Visualizing quality indicator indicative of ablation stability at ablation site

Abstract

A system includes a display and a processor. The processor is configured to: (i) receive a plurality of position measurements indicative of respective positions of the ablation electrodes at respective times during an ablation procedure at an ablation site in an organ of a patient; (ii) estimating a quality indicator indicative of stability of the ablation procedure at the ablation site based at least on the plurality of position measurements; and (iii) visualizing the quality indicator to a user on the display.

Description

Technical Field

[0001] The present disclosure relates generally to tissue ablation, and particularly to methods and systems for visualizing to a user a quality indicator indicating ablation stability at an ablation site. Background Art

[0002] Various techniques have been disclosed for estimating and visualizing the stability of tissue ablation procedures.

[0003] For example, U.S. Pat. No. 6,129,669 describes systems and methods for sensing the stability of an ablation device within a body region. These systems and methods position a tracking element in a fixed position spaced apart from the ablation device. These systems and methods generate an output that varies according to the movement of the ablation device relative to the tracking element over time.

[0004] U.S. Patent Application Publication No. 2021 / 0346103 describes a system for supporting medical intervention, a method for outputting a feedback signal, and a computer program product. The system includes a feedback device for outputting a feedback signal to a user of an intervention device, and a control device for controlling the feedback device. The control device is configured to receive an actual position of the intervention device and a target position of the intervention device. The control device is further configured to determine a deviation between the actual position and the target position and control the output of the feedback signal by the feedback device according to the deviation. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present disclosure will be more fully understood through the following detailed description of examples of the present disclosure in conjunction with the accompanying drawings, in which:

[0006] Figure 1 is a schematic illustration of a catheter-based tracking and ablation system according to an example of the present disclosure;

[0007] Figure 2 a diagram illustrating annotations of ablation sites on a map of a patient's heart according to an example of the present disclosure;

[0008] Figure 3 a chart illustrating annotation of ablation parameters on a map of a patient's heart according to another example of the present disclosure; and

[0009] Figure 4 A flow chart schematically illustrates a method for calculating and visualizing an ablation stability quality indicator on a map of a patient's heart according to an example of the present disclosure. DETAILED DESCRIPTION

[0010] Overview

[0011] Some medical procedures require applying ablation signals to tissue of a patient's organ.For example, a radio frequency (RF) ablation signal may be applied to cardiac tissue at an ablation site for treating arrhythmias.

[0012] Tissue ablation is intended to transform tissue into a lesion that is suitable for blocking the undesired propagation of electrophysiological waves through the tissue intended to be ablated. In response to ablation, tissue cells die, and at least a portion of the ablated tissue is transformed into a lesion. In order to block the propagation of electrophysiological waves, the physician performing the ablation generally defines an ablation line (or loop) including multiple ablation sites, and uses one or more ablation electrodes of a catheter placed in contact with the tissue to apply an ablation signal to the tissue at each ablation site to obtain a suitable lesion. However, in some cases, when an ablation signal is applied at a given ablation site, the ablation electrode may move undesirably relative to the tissue. Such movement reduces the stability of the ablation electrode relative to the tissue at the ablation site, and may therefore reduce the quality of the lesion and leave gaps in the ablation line that may not completely block the propagation of electrophysiological waves.

[0013] In addition, the physician requires an indication of stability relative to the ablated tissue while applying the ablation signal. In this context, the term "stability" refers to the allowed speed of movement and the allowed distance between: (i) a first position, e.g., the position of the ablation electrode when the physician begins applying the ablation signal, and (ii) one or more second positions at which the ablation electrode visits while applying the ablation signal.

[0014] Examples of the present disclosure described below provide methods and systems for improving the estimation and visualization of quality indicators indicative of ablation stability at an ablation site.

[0015] In some examples, a system for applying an ablation pulse to a patient's heart includes: (i) a power source, such as a radio frequency (RF) generator, configured to generate an ablation signal; (ii) a catheter electrically connected to the RF generator and including at least: (a) an ablation electrode, configured to apply the ablation signal to tissue placed in contact therewith; and (b) a position sensor, configured to generate a position signal indicative of a measured position of the ablation electrode in the heart; (iii) a display; and (iv) a processor configured to display the position of the ablation electrode on a map of the patient's heart. Components of the system are described below. Figure 1 Described in detail in.

[0016] In some examples, the processor is configured to receive a plurality of position measurements indicating respective positions of an ablation electrode at an ablation site in a patient's heart at respective times during an ablation procedure. The processor is configured to receive a reference position, which is the position of the ablation electrode when an ablation signal is initially applied to tissue at the ablation site. The processor is further configured to maintain a threshold indicating: (i) an allowable distance between the reference position and the plurality of measured positions of the ablation electrode when the ablation signal is applied, and (ii) an allowable speed of the ablation catheter relative to the reference position. The above operations are described below. Figure 2 and Figure 4 Described in detail in.

[0017] In some examples, based on the multiple position measurements, the reference position, and the threshold, the processor is configured to estimate a quality indicator indicating the stability of the ablation procedure at the ablation site (also referred to herein as an ablation stability quality indicator). In this context, the term "stability" refers to the measured distance and speed relative to the threshold indicating the allowed distance and speed. In other words, the processor is configured to estimate the quality indicator based on the respective distances of at least some of the measured positions from the reference position and / or based on the estimated speed of the ablation electrode when the ablation signal is applied at the ablation site, the estimation being described below. Figure 2 Described in detail in.

[0018] In some examples, the processor is configured to visualize the quality indicator to the physician (and any other user) on a display of the system. For example, when ablating tissue at a given ablation site, the processor is configured to display a spherical or spherical-like icon, also referred to herein as a visitag icon, at the given ablation site. The processor is further configured to assign to the visitag icon a color that indicates the value of the corresponding ablation stability quality indicator relative to a threshold value of the ablation stability quality indicator, as described below. Figure 2 As shown and described in detail in FIG.

[0019] In some examples, in response to identifying that the value of the ablation stability quality indicator exceeds a corresponding threshold, the processor 33 is configured to display a halo around the corresponding visitag icon. In this example, the halo may be displayed for approximately 3 seconds and indicates the termination of ablation at the location marked by the visitag icon, and immediately after the halo disappears, the processor generates a new visitag icon whose calculated centroid is at the measured current location of the ablation electrode. The halo and the new visitag icon provide the physician with an indication of the stability and status of the ablation procedure at the corresponding ablation site, as will be described below. Figure 2 Described in more detail in .

[0020] In some examples, when an estimated distance of a given position of an ablation electrode (during ablation) from a reference position exceeds a distance threshold, the processor calculates and displays one or more contours that are based on the positions visited by the ablation electrode and indicate the corresponding contours traveled by the ablation electrode when an ablation signal is applied to tissue at the given ablation site.

[0021] In some examples, the processor is configured to display to the physician a table including corresponding values ​​of the calculated ablation stability quality indicator. In an alternative example, the processor is configured to display any suitable information selected by the physician on a map of the heart. For example, the processor can display on the map 27 at a given ablation site: (i) a distal end assembly of the catheter (which includes an ablation electrode), (ii) a visitag icon indicating the ablation result at a given ablation site, (iii) an ablation stability quality indicator at a given ablation site, and (iv) any other suitable information related to ablation, such as but not limited to ablation indicators calculated based on the main parameters of the ablation.

[0022] The disclosed technology provides a real-time indication of the stability of an ablation procedure to a user of the system (e.g., a physician) so that if an ablation stability quality indicator exceeds a corresponding threshold, the physician can initiate corrective measures for improving the quality of a lesion formed in the heart.

[0023] System Description

[0024] Figure 1 is a schematic illustration of a catheter-based tracking and ablation system 20 according to an example of the present disclosure.

[0025] In some examples, the system 20 includes: a catheter 22 and a console 24, the catheter being configured to perform cardiac surgery. In the examples described herein, the catheter 22 includes a focusing catheter that can be used for any suitable therapeutic and / or diagnostic purpose, such as for sensing electroanatomical signals and / or for ablating tissue in the heart 26 (inset 23), as will be described in detail below. In the context of the present disclosure and the claims, the term "ablation" refers to a radiofrequency (RF) ablation procedure or an irreversible electroporation (IRE) procedure. These procedures are intended to apply one or more high-voltage unipolar or bipolar electrical pulses to one or more electrodes in contact with the tissue to be ablated so as to form a lesion in a target location in the heart 26 (also referred to herein as an ablation site) and thereby treat arrhythmias in the heart.

[0026] In some examples, console 24 includes a processor 33 (typically a general purpose computer) having suitable front-end and interface circuitry for receiving signals via catheter 22 and for controlling other components of system 20 described herein. Console 24 also includes a user display 35 that is configured to receive graphical and / or textual display items, such as a map 27 of heart 26, from processor 33 and is configured to display map 27.

[0027] In some examples, map 27 may include any suitable type of three-dimensional (3D) anatomical map generated using any suitable technology. For example, a 3D anatomical map may be generated using a suitable medical imaging system, or using a CARTO TM The anatomical map may be generated using the Fast Anatomical Mapping (FAM) technique of the system, or using anatomical images generated using any other suitable technique, or using any suitable combination of the above.

[0028] In some examples, the console 24 includes a recording unit 38 that is configured to record the TM The console 24 includes a patient interface unit (PIU) 44 configured to generate position indication signals and electrocardiogram (ECG) signals that are acquired and processed to exchange signals between the console 24 and multiple entities of the system 20 (e.g., the catheter 22).

[0029] Reference is now made to illustration 23. In some examples, prior to performing an ablation procedure, a physician 30 inserts one or more catheters into the vasculature of a patient 28 lying on an operating table 29 in order to perform electroanatomical (EA) mapping of the tissue of interest of the heart 26. Based on the EA mapping, the physician 30 plans an ablation or IRE procedure, which is performed using the focused catheter 22.

[0030] Reference is now made to illustration 42. In some examples, catheter 22 includes a distal tip assembly (DEA) 40 having one or more ablation electrodes 55 configured to apply an ablation signal to tissue of heart 26. Catheter 22 further includes a position sensor 39, which is generally coupled to the distal tip of catheter 22 and is configured to generate a position signal indicative of a measured position of DEA 40 (and more specifically, ablation electrode 55) in an XYZ coordinate system, as will be described in detail below.

[0031] In some examples, DEA 40 includes a contact force sensor, referred to herein as force sensor 54, which is configured to measure the force applied by DEA 40 of catheter 22 to the endocardial tissue of heart 26. Force sensor 54 is configured to generate a force signal indicating the force applied by DEA 40 to the endocardial tissue of heart 26. In some examples, the force sensor can include a magnetic field transmitter and receiver connected by a spring in DEA 40, and can generate an indication of the force based on measuring the deflection of the spring. Further details of such catheters and force sensors are described in U.S. Patent Application Publications Nos. 2009 / 0093806 and 2009 / 0138007. In other examples, force sensor 54 can include any other suitable type of force sensor.

[0032] In the present example, ablation electrode 55 is positioned at the tip of DEA 40 and placed in contact with endocardial tissue of heart 26 such that the force signal is indicative of a force applied between ablation electrode 55 and the endocardial tissue of heart 26 .

[0033] Now return to reference Figure 1 In some examples, PIU 44 is connected to a power source, such as a radio frequency (RF) generator 49 enclosed within the housing of PIU 44. In alternative examples, the RF generator may be external to the housing of PIU 44 and electrically connected to PIU 44 using a suitable cable. RF generator 49 is configured to apply a suitable RF ablation signal.

[0034] In some examples, the proximal end of catheter 22 is specifically connected to an interface circuit (not shown) of PIU 44 for transmitting ablation signals from PIU 44 to electrodes 55 and applying the ablation signals to tissue of heart 26. The interface circuit is further configured to transmit position signals between position sensor 39 and processor 33.

[0035] In some examples, system 20 includes a neutral electrode 48, also referred to herein as a patch electrode, which is attached to the skin of patient 28 (e.g., on the back of the patient's torso) and electrically connected to PIU 44 via cable 21. In other examples, system 20 can include any suitable number of skin patches configured to adhere respective electrodes (e.g., about four or five electrodes) to the skin of patient 28.

[0036] In the context of the present disclosure and claims, the terms "about" or "approximately" for any numerical values ​​or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for the intended purpose described herein.

[0037] In some examples, system 20 includes a handle 32 that is used by physician 30 to guide DEA 40 through the vasculature of patient 28 and into a target location for performing ablation in heart 26 , also referred to herein as an ablation site.

[0038] In some examples, a position sensor 39 of a magnetic position tracking system is used to measure the position of the distal tip assembly 40 in the vasculature and heart 26 of the patient 28. In this example, the console 24 includes a drive circuit 41 configured to drive a magnetic field generator 36 placed at a known position external to the patient 28 lying on the operating table 29 (e.g., under the patient's torso). The position sensor is coupled to the distal tip and is configured to generate a position signal in response to an external magnetic field sensed from the field generator 36. The position signal (also referred to herein as a position measurement result) indicates the position of the DEA 40 in the XYZ coordinate system of the position tracking system.

[0039] This position sensing method is implemented in various medical applications, for example, in the CARTO manufactured by Biosense Webster Inc. (Irvine, Calif.) TM systems, and are described in detail in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, PCT Patent Publication WO 96 / 05768, and U.S. Patent Application Publication Nos. 2002 / 0065455A1, 2003 / 0120150A1, and 2004 / 0068178A1.

[0040] In some examples, the coordinate system of the position tracking system is registered with the coordinate systems of system 20 and map 27 such that processor 33 is configured to display the position of distal tip assembly 40 on an anatomical or EA map (eg, map 27 ).

[0041] In some examples, processor 33 typically includes a general purpose computer that is programmed in software to perform the functions described herein. The software may be downloaded to the computer in electronic form over a network, for example, or it may alternatively or additionally be provided and / or stored on a non-transitory tangible medium such as magnetic, optical, or electronic storage.

[0042] This particular configuration of system 20 is shown by way of example in order to illustrate certain problems solved by the examples of the present disclosure and to demonstrate the application of these examples in enhancing the performance of such systems. However, the examples of the present disclosure are by no means limited to this particular class of example systems, and the principles described herein may be similarly applied to other types of medical systems configured for other types of tissue ablation procedures.

[0043] Compute and visualize ablation stability quality metrics

[0044] Figure 2 Schematic diagram illustrating annotations of ablation sites 52 and 53 on map 27 of heart 26 according to an example of the present disclosure. Note that ablation sites 52 and 53 include enlarged views of the respective ablation sites displayed on map 27 by processor 33. An example method for generating annotations is described below. Figure 4 Described in.

[0045] In some examples, each annotation includes: (i) an icon, such as icons 50 and 51, at the ablation sites 52 and 53, respectively, and (ii) a table, such as tables 56 and 57, at the ablation sites 52 and 53, respectively. Tables 56 and 57 include calculated quality indicators 58 and 59, respectively, which indicate the stability of the ablation procedure performed at the ablation sites 52 and 53, respectively. In the context of the present disclosure and in the claims, the terms "quality indicator" and "stability quality indicator" are used interchangeably and refer to any suitable type of quantitative dimension or value or metric that indicates the stability of tissue ablation, as will be described in detail in Figures 60 and 61 below.

[0046] Reference is now made to illustrations 60 and 61, which illustrate the calculation of quality indicators 58 and 59 and the generation of icons 50 and 51, respectively. Note that icons 50 and 51 are also referred to herein as visitags or visitag icons, and are generated using a software package referred to herein as VisiTag, produced by Biosense Webster Inc. (Irvine, Calif.). TM The visitag is typically displayed on a map 27 of the heart 26 and provides a visual representation of the corresponding ablation lesions formed during the ablation procedure to the physician 30. Examples related to the calculation, display and use of the visitag are described in more detail, for example, in U.S. Patents 9,498,147 and 9,757,182.

[0047] In some examples, when the physician 30 starts tissue ablation, she / he places the ablation electrode 55 in contact with the tissue of the heart 26 at a first position 64 (e.g., position 64a or position 64b) at a corresponding ablation site (e.g., ablation site 52 or ablation site 53). In this example, based on the position signal received from the position sensor 39, the processor 33 is configured to generate a spherical or spheroid icon 66, the calculated center of mass (COM) of which is position 64a. In this example, the icon 66 has a radius of about 2 mm, but in other examples, the icon 66 can have any other suitable size and / or shape.

[0048] In some cases, ablation electrode 55 may move relative to position 64a when physician 30 applies an ablation signal to tissue at ablation site 52. This relative motion may include respiratory motion of patient 28 and / or other motion of DEA 40 relative to position 64a at the corresponding ablation site. In some examples, when planning an ablation, the physician 30 defines a set of thresholds stored in the processor 33 for each ablation site intended to receive an ablation signal, such as, but not limited to: (i) a minimum contact force between the DEA 40 and the tissue when the ablation signal is applied (e.g., greater than about 5 grams of force), (ii) a minimum duration of application of the ablation signal (e.g., between about 3 seconds and 5 seconds), (iii) a maximum distance between a reference position (e.g., position 64a (also referred to herein as the first position)) and a second (different) position at which the ablation electrode 55 is located when the ablation signal is applied (e.g., about 2 mm or any other suitable size), (iv) a maximum speed of movement of the ablation electrode 55 between the first position and the second position (e.g., about 2.5 mm per second), and (v) a maximum value of the stability quality indicator.

[0049] It should be noted that during the ablation procedure, the physician 30 typically defines a plurality of ablation sites intended to produce ablation lines, which are spatial trajectories of ablation sites that are used to block the undesired propagation of electrophysiological waves through the tissue intended to be ablated. Subsequently, the physician 30 applies the ablation signal discretely to the cardiac tissue site by site using the ablation electrode 55. In some cases, due to the instability of ablation, one or more sites (such as ablation sites 52 and / or 53) may not receive the desired ablation signal in the cardiac tissue along the planned ablation line during ablation (e.g., due to undesired movement of the DEA 40 and / or insufficient ablation power, duration, or contact force). Ablation instability may result in one or more openings in the ablation line, also referred to herein as gaps. If gaps exist, cardiac insufficiency may not be alleviated by the procedure. Therefore, when the ablation signal is applied, each undesired movement of the ablation electrode 55 reduces the stability and quality of the lesion formed at the corresponding ablation site.

[0050] Reference is now made to illustration 60. In the scenario shown in illustration 60, ablation electrode 55 has moved from position 64a (i.e., a first position or reference position) to position 67 (e.g., a second position) while an ablation signal is applied to tissue at ablation site 52. In some examples, based on the position signal from position sensor 39, processor 33 is configured to calculate vector 65 indicating a direction and an average distance between position 64a and position 67. Note that during ablation of tissue at ablation site 52, it is assumed that ablation electrode 55 is in the same location (e.g., position 64a) (and, for example, does not move along an ablation line) during all times during which an ablation signal is applied.

[0051] In other examples, instead of vector 65 , processor 33 is configured to calculate an average distance between position 64a and position 67 , which is indicative of the quality indicator described above. For example, quality indicator 58 of table 56 is based on the calculated average distance between position 64a and position 67 .

[0052] In some examples, based on the position signal and a suitable algorithm, the processor 33 is configured to exclude respiratory motion of the patient 28 and calculate the average size of the vector 65. For example, one embodiment of such an algorithm is described in U.S. Patent Application No. 17 / 188,844, where the processor receives respiratory data and probe position data, identifies periods when the probe is stable relative to the cardiac chamber boundary, and uses an algorithm to notify the surgeon of the time interval in which the probe is stable relative to the cavity boundary. Such an algorithm can be used to exclude respiratory motion and retain motion of the probe relative to the cavity boundary that is not related to respiration.

[0053] Additionally or alternatively, quality indicator 58 may be based on any quantitative dimension including any suitable type of calculated (eg, average, median, maximum) distance, velocity, or combination of calculated distance and velocity of movement of DEA 40 (and ablation electrode 55) relative to position 64a.

[0054] In some examples, based on: (i) the position of ablation electrode 55 received from position sensor 39 when applying the ablation signal, and (ii) the above-mentioned stored threshold, processor 33 is configured to estimate a quality indicator indicating the stability of ablation at the corresponding ablation site.

[0055] In the example of ablation site 52 , the quality indicator is equal to approximately 0.68 mm, which is less than the threshold value of the stability quality indicator and thus indicates sufficiently stable ablation at ablation site 52 .

[0056] Reference is now returned to illustration 61. In some examples, based on the position signal received from position sensor 39, and after excluding respiratory motion of patient 28, processor 33 is configured to calculate (i) position 68 and distance 69 (the distance between position 64b and position 68) and (ii) position 70 and distance 71 (the distance between position 64b and position 70). In some examples, based on the calculated distance (and optionally, the calculated movement speed of DEA 40 within ablation site 53), processor 33 is configured to estimate a quality indicator 59 that indicates ablation stability within ablation site 53. As described above for ablation site 52, during ablation of tissue at ablation site 53, it is assumed that ablation electrode 55 is in the same location during all times in which an ablation signal is applied to the tissue. Therefore, a smaller distance between position 64b and other measured positions of ablation electrode 55 generally indicates a stable ablation procedure at the corresponding ablation site.

[0057] Now return to reference Figure 2 As shown in Table 57, quality indicator 59 has a value of approximately 2.25 mm, which exceeds the threshold value of the stability quality indicator and therefore indicates that the stability of the ablation procedure at the ablation site 53 is insufficient.

[0058] In some examples, processor 33 is configured to display halo 72 that surrounds icon 51 and is displayed immediately upon identifying that quality indicator 59 exceeds a threshold value for a stability quality indicator. In this example, both icons 50 and 51 have the same shape and size (e.g., a pseudo 3D sphere with a radius of approximately 2 mm or any other suitable radius), and as described above, the icons provide physician 30 with a visual representation of the ablation lesion for assisting physician 30 in planning and executing an ablation strategy by displaying one or more parameters of lesion formation.

[0059] In some examples, in response to the display of halo 72, physician 30 typically immediately terminates the application of the ablation signal. In the present example, halo 72 is typically displayed for about 3 seconds (or any other suitable time interval) to indicate to physician 30 that ablation stability has been violated at ablation site 53. In some examples, at the same time, processor 33 is configured to begin calculation and estimation of the stability of a newly developed ablation site (e.g., adjacent to ablation site 53) and display a new icon (not shown) indicating the stability of the ablation procedure at the new ablation site.

[0060] Additionally or alternatively, the processor 33 is configured to visualize the quality indicator by assigning appropriate colors to the icons 50 and 51 indicating the estimated quality indicator. Figure 2In the example of , processor 33 is configured to apply a dark gray color to icon 50 , which indicates stable ablation, and a lighter color at edge 73 to illustrate small movements (fractions of a millimeter), such as movement from position 64a to position 67 .

[0061] In some examples, based on the position signals received from position sensor 39, and after excluding respiratory motion of patient 28, processor 33 is configured to calculate and display one or more contours, such as contours 62 and 63, based on the positions visited by ablation electrode 55. Processor 33 is further configured to display, for example in tables 56 and 57, selected numbers associated with ablation procedures performed at ablation sites 52 and 53, respectively.

[0062] This particular configuration of a graphical user interface (GUI) displayed on the display 35 is shown by way of example in order to illustrate certain problems solved by the examples of the present invention and to demonstrate the application of these examples in enhancing the performance of the system 20 during a tissue ablation procedure. However, the examples of the present invention are by no means limited to this particular type of example GUI and / or system, and the principles described herein may be similarly applied to other types of GUIs in any suitable type of medical system and procedure. For example, the processor 33 is configured to display other suitable types of graphical elements in place of or in addition to the halo 72, the visitag icon (icons 50 and 51), the color of the visitag icon, and the outlines 62 and 63.

[0063] Figure 3 is a schematic diagram illustrating annotation of ablation parameters on a map 27 of a heart 26 according to another example of the present disclosure.

[0064] When applying an ablation signal to tissue of heart 26, for example, at ablation site 53, physician 30's line of sight must generally be focused on the ablation site shown on map 27 and cannot view other elements shown on display 35. In some examples, processor 33 is configured to display an ablation stability quality indicator and / or any other parameters related to the ablation procedure on map 27. Figure 3 In the example, the processor 33 displays: (i) a distal tip assembly 40, (ii) an icon 51 (visitag), (iii) an ablation stability quality indicator 59, and (iv) an ablation indicator 74, which is a calculation of the primary parameters of the ablation signal (e.g., contact force, power, and duration of the ablation signal) applied to the tissue of the heart 26 at the ablation site 53 (and / or any other ablation site).

[0065] In other examples, in addition to or in lieu of the visitag, ablation stability quality indicator, and ablation indicator, processor 33 is configured to display any other suitable type of graphical element indicating other parameters related to the ablation procedure on map 27. For example, the temperature and impedance measured at the ablation site and the contact force between DEA 40 and the ablated tissue may be displayed as annotations on DEA 40 and map 27.

[0066] Figure 4 1 is a flow chart schematically illustrating a method for calculating and visualizing an ablation stability quality indicator 59 on a map 27 of a heart 26 according to an example of the present disclosure.

[0067] The method begins with catheter insertion 100, where a physician 30 inserts a DEA 40 into a catheter 22 having at least an ablation electrode 55 and a position sensor 39, as described above. Figure 1 Described in .

[0068] At position signal receiving step 102, processor 33 receives a plurality of position measurements from position sensor 39 indicating respective positions of ablation electrode 55 at, for example, ablation site 53 at respective times during an ablation procedure, as described above in Figure 1 and Figure 2 Described in detail in .

[0069] At ablation stability estimation step 104, the processor 33 estimates (e.g., calculates) the ablation stability quality indicator 59 based on (i) the position signal received from the position sensor 39 and (ii) a stored threshold for at least one of: (a) an allowed distance (e.g., an average distance of approximately 2 mm) and (b) an allowed speed (e.g., a maximum speed of approximately 2.5 mm per second), as described above in Figure 2 Described in detail in .

[0070] At the end of the display step 106 of the method, the processor 33 displays a visual indication of the ablation stability quality indicator at the corresponding ablation site on the map 27, for example to the physician 30, as described above in Figure 2 and Figure 3 Described in detail in .

[0071] In some examples, processor 33 assigns a color to the visitag icon (e.g., icons 50 and 51) that indicates the value of the corresponding ablation stability quality indicator relative to a threshold value of the ablation stability quality indicator. Figure 2As shown, processor 33 assigns: (i) a first color to icon 50 - indicating that the value of ablation stability quality indicator 58 is less than the threshold value of ablation stability quality indicator, and (ii) a second (different) color to icon 51 - indicating that the value of ablation stability quality indicator 59 exceeds the threshold value of ablation stability quality indicator.

[0072] Additionally or alternatively, in response to identifying that the value of the ablation stability quality indicator 59 exceeds the threshold value of the ablation stability quality indicator, the processor 33 displays a halo 72 around the icon 51. In the present example, the halo 72 is displayed for approximately 3 seconds and indicates the termination of ablation at the location marked by the icon 51, and immediately after the halo 72 disappears, the processor 33 generates a new visitag having a calculated centroid at the measured current location of the ablation electrode 55. These annotations (e.g., the halo 72 and the new visitag) provide the physician 30 with an indication of the stability and status of the ablation procedure at the ablation site 53, as described above in Figure 2 Described in detail in .

[0073] In addition, in the event that the estimated distance of a given position of ablation electrode 55 (during ablation) from a reference position (e.g., position 64b) exceeds a distance threshold, processor 33 calculates and displays one or more contours, such as contours 62 and 63. The displayed contours are based on the positions visited by ablation electrode 55 and indicate the corresponding contours traveled by DEA 40 and ablation electrode 55 when an ablation signal is applied to tissue at ablation site 53.

[0074] Additionally or alternatively, processor 33 displays tables 56 and 57 and the corresponding values ​​of calculated ablation stability quality indicators 58 and 59 to physician 30, as described above in Figure 2 In an alternative example, processor 33 displays any suitable information selected by physician 30 on map 27. For example, processor 33 displays on map 27 at ablation site 53: (i) distal tip assembly 40, (ii) icon 51, (iii) ablation stability quality indicator 59, and (iv) ablation indicator 74, and / or as described above in Figure 3 Any other appropriate information as described in the

[0075] Although the examples described herein primarily address visualization of stability quality indicators of tissue ablation in patient's heart 26, the methods and systems described herein may also be used in other applications, such as for visualization of tissue ablation and lesion formation in any other organ of patient 28 and for any assessment of lesions.

[0076] Example 1

[0077] A system (20) comprising a display (35) and a processor (33), the processor being configured to: (i) receive a plurality of position measurements indicating respective positions of an ablation electrode (55) at an ablation site (52, 53) in an organ (26) of a patient (28) at respective times during an ablation procedure; (ii) estimate a quality indicator (58, 59) indicating stability of the ablation procedure at the ablation site (52, 53) based at least on the plurality of position measurements; and (iii) visualize the quality indicator (58, 59) to a user (30) on the display (35).

[0078] Example 2

[0079] A system as in embodiment 2, wherein the processor is configured to estimate the quality indicator based on respective distances of at least some of the locations from a reference location.

[0080] Example 3

[0081] A system according to Example 2, wherein the reference position includes a first position of the ablation electrode when a first ablation signal is applied to the organ at the ablation site, and wherein at least some of the positions include one or more second positions of the ablation electrode when one or more corresponding second ablation signals subsequent to the first ablation signal are applied to the organ at the ablation site.

[0082] Example 4

[0083] A system as described in Example 2, wherein in response to identifying that the quality indicator exceeds a threshold, the processor is configured to display an outline including the ones of the locations.

[0084] Example 5

[0085] A system according to embodiments 1 to 4, wherein the processor is configured to estimate a velocity of the ablation electrode during the ablation procedure and to estimate the quality indicator based on the velocity.

[0086] Example 6

[0087] A system according to embodiments 1 to 4, wherein in estimating the quality indicator, the processor is configured to exclude respiratory motion of the patient.

[0088] Example 7

[0089] A system according to embodiments 1 to 4, wherein the processor is configured to visualize the quality indicator by displaying an icon at the ablation site and by assigning a color indicative of the estimated quality indicator to the icon.

[0090] Example 8

[0091] A system as described in Example 7, wherein the icon includes a sphere.

[0092] Example 9

[0093] A system as in embodiment 7, wherein in response to identifying that the quality indicator exceeds a threshold, the processor is configured to change the color of at least a portion of the icon.

[0094] Example 10

[0095] A system as described in Example 7, wherein in response to identifying that the quality indicator exceeds a threshold, the processor is configured to display a halo around the icon.

[0096] Embodiment 11

[0097] A method comprising:

[0098] (i) receiving a plurality of position measurements indicating respective positions of an ablation electrode (55) at an ablation site (52, 53) in an organ (26) of a patient (28) at respective times during an ablation procedure,

[0099] (ii) estimating a quality indicator (58, 59) indicative of stability of the ablation procedure at the ablation site (52, 53) based at least on the plurality of position measurements, and

[0100] (iii) visualizing the quality indicators (58, 59) to a user (30).

[0101] Example 12

[0102] A method according to embodiment 11, wherein estimating the quality indicator depends on respective distances of at least some of the positions from a reference position.

[0103] Embodiment 13

[0104] A method according to Example 12, wherein the reference position includes a first position of the ablation electrode when a first ablation signal is applied to the organ at the ablation site, and wherein at least some of the positions include one or more second positions of the ablation electrode when one or more corresponding second ablation signals subsequent to the first ablation signal are applied to the organ at the ablation site.

[0105] Embodiment 14

[0106] A method as in embodiment 13, wherein visualizing the quality indicator comprises displaying an outline including the ones of the locations in response to identifying that the quality indicator exceeds a threshold.

[0107] Embodiment 15

[0108] The method according to embodiments 11 to 14, wherein estimating the quality indicator comprises: (i) estimating a velocity of the ablation electrode during the ablation procedure, and (ii) estimating the quality indicator based on the velocity.

[0109] Example 16

[0110] A method according to embodiments 11 to 14, wherein estimating the quality indicator includes excluding respiratory motion of the patient.

[0111] Embodiment 17

[0112] According to the method of embodiments 11 to 14, visualizing the quality indicator includes displaying an icon at the ablation site, and assigning a color to the icon that indicates the estimated quality indicator.

[0113] Embodiment 18

[0114] A method according to embodiment 17, wherein displaying the icon includes displaying a sphere.

[0115] Embodiment 19

[0116] A method as in Embodiment 17, wherein displaying the icon comprises changing the color of at least a portion of the icon in response to identifying that the quality indicator exceeds a threshold.

[0117] Embodiment 20

[0118] A method as in Embodiment 17, wherein displaying the icon comprises displaying a halo around the icon in response to identifying that the quality indicator exceeds a threshold.

[0119] It should be understood that the above examples 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 and their variations and modifications, which will occur to a person skilled in the art when reading the above description and which are not disclosed in the prior art. The documents incorporated by reference into this patent application are considered an integral part of this application, unless any term defined in these incorporated documents conflicts with the definition explicitly or implicitly given in this specification, in which case only the definition in this specification shall be considered.

Claims

1. A system, comprising: monitor; and A processor, the processor being configured to: receiving a plurality of position measurements indicating respective positions of the ablation electrode at an ablation site in an organ of the patient at respective times during an ablation procedure; estimating a quality indicator indicative of stability of the ablation procedure at the ablation site based at least on the plurality of position measurements; and The quality indicator is visualized to a user on the display. 2 . The system of claim 2 , wherein the processor is configured to estimate the quality indicator based on respective distances of at least some of the locations from a reference location.

3. A system according to claim 2, wherein the reference position includes a first position of the ablation electrode when a first ablation signal is applied to the organ at the ablation site, and wherein at least some of the positions include one or more second positions of the ablation electrode when one or more corresponding second ablation signals subsequent to the first ablation signal are applied to the organ at the ablation site. 4 . The system of claim 2 , wherein in response to identifying that the quality indicator exceeds a threshold, the processor is configured to display an outline including the some of the locations.

5. The system of claim 1, wherein the processor is configured to estimate a velocity of the ablation electrode during the ablation procedure and to estimate the quality indicator based on the velocity. 6 . The system of claim 1 , wherein in estimating the quality indicator, the processor is configured to exclude respiratory motion of the patient. 7 . The system of claim 1 , wherein the processor is configured to visualize the quality indicator by displaying an icon at the ablation site and by assigning a color to the icon that indicates the estimated quality indicator. The system of claim 7 , wherein the icon comprises a sphere. 9 . The system of claim 7 , wherein in response to identifying that the quality indicator exceeds a threshold, the processor is configured to change the color of at least a portion of the icon.

10. The system of claim 7, wherein in response to identifying that the quality indicator exceeds a threshold, the processor is configured to display a halo around the icon.

11. A method comprising: receiving a plurality of position measurements indicating respective positions of the ablation electrode at an ablation site in an organ of the patient at respective times during an ablation procedure; estimating a quality indicator indicative of stability of the ablation procedure at the ablation site based at least on the plurality of position measurements; as well as The quality indicator is visualized to a user.

12. The method of claim 11, wherein estimating the quality indicator depends on respective distances of at least some of the positions to a reference position.

13. A method according to claim 12, wherein the reference position includes a first position of the ablation electrode when a first ablation signal is applied to the organ at the ablation site, and wherein at least some of the positions include one or more second positions of the ablation electrode when one or more corresponding second ablation signals subsequent to the first ablation signal are applied to the organ at the ablation site. 14 . The method of claim 13 , wherein visualizing the quality indicator comprises displaying an outline including the ones of the locations in response to identifying that the quality indicator exceeds a threshold.

15. The method of claim 11, wherein estimating the quality indicator comprises: (i) estimating a velocity of the ablation electrode during the ablation procedure, and (ii) estimating the quality indicator based on the velocity. The method of claim 11 , wherein estimating the quality indicator comprises excluding respiratory motion of the patient. 17 . The method of claim 11 , visualizing the quality indicator comprising displaying an icon at the ablation site, and assigning a color to the icon that indicates the estimated quality indicator. The method of claim 17 , wherein displaying the icon comprises displaying a sphere.

19. The method of claim 17, wherein displaying the icon comprises changing the color of at least a portion of the icon in response to identifying that the quality indicator exceeds a threshold.

20. The method of claim 17, wherein displaying the icon comprises displaying a halo around the icon in response to identifying that the quality indicator exceeds a threshold.

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