阅读说明：本技术 用于心脏标测的系统和方法 (Systems and methods for cardiac mapping ) 是由 M·哈格福什 T·达伦 D·R·斯塔克斯 于 2020-04-03 设计创作，主要内容包括：电解剖标测系统可以标测组织的电激活,并且通过使用局部激活定时信息计算每个点的慢传导度量,特别地使用多个电生理数据点创建慢传导标测图,每个电生理数据点包括局部激活定时信息。慢传导度量可用于将点分类为无传导点、慢传导点和正常传导点,并且结果可以用图形表达,包括作为沿三维解剖表面模型传播的激活波前的动画表示。(The electroanatomical mapping system may map electrical activation of tissue and create a slow-conduction map using, in particular, a plurality of electrophysiology data points, each comprising local activation timing information, by calculating a slow-conduction metric for each point using the local activation timing information. The slow conduction metric can be used to classify points as non-conducting points, slow-conducting points, and normal-conducting points, and the results can be graphically expressed, including as an animated representation of the activation wavefront propagating along the three-dimensional anatomical surface model.)

1. A method for mapping electrical activation of tissue, comprising:

receiving, at an electroanatomical mapping system, a plurality of electrophysiology data points, each of the plurality of electrophysiology data points including local activation timing information; and

for each electrophysiology data point of the plurality of electrophysiology data points, the electroanatomical mapping system calculates a slow-conduction metric from the local activation timing information,

creating a slow-conducting map.

2. The method of claim 1, further comprising:

the electroanatomical mapping system classifying a first subset of the plurality of electrophysiology data points as non-conductive electrophysiology data points; and

the electroanatomical mapping system classifies a second subset of the plurality of electrophysiology data points as slow-conducting electrophysiology data points.

3. The method according to claim 1, further comprising the electroanatomical mapping system outputting a graphical representation of the slow-conduction map on a three-dimensional anatomical surface model.

4. The method according to claim 3, wherein the electroanatomical mapping system outputting the graphical representation of the slow-conduction map on a three-dimensional anatomical surface model comprises:

the electroanatomical mapping system graphically represents non-conductive regions on the three-dimensional anatomical surface model using a first display protocol; and

the electroanatomical mapping system graphically represents slow-conduction regions on the three-dimensional anatomical surface model using a second display protocol.

5. The method of claim 3, wherein the graphical representation of the slow-conduction map comprises an animated representation of an activation wavefront propagating along the three-dimensional anatomical surface model.

6. The method according to claim 5, wherein the electroanatomical mapping system generates the animated representation of the activation wavefront propagating along the three-dimensional anatomical surface model by performing steps comprising:

generating a series of frames, wherein each frame in the series of frames corresponds to an image of the slow-conduction map at a point in time and includes a static representation of the activation wavefront at the point in time, wherein a visibility of the static representation of the activation wavefront at the point in time is related to the slow-conduction metric at a location of the activation wavefront at the point in time; and

the electroanatomical mapping system displays the series of frames in chronological order.

7. The method of claim 6, wherein the visibility of the static representation of the activation wavefront is directly related to the slow-conduction metric at the location of the activation wavefront at the point in time.

8. The method of claim 1, wherein the electroanatomical mapping system calculating a slow-conduction metric from the local activation timing information comprises the electroanatomical mapping system calculating the slow-conduction metric using a weighted standard deviation of the local activation timing information.

9. The method according to claim 1, wherein the electroanatomical mapping system calculating a slow-conduction metric from the locally-activated timing information includes the electroanatomical mapping system calculating the slow-conduction metric using a weighted variance of the locally-activated timing information.

10. A method for mapping electrical activation of tissue, comprising:

receiving a local activation time map comprising a plurality of electrophysiology data points, each electrophysiology data point comprising local activation timing information; and

for each electrophysiology data point of the plurality of electrophysiology data points, calculating a slow conduction metric using the local activation timing information for a subset of the plurality of electrophysiology data points within a preset distance of the respective electrophysiology data point,

creating a slow-conducting map.

11. The method of claim 10, wherein the slow-conduction metric is calculated using one of a weighted variance of the local activation timing information for the subset of the plurality of electrophysiology data points and a weighted standard deviation of the local activation timing information for the subset of the plurality of electrophysiology data points.

12. The method of claim 11, wherein weighting is inversely related to distance from the respective electrophysiology data point.

13. The method of claim 10, further comprising outputting a graphical representation of the slow conduction map on a three-dimensional anatomical surface model.

14. The method of claim 13, wherein the graphical representation of the slow conduction map comprises:

a graphical representation of at least one region of non-conduction represented on the three-dimensional anatomical surface model using a first display protocol; and

a graphical representation of at least one region of slow conduction represented on the three-dimensional anatomical surface model using a second display protocol.

15. The method of claim 13, wherein the graphical representation of the slow-conduction map comprises an animated representation of a cardiac activation wavefront.

16. The method of claim 15, wherein the animated representation of the cardiac activation wavefront comprises a plurality of frames, wherein each frame comprises a static representation of the cardiac activation wavefront at playback, and wherein a visibility of the static representation of the cardiac activation wavefront is related to the slow-conduction metric at a location of the cardiac activation wavefront at the playback.

17. The method of claim 16, wherein the visibility of the static representation of the cardiac activation wavefront is directly related to the slow-conduction metric at the location of the cardiac activation wavefront at the time of the playback.

18. An electro-anatomical mapping system for generating an electrically activated map of tissue, comprising:

activating a mapping processor configured to:

receiving a local activation time map comprising a plurality of electrophysiology data points, each electrophysiology data point comprising local activation timing information; and

for each electrophysiology data point of the plurality of electrophysiology data points, calculating a slow conductance metric using the local activation timing information for a subset of the plurality of electrophysiology data points within a preset distance of the respective electrophysiology data point,

creating a slow-conducting map.

19. The system of claim 18, further comprising a mapping processor configured to output a graphical representation of the slow-conduction map.

20. The system of claim 19, wherein the graphical representation of the slow-conduction map comprises an animated representation of a cardiac activation wavefront.

Technical Field

The present disclosure relates generally to cardiac mapping, such as may be performed in cardiac diagnostic and therapeutic procedures. In particular, the present disclosure relates to systems, devices, and methods for generating electrophysiology maps from data collected by a wandering electrophysiology probe, such as a high density ("HD") mesh catheter or other multi-electrode device. Even more particularly, the electrophysiology maps disclosed herein facilitate identifying areas of slow conduction and/or block using local activation timing information.

Background

Anatomical mapping, such as cardiac electrophysiology mapping, is used in many diagnostic and therapeutic procedures. In certain procedures, for example, various components associated with depolarization waves are detected from electrogram signals obtained from a diagnostic catheter and used to generate maps, such as local activation time ("LAT") maps. Typically, such maps are static maps that employ color and/or shading to represent parameters, such as activation time, when rendered.

In some cases, it may be desirable to understand the propagation of the cardiac activation wavefront. In particular, when studying cardiac arrhythmias, practitioners may wish to identify areas of slow conduction and/or block (e.g., no conduction).

Disclosure of Invention

Disclosed herein is a method of mapping electrical activation of tissue, comprising: receiving, at an electroanatomical mapping system, a plurality of electrophysiology data points, each of the plurality of electrophysiology data points including local activation timing information; and for each of the plurality of electrophysiology data points, the electroanatomical mapping system calculates a slow-conduction metric from the local activation timing information, thereby creating a slow-conduction map.

The method may further comprise: classifying, by the electroanatomical mapping system, a first subset of the plurality of electrophysiology data points as non-conductive electrophysiology data points; and the electroanatomical mapping system classifies a second subset of the plurality of electrophysiology data points as slow-conducting electrophysiology data points.

In additional embodiments of the present disclosure, the method may include the electroanatomical mapping system outputting a graphical representation of the slow-conduction map on a three-dimensional anatomical surface model. For example, the electroanatomical mapping system may graphically represent non-conductive regions on the three-dimensional anatomical surface model using a first display protocol, and may represent slow-conductive regions on the three-dimensional anatomical surface model using a second display protocol.

Alternatively, the graphical representation of the slow-conduction map may include an animated representation of the activation wavefront propagating along the three-dimensional anatomical surface model. For example, the electroanatomical mapping system may generate an animated representation of an activation wavefront propagating along a three-dimensional anatomical surface model by performing steps comprising: generating a series of frames, wherein each frame in the series of frames corresponds to an image of a slow-conduction map at a point in time and includes a static representation of an activation wavefront at the point in time, wherein a visibility of the static representation of the activation wavefront at the point in time is related to a measure of slow-conduction at a location of the activation wavefront at the point in time; and displays a series of frames in time sequence. In conjunction with such an animated representation, it is contemplated that the visibility of the static representation of the activation wavefront may be directly related to the slow-propagation metric at the location of the activation wavefront at that point in time.

According to aspects of the present disclosure, the electroanatomical mapping system may calculate the slow-conduction metric using a weighted standard deviation of the local activation timing information. Alternatively, the electroanatomical mapping system may use a weighted variance of local activation timing information to calculate the slow-conduction metric.

Also disclosed herein is a method of mapping electrical activation of tissue, comprising the steps of: receiving a local activation time map comprising a plurality of electrophysiology data points, each electrophysiology data point comprising local activation timing information; and for each electrophysiology data point of the plurality of electrophysiology data points, calculating a slow conductance metric using local activation timing information for a subset of the plurality of electrophysiology data points within a preset distance of the respective electrophysiology data point, thereby creating a slow conductance map.

The slow-conduction metric may be calculated using one of a weighted variance of the local activation timing information for the subset of the plurality of electrophysiology data points and a weighted standard deviation of the local activation timing information for the subset of the plurality of electrophysiology data points. For example, the weighting can be inversely related to the distance from the respective electrophysiology data point (e.g., the weighting decreases as the distance from the respective electrophysiology data point increases).

The method may further include outputting a graphical representation of the slow conduction map on the three-dimensional anatomical surface model. In an embodiment of the present disclosure, the graphical representation of the slow conductance map includes a graphical representation of at least one region of no conductance represented on the three-dimensional anatomical surface model using a first display protocol; and a graphical representation of the at least one region of slow conduction represented on the three-dimensional anatomical surface model using a second display protocol.

In other embodiments of the present disclosure, the graphical representation of the slow conduction map includes an animated representation of the cardiac activation wavefront. The animated representation of the cardiac activation wavefront may include a plurality of frames, wherein each frame corresponds to a playback time and includes a static representation of the cardiac activation wavefront at the time of playback, and wherein a visibility of the static representation of the cardiac activation wavefront is related to the measure of slow conductance at the location of the cardiac activation wavefront at the time of playback. The visibility of the static representation of the expected cardiac activation wavefront may be directly related to the slow conductance metric at the location of the cardiac activation wavefront at playback.

The present disclosure also provides an electro-anatomical mapping system for generating an electrically activated map of tissue. The system includes an active mapping processor configured to: receiving a local activation time map comprising a plurality of electrophysiology data points, each electrophysiology data point comprising local activation timing information; and for each electrophysiology data point of the plurality of electrophysiology data points, calculating a slow conductance metric using local activation timing information for a subset of the plurality of electrophysiology data points within a preset distance of the respective electrophysiology data point, thereby creating a slow conductance map. The system optionally further includes a mapping processor configured to output a graphical representation of the slow-conduction map, such as an animated representation of the cardiac activation wavefront.

The foregoing and other aspects, features, details, utilities, and advantages of the present invention will be 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 conjunction with aspects of the present disclosure.

Fig. 3 is a flowchart of representative steps that may be performed in accordance with exemplary embodiments disclosed herein.

Fig. 4 is a representative graphical representation of a slow-conduction map in accordance with aspects of the present disclosure.

Fig. 5 is a representative graphical representation of a slow-conduction map according to another embodiment of the present disclosure.

Fig. 6 is an illustrative curve showing the change in opacity (i.e., visibility) over time of a graphical representation of a particular location on the surface of the heart as the activation wavefront approaches and passes that location.

Fig. 7A-7C depict propagation of a cardiac activation wavefront on a graphical representation of a slow conduction map in accordance with a further aspect of the present disclosure.

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 generating electrophysiological maps, and more particularly electro-active maps of tissue, that facilitate identifying areas of slow conduction and/or block. For purposes of illustration, an electroanatomical mapping system (such as EnSite Precision) also from Abbott Laboratories (Abbott Laboratories) will be incorporated^TMCardiac mapping system) reference using a High Density (HD) mesh catheter, such as an Advisor from jacobian laboratories (Abbott Park, Illinois)^TMHD mesh mapping catheter) to describe aspects of the disclosure. However, those of ordinary skill in the art will understand how to apply the teachings herein to good advantage in other contexts and/or with respect to other devices.

Fig. 1 shows a schematic diagram of an exemplary electroanatomical mapping system 8 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. For example, the system 8 may be used 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 a diagnostic data map of the patient's heart 10.

As will be appreciated by one of ordinary skill in the art, the system 8 determines the location and, in some aspects, orientation of objects generally within a three-dimensional space, and expresses those 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, defining 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 (e.g., multiple electrodes on a particular body surface). As a further 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 on lateral sides of the chest region of the patient (e.g., to the skin under each arm of the patient) 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 that is 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 thoracic 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 described in more 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). As far as ECG leads are well understood, and for clarity in the figure, 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. This representative catheter electrode 17 is referred to throughout the specification as a "traveling 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 on twelve catheters disposed within a patient's heart and/or vasculature. In other embodiments, system 8 may utilize a single catheter that includes multiple (e.g., eight) splines, where each spline in turn includes multiple (e.g., eight) electrodes.

However, the foregoing embodiments are merely exemplary, and any number of electrodes and/or catheters may be used. For example, for purposes of this disclosure, a segment of an exemplary multi-electrode catheter, and in particular an HD mesh catheter, is shown in fig. 2. The HD mesh catheter 13 includes a catheter body 200 coupled to paddles 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, which are 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, while 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). It should be understood that the HD catheter 13 may comprise any number of splines; the four-spline arrangement shown in fig. 2 is merely exemplary.

As described above, 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 understood 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 multiple such catheters) is typically introduced into the patient's heart and/or vasculature via one or more introducers and using familiar procedures. Indeed, various methods of introducing the catheter 13 into the patient's heart, such as transseptal methods, are familiar to those of ordinary skill in the art and, therefore, need not be described further herein.

Since each electrode 17 is located within the patient, system 8 may collect position data for each electrode 17 simultaneously. Similarly, each electrode 17 may be used to collect electrophysiological data (e.g., surface electrograms) from the surface of the heart. One of ordinary skill will be familiar with various patterns for acquiring and processing electrophysiology data points (including, for example, both contact and non-contact electrophysiology mapping), such that further discussion thereof is not necessary for an understanding of the techniques disclosed herein. Likewise, various techniques familiar in the art may be used to generate a graphical representation of cardiac geometry and/or cardiac electrical activity from a plurality of electrophysiology data points. Moreover, to the extent that one of ordinary skill would understand how to create an electrophysiology map from electrophysiology data points, aspects thereof will only be described herein 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 the heart 10) is shown on the second catheter 29. For calibration purposes, this electrode 31 may be fixed (e.g., attached to or near the heart wall) or arranged in a fixed spatial relationship with a roving electrode (e.g., electrode 17), and may therefore be referred to as a "navigational reference" or a "local reference". Fixed reference electrode 31 may be used in addition to or in place of surface reference electrode 21 described above. In many cases, the coronary sinus electrode or other stationary 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 the computer 20, the multiplexing switches 24 coupling the surface electrodes to a signal generator 25. Alternatively, the switch 24 may be eliminated 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, that may execute instructions to practice the various aspects described herein.

Typically, three nominally orthogonal electric fields are generated by a series of driven and sensed electric dipoles (e.g., pairs of surface electrodes 12/14, 18/19, and 16/22) to enable catheter navigation in biological conductors. Alternatively, the orthogonal fields can be decomposed and any pairs of surface electrodes can be driven as dipoles to provide effective electrode triangulation. Likewise, 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. In addition, such non-orthogonal methods increase the flexibility of the system. For any desired axis, the potentials measured across the roving 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 measurements are taken with respect to the ground, such as abdominal patch 21. In practice, a catheter within the heart 10 may contain more or fewer than the 16 electrodes shown, and each electrode potential may be measured. As previously described, at least one electrode may be fixed to the inner surface of the heart to form a fixed reference electrode 31, which is also measured with respect to the ground (such as the abdominal patch 21), and may be defined as the origin of a coordinate system relative to which the system 8 measures position. 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, although other coordinate systems are contemplated, such as polar, spherical, and cylindrical coordinate systems.

As should be clear from the foregoing discussion, 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 respiratory compensation values for improving the raw position data of the electrode position, as described, for example, in U.S. Pat. No.7,263,397, which is incorporated herein by reference in its entirety. The electrode data may also be used to compensate for changes in patient 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 electrodes and the intracorporeal electrodes, is measured and stored. Compensation for artifacts such as breathing and/or impedance shifts may be performed as described above.

In aspects of the present disclosure, the system 8 may be a hybrid system that combines both impedance-based (e.g., as described above) and magnetic-based positioning capabilities. Thus, for example, the system 8 may further include a magnetic source 30 coupled to one or more magnetic field generators. For clarity, only two magnetic field generators 32 and 33 are depicted in fig. 1, but it should be understood that additional magnetic field generators (e.g., a total of six magnetic field generators defining three substantially orthogonal axes, similar to the axes defined by patch electrodes 12, 14, 16, 18, 19, and 22) may be used without departing from the scope of the present teachings. Also, one of ordinary skill in the art will appreciate that one or more magnetic positioning sensors (e.g., coils) may be included for positioning the catheter 13 within the magnetic field so generated.

In some embodiments, system 8 is EnSite of Yapei laboratory^TM Velocity^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, RHYHMIA HDX from Boston scientific Inc. (Marburg, Mass.)^TMMapping systemSystems, Biosense Webster, Inc., CARTO navigation and positioning system of deluxe, california, Northern Digital IncOf the system, Sterotaxis, Inc. (St. Louis, Mo.)Magnetic 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 electrophysiological mapping, and in particular to mapping electrical activation of tissue in order to facilitate identification of slow conduction and/or blocked regions. A graphical representation of such a map may also be output, for example, on display 23. Accordingly, system 8 may include an activation mapping module 58, which activation mapping module 58 may be used to generate an anatomical map, and may incorporate a display module to allow for graphical output thereof (e.g., to display 23).

One exemplary method according to the present teachings will be explained with reference to a flowchart 300 of representative steps as shown in fig. 3. For example, in some embodiments, 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 activating the mapping module 58). It should be understood that the representative steps described below may be hardware or software implemented. For purposes of explanation, the term "signal processor" is used herein to describe both hardware-based and software-based implementations of the teachings herein.

In block 302, system 8 receives a Local Activation Time (LAT) map. As will be understood by those of ordinary skill in the art, a LAT map is an electrophysiology map, and thus includes a plurality of electrophysiology data points, each in turn associated with (at least) local activation timing information.

Block 304-310 are exemplary steps that system 8 may perform to calculate a slow conductance metric for a given electrophysiology data point within the LAT map received in block 302. In block 304, the system 8 selects an electrophysiology data point ("selected electrophysiology data point"), while in block 306, the system 8 identifies a subset of electrophysiology data points ("adjacent subset") that fall within a preset distance (e.g., a radius of about 2 mm) of the selected electrophysiology data point.

In block 308, system 8 calculates a slow-conduction metric for the selected EP data point using the local activation timing of the neighboring subset. In an embodiment of the present disclosure, the slow-conduction metric is calculated as a weighted standard deviation (or weighted variance) of the local activation times of the neighboring subsets.

The weight given to the local activation time of any member of the neighboring subset is inversely related to the distance from it to the selected EP data point. In other words, lower weights are assigned to members of the neighboring subset that are further from the selected EP data point, while higher weights are assigned to members of the neighboring subset that are closer to the selected EP data point. In embodiments of the present disclosure, the weights decrease linearly with distance from the selected EP data points, but other weighting schemes or functions are also within the scope of the present disclosure.

Decision block 310 considers whether there are additional electrophysiology data points for which a slow conductance metric should be calculated. If so (yes exit from block 310), the process repeats from block 304 with the new selected electrophysiology data point. If not ("no" exit from block 310), system 8 outputs a slow conduction map in block 312.

In block 314, the system 8 may output a graphical representation of the slow-conduction map, for example, on a three-dimensional anatomical surface model, to assist the practitioner in identifying areas of non-conduction and/or slow-conduction. Various graphical representations are contemplated within the scope of the present teachings. However, to the extent that one of ordinary skill in the art is generally familiar with the graphical representation of an electrophysiology map, the details of the graphical representation of the slow conduction map disclosed herein will be limited to those details necessary for an understanding of the present disclosure.

For example, in some aspects of the present disclosure, system 8 outputs a graphical representation of the slow-conducting map using standard mapping protocols such as color spectrum, grayscale, pattern density range, and the like. In this regard, fig. 4 depicts a graphical representation 402 of a slow-conduction map in grayscale. Potential lines of slow conduction and/or no conduction 404 are visible. Advantageously, using weighting values in calculating the slow-conduction metric facilitates smoothness in the graphical representation 402.

In additional aspects of the disclosure, the system 8 can classify the electrophysiology data points as non-conducting electrophysiology data points, slow-conducting electrophysiology data points, or normal-conducting electrophysiology data points based on their respective slow-conduction metrics. The intended practitioner can select a threshold or cutoff value for each classification of data points. However, for purposes of illustration, for a linear weighted radius of about 2mm (as described above), a non-conducting electrophysiology data point may have a slow conduction metric of less than about 0.4ms, while a slow-conducting electrophysiology data point may have a slow conduction metric of between about 0.4ms and about 1.0 ms.

Once the system 8 classifies the electrophysiology data point, it can graphically represent non-conductive regions (e.g., containing non-conductive electrophysiology data points) using a first display protocol (e.g., a single color) and slow-conductive regions (e.g., containing slow-conductive electrophysiology data points) using a second display protocol (e.g., a single color pattern). A color scale may be used to show the area of normal conduction (e.g., containing normal conduction electrophysiology data points).

Fig. 5 depicts a corresponding graphical representation 502 in which a normally conductive region 504 is depicted using conventional color scale. However, areas that are not conductive are depicted using a single solid color (e.g., brown) 506, while areas that are slowly conductive are depicted using the same single color (e.g., brown) with stippling 508.

In other embodiments of the present disclosure, system 8 outputs an animated representation of the slow-conducting map by delineating the activation wavefront as it propagates along the three-dimensional anatomical model. Those of ordinary skill in the art are generally familiar with propagating an animated representation of an activation wavefront.

For example, as set forth fully herein, U.S. patent application publication No.2017/0360319, which is incorporated herein by reference, describes the use of static frames, each of which is specific to a particular point in time and includes a timing mark representing the position of the activation wavefront at that point in time. The visibility (e.g., opacity and/or brightness) of any given timing mark in any given frame can be related to the distance from the mark to the location of the activation wavefront at the corresponding point in time, such that the timing mark increases the visibility of a series of frames before the activation wavefront arrives, reaches its maximum visibility in a frame coincident with the location of the activation wavefront, and decreases the visibility in a series of frames after the activation wavefront passes. Thus, when the frames are displayed in chronological order, the timing marks fade in, reach maximum visibility, and then fade out, such that the activation wavefront appears to move across the surface of the three-dimensional anatomical model in a manner similar to the objects contained in the movie.

However, in general, an animated representation of the electrically activated wavefront emphasizes areas of rapid conduction. In another aspect, aspects of the present disclosure emphasize regions of slow conduction and/or no conduction.

In particular, the rate at which the visibility of the graphical representation of the activation wavefront decays after it passes through a given location is related to the measure of slow conduction at that location. A higher measure of slow conduction at a given location will result in a longer decay time (e.g., the graphical representation of the activation wavefront at that location remains visible longer), while a lower measure of slow conduction at a given location will result in a shorter decay time (e.g., the graphical representation of the activation wavefront at that location disappears faster). This gives the visual impression that the activation wavefront slows down in the slowly conducting and/or non-conducting areas.

FIG. 6 is a representative plot of the visibility of a graphical representation of an activation wavefront at any particular location. At time 112, the graphical representation begins to fade in as the activation wavefront approaches the particular location, reaching its maximum visibility at time 114, which is the time at which the activation wavefront coincides with the particular location. It then fades out gradually as it moves away from the particular location until it disappears completely at time 116. The length of the attenuation slope 110 along the horizontal axis (e.g., between the time of maximum visibility 114 and the time of fade-out completion 116) is directly related to the slow conduction metric at a particular location — the higher the slow conduction metric, the wider the attenuation slope 110 will be.

In an embodiment of the present disclosure, the decay slope 110 may be a non-linear function of the slow conduction metric that varies in a range of about 2% to about 52% of the period length of the rhythm, with higher slow conduction metrics corresponding to longer duration decay slopes 110.

7A-7C depict three frames of an animated representation (FIGS. 7A-7C are chronological, but they are not directly consecutive frames) added to the slow-conducting map of representation 502 of FIG. 5. In each frame, the location of the activation wavefront is represented by a marker 702 (e.g., 702a in fig. 7A, 702B in fig. 7B, and 702C in fig. 7C). The regions where the marker 702 appears thinner are generally normally conductive regions, while the regions where the marker 702 appears fatter are slow conductive and/or non-conductive regions.

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 teachings herein may be applied in real-time (e.g., during an electrophysiology study) or during post-processing (e.g., for electrophysiology data points collected during an electrophysiology study performed at an earlier time).

As another example, the slow-conduction maps disclosed herein may be displayed not only as stand-alone maps, but also in conjunction with other electrophysiological maps (e.g., superimposed on a peak-to-peak voltage map, a complex subdivided electrogram map, a LAT map, etc.).

As another example, the teachings herein may be applied not only to electrophysiological data points (e.g., as measured by the electrodes 17 on the catheter 13), but also to LAT values assigned (e.g., via interpolation) to individual pixels within a graphical representation (e.g., on the display 23).

As a further example, the animated representation of the activation wavefront may disappear in the non-conductive areas, rather than simply slow down.

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, particularly as to 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. Thus, incorporation by reference does 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.