阅读说明：本技术 用于在虚拟导管上对电生理信号进行分类的系统和方法 (System and method for classifying electrophysiological signals on a virtual catheter ) 是由 D·C·德诺 E·S·奥尔森 D·J·摩根 J·A·施韦策 E·J·沃斯 于 2019-01-08 设计创作，主要内容包括：可以通过接收指定用于虚拟导管的虚拟电极的数量以及定义虚拟导管的路径的用户输入来对来自包括多个电生理数据点的电生理标测图的图形表示的电生理信号进行分类。可以在虚拟导管的路径上定义相应数量的虚拟电极,并且可以识别与虚拟电极处的电活动相关的一个或多个电生理数据点,从而允许输出与所识别的电生理数据点相对应的电生理信号的图形表示。可以通过应用一个或多个相关性标准,诸如距离标准、双极定向标准、时间标准和/或形态标准,来识别相关的电生理数据点。(The electrophysiological signals from the graphical representation of the electrophysiological map including the plurality of electrophysiological data points can be classified by receiving user input specifying a number of virtual electrodes for the virtual catheter and defining a path for the virtual catheter. A corresponding number of virtual electrodes may be defined on the path of the virtual catheter, and one or more electrophysiology data points related to electrical activity at the virtual electrodes may be identified, thereby allowing a graphical representation of the electrophysiology signal corresponding to the identified electrophysiology data points to be output. The relevant electrophysiology data points can be identified by applying one or more correlation criteria, such as a distance criterion, a bipolar orientation criterion, a time criterion, and/or a morphology criterion.)

1. A method of classifying a plurality of electrophysiological signals from a graphical representation of an electrophysiology map generated by an electroanatomical mapping system, the electrophysiology map comprising a plurality of electrophysiology data points, the method comprising:

receiving, via the electroanatomical mapping system, a user input specifying a number of virtual electrodes for a virtual catheter;

receiving, via the electroanatomical mapping system, a user input defining a path of the virtual catheter;

the electroanatomical mapping system defining a plurality of virtual electrodes on the path of the virtual catheter corresponding to the number of virtual electrodes;

the electroanatomical mapping system identifying one or more of the plurality of electrophysiology data points that are correlated to electrical activity at the plurality of virtual electrodes; and

the electroanatomical mapping system outputs a graphical representation of one or more electrophysiological signals corresponding to the identified one or more electrophysiological data points.

2. The method of claim 1, wherein the user input defining a path of the virtual catheter comprises a path traced by the user on the graphical representation of the electrophysiology map.

3. The method according to claim 1, wherein the electroanatomical mapping system identifying one or more of the plurality of electrophysiology data points that are correlated to electrical activity at the plurality of virtual electrodes comprises: for each of the plurality of virtual electrodes,

the electroanatomical mapping system determining whether one or more of the plurality of electrophysiology data points satisfy a distance criterion; and

identifying one or more electrophysiology data points as being related to electrical activity at the virtual electrode if the one or more electrophysiology data points satisfy the distance criterion.

4. The method of claim 3, wherein the distance criteria comprises a preselected maximum distance from the virtual electrode.

5. The method of claim 4, wherein the maximum distance is between 2mm and 6 mm.

6. The method according to claim 3, wherein the electroanatomical mapping system identifying one or more of the plurality of electrophysiology data points that are correlated to electrical activity at the plurality of virtual electrodes further comprises: for each of the plurality of virtual electrodes,

the electroanatomical mapping system identifying an electrophysiology data point of the identified one or more electrophysiology data points that is closest to the virtual electrode; and

the electroanatomical mapping system associates the electrophysiology data point closest to the virtual electrode with the virtual electrode.

7. The method according to claim 3, wherein the electroanatomical mapping system identifying one or more of the plurality of electrophysiology data points that are correlated to electrical activity at the plurality of virtual electrodes further comprises: for each of the plurality of virtual electrodes,

the electroanatomical mapping system applying one or more correlation criteria to the identified one or more electrophysiology data points, wherein the one or more correlation criteria include one or more of a bipolar orientation criterion, a temporal criterion, and a morphological criterion; and

the electroanatomical mapping system associates an electrophysiology data point of the identified one or more electrophysiology data points that meets the one or more correlation criteria with the virtual electrode.

8. The method of claim 7, wherein the bipolar orientation criteria comprises a preselected bipolar orientation of the identified electrophysiology data points relative to a direction of the path of the virtual catheter.

9. The method of claim 7, wherein the time criteria comprises a preselected collection time for the identified electrophysiology data point.

10. The method of claim 7, wherein the morphology criteria includes at least one of a correlation value or a similarity metric of the identified electrophysiology data point relative to other electrophysiology data points of the plurality of electrophysiology data points that are related to electrical activity at the plurality of virtual electrodes.

11. The method according to claim 1, wherein an order in which the electroanatomical mapping system outputs the graphical representation of the one or more electrophysiological signals corresponding to the identified one or more electrophysiological data points corresponds to a direction of the path of the virtual catheter.

12. The method according to claim 1, further comprising the electroanatomical mapping system outputting a graphical representation of the plurality of virtual electrodes on the graphical representation of the electrophysiology map.

13. The method according to claim 1, further comprising the electroanatomical mapping system highlighting the identified one or more electrophysiology data points on the graphical representation of the electrophysiology map.

14. A method of classifying a plurality of electrophysiological signals from a graphical representation of an electrophysiology map generated by an electroanatomical mapping system, the electrophysiology map comprising a plurality of electrophysiology data points, the method comprising:

receiving, via the electroanatomical mapping system, a user input defining a virtual catheter comprising a plurality of virtual electrodes;

for each virtual electrode of the plurality of virtual electrodes, the electroanatomical mapping system applying one or more correlation criteria to the plurality of electrophysiology data points to identify no more than one electrophysiology data point that correlates to electrical activity at the virtual electrode; and

for each of the identified electrophysiology data points, the electroanatomical mapping system outputs a graphical representation of the electrophysiology signal associated with the identified electrophysiology data point.

15. The method according to claim 14, wherein an order in which the electroanatomical mapping system outputs the graphical representations of the electrophysiological signals associated with the identified electrophysiological data points corresponds to an orientation of the virtual catheter relative to the graphical representation of an electrophysiological map.

16. The method of claim 14, wherein the one or more relevance criteria include a distance criterion.

17. The method of claim 16, wherein the one or more correlation criteria further comprise one or more of a bipolar orientation criterion, a temporal criterion, and a morphological criterion.

18. A system for classifying a plurality of electrophysiological signals from a graphical representation of an electrophysiology map generated by an electroanatomical mapping system and including a plurality of electrophysiology data points, the system comprising:

a classification and visualization processor configured to:

receiving, via the electroanatomical mapping system, a user input specifying a number of virtual electrodes for a virtual catheter and a user input defining a path of the virtual catheter;

defining a virtual catheter extending along the path and comprising a plurality of virtual electrodes corresponding to the number of virtual electrodes;

identifying one or more of the plurality of electrophysiology data points that are related to electrical activity at the plurality of virtual electrodes; and

outputting a graphical representation of the one or more electrophysiological signals corresponding to the identified one or more electrophysiological data points.

19. The system according to claim 18, wherein the classification and visualization processor is configured to identify the one or more electrophysiology data points that are correlated to electrical activity at the plurality of virtual electrodes by applying one or more correlation criteria to the plurality of electrophysiology data points.

20. The system of claim 19, wherein the one or more correlation criteria include one or more of a distance criteria, a bipolar orientation criteria, a time criteria, and a morphology criteria.

Technical Field

The present disclosure relates generally to cardiac diagnostic and therapeutic procedures, such as electrophysiology mapping and cardiac ablation. In particular, the present disclosure relates to systems, devices, and methods for classifying electrophysiological signals measured by multi-dimensional catheters, such as high density ("HD") grid catheters, on virtual catheters.

Background

A high density electrophysiology map can be constructed from thousands of electrophysiology data points. Existing electroanatomical mapping systems allow a practitioner to isolate individual electrophysiology data points within a map and view their associated electrophysiology signals. However, existing systems do not allow a practitioner to quickly and simultaneously view the electrophysiological signals associated with adjacent points and/or the electrophysiological signals along a specified path unless the path happens to coincide with the path of the electrophysiology catheter used to collect the electrophysiology data points.

Disclosure of Invention

Disclosed herein is a method of classifying a plurality of electrophysiological signals from a graphical representation of an electrophysiology map generated by an electroanatomical mapping system, the electrophysiology map comprising a plurality of electrophysiology data points, the method comprising: receiving, via an electroanatomical mapping system, a user input specifying a number of virtual electrodes for a virtual catheter; receiving, via an electroanatomical mapping system, a user input defining a path of a virtual catheter; the electroanatomical mapping system defining a plurality of virtual electrodes on a path of the virtual catheter corresponding to a number of virtual electrodes; the electroanatomical mapping system identifying one or more of the plurality of electrophysiology data points that are correlated to electrical activity at the plurality of virtual electrodes; and outputting, by the electroanatomical mapping system, a graphical representation of one or more electrophysiological signals corresponding to the identified one or more electrophysiological data points. In aspects of the present disclosure, the user input defining the path of the virtual catheter may be the path traced by the user on the graphical representation of the electrophysiology map.

Various criteria may be applied in connection with an electroanatomical mapping system that identifies one or more of the plurality of electrophysiology data points that are correlated to electrical activity at the plurality of virtual electrodes. For example, the identifying step may include: for each virtual electrode of the plurality of virtual electrodes: the electroanatomical mapping system determines whether one or more of the plurality of electrophysiology data points satisfy a distance criterion (e.g., a preselected maximum distance from the virtual electrode, such as between about 2mm to about 6 mm); and identifying one or more electrophysiology data points as being related to electrical activity at the virtual electrode if the one or more electrophysiology data points satisfy the distance criterion.

In other embodiments of the present disclosure, the identifying step may include: for each virtual electrode of the plurality of virtual electrodes: identifying, by the electroanatomical mapping system, an electrophysiology data point of the identified one or more electrophysiology data points that is closest to the virtual electrode; and the electroanatomical mapping system associates the electrophysiology data point closest to the virtual electrode with the virtual electrode.

In another embodiment of the present disclosure, the identifying step may include: for each virtual electrode of the plurality of virtual electrodes: the electroanatomical mapping system applying one or more correlation criteria to the identified one or more electrophysiology data points, wherein the one or more correlation criteria include one or more of a bipolar orientation criterion, a temporal criterion, and a morphological criterion; and the electroanatomical mapping system associates an electrophysiology data point of the identified one or more electrophysiology data points that meets one or more correlation criteria with the virtual electrode. The bipolar orientation criterion may include a preselected bipolar orientation of the identified electrophysiology data points relative to a direction of a path of the virtual catheter. The time criteria can include a preselected collection time for the identified electrophysiology data points. The morphology criteria may include a correlation value (such as a pearson correlation value) or a similarity measure of the identified electrophysiology data point relative to other electrophysiology data points of the plurality of electrophysiology data points that are related to electrical activity at the plurality of virtual electrodes.

It is contemplated that the order in which the electroanatomical mapping system outputs the graphical representation of the one or more electrophysiological signals corresponding to the identified one or more electrophysiological data points may correspond to a direction of a path of the virtual catheter. The electroanatomical mapping system may also output a graphical representation of the plurality of virtual electrodes on a graphical representation of the electrophysiology map, and/or highlight the identified one or more electrophysiology data points on the graphical representation of the electrophysiology map.

Also disclosed herein is a method of classifying a plurality of electrophysiological signals from a graphical representation of an electrophysiology map generated by an electroanatomical mapping system, the electrophysiology map comprising a plurality of electrophysiology data points, the method comprising: receiving, via an electroanatomical mapping system, a user input defining a virtual catheter comprising a plurality of virtual electrodes; for each virtual electrode of the plurality of virtual electrodes, the electroanatomical mapping system applies one or more correlation criteria to the plurality of electrophysiology data points to identify no more than one electrophysiology data point that correlates to electrical activity at the virtual electrode; and for each of the identified electrophysiology data points, the electroanatomical mapping system outputs a graphical representation of the electrophysiology signal associated with the identified electrophysiology data point. The order in which the electroanatomical mapping system outputs the graphical representation of the electrophysiological signals associated with the identified electrophysiological data points may correspond to an orientation of the virtual catheter relative to the graphical representation of the electrophysiological map.

In aspects of the disclosure, the one or more correlation criteria include a distance criterion, and may further include one or more of a bipolar orientation criterion, a time criterion, and a morphology criterion.

The present disclosure also provides a system for classifying a plurality of electrophysiological signals from a graphical representation of an electrophysiological map generated by an electroanatomical mapping system and including a plurality of electrophysiological data points. The system includes a classification and visualization processor configured to: receiving, via an electroanatomical mapping system, a user input specifying a number of virtual electrodes for a virtual catheter and a user input defining a path of the virtual catheter; defining a virtual catheter extending along the path and including a plurality of virtual electrodes corresponding to the number of virtual electrodes; identifying one or more of the plurality of electrophysiology data points that are related to electrical activity at the plurality of virtual electrodes; and outputting a graphical representation of the one or more electrophysiological signals corresponding to the identified one or more electrophysiological data points. The classification and visualization processor may be configured to identify one or more electrophysiology data points related to electrical activity at the plurality of virtual electrodes by applying one or more correlation criteria (which may include one or more of a distance criterion, a bipolar orientation criterion, a time criterion, and a morphology criterion) to the plurality of electrophysiology data points.

The foregoing and other aspects, features, details, utilities, and advantages of the present invention will become apparent from reading the following description and claims, and from reviewing the accompanying drawings.

Drawings

Fig. 1 is a schematic diagram of an exemplary electroanatomical mapping system.

Fig. 2 depicts an exemplary catheter that may be used in connection with aspects of the present disclosure.

Fig. 3 is a flow chart of representative steps that may be followed in accordance with exemplary embodiments disclosed herein.

Fig. 4 shows an electrophysiology map and a virtual catheter.

Fig. 5 illustrates the use of distance criteria to identify electrophysiology data points related to electrical activity at several virtual electrodes.

Fig. 6 is a representation of electrophysiological activity at a plurality of virtual electrodes according to aspects of the teachings herein.

While multiple embodiments are disclosed, other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

Detailed Description

The present disclosure provides systems, devices, and methods for classifying electrophysiological signals on a virtual catheter. For purposes of illustration, aspects of the disclosure will be described with reference to classifying cardiac electrophysiological signals (e.g., intracardiac electrograms measured using HD grid catheters). However, it should be understood that the teachings herein may have good advantages in other contexts and/or with respect to other electrode configurations.

Fig. 1 shows a schematic diagram of an exemplary electroanatomical mapping system 8, the exemplary electroanatomical mapping system 8 being used for conducting a cardiac electrophysiology study by navigating a cardiac catheter and measuring electrical activity occurring in a heart 10 of a patient 11 and three-dimensionally labeling the electrical activity and/or information related to or representative of the electrical activity so measured. The system 8 may be used, for example, to create an anatomical model of a patient's heart 10 using one or more electrodes. The system 8 may also be used to measure electrophysiological data at a plurality of points along the surface of the heart and store the measured data in association with location information for each measurement point at which the electrophysiological data was measured, for example to create an electrophysiological map of the patient's heart 10.

As will be appreciated by those of ordinary skill in the art, and as will be described further below, the system 8 determines the location of objects generally within a three-dimensional space, and in some aspects, determines the orientation of the objects and expresses these locations as location information determined relative to at least one reference.

For simplicity of illustration, the patient 11 is schematically depicted as an oval. In the embodiment shown in fig. 1, three sets of surface electrodes (e.g., patch electrodes) are shown applied to the surface of the patient 11, which define three substantially orthogonal axes, referred to herein as the x-axis, y-axis, and z-axis. In other embodiments, the electrodes may be positioned in other arrangements, such as multiple electrodes on a particular body surface. As another alternative, the electrodes need not be on the surface of the body, but may be positioned inside the body.

In fig. 1, the x-axis surface electrodes 12, 14 are applied to the patient along a first axis, such as to the sides of the patient's chest region (e.g., to the patient's skin under each arm), and may be referred to as left and right electrodes. The y-axis electrodes 18, 19 are applied to the patient along a second axis generally orthogonal to the x-axis, such as along the medial thigh and neck regions of the patient, and may be referred to as left leg and neck electrodes. The z-axis electrodes 16, 22 are applied along a third axis that is generally orthogonal to both the x-axis and the y-axis, such as along the sternum and spine of the patient in the chest region, and may be referred to as chest and back electrodes. Heart 10 is located between these pairs of surface electrodes 12/14, 18/19, and 16/22.

An additional surface reference electrode (e.g., a "belly patch") 21 provides a reference and/or ground electrode for the system 8. The abdominal patch electrode 21 may be an alternative to the fixed intracardiac electrode 31, as described in further detail below. It should also be understood that, in addition, the patient 11 may have most or all of the conventional electrocardiogram ("ECG" or "EKG") system leads in place. In certain embodiments, for example, a standard set of 12 ECG leads may be used to sense an electrocardiogram on the patient's heart 10. This ECG information is available to the system 8 (e.g., it may be provided as input to the computer system 20). To the extent that the ECG leads are well understood, and to make the drawing clearer, only a single lead 6 and its connection to the computer 20 are shown in FIG. 1.

Also shown is a representative catheter 13 having at least one electrode 17. Throughout the specification, this representative catheter electrode 17 is referred to as a "wandering electrode," moving electrode, "or" measuring electrode. Typically, a plurality of electrodes 17 on the catheter 13 or on a plurality of such catheters will be used. For example, in one embodiment, system 8 may include sixty-four electrodes disposed on twelve catheters within a patient's heart and/or vasculature. Of course, this embodiment is merely exemplary, and any number of electrodes and catheters may be used.

In particular, for purposes of this disclosure, a portion of an exemplary multi-electrode catheter 13, commonly referred to as an HD grid catheter, is shown in fig. 2. The HD grid catheter 13 includes a catheter body 200 coupled to a paddle 202. The catheter body 200 may further include first and second body electrodes 204, 206, respectively. Paddle 202 may include first spline 208, second spline 210, third spline 212, and fourth spline 214 coupled to catheter body 200 by proximal coupler 216 and to each other by distal coupler 218. In one embodiment, first spline 208 and fourth spline 214 may be one continuous segment, and second spline 210 and third spline 212 may be another continuous segment. In other embodiments, the various splines 208, 210, 212, 214 may be separate segments coupled to one another (e.g., by proximal and distal couplers 216, 218, respectively).

As described above, the splines 208, 210, 212, 214 may include any number of electrodes 17; in fig. 2, sixteen electrodes 17 are shown arranged in a four by four array. It should also be appreciated that the electrodes 17 may be evenly and/or unevenly spaced, as measured along the splines 208, 210, 212, 214 and between the splines 208, 210, 212, 214.

The catheter 13 (or a plurality of such catheters) is typically introduced into the heart and/or vasculature of a patient via one or more introducers and using familiar procedures. Indeed, various methods of introducing the catheter 13 into the left ventricle of the patient's heart 10, such as transseptal methods, will be familiar to those of ordinary skill in the art, and therefore need not be described further herein.

Because each electrode 17 is located within the patient, system 8 can collect position data for each electrode 17 simultaneously. Similarly, each electrode 17 may be used to collect electrophysiological data from the surface of the heart. One of ordinary skill will be familiar with a variety of ways for the acquisition and processing of electrophysiology data points (including, for example, contact and non-contact electrophysiology mapping), such that further discussion thereof is unnecessary for an understanding of the techniques disclosed herein. Likewise, various techniques known in the art may be used to generate the graphical representation from the plurality of electrophysiology data points. To the extent that one of ordinary skill would understand how to create an electrophysiology map from an electrophysiology data point, the aspects herein are described only to the extent necessary to understand the present disclosure.

Returning now to fig. 1, in some embodiments, an optional fixed reference electrode 31 (e.g., attached to the wall of heart 10) is shown on second catheter 29. For calibration purposes, this electrode 31 may be fixed (e.g., attached to or near the heart wall) or disposed in a fixed spatial relationship to a roving electrode (e.g., electrode 17), and may therefore be referred to as a "navigational reference" or a "local reference". In addition to or instead of the surface reference electrode 21 described above, a fixed reference electrode 31 may be used. In many cases, the coronary sinus electrode or other fixed electrode in the heart 10 may be used as a reference for measuring voltages and displacements; that is, the fixed reference electrode 31 may define the origin of a coordinate system, as described below.

Each surface electrode is coupled to a multiplexing switch 24 and pairs of surface electrodes are selected by software running on a computer 20, which computer 20 couples the surface electrodes to a signal generator 25. Alternatively, the switch 24 may be omitted and multiple (e.g., three) instances of the signal generator 25 may be provided, one for each measurement axis (i.e., each surface electrode pair).

The computer 20 may comprise, for example, a conventional general purpose computer, a special purpose computer, a distributed computer, or any other type of computer. The computer 20 may include one or more processors 28, such as a single central processing unit ("CPU") or multiple processing units, commonly referred to as a parallel processing environment, which may execute instructions to practice aspects described herein.

Typically, three nominally orthogonal electric fields are generated by a series of driven and sensed electric dipoles (e.g., surface electrode pairs 12/14, 18/19, and 16/22) to effect catheter navigation in a biological conductor. Alternatively, the orthogonal fields may be decomposed and any pair of surface electrodes may be driven as dipoles to provide effective electrode triangulation. Likewise, the electrodes 12, 14, 18, 19, 16, and 22 (or any number of electrodes) may be positioned in any other effective arrangement for driving current to or sensing current from the electrodes in the heart. For example, multiple electrodes may be placed on the back, sides, and/or abdomen of the patient 11. Furthermore, this non-orthogonal approach increases the flexibility of the system. For any desired axis, the potentials measured across the traveling electrodes resulting from a set of predetermined drive (source-sink) configurations can be combined algebraically to yield the same effective potential as would be obtained by simply driving a uniform current along the orthogonal axes.

Thus, any two of the surface electrodes 12, 14, 16, 18, 19, 22 may be selected as dipole sources and drains with respect to a ground reference (such as the belly patch 21), while the unexcited electrodes measure voltages with respect to the ground reference. Wander electrode 17 placed in heart 10 is exposed to the field from the current pulse and measures with respect to ground, such as abdominal patch 21. In practice, a catheter within the heart 10 may contain more or fewer than the sixteen electrodes shown, and each electrode potential may be measured. As previously described, at least one electrode may be secured to the interior surface of the heart to form a fixed reference electrode 31, which fixed reference electrode 31 is also measured with respect to ground (such as the abdominal patch 21) and may be defined as the origin of the coordinate system of the system 8 relative to its measurement location. The data sets from each of the surface, internal, and virtual electrodes may be used to determine the location of the roving electrode 17 within the heart 10.

System 8 may use the measured voltages to determine the position of an electrode inside the heart (such as roving electrode 17) in three-dimensional space relative to a reference position (such as reference electrode 31). That is, the voltage measured at the reference electrode 31 may be used to define the origin of the coordinate system, while the voltage measured at the traveling electrode 17 may be used to express the position of the traveling electrode 17 relative to the origin. In some embodiments, the coordinate system is a three-dimensional (x, y, z) cartesian coordinate system, but other coordinate systems are contemplated, such as polar, spherical, and cylindrical coordinate systems.

It should be clear from the foregoing discussion that when a surface electrode pair applies an electric field across the heart, data is measured that is used to determine the position of the electrode within the heart. The electrode data may also be used to create a breathing compensation value that is used to improve the raw position data for the electrode position, as described, for example, in U.S. Pat. No.7,263,397, which is incorporated by reference herein in its entirety. The electrode data may also be used to compensate for changes in the patient's body impedance, as described, for example, in U.S. Pat. No.7,885,707, which is also incorporated herein by reference in its entirety.

Thus, in one representative embodiment, system 8 first selects a set of surface electrodes and then drives them with current pulses. While delivering the current pulse, electrical activity, such as voltage measured with at least one of the remaining surface and intracorporeal electrodes, is measured and stored. As described above, compensation for artifacts such as respiration and/or impedance shifts may be performed.

In some embodiments, system 8 is EnSite of Yapei Laboratories (Abbott Laboratories)^TMVelocity^TMOr EnSite Precision^TMA cardiac mapping and visualization system. However, other positioning systems may be used in conjunction with the present teachings, including, for example, RYTHMIA HDX from Boston Scientific Corporation^TMMapping system, CARTO navigation and positioning system from biosensing Webster, Inc., Northern Digital IncSystematic, SterotaxisElectromagnetic navigation system and MediGuide from yapei laboratory^TMProvided is a technique.

The localization and mapping systems described in the following patents (all of which are incorporated herein by reference in their entirety) may also be used with the present invention: U.S. Pat. Nos. 6,990,370; 6,978,168, respectively; 6,947,785, respectively; 6,939,309; 6,728,562, respectively; 6,640,119, respectively; 5,983,126; and 5,697,377.

Aspects of the present disclosure relate to classification of electrophysiological signals for a virtual catheter, for example, to display a graphical representation (e.g., trace) of the electrophysiological signals on the display 23. Accordingly, the system 8 may further include a classification and visualization module 58, the classification and visualization module 58 operable to classify and generate a graphical representation (e.g., a trace) of the electrophysiological signals on the display 23. One of ordinary skill in the art will be familiar with the graphical representation of electrophysiological signal traces in conjunction with an electroanatomical mapping system so that a detailed description thereof is not necessary for an understanding of the present disclosure.

One exemplary method of classifying and visualizing electrophysiological signals in accordance with the present teachings will be described with reference to a flowchart 300 of representative steps as shown in fig. 3. In some embodiments, for example, the flowchart 300 may represent several exemplary steps that may be performed by the electro-anatomical mapping system 8 of fig. 1 (e.g., by the processor 28 and/or the classification and visualization module 58). It should be understood that the representative steps described below may be hardware or software implemented. For purposes of illustration, the term "signal processor" is used herein to describe hardware and software based implementations of the teachings herein.

In block 302, the system 8 generates a graphical representation of the electrophysiology map, such as a map of local activation times, voltages, fractions, conduction velocities, and the like, and includes a plurality of electrophysiology data points. As noted above, one of ordinary skill in the art will be familiar with the graphical representation of electrophysiological maps by an electroanatomical mapping system, such that a detailed discussion thereof is not required herein. For purposes of illustration, however, fig. 4 depicts a representative electrophysiology map in the form of a local activation time map 400. One of ordinary skill in the art will also recognize that each electrophysiology data point includes both location data and electrophysiology data (e.g., intracardiac electrograms and locations of intracardiac electrograms measured on the heart).

In block 304, the system 8 receives user input, such as through a graphical user interface ("GUI"), to define a virtual electrophysiology catheter. For example, the user may define a path of the virtual catheter relative to the electrophysiology map 400, such as by tracing the path 402 on the electrophysiology map 400. The user may also specify the number of virtual electrodes 404 to use for the virtual catheter.

In block 306, system 8 defines a virtual catheter including a desired number of virtual electrodes 404 thereon based on the user input from block 304. For example, fig. 4 depicts five virtual electrodes 404 that are evenly spaced along the path 402 defining the virtual catheter. Fig. 4 also depicts an electrogram 406 corresponding to the virtual electrode 404, which may be generated from related electrophysiology data points according to the following teachings.

In block 308, the system 8 identifies one or more of the plurality of electrophysiology data points comprising the electrophysiology map 400, which electrophysiology data points relate to electrical activity at the virtual electrodes defined in block 306. For purposes of this disclosure, an electrophysiology data point is related to electrical activity at a virtual electrode if it satisfies one or more correlation criteria with respect to the virtual electrode.

Thus, many electrophysiology data points may be related to electrical activity at the virtual electrode. However, it should be understood that in aspects of the present disclosure, only one such relevant electrophysiology data point (and more particularly, its electrophysiology signal) will ultimately be associated with a virtual electrode. In other embodiments of the present disclosure, a composite of electrophysiological signals from a plurality of such related electrophysiological data points may be associated with a virtual electrode. In other aspects of the disclosure, the number of virtual electrodes may be increased, which correspondingly increases the number of associated electrophysiology data points. Of course, it is also contemplated that there may be no electrophysiology data point related to electrical activity at a particular virtual electrode (that is, there may be no electrophysiology data point that satisfies one or more correlation criteria with respect to the virtual electrode), in which case no electrophysiology data point, and therefore no electrophysiology signal, will be associated with that virtual electrode.

The first order correlation criterion is a distance criterion, which may be implemented as a maximum distance (e.g., euclidean distance, geodesic distance) from the location of the virtual electrode. The maximum distance may be user defined or system preset and is typically between about 2mm to about 6 mm. Any electrophysiology data point that falls within a maximum distance from the location of the virtual electrode (e.g., any electrophysiology point that falls within a sphere centered on the virtual electrode and having a radius of the maximum distance) can be considered to satisfy the distance criterion.

In some embodiments of the present disclosure, only the distance criterion is applied. In this case, if more than one electrophysiology data point satisfies the distance criterion, the electrophysiology point closest to the virtual electrode location may have an associated electrophysiology signal associated with the virtual electrode.

For example, FIG. 5 schematically depicts a display device having a plurality of virtual electrodes s₀、s₁、s₂Etc. of virtual catheter 502. FIG. 5 also depicts a plurality of electrophysiology data points a, b, c, d, e, and f. Around each virtual electrode is a dashed circle 504 representing a distance criterion. As shown in FIG. 5, the electrophysiology data point a falls around the virtual electrode s₀Within the dashed circle 504, the electrophysiology data point b falls around the virtual electrode s₁Within the dashed circle 504, the electrophysiology data points c and d fall around the virtual electrode s₃And no electrophysiology data points fall around the virtual electrode s₂And s₄Within the dashed circle 504.

Therefore, the electrophysiological signal of the electrophysiological data point a can be associated with the virtual electrode s₀The electrophysiological signals of the electrophysiological data points b can be correlated with the virtual electrodes s₁And (4) associating. Because the electrophysiology data point d is closer to the virtual electrode s than the electrophysiology data point c₃Therefore, the electrophysiological signal of the electrophysiological data point c can be associated with the virtual electrode s₃And (4) associating. No electrophysiological signal will interact with the virtual electrode s₂And s₄And (4) associating.

The distance criterion may also handle the distance to virtual catheter 502 differently than the distance along virtual catheter 502. For example, the use may be replaced by a sphere (or as in fig. 5 and so on)Two-dimensional, circular) configuration, the distance criteria may be represented by a cylindrical configuration, which may be represented by a virtual electrode (e.g., s)₀、s₁、s₂Etc.) and may have a height along the length of virtual catheter 502.

Additional correlation criteria include, but are not limited to, bipolar orientation criteria, collection time criteria, and morphology criteria. Each of these will be discussed in turn below.

The bipolar orientation criterion may be used when the electrophysiological signals associated with the electrophysiological data points making up the electrophysiological map 400 are bipolar electrograms. The bipole orientation criterion evaluates the orientation of the bipole of the electrophysiology data point relative to a reference orientation. For example, a bipolar orientation criterion may be defined to assess whether the bipole of electrophysiology data points is along the direction of the path 402 of the virtual catheter. Alternatively, a bipolar orientation criterion may be defined to assess whether the bipole of electrophysiology data points is perpendicular to the direction of the path 402 of the virtual catheter. Desirably, using a bipolar orientation criterion increases the likelihood that the electrophysiological signals ultimately associated with each virtual electrode will have the same or similar bipolar orientation. In aspects of the present disclosure, the bipolar orientation criterion is in a range between about 36 degrees and about 40 degrees centered on the direction of the path 402 of the virtual catheter.

The collection time criteria help ensure that the electrophysiological signals ultimately associated with each virtual electrode are collected at about the same time. The collection time criteria may be an absolute criteria measured from a single time reference (e.g., measured from an electrophysiology study), or may be a relative criteria measured from repeated references (e.g., measured from the depolarization of any given heartbeat). In other embodiments of the present disclosure, the benchmark may be an average (e.g., mean or median) collection time of electrophysiological data points proximate to a virtual electrode (e.g., a virtual electrode that satisfies the distance criteria as described above).

The morphology criteria help ensure that the electrophysiological signals ultimately associated with each virtual electrode have similar morphologies (similar to each other and/or similar to the template morphology). The morphology criterion may be expressed as a minimum morphology matching score, which may be calculated, for example, using a correlation value or a similarity metric; one exemplary correlation value is the pearson correlation coefficient. Additional details regarding the morphology matching score may be found in U.S. patent application No.2015/0057507, which is incorporated by reference herein as if fully set forth herein.

In block 310, no more than one electrophysiological signal is associated with each virtual electrode. As described above, it is contemplated that no electrophysiological signal can be associated with a particular virtual electrode if no electrophysiological data point satisfies the correlation criterion for that virtual electrode.

In block 312, the system 8 outputs a graphical representation of the electrophysiological signals associated with the virtual electrodes, for example as a plurality of traces on the display 23, according to techniques familiar to those of ordinary skill. The order of the output traces may correspond to the direction of the path of the virtual catheter 402 on the electrophysiology map 400. For example, fig. 6 depicts a representative output of a plurality of traces corresponding to the illustrative virtual catheter 502 of fig. 5.

Although several embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention.

For example, the system 8 may display a graphical representation of the virtual electrode on a graphical representation of the electrophysiology map. As another example, the electrophysiology data points identified as being relevant to electrical activity at the virtual electrodes can be highlighted on the graphical representation of the electrophysiology map.

As another example, in addition to serving as part of a bipolar orientation criterion, the direction of the path 402 of the virtual catheter may be used to specify the direction in which the 2D electrogram signal (e.g., as part of a full polarity voltage loop) may be projected.

As another example, instead of defining a virtual catheter comprising a plurality of virtual electrodes, all electrophysiology data points within a preset distance of a defined path (e.g., path 402) may be used.

All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations on the position, orientation, or use of the invention. References made in conjunction (e.g., attached, coupled, connected, etc.) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other.

It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.