far apart, the resulting gap may not completely eliminate parasitic electrical pathways, such as cardiac activation waves, and cardiac dysfunction may not be fully alleviated.

[0023] During the procedure, for each location where ablation was applied, a three-dimensional (3D) location and optionally additional characteristics may be stored, such as a quality metric of the ablation, the temperature at which the ablation was created, heart wall thickness, etc. These locations may be displayed to the physician during and / or after the procedure by a display device displaying an image of the heart or a portion thereof.

[0024] Currently, physicians can visually estimate whether the ablation locations form a desired trajectory (sometimes referred to as an "ablation path" or "ablation line"), whether the ablation locations are closed or open, and whether the distance between any two consecutive locations along the trajectory is small enough to eliminate parasitic electrical pathways. However, visual estimates may not be accurate enough. In addition, projecting the 3D ablation locations on a two-dimensional (2D) display may distort the distances and make reliable determinations impossible.

[0025] The natural method of tracking the creation time of the ablation sites (if available) and determining the distance between any two successively created ablations may also not provide a complete solution, because the physician may revisit certain areas after ablating other areas to create another ablation between two previously created ablations. In addition, the physician may create ablations in two or three different areas, where the distance between these areas is large, but this does not cause a problem.

[0026] Some computational solutions have been proposed to determine trajectory and distance, and in particular to identify distances exceeding a threshold within the same area. However, it has been demonstrated that no satisfactory solution of this type exists.

[0027] Thus, embodiments of the present disclosure provide a system and method for more accurately determining and optionally visualizing the trajectory along which ablation points are positioned and the connections between associated cardiac ablation sites. In some embodiments, a processor of a cardiac mapping and ablation system may receive the coordinates of multiple ablation sites on the surface of the heart. The processor may then apply a unique combination of computational methods to determine the connectivity between the ablation sites. The processor may then visualize some or all of the connections. For example, each connection may be marked with a color, width, pattern, or additional indicator representing its size or size range. For example, connections that are longer than a particular threshold can be indicated in a more prominent manner than shorter connections. In other embodiments, only connections with a distance exceeding a threshold may be indicated.

[0028] Using the disclosed solution, the physician is provided with a clear real-time visual display that highlights the trajectory and at least indicates where the connection between ablation points may be of insufficient quality. Using such a display, the physician can review the location in question and successfully complete the ablation procedure.

[0029] System Description

[0030] refer to Figure 1 , which shows an example catheter-based electrophysiological mapping and ablation system 10. The system 10 includes a plurality of catheters that can be inserted into a chamber or vascular structure of a heart 12 by a physician 24 through the vascular system of a patient 23 percutaneously. Typically, a delivery sheath catheter is inserted into the left atrium or right atrium near a desired location in the heart 12. One or more catheters can then be inserted into the delivery sheath catheter to reach a desired location in the heart 12. The plurality of catheters may include a catheter dedicated to sensing intracardiac electrogram (IEGM) signals, a catheter dedicated to ablation, and / or a catheter dedicated to both sensing and ablation. An example catheter 14 configured for sensing IEGM is illustrated herein. The physician 24 can place the distal end 28 of the catheter 14 in contact with the heart wall for sensing a target site in the heart 12. For ablation, the physician 24 can similarly place the distal end of the ablation catheter in contact with the target site for ablating tissue.

[0031] The catheter 14 is an exemplary catheter that includes one (and preferably multiple) electrodes 26, optionally distributed over a plurality of strips 22 at a distal tip 28 and configured to sense IEGM signals. The catheter 14 may additionally include a position sensor 29 embedded in or near the distal tip 28 for tracking the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0032] The magnetic-based position sensor 29 can operate with the positioning pad 25, which includes a plurality of magnetic coils 32 configured to generate a magnetic field in a predetermined working space. The real-time position of the distal tip 28 of the catheter 14 can be tracked based on the magnetic field generated by the positioning pad 25 and sensed by the magnetic-based position sensor 29. The details of the magnetic-based position sensing technology are described in U.S. Patents 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.

[0033] Additionally or alternatively, the system 10 may include one or more electrode patches 38 positioned in contact with the skin of the patient 23 to establish a position reference for impedance-based tracking of the positioning pad 25 and the electrodes 26. For impedance-based tracking, current is directed to the electrodes 26 and sensed at the electrode skin patches 38 so that the position of each electrode can be triangulated via the electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182.

[0034] Recorder 11 may record and display electrograms 21 captured using surface ECG electrodes 18 and IEGMs (intracardiac electrograms) captured using electrodes 26 of catheter 14. Recorder 11 may include pacing capabilities for pacing cardiac rhythms and / or may be electrically connected to a separate pacemaker.

[0035] The system 10 may include an ablation energy generator 50 adapted to conduct ablation energy to one or more electrodes at the distal end of a catheter configured for ablation. The energy generated by the 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.

[0036] A patient interface unit (PIU) 30 may be configured to establish electrical communications between catheters, other electrophysiology equipment, a power source, and a workstation 55 for controlling the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, a plurality of catheters, a positioning pad 25, 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 enabling real-time calculation of the position of the catheters and for performing ECG calculations.

[0037] Workstation 55 includes memory, a processor unit having memory or storage having appropriate operating software stored therein, and user interface capabilities. Workstation 55 can provide a number of functions, which optionally include (1) three-dimensional (3D) modeling of endocardial anatomy and rendering the model or anatomical map 20 for display on display device 27; (2) displaying on display device 27 an activation sequence (or other data) compiled from recorded electrograms 21 as representative visual markers or images superimposed on the rendered anatomical map 20; (3) displaying the real-time position and orientation of multiple catheters within a cardiac chamber; and (4) displaying on display device 27 sites of interest such as where ablation energy is applied. A commercial product embodying elements of system 10 can be manufactured in a CARTO TM The 3 system was purchased from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0038] In the following description, the terms "site," "ablation site," "location," "ablation location," and the like are used interchangeably and are to be broadly interpreted as indicating a location where ablation has been applied.

[0039] In the following description, the terms "connection" and "distance" are used interchangeably and will be broadly interpreted as indicating a line segment connecting two ablation sites. Depending on the context, the terms "distance", "distance length", or "distance weight" may be interpreted as Euclidean distance, distance along body tissue, or a combination of any of the above with additional factors, as described in detail below.

[0040] Reference now Figure 2A , shows a schematic diagram of a heart 12 undergoing ablation according to one embodiment of the present invention. The ablation electrode at the distal end 28 of the catheter 14 contacts the heart chamber at a plurality of ablation sites 200 to induce localized necrosis of the heart tissue. A lesion is formed at each ablation site 200.

[0041] Using position tracking of a position sensor at the distal end 28 or an imaging system as previously described, a recorder (such as Figure 1 The recorder 11) can record the location of the ablation site 200 when the physician 24 forms multiple lesions on the surface of the heart chamber using the ablation electrode. The location of the ablation site 200 can be displayed to the user (such as the physician 24) in real time, stored, and presented later after the operation.

[0042] Electrophysiological (EP) mapping electrodes near the distal end 28 of the catheter 14 or a separate catheter may be used to monitor changes in the cardiac electrical signals measured by the one or more mapping electrodes in response to ablation therapy, as previously described.

[0043] Reference now Figure 2B , shows a schematic diagram of a user 204 (which may be the same as or different from the physician 24) examining an image of the heart 12 (as displayed on the display device 27) with annotations related to the ablation sites 200, according to some embodiments of the present disclosure.

[0044] Figure 2B Inset 208 shows ablation site 200 after being processed by a processor, such as a processor of workstation 55. Figure 2A Magnified view of the ablation area in .

[0045] For some ablation sites 200, the nearest ablation site may be located at a distance equal to or longer than the threshold distance, which may therefore be intolerable because the parasitic electrical pathways of the cardiac activation wave may not be eliminated. The threshold may have a default value or may be set by the user 204. The threshold may also depend on the specific location within the heart 12. Connections with intolerable distances or distance weights may be highlighted to the user 204 with a thick line 216.

[0046] It should be understood that some connections may be longer than they appear, such as the connection along line 220, which is therefore also bold.

[0047] Figure 2A and Figure 2B The illustrations are only for conceptual clarity and are not intended to limit the embodiments of the present invention. Figure 2A and Figure 2B The ablation locations in are shown as open trajectories, but the present disclosure is equally applicable to illustrating closed trajectories, such as those created, for example, to isolate a pulmonary vein.

[0048] Note that Figure 2A and Figure 2B In the figure, for clarity, the lesions at multiple ablation sites 200 are shown as circular, and the diameters of the lesions are shown as being approximately the same. In some cases, one or more ablation sites 200 may not be circular but amorphous, and the diameters of the ablation sites 200 may be different from each other, for example depending on the ablation parameters applied at each ablation site (e.g., ablation time or ablation signal power). In some embodiments, the distance measured between ablation sites 200 does not take into account the site diameter. For example, the distance between the centers or centroids of the ablation sites may be calculated. In other embodiments, the distance measured between ablation sites 200 may depend on the diameter of the site. For example, for the same ablation site center point, the distance between large diameter lesions may be smaller than the distance between small diameter lesions.

[0049] In some embodiments, the processor of the workstation 55 may also scale the distance weights between ablation sites by a scaling factor that depends on the ablation quality (also referred to as an ablation index) or other factors of one or both of the ablation sites, as described in detail below. Thus, a low-quality ablation site will be interpreted as being farther away from the other site than a high-quality site.

[0050] In some applications, such as medical applications and particularly atrial ablation applications, distances may be calculated based on relevant body tissue rather than as Euclidean distances, which may generally increase distances.

[0051] Reference now Figure 3A and Figure 3B , demonstrating the effect of larger distances appearing shorter in a projection onto a plane (such as the display plane of a visual display device).

[0052] Figure 3A Three 3D points are shown, point 300 with coordinates (0,0,0), point 304 with coordinates (1,5,1), and point 308 with coordinates (5,0,1). Therefore, the distances are: 300-304: sqrt(27), 304-308: sqrt(42), 308-300: sqrt(26), i.e., the longest distance is between points 304 and 308, and the shortest distance is between 300 and 308.

[0053] When the point is projected onto the XZ plane, such as Figure 3B As shown, and as shown on the display device 27, the coordinates become 300'(0,0), 304'(1,1), and 308'(5,1), and the corresponding distances are therefore 300'-304': sqrt(2), 304'-308': sqrt(16), 308'-300': sqrt(26). Therefore, the longer distance occurs between points 300' and 308', and the shortest distance occurs between 300' and 304', which does not reflect the relationship between the actual 3D distances.

[0054] Therefore, highlighting distances exceeding a threshold may be particularly important because they may not be perceived by a user (such as a physician examining images of the heart 12 ) and may therefore lead to suboptimal ablation results.

[0055] Reference now Figure 3C , showing the following according to some embodiments of the present disclosure Figure 3B Points in which there are complementary connecting lines.

[0056] The connecting lines between the points, which may represent ablation sites, are supplemented with tick marks, where the distance between any two consecutive tick marks is constant for the entire image. Thus, each of the line segment 312 connecting points 300' and 304' and the line segment 320 connecting points 300' and 308' includes four tick marks, because the distances are almost the same length (sqrt(26) and sqrt(27)), so that rounding the distances ends up with the same number of tick marks. The line segment 316 connecting 304' and 308', which has a length of sqrt(42), has seven (7) tick marks, so it should be understood that it represents a longer distance than the other line segments, even though it appears shorter than line segment 320 in the projection.

[0057] As mentioned above, these distances can be calculated as Euclidean distances, or calculated based on the relevant body tissue. Therefore, since the distances may be even longer than the Euclidean distances, the number of scale markings may even increase.

[0058] It should be understood that the length of a connecting line segment (also referred to as a connection) may be indicated additionally or alternatively by the color, shading, pattern or another characteristic of the line segment. For example, a longer connection may be indicated by a darker shading, a denser pattern, etc. However, the tick marks also provide a quantitative measurement of the connection, which enables the user to easily assess the distance. It should also be understood that two or more indication methods, such as tick marks and / or pattern and / or color and / or shading and / or width, may be used simultaneously.

[0059] In some embodiments, all connected line segments can be displayed so that the physician can see the complete ablation trajectory, where connections with higher weights can be displayed in a more prominent manner. In other embodiments, these line segments can be displayed and supplemented only when the distance between the ablation site and the nearest ablation site exceeds a threshold, so that the physician can easily detect areas where more ablation sites may be needed without cluttering the image unnecessarily.

[0060] In additional embodiments, connections between ablation sites may also be displayed, such as in the case of enhanced wide area circumferential catheter (WACA) ablation surrounding two pulmonary veins.

[0061] Reference now Figure 4 , a flowchart showing steps in a method for determining and displaying trajectories connecting ablation sites and connections therebetween, according to some embodiments of the present disclosure.

[0062] At step 400, the coordinates of the ablation sites may be obtained. The data may be obtained from the ablation system during the ablation procedure, retrieved from a storage device where they were stored during or after the ablation procedure, etc. The ablation sites may be obtained during the procedure when the physician is checking whether additional sites need to be ablated, or when the ablation results need to be checked later.

[0063] The ablation site may be received as a 3D point, optionally with additional parameters such as an ablation index indicating the quality of the ablation, a timestamp of when the ablation was created, etc.

[0064] Ablation sites can be considered as nodes in the graph, and a virtual line segment connecting two ablation sites can be interpreted as an edge in the graph. Edges can be unidirectional or bidirectional, wherein in the present disclosure, an edge can be bidirectional, ie, not associated with a specific direction.

[0065] Each edge may have a weight, where the weight may be equal to the length of the line segment.

[0066] It should be understood that a circle in a graph relates to a closed trajectory connecting a plurality of nodes and does not necessarily relate to a geometric circle.

[0067] At step 402, one or more trajectories may be determined, each trajectory including at least some of the locations, wherein each such trajectory indicates an ablation operation designed to electrically isolate a cardiac region. It should be understood that the ablation trajectory may be open as in apical ablation, or closed as in circumferential ablation.

[0068] Step 402 may include step 404, in which the ablation sites may be clustered. Clustering may generally refer to dividing nodes within a graph into groups, wherein the distance between nodes within the same group is less than the distance between nodes assigned to different clusters. Thus, the ablation sites may be considered as nodes in the graph, and the connection between two ablation sites is an edge. Thus, each cluster may represent ablation sites that were performed to electrically isolate a specific region of the heart, such as one or a pair of pulmonary veins.

[0069] Clustering can be performed using any currently known method or any method that will become known in the future, such as but not limited to K-means clustering, mean shift clustering, density-based spatial clustering of applications with noise (DBSCAN), expectation-maximization (EM) clustering using Gaussian mixture models (GMM), affinity propagation, agglomerative hierarchical clustering, BIRCH, mini-batch K-means, OPTICS, spectral clustering, or other methods.

[0070] In some embodiments, multiple clustering methods may be applied, and the clustering to be used may be selected by majority voting.

[0071] Clustering can use the distance between sites as connection weights, where the distance between two ablation points can be calculated as the Euclidean distance, but can also be calculated as the distance along the heart tissue. Additionally or alternatively, the connection weights can take into account additional factors. For example, the distance between ablation sites can be scaled by a scaling factor that also integrates the size of the ablation site, the quality of one or both of the ablation sites in the ablation site (also known as the ablation index). Thus, a low-quality ablation site can be interpreted as being farther away from other sites than a high-quality site. Additional factors may include the temperature when the lesion is formed at the ablation location, one or more anatomical factors (such as the thickness of the heart wall at the lesion area), and the like.

[0072] Step 402 may include step 408, where connecting line segments (also referred to as edges) may be determined between ablation sites within each cluster.

[0073] In some embodiments, the connecting line segments can form a spanning tree, and in particular a minimum spanning tree. In a graph, the minimum spanning tree includes all nodes of the graph and the number of edges equal to the number of nodes minus one, so that no loop is formed. The minimum spanning tree has a minimum total edge weight, wherein the weight of each edge is as described in detail above, and the total edge weight is the sum of the weights of all edges in the tree. In some embodiments, one or more positions in a cluster can be omitted and are not part of a spanning tree, for example, where the total weight without the position is significantly lower than the total weight with the position.

[0074] The minimum spanning tree may be found using any currently known algorithm or algorithm that becomes known in the future, such as but not limited to Boruvka's algorithm, Prim's algorithm, Kruskal's algorithm, or others.

[0075] At step 410, it may be determined whether additional line segments may be added that, when added to the spanning tree, form a closed trajectory. It will be appreciated that in further iterations, line segments may be added at the top of the spanning tree and line segments added on previous iterations. However, edges that close the trajectory may not always meet the predetermined conditions and may therefore be eliminated and not added, such as in a top ablation where the edge connecting the first position site to the last position site may be too long.

[0076] In some examples, step 410 may include activating an algorithm such as the Floyd-Warshall algorithm that calculates, for each pair of nodes in the current graph, the total weight of a path between the nodes, where the path consists of edges that exist in the spanning tree or that were previously added. It should be understood that because the graph is a tree, a single path exists between any two nodes before the edges are added. For each pair of such nodes, distances such as the Euclidean distance are also calculated.

[0077] It can then be determined whether the pair of nodes that best compromises path weight and distance also meets one or more predetermined conditions, as described in detail below. The goal of the tradeoff is to select the edge with the smallest weight where the total weight within the graph of the paths connecting the edge nodes is the largest. Intuitively, the algorithm aims to find the shortest edge that creates the largest loop.

[0078] It should be understood that the weight calculations detailed above can be applied to calculating edge weights when determining minimum spanning trees and path weights, as well as to calculating connection weights between two ablation locations that are not yet connected by an edge.

[0079] If such a line segment exists ("yes"), then at step 412, the line segment may be added to the graph and a closed trajectory may be formed. Execution may then return to step 410 to search for additional line segments.

[0080] It should be understood that the algorithm is non-trivial, since any three or more nodes and the paths connecting them can be closed into a loop. However, connecting too few points is likely to find local loops that do not cover the closed trajectory of the ablation location, while connecting too many points may introduce a noisy picture.

[0081] In some cases, such as in top ablations, the edge between nodes that provides the best compromise may not meet a predetermined condition, such as its weight, Euclidean distance or distance along the body tissue may exceed a predetermined threshold. Again intuitively, this may be the case where the ablation locations form an elongated shape and are not intended to form a loop.

[0082] Thus, if there are no line segments to be added, or a maximum number of edge addition iterations, such as 5 to 20 iterations, such as 10 iterations, have been performed, execution may continue at step 414 to select the next cluster and continue with the next cluster as described above. If it is determined at step 411 that there are no other clusters, execution may continue to step 416, as described in detail below.

[0083] Reference now Figure 5A and Figure 5B , showing two examples of ablation locations and connections therebetween as created by conventional solutions. Figure 5A A graph 500 is shown that includes two local loops 504 and 508, which may confuse the physician because they are too small to represent a closed trajectory. In addition, graph 500 shows that there is no connection between locations 512 and 516 and between locations 524 and 528.

[0084] Similarly, Figure 5BGraph 532 shows a break between locations 548 and 549, as well as another break as shown in area 560. Additionally, line segment 541 unnecessarily closes an unwanted loop, which may be further confusing.

[0085] Reference now FIG. 5C to FIG. 5F , shows an example of computing connections according to some exemplary embodiments of the present disclosure. It should be understood that FIG. 5C to FIG. 5F The example only considers the Euclidean distance between points as the weight of the connection. FIG. 5C to FIG. 5F If some positions in any of the appear to partially or completely overlap or touch each other, such positions are considered to be pairwise connected to each other.

[0086] Figure 5C It is shown that after calculating the minimum spanning tree, Figure 5A Graph 564 with the same node positions. It can be seen that the graph as a tree contains no closed loops and thus eliminates the local loops of graph 500. In addition, graph 564 does not have any disconnected nodes or groups of nodes.

[0087] Figure 5D 580 after operating the Floyd Warshall algorithm and selecting edges 580 for forming a closed trajectory having the same Figure 5C 576. The result is a larger loop with no breaks and no local loops.

[0088] Figure 5E It is shown that after calculating the minimum spanning tree, Figure 5B 584 of the same ablation locations in FIG. 500. As can be seen, the graph as a tree contains no closed loops and thus eliminates the local loops of graph 500. In addition, graph 584 does not have any disconnected nodes or groups of nodes.

[0089] Fig. 5F shows that after operating the Floyd Warshall algorithm as described above and selecting the edges to add, the Figure 5E 593 of the same ablation locations in FIG. Thus, edges 594 and 596 have been added that close two loops, one edge containing both locations 588 and 590 and the other containing either 588 or 590, and node 597 has been added. The result is a larger loop without breaks and local loops.

[0090] When determining to add an edge, some morphological factors may be considered. For example, the circularity of a circle may be considered, such as by estimating the standard deviation of the position from the centroid of the created shape, and loops with a low standard deviation may be preferred.

[0091] In some exemplary embodiments, the presence or absence of one or more edges connecting the ablation sites can be subject to the user's consideration. Thus, the user can mark certain edges or certain pairs of ablation sites as being connected, and / or mark other edges or pairs of ablation sites as not having a connection. These indications can be used as constraints for trajectory creation, i.e., the presence of edges will be enforced or eliminated if the user so indicates.

[0092] At step 416, it may be determined which line segments connecting the ablation sites are longer than a threshold, such as between 3 mm and 10 mm, e.g., 4 mm, which means that the ablation points connected by the line segments may be too far apart from each other to ensure electrical isolation. Note that this threshold may be different from (e.g., shorter than) the threshold used as a condition for determining the connecting edge to be added at step 410. For example, if no line segments longer than 6 mm were added at step 410, the threshold used at step 416 may be applicable to the added line segments and may indicate line segments longer than 4 mm. It can be seen that although the conventional method indicates multiple long line segments, such as Figure 5A The line segment 520 and Figure 5B , but some of the segments are obviously unnecessary, such as 540 and 541, and the present disclosure only indicates that the segments 536 and 543 are too long, such as Fig. 5F As seen in.

[0093] At step 420 , an image of the heart or a portion thereof may be displayed, for example as image 20 on display device 27 , or as shown in image 208 .

[0094] At step 424, line segments that are at least longer than the threshold value as identified at step 416 may be indicated on the image. However, other line segments that form a closed trajectory may also be indicated. In addition, the length of the displayed line segment may be visually indicated by tick marks, patterns, colors, shading, width, etc., or a combination of two or more of the above, as described above. In other embodiments, all line segments may be indicated on the display, and

[0095] Reference now Figure 6 , shows an image 600 of a heart with ablation points and with two estimated trajectories 604 and 608 displayed on a display device according to some embodiments of the present disclosure.

[0096] It should be understood that some ablation points (such as 602) are not part of any such circle.

[0097] It should also be appreciated that some line segments (such as 612, 616, 620) are shown with markings indicating that they may be longer than a threshold or have a higher weight than a threshold (although this may not appear to be the case due to the 2D projection) and should be further examined.

[0098] Different loops, such as 604 and 608 , may or may not be displayed with different color schemes to better visually distinguish the loops.

[0099] Reference now Figure 7 , a block diagram of a computing platform 700 for determining whether a connection between ablation points exceeds a predetermined threshold according to some exemplary embodiments of the present disclosure is shown.

[0100] It should be understood that the computing platform 700 may be embedded within the workstation 55 , but may also be a stand-alone computing platform or embedded elsewhere and in operative communication with the workstation 55 .

[0101] The computing platform 700 may be implemented as one or more computing platforms that are operably connected to each other. For example, one or more remote computing platforms may be implemented, for example, on a cloud computer. Other computing platforms may be part of a computer network of an associated organization. In other embodiments, all functions may be provided by one or more computing platforms that are all part of an organization's network.

[0102] The computing platform 700 may include one or more processors 704, which may be one or more central processing units (CPUs), microprocessors, electronic circuits, integrated circuits (ICs), etc., located or not located on the same computing platform. The processor 704 may be configured to provide the desired functionality, for example, by loading into memory and activating software modules stored on the storage device 712, which are described in detail below.

[0103] The computing platform 700 may include a communication device 708 for communicating with other devices or other computing platforms, for example, obtaining information from a catheter insertion controller, storing data to a remote storage device or retrieving data from a remote storage device, etc. The communication module 708 may be adapted to interface with any communication channel (such as a local area network (LAN), a wide area network (WAN), a cellular network, etc.), and use any relevant communication protocol.

[0104] The computing platform 700 may include a storage device 712, such as a hard drive, a flash drive, a random access memory (RAM), a memory chip, etc. In some exemplary embodiments, the storage device 712 may retain program code that is operable to cause the processor 704 to perform operations related to any one or more of the modules listed below. Figure 4The program code may include one or more executable units, such as functions, libraries, independent programs, etc., adapted to perform instructions as described in detail below.

[0105] Alternatively or additionally, the provided instructions may be stored on a non-transitory tangible computer-readable medium, such as a magnetic, optical, or electronic memory.

[0106] Storage device 712 may include I / O module 716 for presenting to the user displays to be displayed on display device 27, such as cardiac maps, indications of ablation points and distances therebetween, etc. I / O module 716 is also operable to receive instructions and operating parameters from the user.

[0107] The storage device 712 may include a communication module 720 for transmitting and receiving data to and from other systems (such as an ablation system, an external storage device, etc.).

[0108] The storage device 712 may include a clustering module 724, which may include one or more modules for clustering sites, such as but not limited to a K-means clustering module 726, a mean shift clustering module 728, an EM clustering module using GMM 732, a density-based clustering module 736, or other modules.

[0109] The storage device 712 may include an initial connection line segment calculation module 740, which may include one or more modules for calculating line segments connecting ablation sites, such as but not limited to a minimum spanning tree calculation module 744 (which may be implemented in various ways through various algorithms) or other modules.

[0110] The storage device 712 may include a loop closure module 748, which may include one or more modules for determining how to close a spanning tree into a closed trajectory.

[0111] The loop closure module 748 may include a module for calculating the weight of a path between any two nodes within a tree, such as, but not limited to, the Floyd Warshau algorithm implementation module 752 or other modules.

[0112] The loop closure module 748 may include a distance calculation module 756 for calculating distances or weights between nodes representing ablation sites and / or determining whether one or more of the edge weights exceeds a threshold.

[0113] The loop closure module 748 may include an edge selection module 760 for selecting edges to be added to the initial line segment based on, for example, a tradeoff between the weight of a path connecting two locations, as calculated by the Floyd Warshall algorithm implementation module 752 (or another algorithm), and the distance between the locations, as calculated by the distance calculation module 756. The loop closure module 748 may also determine that edges will not be added such that one or more trajectories are not closed.

[0114] The storage device 712 may include a visual indication calculation module 764, which is used to determine how to visually display the connection. In some embodiments, all connected line segments can be indicated in the image, and the connected line segments whose length exceeds the threshold can be marked accordingly. In other embodiments, only the connected line segments whose length exceeds the threshold can be marked. Various forms of marking can be taken, especially adding scale marks at a constant distance, wherein the distance between two scale marks actually indicates a constant distance or a constant weight, so that the number of scale marks along the line segment indicates its length. Alternative or additional marking methods such as patterns, widths, colors, shadows, etc. can also be used.

[0115] It should be understood that the steps and modules disclosed above are in addition to the software, hardware, firmware or other modules required to operate the catheter, display the catheter insertion process, generate cardiac maps, etc. Further details of the method and system can be found in, for example, US8676305, US9629567, the entire contents of which are incorporated herein by reference for any purpose.

[0116] The present invention may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium (or multiple media) having computer-readable program instructions thereon, which are used to cause a processor to perform various aspects of the present invention.

[0117] A computer-readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. An incomplete list of more specific examples of computer-readable storage media includes the following: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punch card or a raised structure in a groove with instructions recorded thereon, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium should not be understood as a transient 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 light pulse passing through a fiber optic cable), or an electrical signal transmitted by a wire.

[0118] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to a corresponding computing / processing device, or downloaded to an external computer or external storage device via a network (e.g., the Internet, a local area network, a wide area network, and / or a wireless network). The network may include copper transmission cables, transmission optical fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in a computer-readable storage medium in the corresponding computing / processing device.

[0119] The computer-readable program instructions for performing the operation of the present invention may be assembly instructions, instruction set architecture instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages ​​(such as programming languages ​​of Java, C, C++, Python, etc.). The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or completely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer via any type of network (including a local area network (LAN) or a wide area network (WAN)), or may be connected to an external computer (e.g., by using the Internet of an Internet service provider). In some embodiments, in order to perform various aspects of the present invention, an electronic circuit including, for example, a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA) may execute a computer-readable program instruction to personalize the electronic circuit by utilizing the state information of the computer-readable program instructions.

[0120] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each box in the flowchart illustration and / or block diagram and the combination of boxes in the flowchart illustration and / or block diagram can be implemented by computer-readable program instructions.

[0121] These computer-readable program instructions may be provided to a general-purpose computer, a processor of a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create instructions for implementing the flowcharts and / or block diagrams. Figure 1 These computer-readable program instructions may also be stored in a computer-readable storage medium, which may guide a computer, a programmable data processing device, and / or other device to work in a specific manner, so that the computer-readable storage medium having the instructions stored therein includes a computer-readable storage medium having the instructions implemented in the flowchart and / or the block diagram. Figure 1 An article of manufacture that specifies various aspects of the functions / actions in one or more blocks.

[0122] The computer readable program instructions may also be loaded onto a computer, other programmable data processing device or other apparatus to cause a series of operation steps to be executed on the computer, other programmable device or other apparatus to produce a computer-implemented process, so that the instructions executed on the computer, other programmable device or other apparatus implement the flowchart and / or block diagram. Figure 1 Functions / actions specified in one or more boxes.

[0123] The flow charts and block diagrams in the accompanying drawings illustrate the possible specific implementation architecture, functions and operations of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram may represent a module, a fragment or a part of an instruction, and the instruction includes one or more executable instructions for implementing a specified logical function. In some alternative specific implementations, the function indicated in the box may not occur in the order indicated in the accompanying drawings. For example, depending on the function involved, the two boxes shown in succession may actually be executed substantially simultaneously, or the box may sometimes be executed in the opposite order. It should also be noted that each box in the block diagram and / or the flow chart diagram and the combination of the boxes in the block diagram and / or the flow chart diagram can be implemented by a system based on special-purpose hardware that performs a specified function or action or by a combination of special-purpose hardware and computer instructions.

[0124] Example

[0125] Example 1

[0126] A method comprising: obtaining coordinates of locations in a body part of a patient; determining at least one trajectory that includes at least a portion of the locations; determining whether a connection between at least two locations connected along the at least one trajectory exceeds a threshold; providing a visual representation of the body part, the visual representation including visual indications of at least some of the locations and connections between the locations; and providing a visual indication of connection weights if the connections exceed the threshold.

[0127] Example 2

[0128] The method of embodiment 1, wherein determining the at least one trajectory comprises: clustering the locations to form at least one cluster; and determining a tree within each cluster.

[0129] Example 3

[0130] A method according to embodiment 2, wherein the tree is a minimum spanning tree.

[0131] Example 4

[0132] According to the method of embodiment 2, the method also includes: determining at least one line segment connecting the positions within the cluster; and adding the line segment to the tree so that the tree forms at least one closed trajectory.

[0133] Example 5

[0134] The method according to embodiment 4, wherein determining the at least one line segment forming at least one closed trajectory uses a Floyd Warshall algorithm.

[0135] Example 6

[0136] The method of embodiment 4, wherein determining the at least one line segment forming at least one closed trajectory uses a tradeoff between a weight of a path connecting two locations within the tree and a distance between the two locations.

[0137] Example 7

[0138] The method according to embodiment 1, wherein the location is the location of the ablation site in the body of the patient.

[0139] Example 8

[0140] A method according to Example 1, wherein the at least one trajectory surrounds two pulmonary veins of the patient.

[0141] Example 9

[0142] The method of embodiment 1, wherein the visual indication comprises tick marks, and wherein a number of tick marks along a line segment connecting the at least two locations indicates a length of the line segment.

[0143] Example 10

[0144] The method of embodiment 1, wherein the connectivity is quantized as Euclidean distance.

[0145] Embodiment 11

[0146] The method of embodiment 1, wherein the connection is quantified as a distance along the tissue of the patient.

[0147] Example 12

[0148] The method according to embodiment 1, wherein the at least one trajectory is at least one closed trajectory.

[0149] Example 13

[0150] The method according to embodiment 1, wherein determining the at least one trajectory or the distance further uses at least one factor for evaluating connectivity, the at least one factor being selected from the group consisting of: ablation size, ablation index, temperature of the ablated location, and anatomical features.

[0151] Embodiment 14

[0152] A method according to Example 13, wherein the anatomical feature is the thickness of the heart wall in the lesion location.

[0153] Embodiment 15

[0154] A method as in embodiment 1, wherein the at least one track includes at least one line segment indicated as existing by a user.

[0155] Example 16

[0156] A method as in embodiment 1, wherein the at least one trajectory does not include at least one line segment indicated by the user as not existing.

[0157] Embodiment 17

[0158] A computerized device having a processor coupled to a memory unit, the processor being adapted to perform the following steps: obtaining coordinates of locations in a body part of a patient; determining at least one trajectory including at least a portion of the locations; determining whether a connection between at least two locations connected along the trajectory exceeds a threshold; providing a visual representation of the body part, the visual representation including visual indications of at least some of the locations and connections between the locations; and providing a visual indication of connection weights if the connections exceed the threshold.

[0159] Embodiment 18

[0160] A computerized device as described in embodiment 17, wherein the processor is adapted to perform the following steps for determining the at least one trajectory, comprising: clustering the locations to form at least one cluster; and determining a minimum spanning tree within each cluster.

[0161] Embodiment 19

[0162] A computerized device as in embodiment 18, wherein the processor is adapted to determine at least one line segment connecting locations within the clusters, and to add the line segment to the tree such that the tree forms at least one closed trajectory.

[0163] Embodiment 20

[0164] A computer program product comprising a non-transitory computer-readable medium retaining program instructions, which instructions, when read by a processor, cause the processor to perform: obtaining coordinates of locations in a body part of a patient; determining at least one trajectory that includes at least a portion of the locations; determining whether a connection between at least two locations connected along the trajectory exceeds a threshold; providing a visual representation of the body part, the visual representation including visual indications of at least some of the locations and connections between the locations; and providing a visual indication of connection weights if the connections exceed the threshold.

[0165] Although the embodiments described herein are primarily directed to cardiac diagnostic applications, the methods and systems described herein can also be used in other medical applications.

[0166] It should be understood that the above embodiments are cited by way of example, and the present disclosure is not limited to what is specifically shown and described above. On the contrary, the scope of the present disclosure includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which should be expected by those skilled in the art when reading the above description, and which are not disclosed in the prior art.

Claims

1. A method comprising: obtaining coordinates of a location in a body part of a patient; determining at least one trajectory including at least a portion of the location; determining whether a connection between at least two locations connected along the at least one trajectory exceeds a threshold; providing a visual representation of the body part, the visual representation including visual indications of at least some of the locations and connections between the locations; as well as In the event that the connection exceeds the threshold, a visual indication of the connection weight is provided.

2. The method according to claim 1, wherein: Determining the at least one trajectory comprises: clustering the locations to form at least one cluster; and Identify the trees within each cluster.

3. The method according to claim 2, wherein: The tree is a minimum spanning tree.

4. The method according to claim 2, further comprising: determining at least one line segment connecting locations within the cluster; as well as The line segments are added to the tree such that the tree forms at least one closed trajectory.

5. The method according to claim 4, wherein: Determining the at least one line segment forming at least one closed trajectory uses a Floyd Warshall algorithm.

6. The method according to claim 4, wherein: Determining the at least one line segment forming at least one closed trajectory uses a compromise between a weight of a path connecting two locations within the tree and a distance between the two locations.

7. The method according to claim 1, wherein: The location is the location of the ablation site within the patient's body.

8. The method according to claim 1, wherein: The at least one trajectory encircles two pulmonary veins of the patient.

9. The method according to claim 1, wherein: The visual indication comprises tick marks, and wherein a number of tick marks along a line segment connecting the at least two locations indicates a length of the line segment.

10. The method according to claim 1, wherein: The connectivity is quantified as Euclidean distance.

11. The method according to claim 1, wherein: The connectivity is quantified as distance along the patient's tissue.

12. The method according to claim 1, wherein: The at least one trajectory is a closed trajectory.

13. The method according to claim 1, wherein: Determining the at least one trajectory or the distance further uses at least one factor for evaluating connectivity, the at least one factor selected from the group consisting of: ablation size, ablation index, temperature of the ablated location, and anatomical features.

14. The method according to claim 13, wherein: The anatomical feature is the thickness of the heart wall in the location of the lesion.

15. The method according to claim 1, wherein: The at least one trajectory includes at least one line segment indicated as existing by a user.

16. The method according to claim 1, wherein: The at least one trajectory does not include at least one line segment indicated by the user as not existing.

17. A computerized device having a processor coupled to a memory unit, the processor being adapted to perform the following steps: obtaining coordinates of a location in a body part of a patient; determining at least one trajectory including at least a portion of the location; determining whether a connection between at least two locations connected along the at least one trajectory exceeds a threshold; providing a visual representation of the body part, the visual representation including visual indications of at least some of the locations and connections between the locations; as well as In the event that the connection exceeds the threshold, a visual indication of the connection weight is provided.

18. The computerized device of claim 17, wherein: The processor is adapted to perform the following steps for determining the at least one trajectory, comprising: clustering the locations to form at least one cluster; and Determine the minimum spanning tree within each cluster.

19. The computerized device of claim 18, wherein: The processor is adapted to determine at least one line segment connecting locations within the cluster, and to add the line segment to the tree such that the tree forms at least one closed locus.

20. A computer program product comprising a non-transitory computer readable medium retaining program instructions which, when read by a processor, cause the processor to execute: obtaining coordinates of a location in a body part of a patient; determining at least one trajectory including at least a portion of the location; determining whether a connection between at least two locations connected along the at least one trajectory exceeds a threshold; providing a visual representation of the body part, the visual representation including visual indications of at least some of the locations and connections between the locations; as well as In the event that the connection exceeds the threshold, a visual indication of the connection weight is provided.

Images