Automatic mesh remodeling of anatomical maps to expose internal points of interest

Abstract

The invention is entitled "Automatic mesh reshaping of anatomic maps to expose internal points of interest." The invention provides a method of volumetric mapping of at least a portion of a cavity of a body organ including a plurality of mapped locations, and a point cloud of locations marked for treatment in the cavity. The volumetric map is updated by removing a portion of the mapped locations such that the locations marked for treatment fall on a surface of the volumetric map. A map of at least a portion of the cavity is generated using the updated volumetric map, the map including the locations marked for treatment. The map is displayed to a user.

Description

Technical Field

[0001] The present invention relates generally to electroanatomical (EA) mapping, and more specifically to the automatic editing of cardiac EA mapping maps. Background Technology

[0002] Software-based editing tools for assisting in the interpretation of mapped cavities of organs have previously been disclosed in patent literature. For example, in the dental field, U.S. Patent Application Publication No. 2006 / 0286501 describes the use of a computer to create a plan for repositioning teeth in orthodontic patients. The computer receives an initial digital dataset representing the initial position of the patient's teeth and a final digital dataset representing the final position of the teeth. The computer then uses the datasets to generate a treatment path in which the teeth will move from the initial position to the final position. In some embodiments, individual tooth models include data representing hidden tooth surfaces, such as roots imaged by X-ray, CT scan, or MRI techniques. The roots and hidden surfaces can be inferred from outside the visible surface of the patient's teeth.

[0003] For example, U.S. Patent Application Publication No. 2017 / 0325891 describes a method relating to generating a three-dimensional surface representation of an anatomical structure such as a cardiac chamber. More specifically, the three-dimensional surface representation of the anatomical structure is constrained relative to one or more anchor portions corresponding to received input regarding the location of anatomical feature structures of the anatomical structure. The resulting three-dimensional surface representation includes prominent feature structures of the anatomical structure and can therefore be used as a visualization tool during any of a variety of medical procedures, including, for example, cardiac ablation. Summary of the Invention

[0004] The embodiments of the invention described below provide a method comprising receiving or generating a volumetric mapping of at least a portion of a cavity of a body organ including multiple mapped locations, and a point cloud of locations in the cavity marked for treatment. The volumetric mapping is updated by removing a portion of the mapped locations such that the locations marked for treatment fall on a surface of the volumetric mapping. A mapping of at least a portion of the cavity, including the locations marked for treatment, is generated using the updated volumetric mapping. The mapping is then displayed to a user.

[0005] In some implementations, removing the mapping location includes identifying one or more locations marked as treatment sites that fall inside the volume mapping map, and removing the portion such that the identified treatment sites fall on the surface of the volume mapping map.

[0006] In some implementations, identifying a location marked as a treatment site within the volume mapping includes determining a vector from the location marked as a treatment site to the corresponding projection on the surface that is opposite to the outward-pointing normal of the surface at the projection location.

[0007] In the implementation scheme, the location marked for treatment is a location on the cardiac wall tissue and is marked for ablation.

[0008] In another embodiment, generating the mapping includes generating an electroanatomical (EA) mapping of at least a portion of the wall tissue.

[0009] In some implementations, removing the mapping location includes projecting the location marked for treatment onto a corresponding location on the surface of the volume mapping map, and removing a portion of the volume mapping map, which includes the surface connecting the location marked for treatment to the projected location.

[0010] In some implementations, removing the surface connecting the location marked for treatment and the location of projection includes removing the surface defined between a first curve generated by interconnecting the location marked for treatment and a second curve generated by interconnecting the location of projection.

[0011] In other embodiments, the removal of a portion of the volume includes defining a corresponding distance embedded in the surface between each location marked for treatment and a corresponding projected location on the surface, and defining the portion to be removed based on that distance.

[0012] In one implementation, the portion of the volumetric mapping to be removed includes a sphere with a defined diameter corresponding to a distance.

[0013] In another implementation, displaying the mapping map to the user includes presenting one or more icons at locations marked for treatment.

[0014] According to another embodiment of the invention, a system including a memory and a processor is also provided. The memory is configured to store a plurality of mapped locations acquired in a cavity of a body organ, and a point cloud of locations in the cavity marked for treatment. The processor is configured to (i) receive or generate a volumetric mapping map of at least a portion of the cavity including the plurality of mapped locations; (ii) update the volumetric mapping map by removing a portion of the mapped locations such that the locations marked for treatment fall on the surface of the volumetric mapping map; (iii) generate a mapping map of at least a portion of the cavity using the updated volumetric mapping map, the mapping map including the locations marked for treatment; and (iv) display the mapping map to a user. Attached Figure Description

[0015] The invention will be more fully understood through the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, wherein:

[0016] Figure 1 A schematic diagram of a system for electroanatomical (EA) mapping according to an exemplary embodiment of the present invention;

[0017] Figure 2 It is a translucent EA mapping of the volume of the left atrium according to an exemplary embodiment of the present invention, which shows the location marked for ablation and the location of the corresponding projection on the surface of the EA mapping;

[0018] Figure 3 This is a flowchart illustrating, according to an exemplary embodiment of the present invention, a method for exposing cardiac chambers marked as locations for ablation; and

[0019] Figure 4A and Figure 4B This is a non-transparent mapping of the volume of the heart chambers according to an exemplary embodiment of the present invention, which shows the surface of the icon for the ablation site hidden and the mesh-remodeled surface of the icon exposed at the site marked for ablation. Detailed Implementation

[0020] Overview

[0021] The cavities of a patient's organs (such as heart chambers), hereinafter also referred to as cardiac ventricles, can be mapped (e.g., electroanatomical mapping) using a mapping catheter having one or more suitable sensors (such as electrodes) fitted at its distal end for mapping within the organ. Using position signals generated by various sensors, a processor can calculate the sensor positions within the organ (e.g., the positions of sensing electrodes within a heart chamber). Using the calculated positions, the processor can also obtain an anatomical mapping of the cavity surface. In the case of a heart chamber (e.g., a cardiac ventricle), the processor can derive an electroanatomical (EA) mapping of the cavity surface. In some embodiments, such EA mappings also graphically indicate the location of the arrhythmia on the cavity wall tissue that should be ablated to treat the arrhythmia.

[0022] Therefore, typically prior to cardiac ablation, cardiac chambers are mapped to (i) obtain a volumetric representation of the cardiac chamber anatomy and (ii) acquire a point cloud of locations within the cardiac chambers marked for ablation. At least some of these locations are usually located along a curve. For example, in rapid anatomical mapping (FAM) of cardiac chambers, point locations on the inner surface of the chamber are plotted using acquired EA data. The physician can then ablate these locations along the curve to block abnormal electrophysiological signals, such as in the case of isolating the pulmonary vein orifice in the left atrium.

[0023] However, during FAM reconstruction, incorrect catheter positions can also be acquired and automatically added to the lumen surface constructed by the FAM. Examples of such unwanted data points include lumen wall positions deformed by outward pushing of the catheter, and incorrect wall positions due to respiratory-induced motion.

[0024] The accumulation of such unwanted locations affects the accuracy of reconstructed EA mapping. To address these inaccuracies, during or after acquisition, a physician or an expert assisting the physician may manually edit the surface generated from the acquired points to correct the errors. This manual editing typically involves erasing the location from the calculated surface and / or removing (“shaving”) the entire section. However, this manual editing is a time-consuming process.

[0025] Furthermore, in some cases, incorrect catheter placement can obstruct or obscure markers pointing to the selected wall tissue location for treatment, such as the location for ablation of cardiac wall tissue. Typically, while the locations for ablation are marked (e.g., overlaid) on the mapping map as icons (e.g., “visitags”), some of these icons may become invisible due to the aforementioned or other mapping errors, as they appear inside the chamber rather than on its outer surface.

[0026] Embodiments of the present invention use the fundamental assumption that the mapped locations marked for treatment (e.g., ablation) are correct, and that any obstruction of such markings by other locations on the cavity wall is due to mismapping of the wall tissue. Such mismapping causes locations marked for treatment to appear incorrectly inside the cavity. This results in icons (e.g., visitag icons) pointing to these locations being hidden in the typically opaque view of the organ cavity's mapping.

[0027] To overcome such errors, the processor corrects the cavity mapping so that locations marked for treatment fall on the cavity wall. In one implementation, the processor receives or generates an EA mapping of at least a portion of the cardiac cavity volume, and a point cloud of locations marked for treatment (e.g., ablation). The processor identifies one or more locations marked for treatment that fall inside the volume and, in response, updates the volume by removing a portion of the mapped locations so that the locations marked for treatment fall on the surface of the cavity mapping volume. Using the updated EA mapping data, the processor generates a mapping of at least a portion of the cavity, including the locations marked for treatment, and displays the mapping to the user.

[0028] In another implementation, to remove a portion of the mapped location, the processor projects the locations marked for treatment onto the modeling surface of the cavity. The processor then connects the locations marked for treatment with a first spline and the projected locations with a second spline. A "ball rolling" algorithm is then used: a "ball" with a variable radius, found by connecting the corresponding locations marked for treatment and the projected locations, "rolls" along the two splines, removing the anatomical locations from the cavity volume and surface from the cloud. The cavity surface is then reconstructed using an updated dataset to display the original locations marked for treatment (e.g., to make their icons visible in an external view of the model). Typically, shapes other than spheres can be used, such as ellipsoids with variable widths and diameters.

[0029] By exposing hidden landmarks (e.g., icons) marked as locations for treatment, the disclosed technique can assist physicians in improving the quality of complex diagnostic tasks performed during diagnostic catheter insertion, such as marking (e.g., via visual icons) the tissue locations to be ablated. Another advantage of the disclosed technique is that it reduces the editing time of portions of the EA mapping map, for example, when done manually for this purpose.

[0030] System Description

[0031] Figure 1 This is a schematic diagram of a system 21 for electroanatomical (EA) mapping according to an embodiment of the present invention. Figure 1 It shows the use of An EA mapping catheter 29 is used by a physician 27 to perform EA mapping of the heart 23 of a patient 25. The catheter 29 includes one or more arms 20, which may be mechanically flexible, at its distal end, each arm being coupled to one or more electrodes 22. During the mapping procedure, the electrodes 22 acquire unipolar and / or bipolar signals from the tissue of the heart 23 and / or inject the signals into the tissue of the heart.

[0032] The processor 28 in console 30 receives these signals via electrical interface 35 and uses the information contained in these signals to construct the EA mapping map 40 stored in memory 33. During and / or after the procedure, the processor 28 may display the EA mapping map 40 on display 26. User controls 32 of user interface 100 enable physician 27 to communicate with processor 28 and command editing and / or highlighting of portions of the EA mapping map 40. Controls 32 may include, for example, a trackball and control knobs, as well as a keyboard. Other elements of user interface 100 may include touchscreen functionality of display 26.

[0033] In this process, a tracking system is used to track the corresponding positions of the sensing electrodes 22, such that each of these signals can be associated with a signal acquisition location. For example, an active catheter positioning (ACL) system manufactured by Biosense-Webster (Irvine, California) as described in U.S. Patent No. 8,456,182, the disclosure of which is incorporated herein by reference, can be used. In the ACL system, the processor estimates the corresponding positions of these electrodes based on impedance measurements between each sensing electrode 22 and multiple surface electrodes 24 coupled to the skin of the patient 25. For example, three surface electrodes 24 may be coupled to the patient's chest, and another three surface electrodes may be coupled to the patient's back. (For ease of illustration,) Figure 1 Only one surface electrode is shown. Current is transmitted between electrode 22 and surface electrode 24 within the patient's heart 23. Processor 28 calculates the estimated location of all electrodes 22 within the patient's heart based on the ratio between the obtained current amplitudes (or the impedances represented by these amplitudes) measured at surface electrode 24, and the known location of electrode 24 on the patient's body. Therefore, the processor can associate any given impedance signal received from electrode 22 with the location where the signal was acquired.

[0034] Figure 1 The exemplary illustrations shown are chosen solely for conceptual clarity. Other tracking methods, such as those based on measuring voltage signals, can be used. Equivalently, other types of sensing conduits, such as… A catheter (manufactured by Biosense Webster) or a basket catheter. A contact sensor can be fitted at the distal end of the EA mapping catheter 29. As described above, other types of electrodes (such as electrodes for ablation) can be used to acquire the desired location data in a manner similar to that fitted to electrode 22. Therefore, in this case, the ablation electrode used to collect location data is considered as the sensing electrode. In an optional embodiment, processor 28 is further configured to indicate the quality of physical contact between each electrode 22 and the intraventricular surface of the heart chamber during measurement.

[0035] Processor 28 typically includes a general-purpose computer having software programmed to perform the functions described herein. Specifically, processor 28 runs the functions disclosed herein, including... Figure 3 The software contains a dedicated algorithm that enables processor 28 to perform the disclosed steps, as further described below. The software can be downloaded to a computer electronically via a network, or alternatively or additionally set and / or stored on a non-transitory tangible medium (such as magnetic storage, optical storage, or electronic storage).

[0036] Automatic mesh reshaping of anatomical mapping of internal points of interest

[0037] Figure 2 It is a translucent EA mapping 200 of the volume of the left atrium according to an embodiment of the present invention, which shows the location marked for ablation (202) and the corresponding projection location 204 on the surface of the EA mapping.

[0038] Figure 2 The diagram shown is for clarity and simplicity only. The disclosed process does not necessarily require the generation of such an initial diagram. Instead, the processor receives acquisition data, including location information, and applies the disclosed steps to the mapped volume.

[0039] As shown in the figure, the mapping locations 202 marked for ablation are each along the circumference of the orifice 222 of the pulmonary vein. The mapped locations define a contour (not shown) along which subsequent ablation is performed to isolate arrhythmias.

[0040] As described above, an error in the mapping diagram 200 can cause the icon at location 202 to be hidden in a non-transparent view.

[0041] In one embodiment of the disclosed technology, the processor identifies only the locations marked for treatment 202 that fall within the mapped volume by determining whether the vector between each location 202 marked for treatment and its corresponding projected surface location 204 is opposite to the outward-pointing normal of the surface of the cavity at the projected location. The processor then projects the locations 202 onto the surface location 204 to subsequently generate a mapping map in which icons of the locations 202 are visible, as described below.

[0042] In another implementation, the processor projects all points marked for treatment without attempting to identify which locations are internal. If a point is already on the surface, the diameter of the rolling ball or the local volume to be removed will be zero or negligible.

[0043] Although the cavity shown is the left atrium, this description applies to cavities of other organs and treatments that differ from ablation.

[0044] Figure 3 This is a flowchart schematically illustrating a method for exposing cardiac chambers marked as locations for ablation according to an embodiment of the present invention. According to the presented embodiment, the algorithm executes a process that begins at a data receiving step 302 where processor 28 receives an EA mapping of at least a portion of the volume of the cardiac chambers and a point cloud of locations marked as locations for ablation. At this stage, some of the locations marked as locations for ablation may include hidden icons.

[0045] Then, at data projection step 304, processor 28 projects the locations marked for ablation onto the corresponding locations on the surface of the chamber mapping volume.

[0046] At the data connection step 306, the processor 28 connects the marked locations for ablation via the first spline and connects the corresponding projected locations found in step 304 via the second spline.

[0047] Then, at point cloud update step 308, processor 28 generates an updated volume by automatically removing a portion of the volume, which includes the surface connecting the marked location for ablation to the projected location. For example, the processor "rolls" a sphere with a variable diameter (or "rolls" the aforementioned ellipsoid) along two splines and removes the intersection between the chamber volume and the rolled sphere or ellipsoid from the chamber mapping volume.

[0048] At step 310 of the EA mapping generation, using the updated mapped data or chamber volume mapping, processor 28 generates an EA mapping of the heart chamber portion, including visible icons marking the ablation location, as shown below. Figure 4B The mapping diagram 440 shown is shown.

[0049] Finally, at step 312 of the mapping display, the processor 28 presents the EA mapping to the user.

[0050] Figure 3 The exemplary flowcharts shown are chosen solely for clarity of concept. For example, in an alternative embodiment, the cavity is an organ other than the heart.

[0051] Reconstructed mesh of anatomical mapping

[0052] Figure 4A and Figure 4B The non-transparent EA mapping maps 400 and 440, representing the volume of the heart chambers according to an embodiment of the present invention, respectively show a surface 405 with an icon (402) hidden for ablation sites and an icon (404) exposed on a mesh-remodeled surface at the site marked for ablation.

[0053] like Figure 4A As shown, almost all the icon markers 402 used for ablation at the two openings of the pulmonary veins in the left atrium are hidden beneath surface 405. On the other hand, in Figure 4B In the middle, the regenerated surface 410 exposes the corresponding position, as shown in icon 404.

[0054] Physicians can use the 440 map to perform the required ablation.

[0055] It should be understood that the above embodiments are cited by way of example, and the invention is not limited to the specific content shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the above description, and which are not disclosed in the prior art. Documents incorporated herein by reference are considered an integral part of this application, except that if any terminology defined in such incorporated documents conflicts with the definitions expressly or implicitly given in this specification, only the definitions in this specification shall be considered.

Claims

1. A method for exposing hidden landmarks at a treatment location in an anatomical mapping, the method comprising: Receive or generate a volumetric mapping map of at least a portion of a cavity of a body organ, including multiple mapped locations, and a point cloud of locations in the cavity marked for treatment; The volume mapping is updated by removing a portion of the mapped location so that the location marked for treatment falls on the surface of the volume mapping; The updated volume mapping is used to generate a mapping of at least a portion of the cavity, the mapping including the marked locations for treatment; as well as Display the mapping map to the user. The removal of the portion of the mapped location includes projecting the location marked for treatment onto a corresponding location on the surface of the volume mapping map, and removing the portion of the mapping map, which includes the surface connecting the location marked for treatment to the projected location.

2. The method according to claim 1, wherein, Removing a portion of the mapped location includes identifying one or more of the marked locations for treatment that fall inside the volume mapping map, and removing the portion such that the identified marked locations for treatment fall on the surface of the volume mapping map.

3. The method according to claim 2, wherein, Identifying a mark falling inside the volume mapping as a location for treatment includes determining a vector from the location marked for treatment to the corresponding projection on the surface that is opposite to the outward-pointing normal of the surface at the projected location.

4. The method according to claim 1, wherein, The location marked for treatment is a location on the cardiac wall tissue and is marked for ablation.

5. The method according to claim 4, wherein, Generating the mapping includes generating an electroanatomical (EA) mapping of at least a portion of the wall tissue.

6. The method according to claim 1, wherein, Removing the surface connecting the marked location for treatment to the projected location includes removing the surface defined between a first curve generated by interconnecting the marked location for treatment and a second curve generated by interconnecting the projected location.

7. The method according to claim 1, wherein, Removing a portion of the volume mapping includes defining a corresponding distance embedded in the surface between each location marked for treatment and the location of a corresponding projection on the surface, and defining the portion to be removed based on the distance.

8. The method according to claim 7, wherein, The removed portion of the defined volume includes a sphere with a defined diameter corresponding to the distance.

9. The method according to claim 1, wherein, Displaying the mapping map to the user includes presenting one or more icons at the locations marked for treatment.

10. A system for exposing hidden landmarks at locations for treatment in anatomical mapping, the system comprising: A memory configured to store multiple locations of maps acquired in cavities of body organs, and point clouds of locations in the cavities marked for treatment purposes; as well as Processor, the processor being configured to: Receive or generate a volume mapping map of at least a portion of the cavity, including the locations of the plurality of maps; The volume mapping is updated by removing a portion of the mapped location so that the location marked for treatment falls on the surface of the volume mapping; The updated volume mapping is used to generate a mapping of at least a portion of the cavity, the mapping including the marked locations for treatment; as well as Display the mapping map to the user. The processor is configured to project the location marked for treatment onto a corresponding location on the surface of the volume mapping and remove the portion of the mapping, the portion including the surface connecting the location marked for treatment to the projected location.

11. The system according to claim 10, wherein, The processor is configured to identify one or more of the marked locations for treatment that fall inside the volume mapping, and to remove the portion such that the identified marked locations for treatment fall on the surface of the volume mapping.

12. The system according to claim 11, wherein, The processor is configured to identify locations marked for treatment that fall inside the volume mapping by determining a vector from the location marked for treatment to the corresponding projection on the surface that is opposite to the outward-pointing normal of the surface at the projected location.

13. The system according to claim 10, wherein, The location marked for treatment is a location on the cardiac wall tissue and is marked for ablation.

14. The system according to claim 13, wherein, The processor is configured to generate the mapping by generating an electroanatomical (EA) mapping of at least a portion of the cardiac wall tissue.

15. The system according to claim 10, wherein, The processor is configured to remove the surface connecting the marked location for treatment and the projected location by removing the surface defined as being between a first curve generated by interconnecting the location marked for treatment and a second curve generated by interconnecting the location projected.

16. The system according to claim 10, wherein, The processor is configured to remove the portion of the volume by defining a corresponding distance embedded in the surface between each location marked for treatment and a corresponding projected location on the surface, and by defining the portion to be removed based on the distance.

17. The system according to claim 16, wherein, The processor is configured to define the removed portion of the volumetric mapping by defining a sphere with a diameter corresponding to the distance.

18. The system according to claim 10, wherein, The processor is configured to display the mapping map to the user by presenting one or more icons at the locations marked for treatment.

Images