Displaying transitions between heart chambers

Abstract

A system comprising: (i) a processor configured to receive one or more signals in a region between a first region and a second region of an organ of a patient, at least one of the signals comprising a first component and a second component indicative of an electrophysiological (EP) characteristic of the organ, and based on a relationship between the first component and the second component, the processor is configured to estimate a position of at least one transition zone between the first region and the second region; and (ii) a display configured to display at least the estimated transition region on a map of the organ.

Description

Technical Field

[0001] The present disclosure generally relates to medical devices and, in particular, to methods and systems for improving the estimated location of the transition zone between cardiac chambers. Background Art

[0002] Various techniques for estimating the transition zone between cardiac chambers have been published. Accurately mapping the transition zone is important for performing various types of medical procedures, such as tissue ablation.

[0003] The present disclosure will be more fully understood in connection with the accompanying drawings, through the following detailed description of examples of the present disclosure, in which: Brief Description of the Drawings

[0004] Figure 1 is a schematic illustration of a catheter-based electrophysiological mapping and ablation system according to an example of the present disclosure;

[0005] Figure 2 is a schematic illustration of a catheter positioned between the left atrium and a pulmonary vein and signals generated by electrodes of the catheter according to an example of the present disclosure; and

[0006] Figure 3 is a flowchart schematically showing a method for seamless switching between a PFA-based ablation mode and an RF-based ablation mode according to an example of the present disclosure. Detailed Description

[0007] Overview

[0008] Some medical procedures require accurately mapping the transition zone between regions of an organ. For example, in a pulmonary vein (PV) isolation procedure, ablation signals are applied to tissue at the ostium of the pulmonary vein in order to transform the tissue into lesions and thereby reduce or eliminate arrhythmias, such as atrial fibrillation (AF) in a patient's heart. Ablation is applied using one or more ablation electrodes of an ablation catheter, which are placed in contact with tissue along an angular segment at the transition zone. In the case where at least one of the ablation electrodes is not placed at the intended location, the lesions may not completely block the propagation of electrophysiological (EP) waves between the pulmonary vein and the atrium, and thus atrial fibrillation will not be eliminated.

[0009] Examples of the present disclosure described below provide techniques for improving the accuracy of estimating and displaying the transition zone between two chambers of a patient's heart.

[0010] In some examples, a system for treating arrhythmias in a patient's heart includes one or more catheters, at least one of the one or more catheters having one or more ablation electrodes configured to apply radiofrequency (RF) energy to perform ablation of the patient's heart tissue. At least one of the catheters has one or more sensing electrodes configured to sense signals, such as electrical potential and / or impedance on the tissue being discussed, when placed in contact with the tissue.

[0011] In some examples, the system includes a processor configured to receive signals from one or more of the electrodes placed in contact with the tissue. These signals indicate electrophysiological (EP) characteristics of the heart, such as electrical potential. For example, when a sensing electrode is placed in contact with tissue at the transition zone between the PV and the left atrium of the heart, the signal indicating the electrical potential of the tissue may include a first component and a second component, the first component indicating the electrical potential at the left atrium, also referred to herein as the left atrial potential (LAP), and the second component indicating the electrical potential at the PV, also referred to herein as the pulmonary vein potential (PVP). The LAP has a larger amplitude when the sensing electrode is positioned closer to the atrium, and the PVP has a larger amplitude when the sensing electrode is positioned closer to the PV. Based on the relationship between the LAP and the PVP, the processor is configured to estimate the location of the transition zone (e.g., the ostium) between the LA and the PV. In another example, the positions of the LAP and the PVP along the time axis of the time interval indicating the signal can be used to estimate the location of the transition zone. The above examples and additional examples are described in detail below in Figure 2 and Figure 3 are described.

[0012] In some examples, the system includes a display device, also referred to herein as a display for brevity, configured to display at least the estimated transition zone on an anatomical map of the heart.

[0013] The disclosed techniques improve the estimation and display of the transition zones between heart chambers and between regions of other organs of the patient (having electroanatomical signals).

[0014] System Description

[0015] Figure 1 is a schematic illustration of a catheter-based electrophysiological mapping and ablation system 10 according to an example of the present disclosure.

[0016] In some examples, system 10 includes a plurality of catheters that are inserted by physician 24 through the patient's vasculature via the skin into a chamber or vascular structure of heart 12. Typically, a delivery sheath catheter is inserted into the left atrium or right atrium near the desired location within heart 12. Then, one or more catheters can be inserted into the delivery sheath catheter to reach the desired location within heart 12. The plurality of catheters can include a catheter dedicated to sensing intracardiac electrogram (IEGM) signals, a catheter dedicated to ablation, and / or a catheter suitable for performing both sensing and ablation. An example catheter 14 configured for sensing IEGM is illustrated herein.

[0017] Now referring to illustration 17, which shows a cross-sectional view of the atrium of heart 12. In some embodiments, physician 24 can place the distal end 28 of catheter 14 in contact with the heart wall for sensing a target site within heart 12. Additionally or alternatively, for ablation, physician 24 would similarly place the distal end of the ablation catheter in contact with the target site for ablating the tissue intended to be ablated. In the present example, catheter 14 is inserted through the right atrium (RA) and pierces the interatrial septum into the left atrium (LA) 48 of heart 12. As shown in illustration 17, the distal end 28 is positioned at the transition zone, which in the present example is the ostium 47 of pulmonary vein (PV) 46 located between LA 48 and PV 46. In the present example, PV 46 includes the left lower PV, but the process of sensing signals and applying ablation signals (as will be described below) can also be applied to the left upper PV as well as to the right upper PV and right lower PV.

[0018] Now referring to illustration 19, which shows distal end 28. In some examples, catheter 14 includes one and preferably a plurality of electrodes 26 that are optionally distributed along splines 15 that connect shaft 22 at the distal end 28 of basket catheter 14. Electrodes 26 are configured to sense IEGM signals. Catheter 14 can additionally include a position sensor 29 embedded within or near the distal end 28 for tracking the position and orientation of the distal end 28. Optionally and preferably, position sensor 29 is a magnetic-based position sensor that includes three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0019] Now referring back to Figure 1Full view. In some examples, a magnetic-based position sensor 29 may operate in conjunction with a positioning pad 25 that includes a plurality (e.g., three) of magnetic coils 32 configured to generate a plurality (e.g., three) of magnetic fields in a predetermined workspace. The real-time position of the distal end 28 of the catheter 14 may be tracked based on the magnetic fields generated by the positioning pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing techniques are described, for example, in U.S. Patent Nos. 5,539,199, 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.

[0020] In some examples, the system 10 includes one or more electrode patches 38 positioned to contact 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 toward the electrodes 26 and sensed at the electrode skin patches 38 such that the position of each electrode can be triangulated via the electrode patches 38. This technique is also referred to herein as advanced current localization (ACL), and details of impedance-based position tracking techniques are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182. In some examples, magnetic-based position sensing and ACL may be applied simultaneously, for example, to improve the position sensing of one or more electrodes coupled to the shaft of a rigid catheter or to a flexible arm or spline at the distal end of another catheter, such as the basket catheter 14, and available from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618 or catheter.

[0021] In some examples, the recorder 11 displays an electrogram 21 captured using the body surface ECG electrodes 18 and an intracardiac electrogram (IEGM) captured using the electrodes 26 of the catheter 14. The recorder 11 may include pacing capabilities for pacing the heart rhythm and / or may be electrically connected to an independent pacemaker.

[0022] In some examples, system 10 may include an ablation energy generator 50 that is adapted to conduct ablation energy to one or more of the electrodes at the distal end of a catheter configured for ablation. The energy generated by ablation energy generator 50 may include, but is not limited to, bursts of radio frequency (RF) energy or pulsed field ablation (PFA) energy (including unipolar or bipolar high voltage DC pulses that may be used to effect irreversible electroporation (IRE)), or combinations thereof. In another example, catheter 14 may include one or more ablation electrodes (not shown) positioned at distal end 28 and configured to apply bursts of RF energy and / or PFA energy to tissue of the wall of heart 12.

[0023] In some examples, patient interface unit (PIU) 30 is an interface configured to establish electrical connectivity between the catheter, electrophysiology equipment, power source, and workstation 55 for controlling the operation of system 10.

[0024] The electrophysiology equipment of system 10 may include, for example, a plurality of catheters, positioning pads 25, body surface ECG electrodes 18, electrode patches 38, ablation energy generator 50, and recorder 11. Optionally and preferably, PIU 30 additionally has processing capabilities for performing real-time calculations of the position of the catheter and for performing ECG calculations.

[0025] In one example, one or more electrodes 26 are configured to receive current from PIU 30 and measure the impedance between at least one electrode 26 and (i) a corresponding electrode patch 38 or (ii) a corresponding body surface ECG electrode 18.

[0026] In some examples, the workstation 55 includes a storage device, a processor 77 having a suitable random access memory or a storage device storing suitable operating software, an interface 56 configured to exchange data signals (e.g., between the processor 77 and another entity of the system 10), and user interface capabilities. In one example, the processor 77 is configured to generate signals indicative of the electrophysiological (EP) characteristics of the heart 12. For example, (i) a first signal that indicates the electrical potential measured on the tissue in question, the tissue having one or more electrodes 26 placed in contact therewith, and (ii) a second signal that indicates the impedance measured as described above. The workstation 55 may provide a plurality of functions, optionally including: (1) performing three-dimensional (3D) modeling of the endocardial anatomy and rendering a model or anatomic map 20 for display on a display device 27 (also referred to herein as the display for brevity); (2) displaying, on the display device 27, an activation sequence (or other data) compiled from the recorded electrograms 21 as representative visual markers or images superimposed on the rendered anatomic map 20; (3) displaying the real-time position and orientation of a plurality of catheters within the heart chambers; and (4) displaying on the display device 27 sites of interest, such as where ablation energy has been applied. An article of commerce embodying the elements of the system 10 may be the CARTO TM 3 system, which is available from Biosense Webster, Inc., 31A Technology Drive, Irvine, CA 92618.

[0027] Figure 2 is a schematic illustration of an electrode 26 of the distal tip 28 placed in contact with the tissue of the ostium 47 of the PV 46 located between the LA 48 and the PV 46, and a signal 60 received from the electrode 26.

[0028] In some examples, the distal tip 28 is positioned within the ostium 47 and has some electrodes 26 placed in contact with the tissue of the ostium 47, the LA 48, and the PV 46. For example, the electrodes 26a, 26f, and 26g are placed in contact with the tissue of the LA 48, the electrodes 26c and 26d are placed in contact with the tissue of the PV 46, and the electrodes 26b and 26e are placed in contact with the tissue of the ostium 47, which is also referred to herein as the transition zone between the LA 48 and the PV 46.

[0029] In some examples, the processor 77 receives a signal 60 from the electrode 26 indicating the EP characteristics of the heart 12. In this example, the EP characteristics include the electric potential measured on the tissue in contact with the corresponding electrode 26. Additionally or alternatively, the processor 77 may receive another signal from the electrode 26, the other signal indicating the impedance measured between the selected electrode 26 and (i) the corresponding electrode patch 38 or (ii) the corresponding body surface ECG electrode 18.

[0030] In some examples, the signal 60 includes one or more components indicating the position and signal type of the electrode 26. For example, when the electrode 26 is placed in contact with the tissue at the transition region (e.g., the ostium 47) between the PV 46 and the LA 48, the signal indicating the electric potential of the tissue may include a first component and a second component. The first component indicates the electric potential sensed at the LA 48, also referred to herein as the left atrial potential (LAP), and the second component indicates the electric potential measured at the PV 46, also referred to herein as the PV potential (PVP). Note that the morphologies of the LAP and the PVP are shown in the legend 59. Additionally, the morphologies of the LAP and the PVP may be changed, for example, by using the sensing amplitude and proximity between the regions under discussion (e.g., the LA 48 and the PV 46) and the position of the corresponding electrode 26, as will be described below.

[0031] Several non-limiting examples of the signals 61, 62, 63, 64, 65, and 66 illustrate the relationship between the LAP and the PVP in the signals received from the electrode 26. In the signal 61 received from the electrode 26g positioned within the LA 48, the LAP has a large amplitude (e.g., about 1 mV), and the amplitude of the PVP (e.g., about 0.16 mV) is lower than a predetermined threshold, e.g., about 0.2 mV (e.g., stored in the processor 77), and thus, does not appear in the signal 61. In the signal 62 received from the electrode 26d positioned within the PV 46, the PVP has a large amplitude (e.g., greater than about 0.5 mV), and the amplitude of the LAP is lower than another threshold stored in the processor 77 (e.g., about 0.15 mV), and thus, the LAP does not appear in the signal 62.

[0032] In the signal 63 received from the electrode 26a positioned closer to LA 48 than to PV 46, the amplitude of the LAP is greater than the amplitude of the PVP (e.g., the LAP is 0.8 mv and the PVP is 0.2 mv). Further, in the time interval of the signal 63, (i) the LAP occupies the first sub-interval of the time interval of the signal 63, and (ii) the PVP (which is sensed later than the LAP because the electrode 26a is closer to LA 48 than to PV 46) occupies the second (later) sub-interval of the time interval of the signal 63. In the example of the signal 63, the relationship between the first component and the second component (e.g., the LAP and the PVP) includes: (i) the calculated difference in the amplitude magnitudes between the LAP and the PVP (and / or the calculated ratio between the voltages of the amplitudes of the LAP and the PVP), and (ii) the duration calculated between the first position of the LAP and the second (later) position of the PVP along the time axis 58 of the signal 60. In other words, because the electrode 26a is positioned closer to L 48 than to PV 46, the LAP appears before the PVP and has a greater amplitude compared to the amplitude of the PVP. Further, the widths of the LAP signal and the PVP signal along the time axis 58 can be different from each other, as Figure 2 shown.

[0033] In the signal 64 received from the electrode 26b positioned at the orifice 47 but slightly closer to PV 46 than to LA 48, the amplitudes of the LAP and the PVP are approximately equal. Further, in the time interval of the signal 64, the PVP appears slightly before the LAP because the electrode 26b is positioned slightly closer to PV 46 than to LA 48. Note that the sub-intervals in which the LAP and the PVP appear in the signal are also affected by the direction of propagation of the electrophysiological (EP) wave between PV 46 and LA 48. For example, in the case where the electrophysiological wave propagates from PV 46 to LA 48, the PVP can appear before the LAP along the time axis 58. However, the positions of the PVP and the LAP are also affected by the positions of the respective electrodes 26.

[0034] In the example of the signal 65 (which is the potential measured between the electrodes 26d and 26g), the EP wave propagates from PV 46 to LA 48, and thus, the PVP appears before the LAP and the amplitudes of the PVP and the LAP are approximately equal.

[0035] In the example of the signal 66 (which is the potential measured between the electrodes 26e and 26b located substantially at the transition zone (e.g., the orifice 47)), the LAP and the PVP sensed by each of the electrodes 26e and 26b almost overlap each other and have equal amplitudes.

[0036] In some examples, based on the relationship between the LAP and PVP of signals 61 - 66, processor 77 is configured to estimate the location of the transition region (e.g., ostium 47) between LA 48 and PV 46. In such an embodiment, processor 77 is configured to estimate that electrodes 26b and 26e are positioned generally at ostium 47, while electrodes 26a, 26f, and 26g are positioned closer to LA 48, and electrodes 26c and 26d are positioned closer to PV 46. Based on the above position sensing (using the magnetic - based position sensor 29 and the ACL described above in Figure 1 ), processor 77 is configured to estimate the location of ostium 47 and of PV 46 and LA 48.

[0037] In some examples, display device 27 is configured to receive the estimated locations from processor 77 and is configured to display the estimated location of ostium 47 and the estimated locations of PV 46 and LA 48 on the rendered anatomical map 20 described above in Figure 1 . In such examples, physician 24 may use the estimated location of ostium 47 as displayed to place ablation electrodes along the angular segment of ostium 47 to perform a PV isolation procedure by applying ablation signals to the ablation electrodes placed along the angular segment of ostium 47.

[0038] In some examples, processor 77 may control PIU 30 to cause current to flow to one or more (e.g., all) of electrodes 26. Subsequently, processor 77 receives an additional signal from PIU 30 (e.g., from electrodes 26 or from generator 50), the additional signal indicating the impedance measured between each selected electrode 26 and a reference electrode (e.g., electrode patch 38 or the body - surface ECG electrode 18 described above in Figure 1 ). Note that generally, the impedance measured using a given electrode 26 (e.g., electrode 26d) located at PV 46 (which is opposite the current) is higher than the impedance measured using an electrode 26 (e.g., electrode 26g) located at LA 48. In such examples, based on the measured impedance and the location of each electrode 26, processor 77 may estimate the locations of PV 46, LA 48, and ostium 47, which is the transition region between PV 46 and LA 48.

[0039] In a non - limiting example, when the average impedance measured using electrode 26g (located within LA 48) is about 100 ohms, the average impedance measured using electrode 26d (located within PV 46) is about 120 ohms, and the average impedance measured using electrode 26b or 26e (roughly at the mouth 47) is about 110 ohms. Note that the actual measured impedance values depend on: (i) many components of the circuit, including electrode 26, the reference electrode, and the hardware used to allow current flow and measure impedance, (ii) the physiological and electrophysiological properties of the tissue under discussion, and electrical and / or electronic entities located near the above - mentioned circuit. Thus, the processor 77 can use the calculated impedance differences, which are measured using electrodes placed in contact with the tissues of PV 46, mouth 47, and LA 48.

[0040] In some examples, the processor 77 and / or the physician 24 can use the relationship between LAP and PVP as the primary source to estimate the exact location of the mouth 47, and the impedance data can be used as supplementary information to estimate the locations of the mouth 47, PV 46, and LA 48.

[0041] In some examples, the above - mentioned techniques can be used to estimate other transition zones in the heart 12. For example, the above - mentioned techniques can be used to estimate the location of the atrioventricular valve (AVV) located between the LA 48 of the heart 12 and the left ventricle (not shown), and to estimate the location of the AVV located between the right atrium and the right ventricle of the heart 12. Note that in order to apply the disclosed techniques, a catheter having sensing electrodes (such as electrode 26) must be inserted into the corresponding atria, ventricles, and AVV, or any other suitable number of catheters can be used, each catheter having electrodes configured to generate signals indicative of the electrical potential and / or impedance measured at the corresponding locations in the atria, ventricles, and AVV.

[0042] Figure 3 is a flowchart schematically showing a method for estimating and displaying the transition zone between PV 46 and LA 48 according to an example of the present disclosure.

[0043] The method starts at catheter insertion step 100, where the physician 24 inserts the distal end 28 of the catheter 14 between the LA 48 and PV 46 of the heart 12, as shown and described in detail above in Figure 1 and Figure 2 Note that the electrode 26 of the distal end 28 is placed in contact with the tissue of the heart 12.

[0044] At signal receiving step 102, the processor 77 receives signal 60 from the electrode 26 indicative of the electrical potential measured in PV 46, mouth 47, and LA 48. In addition, the processor 77 can also receive signals indicative of the impedance between each electrode 26 and a reference electrode (such as electrode patch 38 or as described above inFigure 1 A signal of the impedance measured between the body surface ECG electrodes 18) described in

[0045] At the position estimation step 104, based on the relationship between the LAP and PVP of the signal 60, the processor 77 estimates the position of the orifice 47, which is the transition region between the LA 48 and the PV 46. Additionally or alternatively, based on one or more signals indicating the measured impedance, the processor 77 can also estimate the position of the orifice 47. As described above Figure 2 The processor 77 can estimate the positions of the orifice 47, the LA 48, and the PV 46 because the impedance in the PV 46 is generally higher than that in the LA 48. In one example, the processor 77 can use the relationship between the LAP and PVP in each signal as the main source to estimate the position of the orifice 47, and can use the impedance data to verify or tune the accurate position of the orifice 47.

[0046] At the display step 106 where the estimation and display method ends, based on the estimated position of the orifice 47, the display device 27 is configured to display the estimated positions of the orifice 47, the LA 48, and the PV 46 on the anatomical mapping diagram 20, as detailed above in Figure 2 described.

[0047] In some examples, after the estimation and display method ends at step 106, the physician 24 can use the information displayed on the anatomical mapping diagram 20 to perform a PV isolation procedure or any other suitable type of tissue ablation. For example, at the tissue ablation step 108, the doctor 24 can position the ablation electrode of the catheter 14 or another catheter (not shown) along the angular section of the orifice 47, which is the estimated transition region. Subsequently, the processor 77 can control the generator 50 to apply an ablation signal to the tissue located at the angular section at the orifice 47.

[0048] Example 1

[0049] A system (20), the system includes a processor (77) and a display (27). The processor (77) is configured to receive one or more signals (60) in the region between the first region and the second region (46, 48) of the organ (12) of the patient (23), at least one signal (61 - 66) in the signals (60) includes a first component and a second component (LAP, PVP) indicating the electrophysiological (EP) characteristics of the organ (12), and based on the relationship between the first component and the second component (LAP, PVP), the processor (77) is configured to estimate the position of at least one transition region (47) between the first region and the second region (46, 48). The display (27) is configured to display at least the estimated transition region (47) on the mapping diagram (20) of the organ (12).

[0050] Example 2

[0051] The system according to embodiment 1, wherein the first component has a first amplitude, and the second component has a second amplitude, and wherein the relationship between the first component and the second component includes a ratio between the first amplitude and the second amplitude.

[0052] Example 3

[0053] The system according to embodiment 1, wherein the first component occupies a first sub-interval of a time interval of the signal, and the second component occupies a second sub-interval of the time interval, and wherein the relationship between the first component and the second component includes a duration between a first position of the first sub-interval and a second position of the second sub-interval.

[0054] Example 4

[0055] The system according to any one of embodiments 1 to 3, wherein the signal includes an electric potential measured by one or more electrodes, the one or more electrodes being placed in contact with tissue of the organ at one or more of the following: (i) the transition region, (ii) the first region, and (iii) the second region.

[0056] Example 5

[0057] The system according to any one of embodiments 1 to 3, wherein the signal includes an additional signal that indicates an impedance measured between a reference electrode and an electrode placed in contact with tissue of the organ at the transition region.

[0058] Example 6

[0059] The system according to any one of embodiments 1 to 3, wherein the organ includes a heart, the first region includes an atrium of the heart, the second region includes a pulmonary vein (PV) extending from the atrium, the transition region includes an ostium of the PV, and the first component and the second component respectively indicate measurements of a first EP characteristic of the atrium and a second EP characteristic of the PV, and wherein, based on the relationship between the first component and the second component, the processor is configured to estimate a position of the ostium between the PV and the atrium.

[0060] Example 7

[0061] The system according to any one of Embodiments 1 to 3, wherein the organ comprises a heart, the first region comprises a given atrium at a given side of the heart, the second region comprises a given ventricle at the given side of the heart, the given ventricle is connected to the given atrium via an atrioventricular valve (AVV), and the transition region comprises the AVV at the given side of the heart, and wherein, based on the relationship between the first component and the second component, the processor is configured to estimate the position of the AVV between the given atrium and the given ventricle.

[0062] Example 8

[0063] The system according to any one of Embodiments 1 to 3, wherein at least one of the signals comprises: (i) the first component, which is associated with the first region, or (ii) the second component, which is associated with the second region, and wherein, based on the components in the signal, the processor is configured to estimate an additional position of the first region or the second region.

[0064] Example 9

[0065] The system according to any one of Embodiments 1 to 3, the system further comprises a catheter inserted into the organ and having a first electrode and a second electrode, the first electrode and the second electrode are configured to generate a first signal and a second signal indicating the EP characteristics of the organ respectively, and wherein, based on the first signal and the second signal, the processor is configured to estimate at least one of the following: (i) the first region, (ii) the second region, and (iii) the transition region.

[0066] Example 10

[0067] The system according to Embodiment 9, wherein the catheter comprises one or more pairs of electrodes, and wherein at least one of the first signal and the second signal comprises a bipolar signal measured between a given pair of the electrodes.

[0068] Example 11

[0069] A method for displaying a transition zone between a first region and a second region of an organ, the method comprising: receiving one or more signals in a zone between the first region and the second region of the organ of a patient, at least one of the signals comprising a first component and a second component indicative of electrophysiological (EP) characteristics of the organ. Estimating a location of the transition zone between the first region and the second region based on a relationship between the first component and the second component. Displaying at least the estimated transition zone on a map of the organ.

[0070] Although the examples described herein are primarily directed to electrophysiological procedures, electrophysiological procedures include sensing signals for estimating the location of the ostia of the pulmonary veins of the left atrium. The methods and systems described herein may also be used in other applications, such as for estimating transition zones between any chambers of a patient's heart and between heart chambers and connected blood vessels. Additionally, the disclosed techniques may be used to estimate the location of any region in any suitable organ of a patient based on suitable electroanatomical signals.

[0071] It should be understood that the above embodiments are cited by way of example and that the present disclosure is not limited to what is specifically shown and described above. Instead, the scope of the present disclosure includes combinations and sub - combinations of the various features described above, as well as their variations and modifications, which would occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art. Documents incorporated by reference into this patent application are considered an inseparable part of this application, unless any terms defined in these incorporated documents conflict with the definitions expressly or implicitly given in this specification, in which case only the definitions in this specification shall be considered.

Claims

1. A system, the system comprising: a processor configured to receive one or more signals in a zone between a first zone and a second zone of an organ of a patient, at least one of the signals including a first component and a second component indicative of electrophysiological (EP) characteristics of the organ; and based on a relationship between the first component and the second component, the processor is configured to estimate a position of at least one transition zone between the first zone and the second zone; and a display configured to display at least the estimated transition zone on a mapping of the organ.

2. The system according to claim 1, wherein, the first component has a first amplitude and the second component has a second amplitude, and wherein the relationship between the first component and the second component includes a ratio between the first amplitude and the second amplitude.

3. The system according to claim 1, wherein, the first component occupies a first sub-interval of a time interval of the signal and the second component occupies a second sub-interval of the time interval, and wherein the relationship between the first component and the second component includes a duration between a first position of the first sub-interval and a second position of the second sub-interval.

4. The system according to claim 1, wherein, the signal includes an electric potential measured by one or more electrodes placed to contact tissue of the organ at one or more of: (i) the transition zone, (ii) the first zone, and (iii) the second zone.

5. The system according to claim 1, wherein, the signal includes an additional signal indicative of an impedance measured between a reference electrode and an electrode placed to contact tissue of the organ at the transition zone.

6. The system according to claim 1, wherein, the organ includes a heart, the first zone includes an atrium of the heart, the second zone includes a pulmonary vein (PV) extending from the atrium, the transition zone includes an ostium of the PV, and the first component and the second component respectively indicate measurements of first and second EP characteristics of the atrium and the PV, and wherein based on the relationship between the first component and the second component, the processor is configured to estimate a position of the ostium between the PV and the atrium.

7. The system according to claim 1, wherein, the organ includes a heart, the first zone includes a given atrium at a given side of the heart, the second zone includes a given ventricle at the given side of the heart, the given ventricle being connected to the given atrium via an atrioventricular valve (AVV), and the transition zone includes the AVV at the given side of the heart, and wherein based on the relationship between the first component and the second component, the processor is configured to estimate a position of the AVV between the given atrium and the given ventricle.

8. The system according to claim 1, wherein, at least one of the signals includes: (i) the first component, the first component being associated with the first region, or (ii) the second component, the second component being associated with the second region, and wherein, based on the component in the signal, the processor is configured to estimate an additional position of the first region or the second region.

9. The system according to any one of claims 1 to 8, the system further comprising a catheter inserted into the organ and having a first electrode and a second electrode, the first electrode and the second electrode being configured to generate a first signal and a second signal indicative of the EP characteristics of the organ, respectively, and wherein, based on the first signal and the second signal, the processor is configured to estimate at least one of the following: (i) the first region, (ii) the second region, and (iii) the transition region.

10. The system according to claim 9, wherein, the catheter includes one or more pairs of electrodes, and wherein at least one of the first signal and the second signal includes a bipolar signal measured between a given pair of the electrodes.

11. A method for displaying a transition region between a first region and a second region of an organ, the method comprising: receiving one or more signals in a region between the first region and the second region of the organ of a patient, at least one of the signals including a first component and a second component indicative of electrophysiological (EP) characteristics of the organ; estimating a position of the transition region between the first region and the second region based on a relationship between the first component and the second component; and displaying at least the estimated transition region on a map of the organ.

12. The method according to claim 11, wherein, the first component has a first amplitude, and the second component has a second amplitude, and wherein estimating the position based on the relationship between the first component and the second component includes: calculating a ratio between the first amplitude and the second amplitude.

13. The method according to claim 11, wherein, the first component occupies a first sub-interval of a time interval of the signal, and the second component occupies a second sub-interval of the time interval, and wherein estimating the position based on the relationship between the first component and the second component includes: calculating a duration between a first position of the first sub-interval and a second position of the second sub-interval.

14. The method according to claim 11, wherein, receiving the signal includes: receiving an electric potential measured by one or more electrodes placed in contact with tissue of the organ at one or more of the following: (i) the transition region, (ii) the first region, and (iii) the second region.

15. The method according to claim 11, wherein, receiving the signal includes: receiving an additional signal indicative of an impedance measured between a reference electrode and an electrode placed in contact with tissue of the organ at the transition region.

16. The method according to claim 11, wherein, the organ includes the heart, the first region includes the atrium of the heart, the second region includes the pulmonary vein (PV) extending from the atrium, the transition region includes the ostium of the PV, and the first component and the second component respectively indicate measurements of the first EP characteristic and the second EP characteristic of the atrium and the PV, and wherein estimating the position of the transition region includes: estimating the position of the ostium between the PV and the atrium based on the relationship between the first component and the second component.

17. The method according to claim 11, wherein, the organ includes the heart, the first region includes a given atrium at a given side of the heart, the second region includes a given ventricle at the given side of the heart, the given ventricle is connected to the given atrium via an atrioventricular valve (AVV), and the transition region includes the AVV at the given side of the heart, and wherein estimating the position of the transition region includes: estimating the position of the AVV between the given atrium and the given ventricle based on the relationship between the first component and the second component.

18. The method according to claim 11, wherein, at least one of the signals includes: (i) the first component, which is associated with the first region, or (ii) the second component, which is associated with the second region, and wherein estimating the position of the transition region includes: estimating the position of an additional position of the first region or the second region based on the first component or the second component in the signal.

19. The method according to any one of claims 11 to 18, wherein, receiving the one or more signals includes: receiving signals from at least a first electrode and a second electrode of a catheter inserted into the organ to respectively generate a first signal and a second signal, and wherein estimating the position of the transition region includes estimating at least one of the following based on the first signal and the second signal: (i) the first region, (ii) the second region, and (iii) the transition region.

20. The method according to claim 19, wherein, receiving the signal includes: receiving a bipolar signal measured between a pair of given electrodes selected from at least the first electrode and the second electrode.

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