Systems and methods for visualizing electrophysiological data

Abstract

The subject matter of the present invention is "System and method for visualizing electrophysiological data." The present invention discloses a method and system for visualizing electrophysiological information sensed by electrodes on a catheter, the method and system comprising recording the time of electrode signal acquisitions, calibrating a reference electrode signal acquisition, specifying a relative time of each recorded time of an electrode signal acquisition relative to the reference electrode signal acquisition, identifying the electrodes having signal acquisitions, associating the specified relative times with the identified electrodes to generate an electrode signal acquisition sequence, and generating a visual representation of the electrode signal acquisition sequence using a graphical image of the electrodes, wherein individual electrodes are visually labeled to represent the electrode signal acquisition sequence.

Description

[0001] This application is a divisional application of the patent application filed on December 31, 2015, with application number 201511030505.3 and invention name “System and method for visualizing electrophysiological data”. Technical Field

[0002] The present invention generally relates to visualization of a patient's electrical activity, and more particularly to spatial visualization of a patient's electrophysiological data detected by a catheter. Background Art

[0003] Arrhythmias are the leading cause of death in the United States. Typically, electrical signals are conducted through the atria and into the ventricles in an orderly fashion, passing each point in the heart only once during each cardiac cycle. The electrical signals at different locations in the heart are well correlated, accounting for normal propagation delays from one area of ​​the heart to another. In response to the local activation signals, the atrial muscle fibers contract in a suitably synchronized manner to pump blood through the atria.

[0004] The heart's electrical conduction system provides the rhythm or sequence of contractions of the myocardium so that it can most efficiently pump blood to the rest of the body. Electrophysiologists study the conduction system to diagnose and treat abnormal heart rhythms, called arrhythmias. It would be desirable to provide methods and devices that assist physicians in diagnosing abnormal heart rhythms and measuring the success of treating these arrhythmias through ablation therapy.

[0005] While it is not important to fully understand all the details of the field of cardiac electrophysiology, understanding the benefits of the present invention does require a basic understanding of how the heart's electrical conduction system works and how some of these arrhythmias are treated.

[0006] Cardiac tissue has several important properties as it relates to the heart's electrical conduction system. First, cardiomyocytes can receive electrical stimulation. Next, they can respond to this stimulation, or become activated. In the case of cardiomyocytes, they contract, thereby causing the heart to compress and pump blood. Electrically, this activity is called depolarization. It is a chemical process within the cell. Once depolarized, the cell needs time (several milliseconds) to recover. During this depolarization phase, the cell is said to be refractory, meaning it has not fully recovered and cannot yet receive another stimulus. Finally, cardiomyocytes can propagate this electrical signal; that is, once stimulated, they can then stimulate cells immediately adjacent to them. Thus, cardiomyocytes are continuously activated, starting from the initial stimulation point and propagating outward through the heart chambers. The refractory nature of the newly stimulated cells prevents the depolarization wave from moving backward; therefore, the wave continues forward through the heart tissue or the walls of the heart chambers in an orderly manner. The analogy of "throwing a stone to test the water" is often used to describe this situation; ripples move outward in an orderly manner from a single stimulation point. Given this context, it's important to note that in the heart, some anatomical structures (e.g., heart valve orifices and vascular openings) create obstacles to the propagation of depolarization waves. Additionally, scars from heart surgery or damaged myocardium are also nonconductive, and the wave must also bypass the outer edges of these scars to progress. In the stone-throwing example, imagine the scars and heart valves as large rocks protruding from the surface of a pond; the ripples propagate around them and converge on the other side. This stimulation point in a normal heart is made up of cardiomyocytes that have an additional property called autorhythmicity. The chemical makeup of these cells allows them to stimulate themselves, thereby initiating a depolarization wave, and then repeatedly stimulate themselves at a specific rhythm. Normal cardiomyocytes do not have this property, so once repolarized and ready, they must simply wait to be restimulated each time. This continuous depolarization and repolarization keeps the heart beating at a regular rhythm, which is regulated to meet the body's oxygen needs.

[0007] In a more macroscopic sense, the heart itself has certain characteristics that allow it to depolarize and contract to pump blood in an orderly and efficient manner. Figure 1As shown, a normal heartbeat with a normal electrical pathway (NEP) begins at the sinoatrial node (SA node comprising those cells with automatic rhythmicity) near the top of the right atrium and propagates through the entire right and left atria, causing them to contract and fill the ventricles with blood (a series of one-way valves in the heart prevent blood from flowing backward). The upper and lower chambers are separated by the atrioventricular septum, which is composed of a membrane tissue that does not conduct electrical signals. Therefore, in a normal heart, the depolarization wave cannot simply continue to advance directly from the atrium to the ventricle. This is regulated by the tissue at an electrical channel connecting them. This collection of myocardial cells (called the AV node) has an additional characteristic that delays depolarization and allows the atria to contract completely. It then sends electrical signals directly to the ventricular apex, where the depolarization wave passing through the ventricle causes effective contraction, thereby sending blood to the lungs and the rest of the body. The delay between atrial and ventricular depolarization causes the "lub-dup, lub-dup" sound of separation of the heart.

[0008] Electrophysiologists use electrode-tipped catheters placed at various locations in the heart to study its electrical conduction system in order to diagnose arrhythmias. They usually use recognized methods. The catheter is a long, thin plastic tube with a wire inside that is connected to a series of uniformly spaced electrodes, or more commonly, pairs of electrodes, at the distal end, which are used to record local activation at discrete locations in the heart. When in contact with the heart wall, a pair of electrodes close to each other will only measure the electrical activity at this small piece of tissue. The recording system processes these electrograms, displays them on a monitor in real time, and also allows the user to freeze and view them. This allows the user to measure and compare the timing differences of all the electrograms obtained from various locations at one moment in order to derive the current activation sequence and make a diagnosis.

[0009] Multipole catheters, typically with five or ten electrode pairs, are particularly useful for analyzing depolarization waves traveling through specific tissue masses. When such catheters are positioned close to the endocardium (the inner wall of the heart) so that they are oriented along the activation wave, the activation delay from one end to the other (distal to proximal or proximal to distal) will result in a skewed electrical activation pattern. Figure 2A In the example of a catheter, the depolarization wave first passes through poles 1-2. A few milliseconds later, it passes through electrodes (or "poles") 3-4, then 5-6, and so on, until it reaches poles 19-20, which it passes through last. On this catheter, poles 1-2 are said to be the "earliest," and poles 19-20 are said to be the "latest." Figure 2BThe resulting electrogram is shown. For each heartbeat or cardiac cycle, the electrogram for poles 1-2 is earliest on the timeline, poles 2-3 are offset several milliseconds later, and poles 19-20 are latest. Similarly, it will be understood that a depolarization wave moving in the other direction would first pass through poles 19-20, then through poles 17-18, 15-16, and so on, until it reached poles 1-2, where poles 19-20 were earliest and poles 1-2 were latest, and the visual pattern would be formed by the electrograms tilted in the other way. A mapping system discussed later describes the timing of electrical activation as a graphical representation using a color scale, where red indicates earlier activation and purple indicates later activation.

[0010] However, when the multipole catheter is oriented transverse to the activation wave, or if there are two intersecting activation waves, the electrogram will have a convex or concave visual pattern to them. Figure 3A In the middle, the wave first passes through the distal poles 1-2 and the proximal poles 19-20 simultaneously, and finally passes through the middle poles 9-10 and 11-12. Figure 3B The electrogram in reflects this situation and forms a concave visual pattern. Similarly, in the opposite case where poles 9-10 and 11-12 are traversed first and poles 1-2 and 19-20 are traversed last, the visual pattern of the resulting electrogram will show a convex curve, as shown in FIG. Figure 3B As shown, with poles 9-10 and 11-12 in front and poles 1-2 and 19-20 in the back.

[0011] In addition, there are an increasing variety of specialized electrode catheters available. These can produce electrogram patterns that are more complex and therefore difficult to interpret from the electrogram pattern alone, such as Figure 4A and 4B shown.

[0012] In practice, using electrograms to diagnose arrhythmias requires a comprehensive understanding of cardiac anatomy and a clear knowledge of the current position of the catheter within the heart chambers. If the physician places the catheter in a different location than intended, or if the catheter moves after being placed in the correct location, the information provided by the catheter's electrogram will be inaccurate, thereby delaying diagnosis or even leading to a missed or incorrect diagnosis.

[0013] Generally speaking, arrhythmias can be broadly classified as local, reentrant or disordered. Local arrhythmias have a single source. A small group of myocardial cells away from the SA node have acquired automatic rhythmic properties and depolarize at a fast rate. Because they activate at a rate faster than the SA node, the cells here do not depolarize independently; the SA node is "inhibited." Atrial tachycardia is an example of this situation. The treatment goal for this type of arrhythmia is to locate this group of cells that depolarize independently and deliver local RF energy (via the end of the ablation catheter positioned at this site) to "ablate" or destroy them.

[0014] In contrast, reentrant arrhythmias do not have a single point of origin. The properties of depolarization, repolarization, and refractoriness allow for a situation in which the driven activation pattern forms a ring around a neutral, non-conducting structure (e.g., a heart valve or surgical scar). Once triggered, the depolarization wave makes its way around the neutral structure in a circle, either clockwise or counterclockwise. Although the depolarization wave returns to the tissue that was just activated because it formed the previous ring, the tissue is now past its refractory period and is ready to be stimulated again, in this case by the returning wave. The arrhythmia continues in this manner, circling indefinitely. Atrial flutter, for example, is an extremely common reentrant arrhythmia that rotates around the tricuspid valve in the right atrium. The treatment strategy for reentry is to ablate a line of tissue (again, via an ablation catheter) from the neutral structure in the center of the ring to another structure near the neutral structure, thereby creating a non-conducting focus or "line of blockade" that disrupts the arrhythmia.

[0015] Although the electrograms provided by the localization catheter are helpful in diagnosing arrhythmias, more precise information is often needed to fully understand the abnormal activation pattern and to target the appropriate area for the treatment phase of the study, which begins after the diagnosis is made. In many cases, detailed sampling of the electrogram over most or all of the endocardial surface of one or more cardiac chambers is required.

[0016] Electroanatomical mapping systems have been developed to (1) clearly define endocardial anatomy as a 3D virtual model, (2) record and catalog sampled electrograms, (3) display activation sequences (or other data) compiled from the electrograms recorded on the virtual model, (4) track and display the current position of the electrode catheter in the heart in real time by projecting a precise representation of the electrode catheter into the virtual environment, and (5) record the precise location of sites of interest, e.g., locations where RF energy has been applied.

[0017] In this two-step mapping-followed-ablation process, electrical activity is sensed and measured, typically by advancing a catheter containing one or more electrical sensors into the heart and collecting data at multiple points. This data is then used to select a target area for ablation.

[0018] Mapping the heart or its regions typically involves recording electrical activity in the region of interest using a mapping catheter with distal and proximal electrodes. The catheter is moved along the endocardial wall, during which the precise location and corresponding electrogram are recorded. As new points are acquired, a three-dimensional anatomical map is generated or formed in real time.

[0019] The local activation time (LAT) is calculated using the recorded electrograms relative to the body surface ECG or a fixed reference catheter. The LAT for each point is the interval between the start of the local electrogram of the mapping catheter and the reference signal. Importantly, because the points are acquired during the same cardiac rhythm with the same cycle length, and because the reference catheter or electrogram always remains fixed, the cumulative number of sampling locations and times can be compiled in real time to accurately describe the activation sequence of one cardiac cycle or heartbeat. The LAT is depicted in color - red represents the earliest activation recorded so far and purple represents the latest activation - and is applied to the anatomical map of the region of interest to produce an activation or LAT map. Each new acquisition or "point" updates the map until a complete or at least sufficient understanding of the activation sequence is provided.

[0020] Figure 5 A series of new LATs are added to the map. Note that in this example the anatomy has been defined and the colors are updated as new data is recorded. The final image shows that a single local activation site has been located near the top of the chamber. The completed LAT map for sampling atrial flutter is shown in Figure 7A The red to purple pattern forms a clockwise ring around the tricuspid annulus (circled by the green border), which has been excised from the map. Also visible in this example are the mapping / ablation catheter shown in white, two additional electrodes shown in dark green, and the ablation site shown in brown.

[0021] Additionally, the completed LAT map can be visualized as a "propagation map," in which the activation sequence on the map is played back by the mapping system as an animation, thereby showing the expansion or propagation of electrical activation throughout the mapped region of interest at each repetition. This can be an extremely beneficial, dynamic alternative to visually matching the rainbow color scale of activation surrounding a static LAT map, in which very subtle, yet potentially important, changes in color tone can be ignored. Figure 6 Shown is obtained from Figure 5 A series of screenshots of a propagation map animation of a local activation sequence is shown. In this animation, a red depolarization wave moves over time across the entire chamber shown in blue. Generally, the animation is continuously looped so that the wave can be studied again as it propagates.

[0022] During the mapping phase, various parameters can be selected and thresholds set according to the needs and expectations of the electrophysiologist. For example, a "window of interest" (WOI) is selected to specify the activation times on the mapping catheter. This is a time interval relative to the electrogram of the catheter in a fixed position or the surface of the body that has been selected as a "timing reference". Only those activation times that fall within this window are collected. Therefore, the WOI is used to limit the selected measured electrogram to only the electrogram of the current heartbeat or cardiac cycle. A WOI that is too wide can include the next or previous cycle. The WOI can also be used in some cases to remove extra records on the mapping catheter electrogram (for example, "stimulation artifacts" or "far-field signals" from the pacing device), including electrograms from another chamber or area that have been detected by the mapping catheter.

[0023] Each time a point is acquired, the system searches for electrograms on the mapping catheter channel within the WOI. The time interval (in milliseconds) between the detected electrogram and the electrogram of the timing reference is calculated. This is recorded as the LAT or local activation time for that point. As the mapping catheter moves and samples different locations, the timing of these locations changes depending on how early or late the depolarization wave passes through the catheter at each specific location during the current heart rhythm. Therefore, these electrograms appear earlier or later than the electrogram of the reference catheter, which remains fixed and therefore has the same electrogram timing for each heartbeat. For this reason, the LAT measured at each new point varies. The points with the lowest or most negative LAT are considered the earliest and are displayed in red and orange on the LAT map; conversely, points with higher or lower negative activation times are later and their areas in the map are darkened in blue and purple. The idea of ​​a fixed reference catheter and its "timing reference" is to allow mapping points from multiple different heartbeats with the same activation sequence to be compiled into a complete LAT map showing the activation sequence for one representative cardiac cycle.

[0024] These well-established, highly accurate mapping systems have been developed based on magnetic field sensing. They utilize sensors attached to the distal end of a catheter to measure the relative strength of an externally generated magnetic field and derive the position and orientation of the catheter from these measurements, which are used to extremely accurately display the distal tip of this "sensor-based catheter" and generate a 3-D anatomical map representing the region of interest. Methods for magnetic-based position sensing are disclosed, for example, in U.S. Patents 5,391,199, 5,443,489, and 6,788,967 to Ben-Haim, U.S. Patent 6,690,963 to Ben-Haim et al., U.S. Patent 5,558,091 to Acker et al., U.S. Patent 6,172,499 to Ashe, and U.S. Patent 6,177,792 to Govari, each of which is incorporated herein by reference in its entirety.

[0025] The mapping system may also include visualization of "non-sensor based catheters" present in the region of interest. Such catheter visualization may show the positioning electrodes of these catheters, where "positioning" (location / orientation detection of the electrodes) is obtained by impedance or current based measurements. For example, the impedance is measured between electrodes attached to the catheter and electrodes arranged on the surface of the body. The orientation of the catheter and its electrodes is then derived from the impedance measurements. Methods for impedance based orientation sensing are disclosed, for example, in U.S. Patent 5,983,126 to Wittkampf, U.S. Patent 6,456,864 to Swanson, and U.S. Patent 5,944,022 to Nardella, the entire contents of which are incorporated herein by reference.

[0026] In general, there are two ways to visualize the presence of a catheter within the area to be mapped. Sensor-based catheters utilize sensors within the end of the catheter to measure the relative strength of an externally generated magnetic field and determine the position and orientation of the catheter. In contrast, the position and orientation of non-sensor-based catheters are derived from current or impedance measurements between the catheter's own electrodes and externally placed electrodes. The Carto 3 mapping system, available from Biosense Webster, Inc., uses a hybrid technology of magnetic position sensing and current-based data to additionally provide visualization of sensor-based and non-sensor-based catheters and their electrodes. A hybrid system called the Advanced Catheter Localization (ACL) architecture is described in U.S. Patent 7,536,218 to Govari et al., the entire disclosure of which is incorporated herein by reference. Figure 7A A sample activation map of the right atrium RA of a patient's heart generated by the CARTO 3 mapping system is shown with visualization of three positioning catheters.

[0027] The ACL technology responds to the movement of the catheter's electrodes and thus updates the electrode image in real time to provide a dynamic visualization of the catheter and its electrodes (appropriately positioned, sized, and oriented relative to the displayed mapping area on the Carto 3 mapping system). The catheter visual representation thus responds to the physician's repositioning, displacement, and slight movement (e.g., caused by the patient's own breathing pattern). This dynamic movement of the catheter image remains intact relative to its 3-D map, which is generated from a set of recorded positions and is therefore fixed.

[0028] Initially, only the XYZ positions of the data points could be used to generate and define the geometry of the chamber being mapped. With so-called "point-by-point" mapping, the electrophysiologist would "build up the shell" as he collected more and more points. More recently, Fast Anatomical Mapping (FAM), a feature on the CARTO 3 mapping system, allows anatomical maps to be quickly generated simply by moving a catheter based on a magnetic position sensor throughout the heart chambers. The electrophysiologist can generate a 3-D anatomical "shell" of the region of interest as quickly as he can move the catheter along the wall of the heart chamber, and can simultaneously or after the shell is generated collect electrical activation data to generate a 3-D electroanatomical map that is color-coded to show its electrical activation sequence (or other data). The process of building the map (manipulating the mapping catheter to multiple locations in the heart chamber to sample electrical data there) takes time. A sufficient map of a simple arrhythmia can be made in just a few minutes, but more complex arrhythmias may require a detailed map that can take fifteen to thirty minutes or more to generate. If the arrhythmia changes or is disrupted, the activation sequence is no longer the same, so new data cannot be added to the map. The electrophysiologist can choose to "remap," in which case only the geometry of the current map is copied to the new map file, and new data points in the new rhythm can be acquired to paint in this "blank canvas." When the sensing catheter is moved from one location to another to acquire new LAT sets, the remap can take as long to generate as the original map, depending on the size of the region of interest.

[0029] For simpler arrhythmias, the electrophysiologist may choose not to remap and instead refer only to the electrogram or an appropriately positioned multipolar catheter (e.g., see Figure 2B and 3B), the multipolar catheter, as previously described, provides additional data for use by the electrophysiologist during the ablation procedure via a display on a recording device. Electrograms can be particularly beneficial for these regions or chambers of the heart, given the existence of recognized, standard catheter positioning and established ablation patterns. Atrial flutter ablation is one of the simplest examples of this. As briefly described above, the reentrant signal of atrial flutter in the right atrium typically follows a circuitous path around the tricuspid annulus (TVA), either clockwise or counterclockwise. Figure 7A A map of clockwise atrial flutter generated using FAM and a dual-purpose sensor-based mapping and ablation catheter is shown. The red to purple pattern in this map can be shown clockwise around the valve (the central circular cutout within the green border), i.e., from the red area in the upper corner around the ring to the purple area, returning to the starting point (CARTO 3 automatically places a brown "early encounter late line" in the map between the red and purple points). Only one cardiac sequence is mapped; in reality, the depolarization wave continues to circle along a continuous ring around the TVA. In Figure 7A In the figure, three catheters are visualized. The catheters used for this procedure typically include a non-magnetic, current-based sensing "Duo-deca" multi-pole catheter (green), which is passed from the IVC into the right atrium, RA, and is typically positioned in an annulus just lateral to the TVA. Its electrogram thus helps describe how electrical activation moves around the tricuspid valve. A longer version of this catheter (actually, one with more widely spaced electrode pairs) (similar to that shown in the figure) can be extended through the right atrial floor (tricuspid isthmus) and into the coronary sinus ostium. A properly positioned Duo-Deca catheter produces a very clear "dipping" electrogram pattern of atrial flutter (see, e.g., Figure 2B ). The direction of the tilt indicates whether it is clockwise or counterclockwise atrial flutter (e.g., Figure 2B Clockwise in the figure). Also visible in this map is the distal tip of the non-magnetic, current-based HIS catheter (green) extending from the right atrium RA through the TCV into the right ventricle RV, and the magnetic mapping and ablation catheter (white) shown extending from the IVC at the tricuspid isthmus.

[0030] The typical ablation pattern used to treat atrial flutter is an ablation line across the tricuspid isthmus CVI (at the base of the heart), thereby creating a "blockade line" between the tricuspid valve TCV and the inferior vena cava IVC. Figure 7AThe map in Figure 1 shows a brown circle on the heart floor marking the ablation site. When the CVI is ablated, the flutter stops and the patient's normal rhythm will resume. However, the true integrity of the ablation line still needs to be confirmed, as flutter can also stop when the tissue is only damaged and not truly ablated. This can be accomplished by pacing (delivering external electrical stimulation) from a catheter positioned only on one side of the ablation line and observing the resulting activation sequence through the DuoDeca electrogram. This can also be accomplished by acquiring new activation points around the valve while still pacing, thereby "re-mapping" the new activation pattern. Here, the visual pattern on the electrogram will be either a slanted line (indicating that the blockade line is complete and the activation wave must travel completely around the valve to depolarize the tissue on the other side) or a curved line (meaning that in addition to traveling up and around the valve, the depolarization wave also traveled to the right across the ablation line). The latter case indicates that more tissue remains to be ablated to form a complete blockade line. Figure 7B Figure 1 is a map of the same procedure made during pacing to demonstrate the complete block line. The pacing stimulus was delivered to the electrode pole just to the right of the ablation line in the red area of ​​the map. The resulting activation sequence can be tracked by following the rainbow colors in order (red, orange, yellow, green, blue, and purple), starting with red and moving up and around the valve in a counterclockwise manner until the purple area ablated to the left of the ablation site is reached, which is the last tissue activated in the chamber during this pacing strategy. The map indicates that the block line is indeed complete. The Duo-deca catheter electrogram from the proximal pole to the pole just to the left of the ablation line will have a shape similar to Figure 2B The tilted pattern.

[0031] Figure 8A and 8B Another example of using the same pacing strategy to confirm that the ablation line in CVI is intact is shown. Figure 8A The activation pattern in FIG, where the depolarization wave (as evidenced by the red to purple pattern of the map) shows that the activation moves from the red area (in the lower right area of ​​the map) not only up and around the top of the valve but also across the ablation line and the base of the heart as shown by the green area on the top and to the left of the ablation line. The last area of ​​activation is the far wall (on the left side of the map). This "split" shown by the two different green areas shows that there is no complete line of blockade and more ablation is needed. The electrogram on the duo-deca catheter in this case will show a clear curved pattern of electrograms (as shown in FIG. Figure 3B More RF energy is delivered, and another remapping occurs again when pacing on the left side of the line ( Figure 8B ). This map clearly shows that the occlusion line is now complete.

[0032] It is not uncommon for an ablation procedure to require several rounds of treatment alternating between ablation and pacing for blockade assessment before the blockade line is deemed complete and successful. If remapping is performed for each blockade assessment, where each remapping for a new LAT group takes 5-10 minutes to produce, these repeated remappings can significantly extend the duration of the ablation procedure. Therefore, in the treatment of atrial flutter in the right atrium, for the reasons described above, the electrophysiologist can rely solely on the electrograms after each round of ablation without remapping to assess blockade. It should be noted that one of the conservative benefits of using a mapping system is that the catheter is visualized without the need for ionizing radiation. Utilizing only fluoroscopy requires the patient to be exposed to radiation to position the catheters and to continuously check their position. In a long procedure, this can accumulate.

[0033] The electrogram of a successful block at the isthmus shows one or more oblique lines, each having the same or similar slope, e.g. Figure 9A and 9B However, the electrogram of a breakthrough through an incomplete blockade usually shows two lines with opposite slopes, e.g. Figure 9C and 9D In terms D1 and D2, the oblique line forms a convex or concave shape depending on the position of the pacing signal. Figure 9A The electrogram in the diagram describes the Figure 7B and 8B The electrogram is generally expected when pacing on the right side of the intact ablation line. Figure 9D The concave shape of the electrogram in Figure 8A The case where the blocking line is incomplete ( Figure 9B and 9C Pacing from the left side of the line is shown, which is also done temporarily to confirm block from both sides or "bidirectional block"). Figures 10A-10D The right atrium with the anatomical structures of the coronary sinus CS, superior vena cava SVC and inferior vena cava IVC are shown schematically. These figures show the location and Figures 9A-9D The corresponding electrogram path P. Figure 10A and 10B In the figure, the earliest activation site S and ablation line A are also shown. Figure 10C and 10D In FIG, a breakthrough due to incomplete ablation line B is shown.

[0034] It should be understood that Figure 7B The DuoDeca catheter shown has widely spaced poles - thereby giving a longer span of coverage compared to other catheters of the same type. This catheter is arranged so that its poles 1-2, 3-4 and 5-6 actually straddle the ablation line. Although Figures 9A-9DThe electrogram in represents a more standard catheter with all distal poles positioned to the left of the line, but the electrophysiologist will have to know and consider the anatomical location of each catheter and its electrodes when analyzing the EGM pattern. Figure 7B The precise electrogram pattern for the situation is shown in Figure 11 Here, poles 1-2, 3-4, and 5-6 (L1) activate early because they are located to the right of the ablation line, closer to the pacing site. The slanted straight line pattern (L2) formed by poles 19-20 through 7-8 shows counterclockwise activation upward and around the tricuspid valve and ends to the left of the line, thus confirming blockade.

[0035] Because experienced electrophysiologists can usually see Figure 9A and 9B The electrogram is identified as a complete block line and Figure 9C and 9D If an electrophysiologist identifies an incomplete block line for atrial flutter as soon as they see the electrogram, they may rely on the electrogram alone and choose not to remap after each ablation treatment to avoid unnecessarily extending the duration of the ablation procedure. However, it would be desirable to provide another way for the electrophysiologist to easily confirm their electrogram readings without having to update the activation map. It would be desirable to provide visualizations of the catheter's LAT and / or other such indicators of electrode activation for easy reference by the electrophysiologist, and also to provide such visualizations on existing displays that the electrophysiologist is already referencing.

[0036] Such desirable features would be particularly advantageous in the diagnosis and treatment of atrial fibrillation (AF), a well-known disease of the heart that causes reduced hemodynamic efficiency and, in severe cases, can lead to cardioembolism, stroke, ventricular arrhythmias, and other potentially fatal complications. AF can originate from abnormal signals entering the left atrium via the pulmonary veins connected to the left atrium. An extremely common, but quite technically challenging, treatment for AF is pulmonary vein isolation surgery (PVI), in which the heart tissue around the ostium of each of the four pulmonary veins in the left atrium is ablated to create a circular occlusion line, thereby preventing these abnormal signals from entering the chamber. While there are many variations of the pulmonary veins used by electrophysiologists, the common goal is the same. Figure 12 The typical left atrial anatomy is shown, with the four pulmonary veins shown in bright yellow (right superior pulmonary vein), bright orange (right inferior pulmonary vein), bright purple (left superior pulmonary vein), and bright pink (left inferior pulmonary vein). The red structure is the left atrial appendage. The tip of the mapping / ablation catheter and the brown "dot label" marking the ablation site near the left superior pulmonary vein are also visualized.

[0037] Due to the ductal structure of the pulmonary veins, a specific shape of circular mapping catheter (e.g. Figure 13A lasso catheter (Biosense Webster, visualized in Figure 1) is commonly used in pulmonary veins to analyze electrograms before, during, and after an ablation procedure. Due to the technical challenges associated with LAT mapping within PVs and the fact that activation sequences continuously change as more tissue is ablated, electrophysiologists almost universally rely on analyzing lasso electrograms on a recording system rather than mapping and remapping each change.

[0038] like Figure 13 As shown, a lasso catheter (royal blue) can be set so that its distal loop is located in the pulmonary vein (represented by the pink "mesh") and its electrodes contact the inner circumference of the vein. The lasso catheter is visualized in an anatomical (anatomical structure only) CARTO map of the left atrium (the vein has been made transparent by the "mesh"). Other catheters and pink dots marking the current ablation progress are also visible. Typically, the size or diameter of the distal loop is adjusted so that the loop and electrode form sufficient contact along the entire inner circumference of the vein to sense any abnormal or pacing signals that enter the vein from the LA through the loop or from the vein into the left atrium, which is usually in normal sinus rhythm. Three-dimensional mapping using hybrid positioning technology shows the orientation of the catheter distal loop and electrode. However, technical factors can cause the distal cannula to be randomly positioned so that its distal and proximal electrodes are in any radial orientation. Additionally, because the size of the pulmonary veins varies significantly, changing the diameter of the loop for a proper fit will also change the correlation of the distal and proximal electrodes of the loop - the poles may overlap in small veins and there may be gaps in large veins. Figure 13 For these reasons, the electrogram alone can show the acquisition poles and the acquisition sequence, but not how this actually relates to the anatomy itself. For this reason, the electrophysiologist must cross-reference the electrogram with the 3-D map and the visualization of the lasso catheter in order to determine the location of the acquisition poles relative to the anatomy and thereby the location of the breakthrough in the ablation line for placement of the ablation catheter.

[0039] Although the procedure is a treatment for AF, it is typically performed in normal sinus rhythm to help better gauge the success of the ablation lesion formation. As the tissue ablation around the ostia of the pulmonary veins progresses, the electrogram pattern on the lasso catheter will change. Generally speaking, the portion that has not yet been ablated will have an earlier corresponding electrogram. When the depolarization wave passing through the heart chamber (at the patient's normal heart rhythm) is blocked from entering the vein and the electrogram disappears completely from the lasso catheter inside the sensing vein, the ablation of the pulmonary vein is complete. This process is repeated for each of the four pulmonary veins.

[0040] Because positioning a mapping / ablation catheter with sufficient contact to create a durable lesion at every location around the ostium of each pulmonary vein is technically challenging, multiple ablations at the same location are often required, and continuous analysis of the lasso electrogram is crucial. The electrogram is studied on the recording system to identify the target electrodes and these electrodes are then positioned on the lasso catheter visualized on the map.

[0041] Mapping systems are particularly useful for this procedure. Knowledge of each patient's specific anatomy, and especially the orientation and position of the catheter within it, is crucial. Marking the ablation site is also extremely important. However, activation mapping is rarely performed. This is because the activation sequence within each pulmonary vein changes continuously during ablation, resulting in any map being usable only for a short period of time before a new map is acquired.

[0042] In addition to the changing activation sequence, the lasso catheter often falls out of place or becomes dislodged when trying to maneuver the mapping / ablation catheter around in the same space. Repositioning the lasso catheter almost always results in a slightly or significantly different radial orientation from the previous one, which means that its electrodes now represent different locations and the electrograms and their corresponding orientation in the map must be reassessed. For these reasons, the following process must be repeated several times for each procedure. First, once in the correct orientation, the electrograms of the lasso are recorded and analyzed on the recording system. Next, a specific pole is determined for the current ablation target. The electrophysiologist then determines where this pole is located on the catheter image of the mapping system. Finally, he uses the mapping system to position the ablation catheter near this pole to ablate the tissue. After this RF application, the process is repeated when changes in the activation sequence on the lasso are observed. In extremely challenging cases, the question "which is now in front" or "where is it" can be asked dozens of times.

[0043] Likewise, it would be desirable to provide an improved way of visualizing the activation of electrodes of a catheter so as to be easily referenced by an electrophysiologist, and further to provide such visualization on an existing display that is already referenced by the electrophysiologist.

[0044] More recently, catheters with more complex shapes, such as those shown in Figure 4A The PentaRay catheter from Biosense Webster has become more common. Although it facilitates faster generation of LAT maps by acquiring multiple points at a time, the electrograms of the PentaRay are extremely difficult to discern from the activation pattern alone (see, e.g., Figure 4B ). Here, there is a need for such improved visualization of catheter electrode activation.

[0045] Therefore, there is a need for systems and methods for real-time visualization of electrode activation on a multi-electrode catheter so that a user can immediately identify the signal acquisition of the electrodes (including the electrode acquisition sequence) without having to refer to an electrogram or 3-D map or wait for any other information. The systems and methods do not need to consider any timing reference and can function independently of any mapping or acquisition / propagation map of any mapping system. However, the systems and methods can utilize LAT information as well as catheter and electrode position to provide visualization of electrode acquisition on a 3-D activation map so that the position of any and all acquisition electrodes relative to the mapping area is displayed. Summary of the Invention

[0046] The present invention includes methods and systems for visualizing electrophysiological information sensed by a catheter, the electrophysiological information including intracardiac electrical signals. The visualization includes display of the continuous propagation of the catheter's electrogram. The activation sequence is displayed in real time or near real time in a movie format and is advantageously presented graphically and objectively in a conventional workspace where the electrophysiologist is previously observing catheter positioning. Without viewing the electrogram, the electrophysiologist can observe, for example, ablation blockade on a graphical image of a multipolar "Halo" or "DuoDeca" catheter, the earliest activation in the pulmonary veins on a graphical image of a multipolar "Lasso" catheter, propagating waves on an entire graphical image of a multipolar "PentaRay" catheter, or general activation of the coronary sinus on a multipolar linear catheter. The visualization naturally indicates the direction of propagation.

[0047] The present invention relates to a method for visualizing electrophysiological information sensed by electrodes on a catheter, comprising: recording the time of electrode signal acquisition, calibrating a reference electrode signal acquisition, specifying the relative time of each recorded time of electrode signal acquisition relative to the reference electrode signal acquisition, identifying electrodes with signal acquisition, associating the specified relative time with the identified electrodes to generate an electrode signal acquisition sequence, and generating a visual representation of the electrode signal acquisition sequence using a graphic image of the electrodes, wherein each electrode is visually marked to represent the electrode signal acquisition sequence.

[0048] In some embodiments, the method includes generating a visual representation using a plurality of images shown in a series to represent the progress of the electrode signal acquisition sequence. In more detailed embodiments, each image shows a different electrode that is visually marked, or each image shows at least one different electrode that is visually marked.

[0049] In some embodiments, the catheter has rod segments extending between adjacent electrode pairs, and the method further includes assigning a relative time to each rod segment based on the relative time of its adjacent electrode pairs, and associating the relative time of each rod segment with the relative time of its adjacent electrode pairs, wherein the visual representation includes a series of graphic images of the rod segments displayed in a movie format, and visually marking individual rod segments in the series of graphic images according to the sequence.

[0050] In some embodiments, the method includes adjusting the time scale of the visual representation in response to a user-selected time scale and / or adjusting or limiting the ratio of the visual representation relative to the actual cardiac cycle to facilitate viewing ease and avoid overlapping electrode acquisition sequences.

[0051] The present invention also relates to a method for visualizing electrophysiological information collected by a catheter having multiple electrodes, wherein each electrode is suitable for collecting electrical signals, the method comprising receiving data about the electrode configuration of the catheter, recording the time of electrode signal collection of the electrodes, calibrating the earliest electrode signal collection as a reference, specifying a relative time for each recording time relative to the reference, identifying the electrodes with electrical signal collection based on the data about the electrode configuration, associating the specified relative time with the identified electrodes to produce an electrode collection sequence; and generating a visual representation of the electrode collection sequence, wherein the visual representation includes a series of graphic images of the electrodes, and each electrode is visually marked to represent the electrode signal collection sequence.

[0052] In some embodiments, the catheter includes rod segments, each rod segment extending between adjacent electrode pairs, and the method further includes specifying the relative time of each rod segment based on the relative time of its adjacent acquisition electrode pairs, and associating the relative time of each rod segment with the relative time of its adjacent acquisition electrode pairs, wherein generating the visual representation includes providing a graphical image of each rod segment and visually marking each rod segment according to the sequence.

[0053] In some detailed embodiments, each rod segment is assigned a weighted relative time. The weighted relative time may depend on the position of the rod segment between adjacent pairs of collecting electrodes. In some detailed embodiments, the electrodes collecting electrical signals are identified by their leads.

[0054] The present invention also relates to a system for collecting and visualizing electrophysiological information. In some embodiments, the system includes: a catheter having electrodes adapted to acquire signals; a signal processing unit configured to receive intracardiac signal acquisitions from a plurality of electrodes and identify electrodes having intracardiac acquisitions; a timer configured to time intracardiac signal acquisitions and identify a reference time for the earliest intracardiac signal acquisition; a control unit configured to specify relative times of intracardiac signal acquisitions relative to the reference time and associate the relative times with the identified electrodes to generate a signal acquisition sequence; and a display configured to display the signal acquisition sequence in a graphical image of at least the electrodes.

[0055] The present invention also relates to a system for visualizing electrophysiological data, the system comprising: a signal processing unit configured to receive intracardiac signal acquisitions from multiple electrodes, the signal processing unit configured to identify electrodes with intracardiac acquisitions; a timer configured to time the intracardiac signal acquisitions and identify the earliest intracardiac signal acquisition; a control unit configured to specify a relative time of the intracardiac signal acquisition relative to the earliest intracardiac signal acquisition and associate the specified relative time with the identified electrodes to generate a signal acquisition sequence; and a display configured to display the signal acquisition sequence in a graphic image of at least the electrodes.

[0056] The visual display of the activation sequence may include graphically highlighting the acquisition electrodes and / or the rod segments therebetween by various markings (eg, color, transparency, size, and / or sharpness). One or more catheter electrodes may be highlighted in this manner as desired or appropriate. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] This patent or patent application file contains at least one drawing executed in color. Copies of this patent or patent application publication in color will be provided by the U.S. Patent and Trademark Office upon request and payment of the necessary fee.

[0058] These and other features and advantages of the present invention will be better understood by reference to the following detailed description considered in conjunction with the accompanying drawings, in which:

[0059] Figure 1 Schematic diagram of the heart showing normal electrical pathways.

[0060] Figure 2A Figure 2 shows a DuoDeca catheter positioned roughly parallel to the depolarization wave of cardiac cells.

[0061] Figure 2B To express Figure 2A Electrogram of the catheter electrode signal acquisition.

[0062] Figure 3A Figure 2 shows a DuoDeca catheter positioned roughly transverse to the cardiac cell depolarization wave.

[0063] Figure 3B To express Figure 3A Electrogram of the catheter electrode signal acquisition.

[0064] Figure 4A Figure 3: A view of the PentaRay catheter positioned during a myocyte depolarization wave.

[0065] Figure 4B To express Figure 4A Electrogram of the catheter electrode signal acquisition.

[0066] Figure 5 Shown is a series of new local activation times (LATs) added to the LAT map. Red shows the earliest depolarization, followed by orange, yellow, green, and blue, and purple shows the latest depolarization. Dark green highlights the catheter. Brown indicates ablation.

[0067] Figure 6 Shown is obtained from Figure 5 A series of screenshots from a propagation map animation of a local activation sequence is shown. The depolarization wave is shown in red, contrasting with the cardiac anatomy in blue.

[0068] Figure 7A A LAT map of atrial flutter acquired with electrodes from a DuoDeca catheter. Red shows the earliest depolarizations, followed by orange, yellow, green, and blue, with purple showing the latest depolarizations. Dark green highlights the catheter. Brown indicates ablation.

[0069] Figure 7B To verify complete blockade during pacing Figure 7A Map of a 3D-surgery procedure. Red shows the earliest depolarizations, followed by orange, yellow, green, and blue, with purple showing the latest depolarizations. Dark green highlights the catheter. Brown indicates ablation.

[0070] Figure 8A Shows the use of Figure 7B Another example of confirming the integrity of a CVI ablation line using the same pacing strategy. Red shows the earliest depolarization, followed by orange, yellow, green, and blue, and purple shows the latest depolarization.

[0071] Figure 8B When pacing on the right side of the CVI ablation line Figure 8AA remap of , showing the blockade line as intact. Red shows the earliest depolarizations, followed by orange, yellow, green, and blue, and purple shows the latest depolarizations.

[0072] Figure 9A and 9B The electrogram indicates successful blockade.

[0073] Figure 9C and 9D Electrogram showing incomplete blockade.

[0074] Figure 10A For use Figure 9A Schematic diagram of the catheter arrangement for the electrogram.

[0075] Figure 10B For use Figure 9B Schematic diagram of the catheter arrangement for the electrogram.

[0076] Figure 10C For use Figure 9C Schematic diagram of the catheter arrangement for the electrogram.

[0077] Figure 10D For use Figure 9D Schematic diagram of the catheter arrangement for the electrogram.

[0078] Figure 11 for Figure 7B Electrogram of DudoDeca.

[0079] Figure 12 3-D electroanatomical image of typical left atrial anatomy with the four pulmonary veins shown in bright yellow (right superior pulmonary vein), bright orange (right inferior pulmonary vein), bright purple (left superior pulmonary vein), and bright pink (left inferior pulmonary vein).

[0080] Figure 13 A royal blue lasso catheter is shown positioned with its distal loop in a pink pulmonary vein.

[0081] Figure 14A is an illustration of a system for performing an exemplary catheterization procedure on the heart of a living subject, according to one embodiment of the present invention.

[0082] Figure 14B According to one embodiment of the present invention Figure 14A Schematic block diagram of the system.

[0083] Figures 15A-15E Schematic diagram showing the display of an electrode signal acquisition sequence according to an embodiment of the present invention.

[0084] 16A-16R are schematic diagrams showing a display of an electrode signal acquisition sequence according to another embodiment of the present invention, wherein the catheter is shown in green and the electrodes and their interrod segments are highlighted in red.

[0085] Figure 17 FIG. 1 is a flow chart of an embodiment of the present invention.

[0086] Figures 18A-18E To express Figure 17 Table of the specific implementation of the portion of the flowchart.

[0087] Figures 19A-19G Schematic diagram showing the display of an electrode signal acquisition sequence according to an embodiment of the present invention.

[0088] Figures 20A-20C Schematic diagram showing the display of an electrode signal acquisition sequence according to another embodiment of the present invention.

[0089] Figures 21A-21I and Figures 15A-15E Schematic diagram showing the display of an electrode signal acquisition sequence according to another embodiment of the present invention.

[0090] Figure 22 FIG. 4 is a flow chart of an embodiment of the present invention.

[0091] Figure 23 FIG. 4 is a flow chart of an embodiment of the present invention.

[0092] Figure 24 is a detailed perspective view of a distal tip portion according to one embodiment.

[0093] Figure 25 According to another embodiment of the present invention Figure 14A Schematic block diagram of the system.

[0094] Figure 26 Schematic diagram of a heart showing the arrangement of catheters for sensing intracardiac signals.

[0095] Figure 27 Schematic diagram of a heart showing placement of a reference catheter. DETAILED DESCRIPTION

[0096] The present invention relates to systems and methods for real-time visual depiction of an acquisition sequence of electrodes on a catheter, and more specifically, for real-time visual depiction of an acquisition sequence of electrodes used to acquire local activation signals to generate an electrogram of the heart. In some embodiments, the visualization of the electrode acquisition sequence includes an image of the catheter and its electrodes, and visual indicia of electrical propagation along at least the electrically sensing portion of the catheter, the visual indicia including, for example, visual indicia that distinguishes between acquisition electrodes and non-acquisition electrodes in real time. In some embodiments, the image includes visual indicia of electrical propagation along the electrically sensing portion and the non-electrically sensing portion of the catheter (including, for example, the acquisition electrodes and non-conductive tubing extending therebetween). In some embodiments, the visualization of the electrode acquisition sequence includes an image of the catheter and its electrodes superimposed on a cardiac chamber map, wherein the visualization is dynamic and responsive in real time to movement of the catheter within the cardiac chamber, and the cardiac chamber map is 3-D and provides anatomical information as needed by the physician, as well as any additional information currently available in the CARTO mapping system, such as LAT or voltage.

[0097] In a broader sense, embodiments of the present invention encompass one or more of the following aspects of localization and mapping: a first aspect is directed to processing localization information; a second aspect is directed to processing sensed electrical information; a third aspect is directed to integrating the previously processed information; and a fourth aspect is directed to processing the integrated information to produce a 3-D image of the heart chamber with the catheter superimposed thereon. These aspects, as described in U.S. Patent No. 5,391,199, are described in more detail below.

[0098] The catheters will be introduced percutaneously into the heart chambers. Each catheter will be trackable (using methods previously described). One or more reference catheters can be left at known landmarks, and the catheters will be used as mapping / ablation catheters. The positions of the reference catheters will be used to align the positions of the heart chambers relative to the positions of the heart chambers on the "base image."

[0099] The present invention may be better understood with reference to the accompanying drawings. Figure 14A , which is an illustration of a system S for performing an exemplary catheterization procedure on a heart 12 of a living subject or patient 13, the system S being constructed and operative in accordance with the disclosed embodiments of the present invention. The system includes a catheter 14 that is inserted percutaneously through the patient's vascular system into a chamber or vascular structure of the heart 12 by an electrophysiologist or operator 16. The catheter 14 has a distal tip carrying a plurality of electrodes and a control handle that can be manipulated by the operator 16 to steer and deflect the catheter.

[0100] The console 24 can then be used to prepare electro-activation maps, anatomical location information (i.e., information about the distal portion of the catheter), and other functional images according to the methods disclosed in U.S. Patents 6,226,542 and 6,301,496, and commonly assigned U.S. Patent 6,892,091, the entire disclosures of which are incorporated herein by reference. One commercial product that implements components of the console 24 is the Biosense ® 1000 , available from Biosense Webster, Inc. (3333 Diamond Canyon Road, Diamond Bar, CA 91765). 3 system that can perform catheter positioning as needed and generate a 3-D electroanatomical map of the heart. The system can be modified by those skilled in the art to implement the principles of the invention described herein.

[0101] Areas determined to be abnormal, for example, by electro-activation map evaluation, can be targeted and ablated by applying thermal energy, for example, by transmitting radiofrequency current from a radiofrequency (RF) generator 25 of a console 24 through a cable 34, thereby providing current to the catheter 14, including providing current to ablation electrodes 32 at the distal end, which apply radiofrequency energy to the target tissue. The console 24 typically includes one or more ablation power generators 25, a patient interface unit (PIU) 26, and one or more displays 27 and 28 for displaying 3-D maps and electrograms. The catheter 14 is adapted to conduct ablation energy to the heart using radiofrequency energy. Such methods are disclosed in commonly assigned U.S. Patents 6,814,733, 6,997,924, and 7,156,816, which are incorporated herein by reference. The ablation energy can be transmitted from the RF generator 25 to the heart 12 through the catheter electrodes via a cable 34 connected to the console 24. Pacing signals and other controller signals may also be transmitted from console 24 to heart 12 through cable 34 and catheter electrodes. Additionally, electrical signals (eg, intracardiac ECG signals) are transmitted from heart 12 to console 24 via catheter electrodes.

[0102] As part of system S, an ECG body surface patch (including at least patch 38) is attached to the patient's body. While the catheter electrodes are sensing intracardiac ECG signals, the multiple electrodes in ECG body surface patch 38 measure ECG signals between the heart and torso to provide a reference signal for the intracardiac ECG signals measured by the catheter electrodes.

[0103] As part of the catheter positioning capability of console 24, a magnetic field is generated around patient 13, for example, by a positioning pad disposed beneath the patient that includes a magnetic field generator coil 28. The magnetic field generated by coil 28 generates an electrical signal in a coil of an electromagnetic (EM) sensor 22 located at the distal end of catheter 14. The electrical signal is transmitted to console 24, which includes a processor or "workstation" 22 that analyzes the signal to determine the position coordinates and orientation of the catheter.

[0104] As another part of console 24's catheter positioning capabilities, the catheter electrodes are connected to current and voltage measurement circuitry in processor 22 via leads (not shown) in the catheter and cables 34. Processor 22 and console 24 are also connected to a plurality of body-surface electrodes 30 via wires and patch units 31. These body-surface electrodes 30 can be any type of body electrode known in the art, such as battery electrodes, needle electrodes, subcutaneous probes, or patch electrodes. The body-surface electrodes 30 typically make electrical contact with the body surface of patient 13 and receive body-surface current therefrom. The body-surface electrodes 30 can be adhesive skin patches (commonly referred to as active current location (ACL) patches) and can be placed at any convenient location on the body surface of patient 13 near catheter 14. In the disclosed embodiment, there are six ACL patches 30, three of which are attached to the anterior surface of the patient's torso and three to the posterior surface. Console 24 includes a voltage generator connected to the ACL patches 30 via wires 35 and used by processor 22 to measure the impedance of the patient's tissue at the locations of the patches 30. Therefore, console 24 uses magnetic-based position sensing and impedance-based measurements for catheter positioning as described in US Patent 7,536,218 to Govari et al. and US Patent 8,478,383 to Bar-Tal et al., the entire disclosures of which are incorporated herein by reference.

[0105] As described above, catheter 14 is coupled to console 24, which enables operator 16 to observe and control the functions of catheter 14. Processor 22 and / or console 24 include appropriate signal processing circuitry and are coupled to drive monitor 29 to display visual images, including 3-D electroanatomical maps. The signal processing circuitry typically receives, amplifies, filters, and digitizes signals from catheter 14, including signals generated by catheter electrodes and EM sensors.

[0106] Figure 14B1 is a schematic block diagram of a system S for displaying electrode acquisition sequences for a linear multipolar catheter 100 according to one embodiment of the present invention. The catheter has electrodes or poles 1-5 positioned to detect intracardiac activation sequences, such as ventricular tachycardia (VT) in the right ventricle (RV). Local electrograms or signals acquired by the poles 1-5 are received and processed (amplified, digitized, etc.) by an EP signal processor 112 and sent to a control unit 122 having a signal processor 118 and a memory 119. The signal processor 112 also identifies specific electrodes and associates specific electrodes with their corresponding signals and / or local electrograms. The system includes an ECG unit 115 (e.g., having surface electrode patches) for detecting cardiac cycles to provide a reference ECG signal. The system also includes a timer 113 to handle the timing of electrode acquisition events, including recording the timing of such events and determining the relative electrode acquisition of each electrode relative to the earliest electrode acquisition event within a single cardiac cycle. Based on this correlation and relative electrode acquisition timing, control unit 122 drives monitor 120 to display a visualization of the catheter electrode acquisitions, including a movie of the catheter electrode acquisition sequence. The display includes a 3-D electroanatomical map (including a graphical image of the mapped anatomical structure).

[0107] According to a feature of the present invention, as signals are acquired in an order or sequence of acquisitions during a cardiac cycle, a catheter electrode acquisition sequence is displayed on the monitor 120, wherein the electrodes are visually assigned, highlighted, or otherwise distinguished by color contrast relative to the color of the distal tip. As shown by an intracardiac activation sequence (e.g., the VT arrow in the right ventricle RV), the signal travels clockwise from the ventricular apex VA, with the signal being acquired first by Pole 1, then by Pole 2, then by Pole 3, then by Pole 4, and then by Pole 5. The acquisition sequence is displayed in an animated or movie mode, wherein for one cardiac cycle, a graphical image of Pole 1 is visually labeled ( Figure 15A ), and then the graphical image of pole 2 is visually marked ( Figure 15B ), and then the graphical image of pole 3 is visually marked ( Figure 15C ), and then the graphical image of pole 4 is visually marked ( Figure 15D ), and then the graphical image of pole 5 is visually marked ( Figure 15E ). Any or all poles that are activated may be visually marked for their duration of the cycle, or alternatively, only a single pole may be visually marked during its acquisition and not visually marked during the acquisition of another pole, e.g. Figures 15A-15E The contrasting colors that visually mark the poles can also be different to indicate the relative timing of the pole acquisitions, much like the color-coded scale of a typical LAT acquisition map where the colors represent the relative timing with respect to a reference time. Figures 15A-15EFor example, pole 1 may be displayed as red when collected, pole 2 may be displayed as orange when collected, pole 3 may be displayed as yellow when collected, pole 4 may be displayed as green when collected, and pole 5 may be displayed as blue when collected.

[0108] In another embodiment, the non-sensing portion of the rod between the poles may also be displayed in a manner consistent with the acquisition sequence. Figures 19A-19G As shown, rod segments S between adjacent poles are visually marked in time and space to help visually understand the direction of the acquisition sequence. While different acquisition poles are highlighted in different colors as described above, the color of each rod segment S can be a blend of the colors of the adjacent poles. For example, rod segment S1 between poles 1 and 2 can be displayed in orange-red, a blend of the red of pole 1 and the orange of pole 2.

[0109] Figures 16A-16R illustrate acquisition sequences where the acquisition sequence has a scattered or fragmented nature, which is generally indicative of incomplete blocking, such as e.g. Figure 8A As shown in FIG16A , the earliest acquisition occurs at pole 7, followed by poles 6 and 8 as shown in FIG16E , then poles 5 and 9 as shown in FIG16I , and so on. FIG16B-16D and FIG16F-16H illustrate the direction of the acquisition sequence by visually marking the rod segments (red) between the poles (see arrows).

[0110] Figure 17 A flow chart representing a method applied by the system S including the control unit 122 and processor 119 of FIG. 14 is shown according to one embodiment of the present invention. The method begins at box 200, where the processor 119 receives and loads parameters of a physical model of the physical structure, configuration, and characteristics of the sensing catheter selected by the user at box 202, including, for example, the type of catheter (linear, annular / lasso, cage, etc.) and the position of electrodes on the catheter relative to a reference point on or in the catheter. The system then begins electrode acquisition at box 203. This step may include, for example, providing a visual or audible indicator indicating the start of acquisition. At box 203, the system begins acquisition according to, for example, reference to the above. Figure 5 and Figure 6The discussion provided regarding 3-D mapping is used to generate electrode acquisitions of electrical activity within a window of interest. The electrical activity detected by the electrodes of the catheter may be naturally present within the detected tissue in the region of interest, or the electrical activity may originate from a pacing signal sent to a suitable location in or near the heart, where the signal may travel to and / or pass through the region of interest in the heart chamber where the sensing catheter is placed. Applying the window of interest limits the recorded signals to only those signals that visually represent the electrical activation sequence associated with the catheter. In one embodiment, the user selects a specific window of interest to be used for this purpose according to box 204. Alternatively, the present invention may use an existing mapping window of interest that has been selected for the mapping phase, as previously described. In one (right) branch of the flowchart, the timing of the electrode acquisition events within the window of interest is recorded (box 206) and a relative acquisition time relative to the earliest electrode acquisition timing is assigned to each electrode acquisition event (box 207). For a sensing catheter with poles 1-5, for example, as shown in FIG. Figures 15A-15E As shown, where pole 1 is first acquired at time t(a), then pole 2 is acquired at a later time t(b), then pole 3 is acquired at a later time t(c), and then poles 4 and 5 are acquired at later times t(d) and t(e), respectively, the times t(a)-t(e) are recorded (box 206), and the relative acquisition times T(a)-T(e) are specified (box 207).

[0111] In the other (left) branch of the flowchart, identification of acquisition poles 1-5 on the catheter is obtained (block 205), for example, by identifying the leads through which the acquired signals are transmitted from the catheter to the electrophysiological signal processor 112, and these identifications of the poles P1-P5 and the above-specified relative times T(a)-T(e) of electrode acquisition are then associated with each other (block 213) to generate an electrode acquisition sequence (block 214). Figures 15A-15E An example of the treatment of the catheter blocks 206, 207, 205, 213 and 214 is shown in Figure 18A middle.

[0112] The sequence is then displayed according to block 215 using an animation of a series of graphical images of at least the electrodes, thereby providing a visualization of the sequence and the order of electrode acquisition. Figures 15A-15E , the animation shows a movie-like image of the five electrodes, with Pole 1 highlighted ( Figure 15A ), then Pole 2 is highlighted ( Figure 15B ), then pole 3 is highlighted ( Figure 15C ), then pole 4 is highlighted ( Figure 15D ), then pole 5 is highlighted ( Figure 15E ).

[0113] However, if, for example, pole 3 of a five-pole catheter is acquired earliest at time t(a), poles 2 and 4 are then acquired simultaneously at time t(b), and poles 3 and 5 are then acquired simultaneously at time t(c), an example of processing according to blocks 206, 207, 205, and 204 is shown in FIG. Figure 18B The resulting display sequence according to block 215 is provided as follows Figures 20A-20C Animation shown.

[0114] Since the entire electrode acquisition sequence may have a duration in the order of several milliseconds and thus be difficult to perceive by the human eye, the animation speed may be adjusted. Figure 17 Query 216 asks the user whether it is desired to adjust the display sequence, for example, by selecting a time scale for the animation display according to block 218. If not, processing ends at block 220. If so, block 218 allows the user to make a selection to increase the duration of the animation by a selected factor N, for example, by multiplying each relative time T(i) by N, and reassociation is performed in block 214 according to the selected time scale. An example of processing for blocks 214, 216, and 218 is shown in FIG. Figure 18C For another example, instead of or in addition to block 218, block 219 allows the user to adjust or limit the ratio of the visual representation to the actual cardiac cycle to facilitate ease of viewing and avoid overlapping electrode acquisition sequences. The user can select the electrode sequence to be displayed, including whether the animation includes acquisition sequences for every "n" cardiac cycle. After the user selects, reassociation is performed in block 214.

[0115] refer to Figures 19A-19G The animation can also show an image of a catheter with five poles P1-P5 in the form of a movie, where the poles and the rod segments S1-S5 between the poles are highlighted according to the acquisition sequence and propagation direction. For example, if pole 3 is acquired first, then poles 4 and 2, then pole 5, and finally pole 1, the movie image will highlight pole 3 ( Figure 19A and Figure 19B ) but after highlighting poles 4 and 2 ( Figure 19C ) before highlighting pole segments S2 and S3. In this regard, it should be understood that the pole acquisition in this example is intentionally asymmetrically spaced outward from pole 3 through poles 2 and 4, such that pole 5 is acquired before pole 1. The movie-like image thus highlights poles 4 and 2 ( Figure 19C ) but after highlighting pole 5 ( Figure 19E ) before appropriately highlighting rod segment S4 ( Figure 19D ), and furthermore, in highlighting the pole 5 ( Figure 19E ) but before highlighting Pole 1 ( Figure 19G ) before highlighting rod segment S1 ( Figure 19F ).

[0116] according to Figure 17 The pole segments that are calibrated in block 209 depend on the identification of the two previous poles and the order in which they were acquired. For example, if pole 2 is acquired first and pole 3 is acquired later, pole segment S2 between poles 2 and 3 is calibrated with poles 2 and 3 as the adjacent pole pair for pole segment S2. For example, if pole 3 is acquired first and poles 2 and 4 are acquired simultaneously thereafter, pole segments S2 and S4 are both calibrated with poles 2 and 3 as the adjacent pole pair for pole segment S2 and poles 3 and 4 as the adjacent pole pair for pole segment S4. Then according to Figure 17 Block 210 assigns a relative time T to each calibrated pole segment. In addition, the relative time T(Si) assigned to each calibrated pole segment S can be accomplished by assigning a weighted relative time, for example, by equally weighting the relative times of its two adjacent pole pairs, for example, by averaging the relative times Ti of the two adjacent pole pairs, as described below:

[0117] T(S)=T 较早 +(T 较晚 –T 较早 )*(0.5) (Formula 1)

[0118] Where T(S) = the specified relative time of the rod segment between two adjacent poles

[0119] T 较早 = the specified relative time of the adjacent pole collected earlier

[0120] T 较晚 = the relative time specified for the adjacent pole collected later

[0121] An example of the processing of rod segment S by blocks 209 and 210 (applying Equation 1) is shown in Figure 18D , the figure also shows the processing of poles 1-5 by blocks 206, 207 and 205 and the associating of relative times T(i) and T(Si) for the poles and rod segments by blocks 214 and 215 to provide Figures 19A-19G An example of a display sequence is shown.

[0122] For visualization of catheters where adjacent poles are separated by wider rod segments, e.g. Figures 21A-21I As shown, the rod segment can be subdivided into a plurality of sub-segments Sx, for example, m sub-segments, for the purpose of visual aesthetics of the image film. The designation of the relative times T(Sx) for these rod sub-segments can be accomplished as follows:

[0123] T(Sx1)=T 较早 +(T 较晚 –T较早 )*[1 / (m+1)] (Formula 2)

[0124] T(Sx2)=T 较早 +(T 较晚 –T 较早 )*[2 / (m+1)] (Formula 3)

[0125] …

[0126] T(Sxm)=T 较早 +(T 较晚 –T 较早 )*[m / (m+1)] (Formula 4)

[0127] Where T(Sxm) = the specified relative time for pole segment m.

[0128] T 较早 = the specified relative time of the adjacent pole collected earlier

[0129] T 较晚 = the relative time specified for the adjacent pole collected later

[0130] m = number of sub-segments

[0131] In one embodiment, the assigned relative time T(Sxm) for each pole sub-segment is weighted according to its position between adjacent poles acquired earlier and later, and the weighting is applied linearly and depends on the number of sub-segments between adjacent poles. Examples of the processing of block 209 for calibration and block 210 for assigning relative times to pole sub-segments (applying equations 2, 3, and 4) and examples of the processing of blocks 206, 207, and 205 for poles are shown in FIG. Figure 18E Based on the processing of blocks 214 and 215 for associating relative times for poles and rod segments, the system and method of the present invention generates the following Figures 21A-21I The display sequence shown.

[0132] Where the systems and methods of the present invention also drive a display to reflect in real time the position and orientation of the catheter tip within the heart chamber, the process includes spatial electrode position. Figure 22 In the flowchart of FIG. 2 , electrode positions are obtained by measuring the orientation of the catheter using a magnetic field sensor, typically located in the distal portion of the catheter, according to block 208 and determining the electrode positions using the magnetically measured orientation according to block 211. Electrode positions are also obtained by measuring the impedance of each electrode, according to block 212, to determine the positions of the electrodes based on an impedance map according to block 217.

[0133] The positioning data (magnetic and / or impedance-based) is associated with the electrode identification according to box 214 and the acquisition time relative to the electrodes to drive the display according to box 215 in the following manner, where the graphical image of the catheter and its electrodes moves dynamically corresponding to the actual movement of the electrodes.

[0134] Advantageously, the visualization method of the present invention accommodates both hybrid and non-hybrid catheters. In the case where the sensing catheter is a non-hybrid, magnetic-based catheter, positioning of its electrodes is accomplished via blocks 208 and 209. However, in the case where the sensing catheter is a hybrid catheter, an impedance map and a calibration map on which the impedance map depends can be generated, such as Figure 23 As shown in the flow chart of FIG. 1 , the hybrid catheter has an electromagnetic sensor 22 including three coils 24, 26 and 28, which respond to the electromagnetic field generated by a magnetic field generator 119 (e.g. Figure 25 The three magnetic fields generated by magnetic field generator coils G1, G2, and G3 driven by a magnetic field sensor (shown in FIG. 1 ) generate electrical signals. Coils G1, G2, and G3 are incorporated into a pad 117 positioned on the patient's surface. These signals are transmitted to a control unit 122, which analyzes them to determine the coordinates of catheter 20. Alternatively, the coils in magnetic field sensor 22 can be driven to generate a magnetic field through coil 28.

[0135] The catheter 20 also carries electrodes 30, 32 and 34, as shown. Figure 24 The signals of these electrodes are Figure 25 The impedance measurement circuit 123 in the control unit 122 shown receives it. The control unit 122 is connected to the surface patch via a wire via the EP signal processor 112 and the surface ECG unit 115. The impedance between the surface patch and the electrodes 30, 32 and 34 is measured according to the method described in U.S. Patent 7,869,865 by Govari et al., the entire disclosure of which is incorporated herein by reference. The control unit 122 drives current to flow through one or more circuits, each of which includes a catheter electrode, a corresponding surface electrode and intervening body tissue. According to Ohm's law, the impedance between the electrode and the patch in each circuit is equal to the voltage between the electrodes divided by the current flowing through the circuit. In an alternative embodiment of the present invention, a voltage can be applied between the surface electrode pairs, as described in the above-mentioned U.S. Patent 5,983,126 by Wittkampf. The corresponding voltage drop at the catheter electrode is measured to determine the relative impedance.

[0136] Figure 26FIG2 is a schematic diagram of a hybrid catheter 20 positioned within a chamber of a heart 38 during the generation of a calibration map according to one embodiment of the present invention. Signals received from a magnetic field sensor 22 are used to calculate the position and orientation of the catheter at multiple locations. Specifically, the position coordinates of electrodes 30, 32, and 34 at these locations are derived based on magnetic coordinate measurements and the known displacement of the electrodes relative to the sensor 22. Impedance measurements are also taken of electrodes 30, 32, and 34 at different catheter locations, and these measurements are correlated with the electrode positions determined by the magnetic position measurements. In this manner, a calibration map is generated.

[0137] Figure 27 FIG2 is a schematic illustration of a second catheter 58 inserted into heart 38 during or after the generation of a calibration map, according to one embodiment of the present invention. As catheter 58 moves through the heart chambers, impedance measurements obtained at electrodes 60, 62, and 64 on the catheter are correlated with impedance measurements previously recorded at known locations on the calibration map. In this way, the coordinates of catheter 58 can be accurately determined despite fluctuations and nonlinearities in the impedance of the subject's body.

[0138] Figure 23 Flowchart illustrating a method for generating and applying a calibration map using tissue impedance according to one embodiment of the present invention. In an initial step 266, the hybrid catheter 20 is inserted into a chamber of the heart 38. In a magnetic measurement step 268, the magnetic field sensor 22 is used to determine the catheter's positional coordinates and thereby locate the specific locations of the catheter electrodes 30, 32, and 34. Impedance measurements at these catheter electrodes are then obtained in an impedance measurement step 270. Next, in a correlation step 272, the impedance measurements are correlated with the electrode positions determined in step 268.

[0139] In decision step 274, a determination is made as to whether sufficient data has been collected for calibration of the map based on the needs of subsequent procedures. If more data is needed, the mixing catheter is moved to a new position in the heart chamber at positioning step 276, and steps 268 through 274 are repeated. In practice, steps 268 and 270 are performed continuously, such that steps 266 through 276 may also be performed in a continuous process as the catheter is gradually moved through different portions of the cavity to be mapped.

[0140] Once sufficient data has been collected, a calibration map is generated in a mapping step 278. Typically, the calibration map comprises a coordinate grid determined by magnetic sensing and a set of impedance measurements recorded at each point in the grid (relative to each of the body-surface electrodes or to pairs of body-surface electrodes). Alternatively, the grid can be inverted so that the map indicates the actual, calibrated position coordinates for each set of impedance measurements.

[0141] After the calibration map is completed, the second catheter 58 is inserted into the body cavity in an insertion step 280. The second catheter 58 includes electrodes 60, 62, and 64 that can be used to measure impedance, but typically does not contain a magnetic field sensor. In a second impedance measurement step 282, the impedance between the electrodes of the second catheter and the electrodes on the body surface is measured. In a position sensing step 284, the position coordinates of these catheter electrodes are determined by comparing the measured impedance with the calibration map. Based on the electrode positions, the positions of other components of the second catheter can also be determined. Steps 282 and 284 can be repeated to continuously track the catheter 58 until the process is determined to be complete in a completion step 286.

[0142] The foregoing description has been made with reference to the presently preferred embodiments of the invention. Those skilled in the art to which the invention pertains will appreciate that changes and modifications may be made to the structures described without intentionally departing from the principles, spirit and scope of the invention. It will be understood by those of ordinary skill in the art that the drawings are not necessarily drawn to scale. In addition, the different features of the different embodiments may be combined as needed or appropriate. Furthermore, the catheters described herein may be configured to apply various forms of energy, including microwaves, lasers, radiofrequency and / or cryogens. Therefore, the foregoing description should not be construed as relating solely to the precise structures described and illustrated in the accompanying drawings, but should be construed as consistent with and as support for the claims below, which have the fullest and reasonable scope.

Claims

1. A method for visualizing electrophysiological information sensed by electrodes on a catheter (14), comprising: receiving data regarding an electrode configuration of the catheter (202, 214); Record the time of electrode signal acquisition (203, 206); Identifying the electrodes (205) with signal acquisition; calibrating the earliest electrode signal acquisition among the electrode signal acquisitions as a reference electrode signal acquisition; Specifying the relative time of each recording time of electrode signal acquisition relative to the reference electrode signal acquisition time (210); Identifying the electrodes with signal acquisition based on the data on electrode configuration (213); Obtaining electrode position data (208, 211, 212, 217); associating the designated relative times with the identified electrodes and the electrode position data to generate an electrode signal acquisition sequence (213, 214); generating a visual representation (215) using a graphical image of the position and orientation of the electrodes based on the data regarding the electrode configuration and the electrode position data, and wherein individual electrodes are visually labeled to represent the electrode signal acquisition sequence (215), and wherein the electrodes are dynamically moved corresponding to actual movement of the electrodes; and A display is driven to display the visual representation.

2. The method according to claim 1, wherein The generating of the visual representation includes showing a plurality of images (215) in a series to represent the progress of the electrode signal acquisition sequence.

3. The method according to claim 2, wherein: Each image shows a different electrode (215) visually labeled.

4. The method according to claim 2, wherein: Each image shows at least one different electrode (215) visually marked.

5. The method according to claim 1, wherein The catheter has shaft segments (S1-S5), each shaft segment extending between adjacent electrode pairs (P1-P5), the method further comprising: assigning relative timing to each rod segment based on the relative timing of adjacent pairs of electrodes for each rod segment (209, 210); and correlating the relative timing of each rod segment with the relative timing of its adjacent electrode pair (213), Wherein said generating the visual representation comprises providing a graphical image of each rod segment and visually labeling each rod segment according to said sequence (215).

6. The method of claim 1, wherein: The identification of the electrode with signal collection includes a lead (205) identifying the electrode.

7. The method of claim 1, further comprising adjusting a time scale of the visual representation in response to a user-selected time scale (218).

8. The method of claim 1, wherein: The generating of a visual representation of the electrode acquisition sequence includes the electrode acquisition sequence for one or more cardiac cycles (219).

9. The method of claim 8, wherein: The generating of the visual representation includes the electrode acquisition sequence of the user's selected cardiac cycle.

10. The method of claim 1, wherein: The catheter (14) has a plurality of electrodes, wherein each electrode is adapted to collect an electrical signal.

11. The method according to claim 10, wherein: The catheter comprises rod segments (S1-S5), Each rod segment extends between adjacent electrode pairs (P1-P5), the method further comprising: assigning relative timing of each rod segment according to the relative timing of adjacent acquisition electrode pairs of each rod segment (290, 210); and correlating the relative time of each rod segment with the relative time of its adjacent acquisition electrode pair (213), Wherein said generating the visual representation comprises providing a graphical image of each rod segment and visually labeling each rod segment according to said sequence (215).

12. The method of claim 10, wherein: The electrode for identifying and collecting electrical signals includes a lead for identifying and collecting the electrode for electrical signals.

13. The method of claim 10, wherein: The catheter includes rod segments, each rod segment extending between adjacent pairs of electrodes, the method further comprising: assigning the relative timing of each rod sub-segment based on the relative timing of adjacent pairs of acquisition electrodes of each rod sub-segment and their positions between the adjacent pairs; and correlating the relative timing of each rod segment with the relative timing of its adjacent acquisition electrode pair, Wherein said generating the visual representation comprises providing a graphical image of each rod segment and visually labeling each rod segment according to said sequence.

14. The method of claim 13, wherein: Specifying the relative time of each pole segment includes specifying a weighted relative time.

15. The method of claim 14, wherein: The relative time of the weighting depends on the position of the rod segments between the adjacent pairs of acquisition electrodes.

16. The method of claim 1, further comprising: receiving a signal collected by the electrode (203); as well as A visual representation of the electrode signal acquisition sequence is generated, wherein the visual representation includes a graphical image of the electrodes (215).

17. A system for collecting and visualizing electrophysiological information, comprising: a catheter (14) having electrodes adapted to collect signals; a signal processing unit (112) configured to receive intracardiac signal acquisitions from a plurality of electrodes and receive data on electrode configuration and electrode position data of the catheter (14), and identify the electrodes having intracardiac signal acquisitions based on the data on electrode configuration; a timer (113), the timer (113) being configured to time the intracardiac signal acquisition and identify a reference time for the earliest intracardiac signal acquisition; a control unit (122) configured to specify a relative time of the intracardiac signal acquisition relative to the reference time and to associate the specified relative time with the identified electrodes and the electrode position data to generate a signal acquisition sequence; as well as A display (120) configured to display a graphical image of the position and orientation of the electrodes based on the data regarding the electrode configuration and the electrode position data, wherein individual electrodes are visually labeled to represent the electrode signal acquisition sequence, and wherein the electrodes move dynamically corresponding to actual movement of the electrodes.

18. The system of claim 17, wherein: The display (120) is configured to display the signal acquisition sequence in a series of graphical images of at least the electrodes.

19. The system according to claim 18, wherein The rod segments (S1-S5) between the electrodes (P1-P5) are also visually marked in the graphical image to represent the electrode signal acquisition sequence.

Images