Catheter Assembly Tracking and Visualization

Abstract

A system for use in electrophysiology procedures is disclosed, including an elongate catheter assembly with a tracking sensor and a controller configured to track a catheter assembly position within an organ based on a plurality of electrical signals from the tracking sensor, determine a first catheter assembly position based on a first electrical signal, determine a second catheter assembly position based on a second electrical signal, constrain the second position by the first position, and generate an anatomical map of the organ for the electrophysiology procedures using a visualization representation of the catheter assembly with the second position constrained by the first position.

Description

[Technical Field]

[0001] The present disclosure relates generally to medical systems and methods for electrophysiology procedures, such as ablation of tissue within a patient via a catheter assembly, and more particularly, to medical systems and methods for tracking a catheter assembly within a patient during an electrophysiology procedure. [Background technology]

[0002] Electrophysiology procedures involve navigating a catheter assembly within the heart and tracking its position relative to the heart. Catheter ablation is a minimally invasive electrophysiology procedure for treating various cardiac disorders, such as supraventricular and ventricular arrhythmias. Such procedures may include visualization of the heart, cardiac activity, and the position of the catheter assembly within the heart. A common visualization system uses fluoroscopy, which can expose the patient and clinician to ionizing radiation. Electroanatomical mapping is an alternative visualization technique that does not use ionizing radiation. Electroanatomical mapping allows clinicians to precisely locate arrhythmias, define cardiac geometry in three dimensions, delineate anatomical regions of interest, and spatially localize the catheter assembly for positioning and manipulation.

[0003] A catheter assembly includes multiple catheter elements, such as a catheter, a sheath, a dilator, a guidewire, and a needle. For example, a catheter assembly may include a catheter and a sheath. Navigation-enabled catheter assembly elements, such as a navigation-enabled catheter, use magnetic fields to track magnetic sensors within the catheter elements relatively accurately in an electroanatomical mapping system. However, not all catheter elements include magnetic sensors. Impedance-based catheter elements, such as a catheter sheath or catheter, use electric fields to track catheter elements with lower-cost components, such as electrodes, but are generally less accurate than navigation-enabled catheter elements in an electroanatomical mapping system. Regardless of whether the catheter elements are navigation-enabled or impedance-based, the electroanatomical mapping system uses electrical measurements to determine the pose of the catheter or the three-dimensional curve of the distal portion of the catheter assembly, across which multiple electrodes extend. Summary of the Invention

[0004] In Example 1, a system for use in electrophysiology treatment includes an elongate catheter assembly having a tracking sensor and a controller configured to track multiple catheter assembly positions within an organ based on multiple electrical signals from the tracking sensor, determine a first catheter assembly position based on a first electrical signal of the multiple electrical signals, determine a second catheter assembly position based on a second electrical signal of the multiple electrical signals, constrain the second position by the first position, and generate an anatomical map of the organ for the electrophysiology treatment using a visualization representation of the catheter assembly with the second position constrained by the first position.

[0005] In Example 2, the system of Example 1, wherein the controller is configured to place a tag representing an anatomical landmark on the anatomical map of the organ at the first catheter assembly location.

[0006] In Example 3, in the system of Example 2, the anatomical landmark is the interatrial septum. In Example 4, the system of any of Examples 1-3, wherein the controller is configured to track the catheter assembly independent of anatomical landmarks.

[0007] In Example 5, in the system of any of Examples 1-4, the controller is configured to track multiple catheter assembly positions of the catheter assembly via the tracking sensors using a tracking method over time as the catheter assembly passes through the heart.

[0008] In Example 6, the system of any of Examples 1-5, wherein the controller is configured to substantially simultaneously track multiple catheter assembly positions of the catheter assemblies via the tracking sensors using the tracking method.

[0009] In Example 7, in the system of any of Examples 1 to 6, the first catheter assembly position includes a first position in space and a first tangent, and the second catheter assembly position includes a second position in space and a second tangent.

[0010] In Example 8, the system of any of Examples 1-7, wherein the controller is configured to constrain the first position to the second position using bending energy data related to bending energy of the catheter assembly.

[0011] In Example 9, the system of any of Examples 1-8, wherein the controller is configured to constrain the first location to the second location via the path. In Example 10, the system of Example 1 includes a catheter assembly including a plurality of coaxially arranged catheter elements, the plurality of catheter elements including a first catheter element and a second catheter element, the first catheter element forming an elongate lumen, the second catheter element disposed within the lumen, the first and second catheter elements relatively movable along the axis, the first catheter element including a first tracking sensor, and the second catheter element including a second tracking sensor, the controller is configured to generate a first position of the first catheter element based on a first electrical signal of the plurality of electrical signals, generate a second position of the second catheter element based on a second electrical signal of the plurality of electrical signals, laterally align the first position with the second position based on lateral and rotational displacements determined from the first position and the second position, and longitudinally adjust the first position relative to the second position based on detection of the first tracking sensor of the second tracking sensor.

[0012] In Example 11, in the system of Example 10, the first catheter assembly position includes a first position in space and a first tangent, and the second catheter assembly position includes a second position in space and a second tangent.

[0013] In Example 12, in the system of Example 11, the first position and first tangent are laterally aligned with the second position and second tangent based on a lateral deviation and a rotational deflection determined from the first tangent and the second tangent.

[0014] In Example 13, the system of any of Examples 11-12, wherein the controller is configured to longitudinally adjust the first position relative to the second position based on sheath detection.

[0015] In Example 14, the system of any of Examples 10-13, wherein the controller is configured to track the first catheter element via impedance tracking and track the second catheter element via magnetic tracking.

[0016] In Example 15, the system of any of Examples 10-14, wherein the controller is configured to laterally align the second location to coincide with the first location. In Example 16, a system for use in electrophysiology procedures includes an elongate catheter assembly and a controller, the elongate catheter assembly including a plurality of coaxially arranged catheter elements, the catheter elements including a first catheter element and a second catheter element, the first catheter element forming an elongate lumen, the second catheter element disposed within the lumen, the first and second catheter elements relatively movable along an axis, the first catheter element including a first tracking sensor, and the second catheter element including a second tracking sensor. The controller is configured to determine an anatomical map of the heart for the electrophysiological procedure, track a catheter assembly position within the organ based on a first electrical signal from the first tracking sensor and a second electrical signal from the second tracking sensor, generate a first position of the first catheter element based on the first electrical signal, generate a second position of the second catheter element based on the second electrical signal, laterally align the first position with the second position based on lateral and rotational displacements determined from the first position and the second position, and longitudinally adjust the first position with respect to the second position based on detection of the first tracking sensor by the second tracking sensor.

[0017] In Example 17, the system of Example 16 further includes a controller configured to generate a visualization of the catheter element relative to an anatomical map of the heart after the catheter element is laterally aligned and longitudinally adjusted.

[0018] In Example 18, in the system of Example 16, the first catheter assembly position includes a first position in space and a first tangent, and the second catheter assembly position includes a second position in space and a second tangent.

[0019] In Example 19, in the system of Example 18, the first location and first tangent are laterally aligned with the second location and second tangent based on a lateral deviation and a rotational deflection determined from the first tangent and the second tangent.

[0020] In Example 20, the system of Example 16, wherein the controller is configured to longitudinally adjust the first position relative to the second position based on the sheath detection. In Example 21, the system of Example 16, wherein the controller is configured to apply a confidence value to the second location.

[0021] In Example 22, in the system of Example 21, if the second catheter element is magnetically tracked in the electrophysiology system, the confidence value is 1.0. In Example 23, in the system of Example 16, the first catheter element is a sheath and the second catheter element is a catheter disposed within the sheath.

[0022] Example 24 describes a process for using an elongated catheter assembly during an electrophysiology procedure on a heart, the catheter assembly including a plurality of coaxially arranged catheter elements, the catheter elements including a first catheter element and a second catheter element, the first catheter element forming an elongated lumen, the second catheter element disposed within the lumen, the first and second catheter elements being relatively movable along the axis, the first catheter element including a first tracking sensor, and the second catheter element including a second tracking sensor. The process includes the steps of tracking a catheter assembly position within the heart based on a first electrical signal from a first tracking sensor and based on a second electrical signal from a second tracking sensor; generating a first position of the first catheter element based on the first electrical signal and a second position of the second catheter element based on the second electrical signal; laterally aligning the first position with the second position based on lateral and rotational displacements determined from the first and second positions; and longitudinally adjusting the first position with respect to the second position based on detection of the first tracking sensor of the second tracking sensor.

[0023] In Example 25, the process of Example 24 further includes generating an electroanatomical map of the heart and providing a visualization of the catheter element relative to the electroanatomical map of the heart.

[0024] In Example 26, in the process of Example 24, the first catheter assembly position includes a first position and a first tangent in space, the second catheter assembly position includes a second position and a second tangent in space, and the first position and the first tangent are laterally aligned with the second position and the second tangent based on a lateral deviation and a rotational deflection determined from the first tangent and the second tangent.

[0025] In Example 27, in the process of Example 24, the step of longitudinally adjusting includes correcting for protrusion by sheath detection of the first catheter element and the second catheter element. Example 28 provides a system for use in electrophysiology treatment, the system comprising: an elongate catheter assembly having a tracking sensor; and a controller configured to track a plurality of catheter assembly positions within an organ based on a plurality of electrical signals from the tracking sensor, determine a first catheter assembly position based on a first electrical signal of the plurality of electrical signals, determine a second catheter assembly position based on a second electrical signal of the plurality of electrical signals, constrain the second position by the first position, and generate an anatomical map of the organ for the electrophysiology treatment using a visualization representation of the catheter assembly with the second position constrained by the first position.

[0026] In Example 29, the system of Example 28, wherein the controller is configured to place a tag representing an anatomical landmark on the anatomical map of the organ at the first catheter assembly location.

[0027] In Example 30, the system of Example 29, wherein the controller is configured to track the catheter assembly independent of anatomical landmarks. In Example 31, in the system of Example 28, the controller is configured to track multiple catheter assembly positions of the catheter assembly via the tracking sensor using a tracking method over time as the catheter assembly passes through the heart.

[0028] In Example 32, the system of Example 31, wherein the controller is configured to constrain the first position to the second position using bending energy data related to bending energy of the catheter assembly.

[0029] In Example 33, the system of Example 28, wherein the controller is configured to constrain the first location to the second location via the path. In Example 34, the system of Example 33, wherein the controller is configured to highlight the path in the visualization.

[0030] In Example 35, the system of Example 28, wherein the catheter assembly includes a plurality of coaxially arranged catheter elements, the catheter elements including a first catheter element and a second catheter element, the first catheter element forming an elongate lumen, the second catheter element disposed within the lumen, the first and second catheter elements relatively movable along an axis, the first catheter element including a first tracking sensor, and the second catheter element including a second tracking sensor, the controller is configured to generate a first position of the first catheter element based on a first electrical signal of the plurality of electrical signals, generate a second position of the second catheter element based on a second electrical signal of the plurality of electrical signals, laterally align the first position with the second position based on lateral and rotational displacements determined from the first position and the second position, and longitudinally adjust the first position relative to the second position based on detection of the first tracking sensor of the second tracking sensor.

[0031] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 illustrates an exemplary clinical environment having an exemplary electrophysiological system for treating a patient and for treating the patient's heart. [Figure 2] FIG. 2 is a block diagram illustrating an exemplary controller for use in the exemplary electrophysiology system of FIG. 1. [Figure 3A] FIG. 3 is a flow diagram illustrating an example configuration of the example controller of FIG. 2. [Figure 3B] FIG. 3B is a schematic diagram illustrating an exemplary embodiment of the exemplary configuration of FIG. 3A. [Figure 4] 3 is a flow diagram illustrating another exemplary configuration of the example controller of FIG. 2. [Figure 5] 2 is a schematic diagram illustrating isolated exemplary sections of exemplary catheter elements of an exemplary catheter assembly for use in the exemplary electrophysiology system of FIG. 1. [Figure 6A] 6 is a schematic diagram illustrating the implementation of the process of FIG. 4 using the exemplary catheter element of FIG. 5. [Figure 6B] FIG. 6B is a schematic diagram illustrating a representation of a device model from tracking the exemplary catheter element of FIG. 6A. [Figure 6C] 6C is a schematic diagram illustrating an embodiment of the process features of FIG. 4 using the device model of FIG. 6B. [Figure 6D] 6D is a schematic diagram illustrating an implementation of another aspect of the process of FIG. 4 using the device model of FIG. 6C. DETAILED DESCRIPTION OF THE INVENTION

[0033] While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the specific embodiments described. Rather, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

[0034] For purposes of promoting an understanding of the principles of the present disclosure, reference will be made to the examples illustrated in the drawings described below. The illustrative examples disclosed herein are not intended to be exhaustive or to limit the disclosure to the precise form disclosed in the following detailed description. Rather, these exemplary embodiments were chosen and described so that those skilled in the art might utilize their teachings. It would not be beyond the scope of the present disclosure to use multiple (e.g., all) features in the examples throughout all the examples. Thus, no figure should be interpreted as having any dependency or requirement relating to any single component or combination of components shown. In addition, various components shown in the figures may, in some examples, be combined with various of the other components shown (or components not shown), all of which are considered to be within the scope of the present disclosure.

[0035] Examples of electrophysiology procedures and systems in which an electroanatomical mapping system tracks a catheter assembly are described in this disclosure along with electrophysiology testing and ablation systems for illustrative purposes. Ablation procedures are used to treat many different conditions in patients. Ablation can be used to treat cardiac arrhythmias, benign tumors, cancerous tumors, and to control bleeding during surgery. Ablation is typically achieved by thermal ablation techniques, including radiofrequency (RF) ablation and cryoablation. In RF ablation, a catheter is inserted into a patient and radiofrequency waves are transmitted through the catheter to surrounding tissue. The radiofrequency waves generate heat, which destroys surrounding tissue and cauterizes blood vessels. In cryoablation, a hollow needle or cryoprobe is inserted into the patient and a low-temperature, heat-conducting fluid is circulated through the probe, freezing and killing surrounding tissue. RF ablation and cryoablation techniques can indiscriminately kill tissue through necrosis, which can damage or kill other healthy tissue, such as tissue in the esophagus, phrenic nerve cells, and tissue in the coronary arteries.

[0036] Another ablation technique uses electroporation. In electroporation, or electropermeabilization, an electric field is applied to cells to increase the permeability of the cell membrane. Electroporation can be reversible or irreversible depending on the strength and duration of the electric field. If electroporation is reversible, the temporarily increased permeability of the cell membrane can be used to introduce chemicals, drugs, or deoxyribonucleic acid (DNA) into the cells prior to cellular healing and recovery. Tissue recovery can occur over minutes, hours, or days after ablation is complete. If electroporation is irreversible, the affected cells die, for example, via some form of cell death (e.g., programmed cell death, perhaps via apoptosis, or traumatic cell death, e.g., via necrosis).

[0037] Irreversible electroporation can be used as a non-thermal ablation technique. Irreversible electroporation uses a train of brief, high-voltage pulses to generate an electric field strong enough to kill cells. For cardiac tissue ablation, irreversible electroporation can be a relatively safe and effective alternative to the indiscriminate killing of thermal ablation techniques such as RF ablation and cryoablation. Irreversible electroporation can be used to kill target tissue, such as myocardial tissue, by selecting an electric field strength and duration that is ineffective at permanently killing other cells or tissues, such as non-target myocardial tissue, red blood cells, vascular smooth muscle tissue, endothelial tissue, and nerve cells. In this disclosure, an irreversible electroporation system is presented for illustrative purposes, but the catheter and assembly tracking concepts can also be applied to other systems.

[0038] Cardiac ablation, as well as other electrophysiology procedures, can involve the use of catheter assemblies. Catheter assemblies include multiple catheter elements, which may include catheters, sheaths, dilators, guidewires, and needles. As electrophysiology procedures move toward less use of fluoroscopy, catheter elements include tracking devices or sensors to facilitate tracking in an electroanatomical mapping system. Typically, multiple catheter elements within a catheter assembly are tracked separately via multiple tracking systems within the electroanatomical mapping system. Because multiple tracking systems are imprecise and provide approximations of the positions of the catheter elements within an organ, different catheter elements within a catheter assembly may be rendered in a visualization as displaced or separate from one another, even when the catheter assembly is positioned within a patient. For clinical interpretation, it is desirable for the catheter elements to be presented in their accurate positions relative to one another and relative to the heart. If the tracked elements are physically coaxial, for example, it is desirable to use this information to improve estimation of the catheter element positions and to render the catheter elements as coaxial in a visualization, for example. Similarly, it may be desirable to render multiple catheter elements as a single catheter assembly, for example, when one of the tracked elements is advanced past another.

[0039] FIG. 1 illustrates an exemplary clinical environment 10 for treating a patient 20 (e.g., for treating a heart 30 of the patient 20) using an electrophysiology system 50 according to the present disclosure. The electrophysiology system 50 includes an electroporation catheter system 60 and an electroanatomical mapping (EAM) system 70. The exemplary electroporation catheter system 60 includes an elongated catheter assembly 100, which in this example includes an electroporation catheter 105 and an introducer sheath 110, and an electroporation console 130. Additionally, the electroporation catheter system 60 includes various connecting elements (e.g., cables) that operably connect the components of the electroporation catheter system 60 to each other and to the components of the EAM system 70. Generally, the EAM system 70 includes a localization field generator 80, a mapping and navigation controller 90, and a display 92. The clinical environment 10 may also include additional equipment, such as imaging equipment 94 (represented by a C-arm), and various controller elements (e.g., foot controller 96) configured to allow an operator to control various aspects of the electrophysiology system 50. The clinical environment 10 may have other components and arrangements of components not shown in FIG.

[0040] The electroporation catheter system 60 is configured to deliver electric field energy to target tissue within a patient's heart 30 to induce cell death in the tissue, e.g., to render the tissue unable to conduct electrical signals. An elongated catheter assembly (e.g., catheter assembly 100) may include multiple coaxially arranged catheter elements. For example, the catheter elements (e.g., sheaths or catheters) define a longitudinal axis passing through the cross-sectional centroid of the catheter element (e.g., the cross-sectional centroid of the catheter shaft or the cross-sectional centroid of the sheath lumen). The multiple coaxially arranged catheter elements are arranged such that one catheter element is positioned within another catheter element such that the longitudinal axes of each catheter element generally follow the same three-dimensional curve or path to their distal-most point. The catheter elements may include a first catheter element (e.g., elongated introducer sheath 110) and a second catheter element (e.g., an elongated catheter such as electroporation catheter 105). The first catheter element includes an elongate lumen, and the second catheter element is disposed within the lumen. In one example, the catheter 105 is disposed within the introducer sheath 110. The first and second catheter elements are movable relative to each other along their longitudinal axes. For example, the distal end of the catheter 105 can be manipulated to extend from the distal tip of the introducer sheath 110, or the distal tip of the introducer sheath 110 can be retracted from the distal end of the catheter 105. In addition, the distal end of the catheter 105 can be retracted from the distal tip of the introducer sheath 110. The first catheter element includes a first tracking sensor, and the second catheter element includes a second tracking sensor. For example, each of the first and second catheter elements can include one or more tracking sensors. Examples of tracking sensors can include a magnetic navigation device and an electrode.

[0041] The introducer sheath 110 is operable to provide a delivery conduit through which the catheter 105 may be deployed to a specific target site within the patient's heart 30. Access to the patient's heart may be achieved through a blood vessel (e.g., a peripheral artery or vein). Once vascular access is obtained, the electroporation catheter 105 may be guided into the patient's heart (e.g., into a chamber of the heart). In one example, the catheter assembly 100, including the introducer sheath 110, is adapted for use in a transseptal puncture. The left atrium of the heart is a relatively difficult chamber to access percutaneously, and a transseptal puncture allows a direct route to the left atrium via the intraatrial septum and the systemic venous system.

[0042] The exemplary catheter 105 includes an elongate catheter shaft and a distal end configured to be deployed near a target tissue (e.g., within a patient's heart chamber). The distal end may include a basket, balloon, spline, structured tip, or other electrode deployment mechanism for delivering therapy. The electrode deployment mechanism includes an electrode assembly or electrode array. For example, the electrode assembly may include multiple spaced electrodes, multiple sets of spaced electrodes, or multiple groups of spaced electrodes. In some examples, electrodes (e.g., multiple spaced electrodes) may be deployed on the catheter shaft in addition to or instead of electrodes on the electrode deployment mechanism. In one example, the multiple electrodes may be formed from a conductive solid-surface biocompatible material and spaced apart via an insulator. Each of the multiple electrodes is electrically connected to a corresponding elongate lead conductor that extends along the shaft to the catheter proximal end. In one example, each electrode of the multiple spaced electrodes corresponds to a separate, single lead conductor. In another example, the multiple electrodes may be connected to a single lead conductor. Other configurations are also contemplated. Multiple lead conductors may be insulated from one another along the catheter shaft within an insulating sheath (e.g., an insulating polymer sheath). The multiple lead conductors may be electrically connected to a plug (e.g., a plug configured for mechanical and electrical connection to the electroporation console 130) within a proximal region of the catheter 105, e.g., directly or via an intermediate electrical conductor such as cabling. In one example, the electroporation console 130 is configured to provide electrical signals (e.g., multiple simultaneous or time-spaced electrical signals) to the electrically connected catheter 105 along the lead conductors to the spaced electrodes. In the example electroporation catheter, the spaced electrodes are configured to generate selected electric fields near the target tissue to perform electroporation based on the electrical signals from the electroporation console 130.

[0043] A selected electric field can be generated using electrodes to perform electroporation. By selecting a first electrode or a first group of electrodes as an anode and a different second electrode or group of electrodes as a cathode, an electric field can be generated between the anode and the cathode based on a signal (e.g., a pulse) provided to the electrodes from the electroporation console 130. The console 130 delivers electric pulses of different lengths and magnitudes to the electrodes on the catheter 105. The electric pulses can be delivered in a continuous pulse stream or multiple discrete pulse trains. Pulse parameters of interest include the number of pulses, the pulse duty cycle, the interval between pulse trains, the pulse voltage or magnitude (including peak voltage), and the voltage duration. For example, the console 130 can select two or more electrodes of an electrode assembly and deliver pulses to the selected electrodes to generate an electric field between the selected electrodes and provide pulsed field ablation (PFA). For example, PFA can be performed using monophasic and biphasic waveforms. Without being limited to a particular theory, electric field strengths in the range of approximately 200-250 volts per centimeter (V / cm) with microsecond-scale pulse durations have been demonstrated to provide reversible electroporation in cardiac tissue. Electric field strengths of approximately 400 V / cm have been demonstrated to provide irreversible electroporation in cardiac tissues of interest (e.g., targeted myocardial and endocardial tissues) with demonstrable sparing of red blood cells, vascular smooth muscle tissue, endothelial tissue, nerves, and other non-target nearby tissues.

[0044] The electroporation console 130 is configured to control aspects of the electroporation catheter system 60. In embodiments, the electroporation console 130 is configured to provide one or more of the following: modeling an electric field that may be generated by the electroporation catheter 105, which often includes consideration of the physical characteristics of the electroporation catheter 105, including the electrodes, the spatial relationship of the electrodes on the electroporation catheter 105, and whether the electroporation catheter 105 is in bipolar or monopolar mode; generating a graphical representation of the electric field, which often includes consideration of the location of the electroporation catheter 105 within the patient 20 and the characteristics of the surrounding tissue; and overlaying the generated graphical representation on an anatomical map on the display 92. In some examples, the electroporation control console 130 is configured to generate the anatomical map. In some examples, the EAM system 70 is configured to generate the anatomical map for display on the display 92.

[0045] The electroporation console 130 includes a controller (e.g., one or more controllers, processors, or computers) that executes instructions or code (e.g., processor-executable instructions) from a non-transitory computer-readable medium (e.g., a memory device or memory) to, for example, control or perform aspects of the electroporation catheter system 60. The memory may be part of the one or more controllers, processors, or computers, or may be part of a memory device accessible over a computer network. Examples of computer networks include a local area network, a wide area network, and the Internet.

[0046] The EAM system 70 is operable to track the positions of various components of the electroporation catheter system 60 and generate high-fidelity three-dimensional anatomical and electroanatomical maps of the heart, including portions of the heart (e.g., heart chambers of interest or other structures of interest (e.g., the sinoatrial node or atrioventricular node)). In one illustrative example, the EAM system 70 may include the RHYTHMIA™ HDx mapping system sold by Boston Scientific Corporation. The mapping and navigation controller 90 of the EAM system 70 includes one or more controllers, such as a microprocessor or computer, that executes code from a memory to control or perform functional aspects of the EAM system 70, and the memory may be part of one or more controllers, microprocessors, computers, or may be part of a memory device accessible over a computer network.

[0047] EAM system 70 generates a localization field via magnetic field generator 80 to form a localization volume around heart 30, and position sensors or sensing elements on the tracked device (sensors on electroporation catheter 105) generate outputs that can be processed by mapping and navigation controller 90 to track the position and orientation of one or more sensors, and thus the corresponding device, within the localization volume. In the illustrated example, device tracking is performed using magnetic tracking techniques, field generator 80 is a magnetic field generator that generates a magnetic field that forms the localization volume, and the position sensors on the tracked device are magnetic field sensors.

[0048] In other examples, impedance tracking methods can be used to track the positions of various devices. In such examples, the localization fields are independently oriented and spatially varying sets of electric fields generated, for example, by external field generator arrangements (e.g., surface electrodes), by intrabody or intracardiac devices (e.g., intracardiac catheters), or both. In these examples, the position sensing elements can comprise electrodes on the tracked devices that generate outputs that are received and processed by the mapping and navigation controller 90 to track the positions of the various position sensing electrodes within the localization volume.

[0049] The EAM system 70 can include both magnetic and impedance tracking capabilities. In such instances, impedance tracking accuracy can be enhanced by first creating a map of the electric field induced by the electric field generator within the cardiac chamber of interest using a probe equipped with a magnetic position sensor, as is possible with the RHYTHMIA HDx™ mapping system. One exemplary probe is the INTELLAMAP ORION™ mapping catheter sold by Boston Scientific Corporation.

[0050] Regardless of the tracking method used, EAM system 70 utilizes the positional information of the various tracking devices and cardiac electrical activity acquired, for example, by electroporation catheter 105 equipped with sensing electrodes or another catheter or probe, to generate and display on display 92 a detailed three-dimensional geometrical anatomical map or representation of cardiac tissue and air spaces (e.g., heart chambers), as well as an electroanatomical map in which cardiac electrical activity of interest is superimposed on the geometrical anatomical map. Additionally, EAM system 70 can generate a graphical representation of the various tracked devices within the geometrical anatomical map or electroanatomical map.

[0051] The exemplary EAM system 70 tracks the positions of the catheter elements of the catheter assembly 100 using processes known in the art. In one example, the EAM system 70 provides equations that include the position and possibly the velocity of each electrode. A tracked device, such as a catheter element of the catheter assembly 100, is characterized in the EAM system 70 as a device model that includes electrode positions and tangents, among other parameters. In one illustrative example, tracking may involve the application of external electrodes that generate multiple non-parallel electric fields throughout the body for impedance tracking. A magnetically tracked device is used to associate an electric field or impedance value with each location in magnetically determined space. The resulting data structure is presented as a field map. If only impedance devices are being tracked, the field map is inverted to estimate the position of each electrode. The estimated positions are smoothed, and the process includes various constraints on the shape of the flexible device comprised of all the electrodes. While the body is nearly transparent to magnetic fields, the electrical properties of body tissues significantly affect the shape of the electric field, making impedance tracking less accurate than magnetic tracking.

[0052] FIG. 2 illustrates an example controller 200, such as a controller of an example electroporation catheter system 60, that can be used with the example electrophysiology system 50, and which may include a controller of an example EAM system 70, such as the mapping and navigation controller 90. The controller 200 may be implemented to provide a device model and visualization of a catheter assembly as a single unit within a patient, even when catheter elements of the catheter assembly are independently tracked and tracked differently during an electrophysiology procedure. The controller 200 may include a processor 202 and a memory 204. The memory 204 stores processor-executable instructions 206. In one example, the processor-executable instructions may be in the form of a program (e.g., a computer program or application). The processor 202 can execute the instructions 206, which may be included in configuring the controller 200. In one example, the controller 200 may be implemented to include a computing device (e.g., a laptop computer, a workstation, a desktop computer, a tablet, or a smartphone). In such examples, the controller 200 may include additional components (e.g., a display, a touch screen, a speaker or other output device, a keyboard or other input device, or communication circuitry (e.g., a computer network adapter)). The controller 200 may be implemented in a variety of architectures, and the components (e.g., the processor 202 and memory 204) may be distributed in a variety of locations.

[0053] In one example, processor 202 may include multiple main processing cores for executing an operating system and performing general-purpose tasks on an integrated circuit. Processor 202 may also include embedded logic or programmable functional units with similarly heterogeneous instruction set architectures on the same integrated circuit. In addition to multiple general-purpose main processing cores and application processing units, controller 200 may include other devices or circuits (e.g., graphics processing units or neural network processing units) that may include heterogeneous or homogeneous instruction set architectures along with the main processing cores. For example, controller 200 may be used to perform other tasks, such as in the case of a computing device that includes a resonant sound amplification device.

[0054] Memory 204 is an example of a computer storage medium. Computer storage media includes RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device, USB flash drive, flash memory card or other flash storage device, or other storage medium that can be used to store desired information and that can be accessed by processor 202. Any such computer storage medium may be part of controller 200 and implemented as memory 204. Memory 204 is a non-transitory processor-readable memory device. Thus, a propagating signal does not, in itself, qualify as a storage medium or memory 204.

[0055] The controller 200 may be configured to receive input or information from the electrophysiology system 50 (e.g., input from the electroporation catheter system 60, including the electroporation console 130 and the mapping and navigation controller 90, and the EAM system 70) for storage in the memory 204 and use by the instructions 206. For example, the controller 200 may receive input representing an anatomical map of the heart or cardiac map data 208, which may include data regarding representations of a geometrical anatomical map of the heart and an electroanatomical map of the heart, such as from the EAM system 70. In addition, the cardiac map data 208 may include cardiac annotations, markings, or user-added tags, which may include markings of anatomical locations of interest or other data, for generating visualizations that may be of interest to a clinician during a procedure. The controller 200 may also receive tracking position data 210 for each catheter element of the catheter assembly. The tracking position data may be generated by magnetic tracking techniques, impedance tracking approaches, or other tracking procedures, and may be generated by other functions of the EAM system 70 or the electrophysiology system 50. In one example, the tracking position data 210 includes information used to determine the location of sensors on the catheter elements relative to the heart. The tracking position data 210 may also include information regarding the number of electrodes exposed from the sheath in the catheter, i.e., sheath detection data, if the electrophysiology system 50 includes a sheath detection mechanism. In some examples, the processor 200 may receive catheter assembly parameter data 212, which includes information regarding catheter element parameters such as the number and spacing of electrodes on the catheter elements, the type of tracking method used, and various other parameters such as mechanical properties and conditions of the catheter elements (in one embodiment, properties related to the bending or bending energy of the catheter elements) that may be used to determine constraints. In one catheter assembly, the parameter data 212 may include a separate entry for each catheter element.In one example, cardiac map data 208 and tracking location data 210 are stored in memory 204 for use by processor 202 executing instructions 206 .

[0056] The controller 200 is configured to generate a visualization 220 based on the received tracking data of the catheter elements, which may include the determined position of the catheter assembly as a single unit with reference to an anatomical map of the heart. In one example, the controller 200 is configured to generate the visualization 220 using cardiac map data 208 based on constraints applied to the tracking data 210 and catheter parameter data 212.

[0057] 3A illustrates a process 300 for configuring a controller (e.g., controller 200) in tracking a catheter assembly having catheter elements using tracking sensors. Process 300 includes, at 302, configuring the controller to receive electroanatomical map data of an organ (e.g., receive cardiac map data 208). The controller is configured, at 304, to track multiple catheter assembly positions within the organ based on multiple electrical signals from the tracking sensors. For example, the controller can track the position of the catheter assembly via the tracking sensors using a tracking method over time as the catheter assembly passes through the heart. In another example, multiple tracking signals are generated simultaneously or nearly simultaneously, e.g., multiple tracking sensors of a catheter assembly can be tracked within the same sample. The controller is configured, at 306, to determine a first catheter assembly position based on a first electrical signal of the multiple electrical signals and to determine a second catheter assembly position based on a second electrical signal of the multiple electrical signals. The first and second catheter assembly positions may each include a set of data related to the catheter elements in space determined by the mapping and navigation controller 90 (e.g., the catheter's attitude as included in the tracking position data 210 or a three-dimensional curve of the distal portion of the catheter with the tracking sensor). In one example, the first catheter assembly position includes a first position and a first tangent in space of the catheter assembly as determined by the EAM system 70, and the second catheter assembly position includes a second position and a second tangent in space of the catheter assembly as determined by the EAM system 70. At 308, the second position is constrained by the first position. In one example, catheter parameter data 212 is applied to the tracking position data 210 to constrain the position. The controller is configured to generate an electroanatomical map of the organ for electrophysiology treatment at 310 along with a visualization of the catheter assembly whose second position is constrained by the first position.

[0058] In one example, process 300 may be implemented as a set of processor-executable instructions (e.g., instructions 206) stored in a non-transitory memory (e.g., memory 204) that are executed by processor 202 to configure controller 200. The instructions for performing process 300 may be configured to receive information, such as cardiac map data 208 and tracking position data 210 and catheter parameter data 212 related to catheter elements including a plurality of catheter elements, from memory 204. Furthermore, the instructions for performing process 300 may be configured to annotate, adjust, or write to cardiac map data 208, and to generate a visualization (e.g., visualization 220 on a display of a graphical representation).

[0059] Process 300 provides visualization and tracking of a catheter assembly or catheter element. In one example, process 300 can be implemented to combine anatomical landmarks and catheter mechanics for visualization and tracking of the catheter. As the catheter assembly is tracked in real time, the current position of the catheter assembly within the heart is presented as a visualization.

[0060] FIG. 3B provides a simplified schematic diagram 350 of a process 300 implemented to combine anatomical landmarks and catheter structure for catheter visualization and tracking. A distal region of a catheter 352 is shown advanced through a patient's vasculature into a heart 354. The heart 354 includes a right atrium 356, a left atrium 358, and an intra-atrial septum 360. The distal region of the catheter 352 includes a tracking sensor 362, in this example, multiple electrodes 364 disposed along a shaft 366. In process 300, anatomical landmarks are preserved by tags as the catheter advances past the landmarks, such as at 304. In one example, the catheter 352 may cross the intra-atrial septum 360 from the right atrium 356 to the left atrium 358 at a crossing point 368 of the intra-atrial septum 360. At 304, a tag 370 may be manually placed by an operator or automatically placed at the anatomical landmark of interest by process 300. At 306, electrodes 364 are tracked on the distal region of the catheter. The shape of the catheter shaft 366 from the tag 370 to the tracked electrode 364 generally follows a path that reduces the mechanical bending energy of the shaft. At 308, the process 300 determines the catheter position based on, for example, the positions of the tag 370 and electrode 364, and imposes constraints related to the shape of the catheter in the device model. The dashed line represents the device model 372. The bending energy of the catheter, a parameter determinable by the catheter parameter data 212, can be applied along with other constraints to determine the catheter trajectory in the device model 372.

[0061] The visualization generated at 310 can highlight anatomical regions crossing the intra-atrial septum with markers or a selected color, where the selected color indicates the location of the electrodes relative to the cardiac map, and another color as a line, arc, or spline passing through the markers and electrodes that follows a shape constrained to the catheter position based on the catheter parameter data 212. In one example, the catheter elements are tracked independently of the anatomical landmarks, and the bending energy-reduced curve or path is also determined independently. In another example, the catheter elements are tracked with additional constraints based on both the anatomical landmarks and the bending energy from the catheter parameter data 212.

[0062] FIG. 4 illustrates a process 400 for configuring a controller (e.g., controller 200) to track multiple catheter elements of a catheter assembly, each catheter element having a tracking sensor. For example, process 400 may be an example of process 300 of FIG. 3. In the exemplary process 400, a catheter assembly includes multiple coaxially arranged catheter elements, the multiple catheter elements including a first catheter element and a second catheter element. The first catheter element forms an elongated lumen, and the second catheter element is disposed within the lumen. The first and second catheter elements are axially movable relative to each other. An example of the first catheter element may be a sheath, and an example of the second catheter element may be a catheter disposed within the lumen of the sheath. The first catheter element includes a first tracking sensor, and the second catheter element includes a second tracking sensor. Process 400 may receive parameters related to the first catheter element and the second catheter element via catheter parameter data 212.

[0063] The process 400 includes configuring a controller to receive electroanatomical map data of an organ (e.g., receive cardiac map data 208) at 402. The controller is configured to track a catheter assembly position within the heart based on a first electrical signal from a first tracking sensor and based on a second electrical signal from a second tracking sensor at 404. In this example, the positions of the catheter elements are tracked substantially simultaneously. The controller is configured to generate a first position of the first catheter element based on the first electrical signal and a second position of the second catheter element based on the second electrical signal at 406. For example, the controller is configured to generate a position of each electrode on the first catheter element, and similarly for the second catheter element, based on a set of magnetic or electrical signals. The positions of the first and second catheter elements may each include a set of data related to the catheter elements in space determined by the mapping and navigation controller 90 (e.g., a catheter orientation or a three-dimensional curve of a distal portion of the catheter with the tracking sensors, as included in the tracking position data 210). In one example, the position of the first catheter element includes a first position and a first tangent of the catheter element in space determined by the EAM system 70, and the position of the second catheter element includes a second position and a second tangent of the catheter element in space determined by the EAM system 70. In one example used in this disclosure, two objects are considered to be coaxial at a point if they are touching at the point and have the same tangent at the point. At 408, the first position is laterally aligned with the second position based on the lateral displacement of the first catheter element relative to the second catheter element. For example, the first position and first tangent are laterally aligned with the second position and second tangent based on lateral and rotational displacements determined from the first position and first tangent and the second position and second tangent, respectively. For example, the tangents at the point may be aligned by a rigid transformation, such as a rotation, or may be aligned by using a point along one device to locally modify the tangent of the other device.At 410, the first position is longitudinally adjusted relative to the second position based on detection of the second tracking sensor using the first tracking sensor. For example, the first position is longitudinally aligned relative to the second position based on detection of the first tracking sensor using the second tracking sensor. At 412, the controller is configured to generate an electroanatomical map of the organ for electrophysiological treatment using a visualization representation of the catheter assembly in which the device model of the first catheter element is constrained by the device model of the second catheter element.

[0064] The lateral alignment at 408 and the longitudinal adjustment at 410 may be performed based on various determinations from the tracking position data 210 and the catheter parameter data 212. The lateral alignment at 408 may be applied to correct for deviations or displacements in the device model of the catheter elements. In one example, the deviations or displacements are addressed by translational movements or movements along a vector from one point to another. Additionally, the lateral alignment at 408 may be applied to correct for deflections or rotations in the device model of the catheter elements. In one example, the rotations are applied by moving by an angle. The longitudinal adjustment at 410 may be applied to correct for protrusions or longitudinal displacements of one catheter element relative to another catheter element. A determination of the number of electrodes exposed or uncovered by the sheath may be used to provide the longitudinal adjustment. In one example of a tracked catheter and sheath, sheath detection, or a technique used to determine whether and how many electrodes of the catheter are exposed from the sheath, is used to impose constraints on the relative positions of the catheter and sheath device models, such as for longitudinal adjustment at 410. Rotational alignment may be applied to align local tangents by rotating one or both objects, or by using one object to modify the local shape of the other. In another example at 408, the position and orientation of the catheter elements may be determined by tracking the catheter elements of a catheter assembly, applying a likely curve of the catheter assembly using reduced bending energy as determined from catheter parameter data 212, and again finding the position and orientation while constrained to the likely curve. This exemplary process may be repeated.

[0065] One or more catheters of the device model of the catheter element may be aligned and adjusted. Upon determining the lateral alignment at 408 and the longitudinal alignment at 410, a weight may be assigned to each of the multiple device models of the catheter element based on the confidence that the tracked catheter element is at a location in space relative to the heart as represented in the tracking. Generally, the confidence in the tracking of the two elements may be used to weight the operations applied to each element to affect the desired constraint. For example, magnetic tracking is relatively accurate and faithfully represents the location of the catheter element location in space relative to the heart. If the catheter is configured for magnetic tracking and the sheath is configured for impedance tracking, an approach would be to assign a high confidence value (e.g., 1.0) to the device model of the catheter, and the device model of the sheath would be laterally aligned to the tracked location of the device model of the catheter, taking into account the relative accuracy of the magnetic tracking. If the catheter is configured for impedance tracking and the sheath is configured for impedance tracking, the catheter device model may be given a confidence value less than 1.0 and the sheath device model may be given a confidence value less than 1.0 based on information about the likelihood of accurate tracking from the catheter parameter data.

[0066] FIG. 5 shows an exemplary catheter assembly 500 having multiple separate distal sections of multiple catheter elements, including a catheter 502 and a sheath 504, which may be one example of the catheter 105 and sheath 110 of FIG. 1. The distal section of the catheter 502 includes a shaft 506 disposed on a longitudinal axis A1, the shaft 506 having a proximal region 508 and a distal region 510. The distal region 510 includes multiple electrodes 512 for ablating tissue. The multiple electrodes 512 in this example include a tip electrode 514 and ring electrodes 516, 518 carried on a distal portion 520 of the shaft 506. While the catheter shaft 506 may be flexible along the entire length of the distal section, in the example shown, the distal portion 520 carrying the electrodes 512 is rigid and not bendable. The catheter shaft 506 may include a navigation device (not shown) within or near the distal portion 520 of the shaft 506 for magnetic tracking. The distal portion of the sheath 504 defines a lumen along the longitudinal axis A2 that can accommodate the catheter 502. The distal portion of the sheath 504 includes a proximal region 528 and a distal region 530. The distal region 530 includes multiple ring electrodes 532, 534 for impedance tracking and sheath detection of the catheter electrodes 512. In one example, the electrophysiology system 50 applies sheath detection to determine whether the catheter distal section 520 is disposed within the sheath 504 and / or the number of catheter electrodes 512 that are exposed from the sheath 504. An example of sheath detection is described in U.S. patent application Ser. No. 16 / 686,591, filed Nov. 18, 2019, to Salehi et al., and assigned to the present assignee, entitled "SHEATH DETECTION USING LOCAL IMPEDANCE INFORMATION," the contents of which are incorporated by reference herein to the extent not inconsistent therewith. In this example, the distal portion of sheath 504 is flexible throughout its entire length, including sheath distal region 530, except for a possibly relatively small distal-most portion.

[0067] The EAM system 70 generates multiple device models of the distal portions of the catheter elements 502, 504 for processing. In one example, the device models include data from the distal tip of the catheter element to the proximal boundary of the articulatable section or distal portion of the catheter element. For example, the device model of each catheter element 502, 504 includes one point and three device segments. The point is the tip of the catheter element. The most distal point of the catheter element is the tip, such as catheter tip 540-1 and sheath tip 550-1. The device segments of the catheter element device model include a head segment, a neck segment, and a body segment. The head segment 542, 552 comprises the most distal rigid tip segment of the catheter element. In the catheter 502, the head segment 542 is between 540-1 and 540-2. In the sheath, the head segment 552 is between 550-1 and 550-2. Neck segments 544, 554 comprise flexible, articulatable segments proximal to head segments 542, 552, respectively. In catheter 502, neck segment 544 is located between 540-2 and 540-3. In sheath 504, neck segment 554 is located between 550-2 and 550-3. Body segments 546, 556 comprise the proximal-most flexible segments of the catheter elements. In catheter 502, body segment 546 is located between 540-3 and 540-4. In sheath 504, body segment 556 is located between 550-3 and 550-4.

[0068] Based on the electrode position values ​​and electrode tangent values, the EAM system can constrain each device segment of the device model to a geometric shape. In one example, catheter elements used in electrophysiology procedures are classified as either rigid or flexible devices. A rigid device is one in which all electrodes are located on the head segment, such as the exemplary catheter 502, and a flexible device is one in which all electrodes are located on the neck segment, such as the exemplary sheath 504. The geometric shapes used to represent device segments may include points, lines, circles, any other defined geometric shapes, or splines. For a rigid device, such as the catheter 502, the device model is fitted as follows: (a) the head segment 542 is fitted as a line relative to the electrodes 512; (b) the tip 540-1 is fitted as a point at the end of the head segment 542; and (c) the neck segment 544 is fitted as a spline (where the neck of the catheter 502 extends from the sheath 504). For a flexible device, such as the sheath 504, the device model is fitted as follows: (a) the head segment 542 is fitted as a line relative to the electrodes 512; (b) the tip 540-1 is fitted as a point at the end of the head segment 542; and (c) the neck segment 544 is fitted as a spline (where the neck of the catheter 502 extends from the sheath 504). (a) The neck segment 554 is fitted as a spline (in other examples, the segment can be fitted as a circle or a line), (b) the head segment 552 is fitted as a line using a tangent to the distal-most electrode 532, and (c) the tip 550-1 is fitted as a point at the end of the head segment 552. For flexible devices, the spline fitted to the electrodes can take the shortest path connecting the electrodes, subject to smoothness constraints such as continuity of the first and second spatial derivatives. However, this path may not satisfy, for example, the known distance between the electrodes. To satisfy this constraint, a simple geometric object such as a circle can be used to constrain the spline over some or all of the flexible device segment. In one example, a geometric object such as a circle can be used to add additional points that constrain the spline to fit using only points. In another example, a geometric object such as a circle can be used to calculate a tangent that constrains the spline to fit using both points and tangents.In another example, a geometric object such as a circle may be used to calculate tangents and inter-electrode distances that constrain the spline to fit using points, tangents, and inter-electrode distances.

[0069] In the following example, catheter 502 is tracked by magnetic tracking and sheath 504 is tracked by impedance tracking, and the catheter tracking is given a confidence value of 1.0, so that during application of process 400, the sheath 504 device model is adjusted and aligned to match the model of catheter 502. In another embodiment, the sheath tracking is given a confidence value of 1.0, and the catheter device model is adjusted to align and match the sheath model. In another embodiment, both devices are given confidence values ​​between 0.0 and 1.0 due to noise levels or other indicators of tracking accuracy, and the two device models are shifted toward each other (e.g., toward a noise-weighted average). Catheter assembly 500 also performs sheath detection.

[0070] Sheath detection data may be included with catheter position data 210, including the state or number of exposed electrodes on the catheter 502. For example, the sheath detection data may report covered, partially covered, and uncovered states. A covered state is when the sheath 504 completely covers the catheter 502, such as when the sheath 504 covers all of the electrodes 512 on the catheter 502. A partially covered state is when some, but not all, of the electrodes 512 on the catheter 502 are exposed through the sheath 504. An uncovered state is when all of the electrodes 512 on the catheter 502 are exposed through the sheath 504. In other embodiments, the coverage state may be determined by purely geometric means that quantify the geometric relationship between two device models. In other cases, the coverage state may be initially determined by input from a user, and state transitions may be implemented by a state machine that uses geometric information to control transitions between adjacent states.

[0071] In the covered state, a constraint is applied to the catheter elements when the catheter tip 540-1 advances (distally) beyond the most proximal sheath electrode 532. The point on the sheath body 556 closest to the tip of the catheter head 542 is determined. The device model of the sheath body 556 is translated to be coaxial with the closest point of the device model of the catheter head 542. With respect to the same axis in space, the two device models are constrained to intersect at that point and have parallel tangents at that point. The sheath tip 550-1 is also adjusted to match the number of exposed electrodes 512, which is zero in the covered state. To translate the device model of the sheath 504 to the device model of the catheter 502 in the covered state (which involves transforming vectors from one point to another), the device model of the sheath body 556 is moved laterally relative to the device model of the catheter head 542 and longitudinally to satisfy the sheath detection of no exposed electrodes. Also, the device model of the sheath 504 is rotated or otherwise modified about the tip of the catheter device model to match the local tangent to the catheter 502 .

[0072] In the partially covered state, the device model of sheath head 552 is translated to be coaxial with the device model of catheter head 542, and the device model of sheath tip 550-1 is translated to expose the number of electrodes dictated by the sheath detection data. To translate the device model of sheath 504 to the device model of catheter 504 in the partially covered state (which involves transforming a vector from one point to another), the translation is defined by the shortest vector between the device model of sheath tip 550-1 and the device model of catheter head 542. The device model of sheath 504 is translated longitudinally to satisfy the sheath detection data that the appropriate number of electrodes is exposed. Additionally, the device model of sheath tip 550-1 is rotated or otherwise modified about the device model of catheter tip 540-1 to match the local tangent of catheter tip 540-1.

[0073] In the uncovered state, a constraint is applied to the device models of the catheter elements 502, 504 such that the protrusion of the catheter tip 540-1 is less than the boundary of the catheter neck 544. The device model of the sheath head 552 is translated to match the articulation of the device model of the catheter neck 544. The device model of the sheath tip 550-1 is also adjusted to match the number of exposed electrodes 512, which is all electrodes in the uncovered state. In the covered state, to translate the device model of the sheath 504 to the device model of the catheter 502 (which involves transforming vectors from one point to another), the device model of the sheath tip 550-1 is moved laterally relative to the device model of the catheter head 542, and the device model of the sheath tip 550-1 is moved longitudinally to satisfy sheath detection of all exposed electrodes. Additionally, the device model of sheath tip 550-1 is rotated or otherwise modified about the device model of catheter tip 540-1 to match the local tangent.

[0074] 6A-6D illustrate an exemplary embodiment of process 400 applied to a catheter assembly 500. In the exemplary implementation shown, catheter 502 is tracked using magnetic tracking and sheath 504 is tracked using impedance tracking. In this case, the tracking of catheter 502 is given a confidence value of 1.0, so during application of process 400, the device model of sheath 504 is adjusted and aligned to match the determined position of the device model of catheter 502. Additionally, electrophysiology system 50 includes sheath detection technology, and process 400 implements the use of sheath detection data as part of catheter position data 210.

[0075] 6A shows the actual position of catheter assembly 500 in space and deployed within a heart chamber. Catheter assembly 500 includes multiple coaxially arranged catheter elements, such as catheter 502 and sheath 504. Sheath 504 defines an elongate lumen within which catheter 502 is disposed. Catheter 502 and sheath 504 are movable relative to one another along axis A10, and as shown, catheter 502 protrudes from sheath 504 such that catheter tip 540-1 extends beyond sheath tip 550-1.

[0076] 6B shows a visual representation of a device model catheter assembly 600 constructed for independent tracking of catheter elements 502, 504 prior to application of process 400. The device model catheter assembly 600 includes a device model for catheter 602 and a device model for sheath 604 corresponding to catheter 502 and sheath 504, respectively. FIG. 6B shows an exaggerated representation of the divergence of the device models of catheter elements 602, 604 for illustrative purposes. The device model for catheter 602 includes a device model catheter tip 640-1, and the device model for sheath 604 includes a device model sheath tip 650-1. As shown, the device model for catheter 602 is laterally displaced from the device model for sheath 604 at a starting point prior to application of process 400. Also as shown, the device model of catheter 602 is positioned along axis A12, and the device model of catheter 604 is positioned along axis A14; axes A12 and A14 are not coincident but are deflected by rotational displacement before applying process 400. Although catheter assembly 500 is coaxial within the heart, the device model of catheter 602 and the device model of sheath 604 appear to float and appear to be at different positions in space, following independent tracking. Process 400 aligns the device model of sheath 604 laterally with respect to the device model of catheter 602 at the location of the device model of catheter 602. For example, axes A12 and A14 of device models 602 and 604 in the figure are first made parallel and then superimposed. Process 400 adjusts and aligns the device model of sheath 604 longitudinally with respect to the device model of catheter 602 at the location of the device model of catheter 602.

[0077] 6C shows a visual representation of process 400 (e.g., at 408) in which the device model catheter 602 and device model sheath are laterally aligned. In this example, the position of the device model of the sheath 604 has been translated to the position of the catheter 602 to correct for deviation. Additionally, the device model of the sheath 604 has been rotated to the position of the catheter 602 to correct for deflection. In this example, axes A12 and A14 now include coincident, intersecting, and parallel tangents. Also, as shown, the device model of the catheter 602 protrudes from or is still longitudinally or axially displaced from the device model of the sheath 604.

[0078] FIG. 6D shows a visual representation of process 400 (e.g., 410) in which the device model catheter 602 and device model sheath are longitudinally aligned. In this example, to correct for protrusion, the position of the device model of the sheath 604 is translated to the position of the catheter 602 on axis A14. This correction may be based on sheath detection data. As shown, axes A12 and A14 are coincident. As shown in FIG. 6D, the deviation, deflection, and protrusion have been corrected, and the device model of the catheter assembly 600 may be provided for presentation in a visualization display at 412.

[0079] Various modifications and additions can be made to the exemplary embodiments described without departing from the scope of the present disclosure. For example, while the above embodiments refer to particular features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the claims, together with all equivalents thereof.

Claims

1. 1. A system for use in electrophysiology procedures, comprising: an elongate catheter assembly having a tracking sensor; a controller, tracking a plurality of catheter assembly positions within the organ based on a plurality of electrical signals from the tracking sensors; determining a first catheter assembly position based on a first electrical signal of the plurality of electrical signals, and determining a second catheter assembly position based on a second electrical signal of the plurality of electrical signals; constraining the second position by the first position; and the controller configured to generate an anatomical map of the organ for the electrophysiological treatment using a visualization of the catheter assembly with the second position constrained by the first position.

2. The system of claim 1 , wherein the controller is configured to place a tag representing an anatomical landmark on the anatomical map of the organ at the first catheter assembly location.

3. The system of claim 2 , wherein the anatomical landmark is the interatrial septum.

4. The system of claim 1 , wherein the controller is configured to track the catheter assembly independent of anatomical landmarks.

5. 5. The system of claim 1, wherein the controller is configured to track the multiple catheter assembly positions of the catheter assembly via the tracking sensor using a tracking method over time as the catheter assembly passes through the heart.

6. The system of claim 1 , wherein the controller is configured to substantially simultaneously track the plurality of catheter assembly positions of the catheter assembly via the tracking sensors using a tracking method.

7. 7. The system of claim 1, wherein the first catheter assembly position comprises a first position in space and a first tangent, and the second catheter assembly position comprises a second position in space and a second tangent.

8. The system of claim 1 , wherein the controller is configured to constrain the first position to the second position using bending energy data related to bending energy of the catheter assembly.

9. The system of claim 1 , wherein the controller is configured to constrain the first location to the second location via a path.

10. The catheter assembly includes a plurality of coaxially arranged catheter elements, the plurality of catheter elements including a first catheter element and a second catheter element, the first catheter element defining an elongate lumen, the second catheter element being disposed within the lumen, the first and second catheter elements being relatively movable along an axis, the first catheter element including a first tracking sensor, and the second catheter element including a second tracking sensor; The controller generating a first position of the first catheter element based on a first electrical signal of the plurality of electrical signals, and generating a second position of the second catheter element based on a second electrical signal of the plurality of electrical signals; laterally aligning the first location with the second location based on lateral and rotational displacements determined from the first location and the second location; The system of claim 1 , configured to longitudinally adjust the first position relative to the second position based on detection of the first tracking sensor by the second tracking sensor.

11. 11. The system of claim 10, wherein the first catheter assembly position comprises a first position in space and a first tangent line, and the second catheter assembly position comprises a second position in space and a second tangent line.

12. 12. The system of claim 11, wherein the first location and the first tangent are laterally aligned with the second location and the second tangent based on a lateral deviation and a rotational deflection determined from the first tangent and the second tangent.

13. 13. The system of claim 11 or 12, wherein the controller is configured to longitudinally adjust the first position relative to the second position based on sheath detection.

14. 14. The system of claim 10, wherein the controller is configured to track the first catheter element via impedance tracking and the second catheter element via magnetic tracking.

15. 15. The system of claim 10, wherein the controller is configured to laterally align the second position to coincide with the first position.

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