Automated pulmonary vein anatomic characterization-based assistance and guidance of expandable catheter

Abstract

The present invention is entitled "Automatic Pulmonary Vein Anatomical Characterization for Fitting and Guiding Expandable Catheters". The invention provides a method comprising using anatomical data to calculate multiple cross-sectional shapes of the lumen of an organ within a patient's body at multiple corresponding locations along a medial axis of the lumen. One or more locations on the medial axis are identified at which a given expandable frame of the catheter will fit the cross-sectional shape. The one or more identified locations are presented to a user.

Description

Technical Field

[0001] This invention relates generally to medical probes, and more specifically, to methods of using balloon catheters. Background Technology

[0002] Various methods for estimating the cross-sectional geometry of a lumen to facilitate catheter-based treatments are reported in patent literature. For example, U.S. Patent Application Publication 2009 / 0182287 describes an apparatus, system, and method for identifying the location of intraluminal structures and medical devices during non-surgical medical techniques (such as cardiac ablation) by determining the intraluminal conductivity and / or cross-sectional area at multiple locations within a body cavity. In one embodiment, when a clinician manipulates a balloon catheter, the manipulation relatively reflects the changing conductivity of the lumen, and thus its changing cross-sectional area.

[0003] For example, U.S. Patent 10,096,105 describes a method and system for automatically locating a target therapeutic structure (such as the pulmonary vein orifice) based on anatomical images. The method includes calculating the most probable path of blood flow through the pulmonary vein based on cross-sectional area minimization techniques, and calculating the pulmonary vein geometry as a function of length. For example, the pulmonary vein orifice can be located by analyzing variations in pulmonary vein size or other anatomical factors (such as absolute size). The method may include determining multiple centroids along the length of the pulmonary vein. This method may be an algorithm executed by a processing unit of a navigation system or other components of a medical system.

[0004] U.S. Patent Application Publication 2019 / 0343578 describes an electrophysiological catheter conforming to the shape of a pulmonary vein receiving arrhythmia ablation therapy and producing a consistent tissue ablation line along the length and circumference of the pulmonary vein tissue. During dilation, certain portions of the elliptical cross-sectional shape of the pulmonary vein may be subjected to excessive stress, while other portions of the pulmonary vein do not contact the ablation balloon, thereby limiting the efficacy of the ablation therapy. Therefore, aspects of this disclosure relate to an ablation balloon having a substantially elliptical shape. Summary of the Invention

[0005] The embodiments of the present invention described below provide a method comprising using anatomical data to calculate multiple cross-sectional shapes of the lumen of an organ within a patient at multiple corresponding locations along a medial axis of the lumen. One or more locations on the medial axis are identified at which a given expandable frame of a catheter will fit the cross-sectional shape. The one or more identified locations are presented to a user.

[0006] In some implementations, one or more identified locations include a continuous range of locations along the inner axis of the cavity.

[0007] In some embodiments, the calculated cross-sectional shape is orthogonal to the inner axis at the corresponding location. In other embodiments, the cross-sectional shape is elliptical.

[0008] In one implementation, identifying locations includes fitting the cross-sectional shape to the corresponding ellipse and identifying one or more locations where the ellipse has an ellipticity index greater than a predefined value, wherein the ellipticity index is defined as the maximum value of a circle.

[0009] In some embodiments, the method further includes, for at least one of the identified locations, presenting the user with an indication of the diameter of an expandable frame that will fit the cross-sectional shape of the catheter into the lumen.

[0010] In one embodiment, presenting the identified locations includes marking one or more identified locations on an internal cross-sectional view of the cavity.

[0011] In another embodiment, the lumen is a pulmonary vein (PV), and the identification location includes identifying one or more locations where a given expandable frame of the catheter will completely occlude the PV.

[0012] In some implementations, the method further includes identifying at one or more locations the orientation in which a given expandable frame of the catheter will fit the corresponding cross-sectional shape.

[0013] In some implementations, the lumen is a pulmonary vein (PV), and identifying the corresponding direction includes identifying the corresponding direction in which a given expandable frame of the catheter will completely occlude the PV.

[0014] In one implementation, the method further includes using a graphical tool to indicate to the user that the orientation of the given expandable frame is aligned at an angle to the tangent of the inner axis of the cavity at one or more locations within a pre-specified tolerance.

[0015] In another embodiment, instructing a given expandable frame to be angled aligned includes recoloring a display of electrodes positioned above the expandable frame of the catheter.

[0016] According to another embodiment of the invention, a system including a memory and a processor is also provided. The memory is configured to store anatomical data of the lumen of an organ in a patient's body. The processor is configured to (a) calculate multiple cross-sectional shapes of the lumen at multiple corresponding locations on a medial axis of the lumen based on the anatomical data, (b) identify one or more locations on the medial axis at which a given expandable frame of a catheter will fit the cross-sectional shape, and (c) present one or more identified locations to a user.

[0017] The invention will be more fully understood through the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, wherein: Attached Figure Description

[0018] Figure 1 A schematic diagram of a balloon catheter-based ablation system according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the variable cross-sectional ellipticity of the pulmonary vein (PV) anatomy according to an embodiment of the present invention;

[0020] Figure 3 According to an embodiment of the present invention, along the inner axis of PV Figure 2 A graph showing the ellipticity index and average diameter of the PV.

[0021] Figure 4 A flowchart illustrating a method for estimating the suitability and optimal location for performing a single balloon ablation in a pulmonary vein (PV) according to an embodiment of the present invention is provided.

[0022] Figure 5 This is a schematic illustration of a graphical user interface according to an embodiment of the present invention, which is configured to visually indicate at a suggested inner position of the PV. Figure 1 Recommended direction of the balloon catheter; and

[0023] Figure 6 This is a schematic illustration of a graphical user interface according to an embodiment of the present invention, configured to visually indicate ready electrodes by graphically indicating them. Figure 1 The appropriate orientation of the balloon catheter. Detailed Implementation

[0024] Overview

[0025] Various medical conditions involving the body cavity, such as drug-resistant atrial fibrillation (AF), can be treated with an expandable catheter that has a generally elliptical surface relative to the longitudinal axis of the catheter on at least a portion of the expandable frame of the catheter.

[0026] For example, the lumen can be treated by ablation or dilation using a balloon catheter or by another type of dilatant catheter used for ablation, such as a basket catheter.

[0027] In a typical AF balloon ablation procedure, the distal end of a catheter equipped with a balloon including an ablation element (e.g., an electrode) is inserted into the ostium of the pulmonary vein (PV) to ablate arrhythmogenic tissue at the ostium of the PV. For effective and safe isolation of the arrhythmia, it is preferable to ablate the entire circumference of the ostium simultaneously (i.e., in a “single” ablation).

[0028] When ablation PVs using balloon ablation catheters, results show that the success rate of a single ablation is highly correlated with the anatomical features of the PV being treated. For example, narrow or highly elliptical PVs have lower success rates than larger and more rounded PVs, often due to lower balloon occlusion. To date, ablation has been optimized primarily based on operator expertise and / or by verifying occlusion through additional modalities such as fluoroscopy.

[0029] The embodiments of the invention described below use a processor to combine the average diameter of the cavity (e.g., Figure 3 The processor determines preferred locations (e.g., regions) along the medial axis (a curve representing the average diameter of the PV) for placement of an expandable catheter, such as an expandable ablation balloon catheter. In some embodiments, the processor also determines a preferred orientation of the expandable catheter at the preferred respective locations. Embodiments use pre-acquired anatomical data of the lumen, such as an anatomical mapping of the PV, based on which the processor calculates the medial axis of the PV, and then calculates multiple cross-sectional shapes of the lumen (e.g., the PV) at multiple corresponding locations along the medial axis. In one embodiment, the calculated cross-sectional shapes are orthogonal to the medial axis at the corresponding locations.

[0030] Then, based on the cross-section, the processor identifies (e.g., estimates) one or more locations (e.g., a range of locations) where a given expandable frame of the catheter will fit the cross-sectional shape. For example, the processor may identify the location where a particular balloon best fits to occlude the lumen. In one embodiment, one or more identified locations comprise a continuous range of locations along the medial axis of the lumen. The processor typically presents one or more identified locations to the user.

[0031] The processor can estimate, for example, the cross-sectional ellipticity of the PV, where a balloon with a specific equatorial diameter will fit optimally. For example, for a single ablation, the processor can prefer the inner location where the lumen ellipticity is close to a circle and exclude the inner location with high PV cross-sectional ellipticity.

[0032] In some implementations, the processor calculates an ellipticity index as a function of the inner axis position and uses the ellipticity index to determine the most suitable PV region for locating a balloon of a given equatorial diameter at that location. For example, in one implementation, the processor determines PV regions with an ellipticity index above a certain threshold (where the ellipticity index is defined as the maximum value of a circular cross-section) suitable for single-surge balloon ablation. The processor then compares the average diameter of the PV at those regions with the diameter of an available balloon to check if a suitable balloon is available for performing a single ablation. Alternatively, the processor may determine that only segmental (e.g., fragmented) ablation can be performed to ablate the entire circumference of the PV.

[0033] In some embodiments, the processor is further configured to, for at least one of the identified locations, present to the user an indication of the diameter of the expandable frame of the catheter that will fit the cross-sectional shape of the lumen. In one embodiment, the processor is configured to present the identified locations by marking one or more identified locations on an internal cross-sectional view of the lumen.

[0034] In one implementation, the processor colors the mapping map of the PV indicating the optimal fit area. In one implementation, the color of the area is selected based on an ellipticity index higher than a predefined threshold. In another implementation, color codes are used to reflect different values ​​of the ellipticity index along the medial axis. Thus, the color display assists the operator in determining whether a single-balloon ablation procedure can be performed at the medial location of the PV and, if so, where within the medial location of the PV.

[0035] In yet another implementation, the processor uses an additional criterion of ellipticity index (e.g., using a metric to determine whether the fit is very good, good, average, or poor) to estimate the quality of the fit between the balloon and the PV anatomy (e.g., optimal fit). For example, in addition to a PV having a sufficiently large ellipticity index at the PV location, an optimal fit method can be used that requires the equatorial diameter of the balloon to give an area equal to the cross-sectional area of ​​the PV. Using such a requirement, the processor can find the optimal medial axis location that minimizes the difference between the circumference of the PV and the equatorial circumference of the balloon, where such difference depends on the ellipticity index, as described below.

[0036] In some implementations, the processor calculates the tangent of the inner curve at a preferred location, which serves as the preferred orientation of the expandable frame of the conduit at the corresponding location.

[0037] In some implementations, during invasive procedures, the position and orientation of the expandable frame of the catheter are tracked, and the user receives an indication of how accurately the catheter is positioned and guided on an anatomical mapping. To do this, the processor compares the tracking direction of the frame's longitudinal axis with the tangent on the inner side at that location and indicates whether the frame is angularly aligned with the tangent within a pre-specified angular tolerance.

[0038] Because the electrodes are typically arranged radially above the frame (e.g., the balloon membrane), proper angular alignment of the frame's longitudinal axis guides the catheter in a direction symmetrical with respect to the anatomy, allowing for more robust contact between the electrodes. In one embodiment, the processor indicates the degree of catheter orientation accuracy by graphically (e.g., coloring) showing a progressively larger number of electrodes in contact with the tissue. When all electrodes are colored (e.g., considered within tolerance by angular alignment), the user knows that the catheter is sufficiently well oriented relative to the anatomy to perform its function (e.g., balloon ablation at the pore of the PV).

[0039] Available balloon diameters for PV ablation fall within the range of approximately 15-30 mm, and during the optimal fit check, the processor identifies the most suitable balloon diameter to select. As mentioned above, and less commonly, the processor may determine that a single balloon ablation of PV is not possible because the area without PV is sufficiently round and sized to accommodate a balloon of the available diameter. In the latter case, as suggested above, the physician may select a balloon suitable for performing segmented ablation (i.e., multiple ablations).

[0040] Typically, processors are programmed with software containing specific algorithms that enable them to perform each of the processor-related steps and functions listed above.

[0041] The following detailed description should be read in conjunction with the accompanying drawings, in which the same elements are numbered the same across different drawings. The drawings (not necessarily drawn to scale) illustrate selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention by way of example rather than limitation. This description will clearly enable those skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is now believed to be the best mode for carrying out the invention.

[0042] As used herein, the term “about” or “approximately” for any numerical or numerical range indicates that a portion or collection of multiple components is permitted to perform suitable dimensional tolerances for their intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of ±10% of the enumerated values; for example, “about 90%” may refer to a range of 81% to 99% of the values. Additionally, as used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject and are not intended to limit the system or method to human use, but use of the subject matter invention in human patients represents a preferred embodiment. It should also be noted that the term “proximal” refers to a position closer to the operator, while “distal” refers to a position further away from the operator or physician.

[0043] Although the disclosed embodiments describe an elliptical inner cavity cross-section, the method can be applied to other inner cavity cross-section shapes (e.g., a twisted circle) and best-fitting non-circular balloons (e.g., a hemispherical shape).

[0044] By estimating the PV region most suitable for positioning a particular balloon, and optionally estimating the optimal orientation of the balloon in the PV region, balloon treatment, and especially balloon ablation procedures, can generally be made safer and more effective.

[0045] System Description

[0046] Figure 1This is a schematic diagram of a balloon catheter-based ablation system 20 according to an embodiment of the present invention. The system 20 includes a catheter 21, wherein, as seen in illustration 25, an ablation balloon 40, fitted at the distal end of the catheter shaft 22, is inserted by a physician 30 through a sheath 23 into the left atrium 45 of the heart 26 of a patient 28 lying on a workbench 29.

[0047] To reach the target location inside the left atrium 45 (shown as the orifice of the pulmonary vein (PV) 47), the physician 30 navigates the distal end of the shaft 22 by manipulating the shaft 22 near the proximal end of the catheter and / or deflecting it from the sheath 23. The physician 30 then manipulates the balloon 40 inside the left atrium 45 using the catheter handle 31 to access and contact the target PV 47 orifice tissue.

[0048] To navigate the balloon 40, electrical signals from the individual electrodes 44 of the balloon can be used with an electrical tracking subsystem and method called Advanced Current Location (ACL), and are implemented in various medical applications, such as in CARTO manufactured by Biosense-Webster. TM Implemented in the system. The ACL method enables tracking of the position and orientation of the catheter frame (e.g., the orientation of the longitudinal axis of the balloon catheter, see...). Figure 5 (in Chinese). The system and method are described in detail in U.S. Patent 8,456,182, the disclosure of which is incorporated herein by reference.

[0049] As mentioned above, the PV 47 orifice can have an odd-numbered cross-section (e.g., elliptical), and it is important to determine the correct inner position along the orifice region for balloon placement, i.e., where the ellipticity is minimized, in order to achieve uniform single-surge balloon ablation.

[0050] The proximal end of catheter 21 is connected to console 24, which includes a processor 41, typically a general-purpose computer. Processor 41 has suitable front-end and interface circuitry 38 for receiving signals from catheter 21, for administering treatment via catheter 21 to the heart 26, and for controlling other components of system 20. Processor 41 is programmed in software to perform the functions described herein. This software can be downloaded electronically to a computer via a network, or alternatively or additionally, it can be set and / or stored on a non-transitory tangible medium (such as magnetic storage, optical storage, or electronic storage). Specifically, processor 41 operates as disclosed herein. Figure 4 The included dedicated algorithm enables processor 41 to perform the disclosed steps, as further described below.

[0051] Figure 1The exemplary configuration shown is chosen solely for clarity of concept. Other system components and setups can be used to similarly apply the techniques disclosed in this invention. For example, system 20 may include other components and perform non-cardiac treatments.

[0052] Ablation balloon based on automated pulmonary vein anatomy characterization

[0053] Figure 2 This is a schematic diagram of the variable cross-sectional ellipticity of the pulmonary vein (PV) 47 anatomy according to an embodiment of the invention. As can be seen, at the medial axis location (a) where the openings of the left atrium 45 and PV 47 substantially join, the cross-section 56 of the PV is highly oval in shape, wherein the oval (e.g., elliptical) shape has a major axis v significantly larger than its minor axis u. As can be further seen, around the medial axis location 62, between medial locations (b) and (c), the cross-section 58 of the PV is generally circular in shape, and at the medial axis location (d), the cross-section 60 is also elliptical. As used herein, “medial axis” is used to indicate one or more central lines (or central curves) defining the surface of the lumen of an organ (such as, for example, the pulmonary vein entering the left atrium). In the context of the invention, the term “medial axis” is also referred to as “central line” or “midline”.

[0054] Ellipticity can be defined in various ways. This specification provides two useful definitions below.

[0055] The first ellipticity index O—index 1—is defined as...

[0056]

[0057] As can be seen, a circle (with v = u) has an O-exponent 1 = 100.

[0058] A slightly ovate ellipse (e.g., where v = 1.25u) has an O-index of 80. And a highly ovate ellipse (e.g., where v = 2u) has an O-index of 1 = 50.

[0059] Another definition of the ellipticity index is based on the ratio η.

[0060] Equation 1

[0061] Using η, the ellipticity exponent O - exponent 2 is defined as

[0062] Equation 2 O-exponent 2 = 100[1-2η], for η < 0.5

[0063] For O-index values ​​above 80, the two definitions of ellipticity indices are nearly identical (e.g., differing by a small percentage) and similar for most practical purposes; for example, the difference is no more than 10% for O-index values ​​above 60. Therefore, the choice of which O-index to use may depend on other considerations, such as the best-fit method used, as described below regarding the use of O-index 2. However, in cases of extreme ellipticity (e.g., for v ≥ 3u; η ≥ 0.5), O-index 1 should be used.

[0064] Now, we define an additional useful measure for PV, which is the average diameter of PV at a given inner location, said average diameter being (v+u). As can be seen, the average diameter of a circular cross-section PV is the diameter of the circle of the circular cross-section PV. Using another definition of average diameter, This results in a slightly lower average diameter, v ≤ 3u.

[0065] as follows Figure 3 As shown, given that the ellipticity index and average diameter of the PV are functions of the position of the inner axis of the PV 47, a processor such as processor 41 can identify the optimal region on the inner axis for placing an ablation balloon of a given diameter. The processor can also determine that a single balloon ablation of the PV 47 is infeasible, for example, if no region of the PV 47 is sufficiently round. A single ablation can also be considered infeasible if no balloon size is available for any region considered sufficiently round, because the lumen diameter is either too small or too large for the balloon.

[0066] Figure 3 According to an embodiment of the present invention Figure 2 The curve showing the ellipticity index and average diameter of PV 47 along its inner axis 55. (See diagram below.) Figure 3 As seen in the bottom curve, in the inner axis region between the inner axis positions (b) and (c), the ellipticity index (O-index 2) of PV 47 (referred to as the “PV O-index” in the curve (e.g., calculated by processor 41)) exceeds a value of 80. In one embodiment, this value is set as a lower threshold of the best fit criterion, making the region suitable in principle for balloon placement.

[0067] like Figure 3 As shown in the top curve, the calculated average diameter, as a function of the medial axis position within the ellipticity index, is in the range of 15 mm to 25 mm relative to the qualified area for balloon treatment (i.e., between the medial positions (b) and (c)).

[0068] Since balloon diameters between 15 mm and 25 mm are generally available, physicians are informed by the system that such balloons (e.g., balloons with a diameter of approximately 20 mm) can be used to perform a single ablation of PV 47 in the areas (b)-(c) of PV 47.

[0069] like Figure 2 As further seen, once the inner axis position 62 is determined, the processor 41 calculates the tangent 202 of the inner curve at that position. In some embodiments, this tangent is used as the target (e.g., suggested) direction of the balloon 40, such as... Figure 5 As described above. By extension, tangents can be calculated for a range of medial positions around the medial axis position 62, and each position deemed sufficient for placing an ablation balloon of a given diameter is also associated with the corresponding recommended direction of the balloon catheter.

[0070] Optimize the balloon using a circumference-based metric.

[0071] As described above, in another embodiment, the processor uses a metric above the ellipticity index to estimate the fit quality of the balloon to the anatomy. Additional metrics can be more complex than the ellipticity index. For example, using such metrics, the processor can determine whether the fit is very good, good, average, or poor. In one embodiment, an optimal fit criterion is provided, requiring the balloon's equatorial diameter to give an area equal to the cross-sectional area of ​​the elliptical PV.

[0072] Using additional metrics, the processor can find the optimal inner axis position that minimizes the difference between the circumference of the PV and the equatorial circumference of the balloon, where such a difference depends on the ellipticity index.

[0073] To define the above metric, the perimeter of an ellipse having an area πuv and a given corresponding η > 0 value (as derived mathematically by Zafary, 2009) can be written as follows:

[0074]

[0075] The same cross-sectional area of ​​the balloon is required for production, using the balloon's equatorial diameter D. The equatorial circumference of the balloon needs to be

[0076]

[0077] Note that L E >L B For all η > 0, the following metric can be defined:

[0078] Equation 3 The D value that minimizes the positive function (i.e., the metric) F(u,v) will be the diameter of the optimally fitted balloon. Such a fit can be defined with tolerances because the PV elasticity allows for less stringent fit criteria, such as the practical minimum in Equation 3.

[0079] Combining the requirement for a balloon diameter that satisfies an ellipticity index (e.g., as defined in Equation 2) above a given threshold, while simultaneously minimizing a metric (e.g., the metric F(u,v) defined in Equation 3), provides a flexible tool to determine the adequacy and availability of balloon treatment for a given PV.

[0080] The above-described optimal matching method is given by way of example, and other methods may be used, such as methods that require the same circumference of the PV and the equatorial circumference of the balloon, and minimize the differences between the corresponding areas covered by the embodiments of the present invention.

[0081] Select ablation balloon for PV

[0082] Figure 4 A flowchart illustrating a method for estimating the suitability and optimal location for performing a single balloon ablation in a pulmonary vein (PV) 47 according to an embodiment of the present invention is provided. According to the presented embodiment, the algorithm executes a process beginning with receiving a pre-acquired anatomical mapping of the PV 47 at the anatomical data receiving step 70. The pre-acquired anatomical mapping can be uploaded by the processor 47 from the memory 33 of the system 20.

[0083] In the cross-section calculation step 72, the processor 40 calculates the elliptical cross-section of PV at the PV position on the inner axis 55, such as... Figure 2 As described in [the text].

[0084] Next, at point 74 in the ellipticity exponent calculation, processor 40 uses one of the definitions given above to calculate the ellipticity exponent. The ellipticity exponent can then be plotted as a function of the inner position, such as... Figure 3 As shown in the image.

[0085] At ellipticity estimation step 76, processor 40 checks which of the inner positions has an ellipticity exponent higher than a predefined threshold, such that the ellipticity is low enough to approach the zero ellipticity of a circle.

[0086] If a location with sufficiently low ellipticity is not found, at notification step 78, processor 40 notifies physician 30 (e.g., on the display of system 20) that PV 47 is not possible to perform a single balloon ablation procedure.

[0087] At step 80 of the balloon equatorial diameter calculation, processor 40 calculates the optimal fitting equatorial diameter at the location found to satisfy the criteria of step 76. The processor can define the optimal fit using Equation 3 or another optimal fit method.

[0088] At recording step 82, processor 40 stores the PV position that meets the criteria of step 76 and the corresponding optimal matching balloon equatorial diameter in memory 33.

[0089] At balloon diameter check step 84, processor 40 checks which (if any) best-fit equatorial diameters fall within the range of useful (e.g., available) balloon diameters.

[0090] If no diameter is found to be useful, at notification step 86, processor 40 notifies physician 30 (e.g., on the display of system 20) PV 47 that a single balloon ablation procedure is not possible.

[0091] At step 88, processor 40 uses, for example, a method such as... Figure 3 The accompanying diagrams present to physician 30 the appropriate position and diameter that meet the criteria of steps 76 and 84.

[0092] At step 90, based on step 88, physician 30 selects an ablation balloon to perform a single ablation of PV 47.

[0093] Recommendations for ablation balloons based on anatomical characterization

[0094] Figure 5 As a schematic illustration of a graphical user interface according to an embodiment of the present invention, the graphical user interface is configured to visually indicate to the user at a correspondingly suggested medial position 502 of the pulmonary vein (PV). Figure 1 The recommended orientation of the balloon catheter 40 is 504. The graphical user interface is executed by the processor 41.

[0095] Figure 5 Anatomical mapping 500 of the left atrium 45 is shown, with the tracking position and orientation of the balloon 40 placed inside the ostium of PV47. The tracking orientation of the balloon catheter 40 is given by the longitudinal axis 506 of the catheter, which is defined as a direction parallel to the distal end of axis 22.

[0096] Two other PV 47s are shown, with the suggested balloon location 502 (such as...) Figure 2 Position 62) and corresponding direction 504 (such as Figure 2 The direction 202) overlaps. During procedures such as balloon ablation, physicians can use a tracking system to place the balloon in the recommended location and corresponding direction to ablate the PV.

[0097] In some implementations, a robotic arm is used to place a balloon catheter, and a processor commands the movement of the arm to bring the catheter into a tracked position and orientation with pre-specified tolerances relative to a proposed position and orientation.

[0098] Figure 6 The graphical application described herein can assist physicians in determining the positioning and guidance of the balloon as needed (either manually by the physician or automatically by a robotic arm).

[0099] GUI for optimal alignment of the ablation balloon at the selected pulmonary vein location.

[0100] Figure 6 This is a schematic illustration of a graphical user interface according to an embodiment of the present invention, which is configured to indicate graphically... Figure 1 The ready electrodes 44 of the balloon catheter 40 visually indicate to the user the appropriate orientation of the balloon catheter. As can be seen, the mapping diagram shows the balloon 40 placed inside the PV 47, which has a calculated inner axis 55, and the catheter is visually indicated to be in the appropriate position and orientation as described above, for example, by changing the color of the balloon 605 (e.g., from blue to green), recoloring the electrodes radially positioned above the expandable frame of the catheter (607), and / or underlining the gradually increasing number of electrodes ready for ablation (606).

[0101] Text and / or audiovisual instructions may also be provided.

[0102] Although the implementation scheme described herein is primarily for pulmonary vein isolation, the methods and systems described herein can also be used in other applications, such as ENT or neurological procedures.

[0103] Therefore, it should be understood that the embodiments described above are cited by way of example, and the invention is not limited to what is specifically shown and described above. Rather, the scope of the invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art. Documents incorporated herein by reference are considered an integral part of this application, except that if any terminology defined in such incorporated documents conflicts with the definitions expressly or implicitly given in this specification, only the definitions in this specification shall be considered.

Claims

1. A method of using a balloon catheter, comprising: Using anatomical data, the cross-sectional shapes of the lumens of organs within the patient's body at multiple corresponding locations on the inner axis of the lumens were calculated. Identify one or more of the locations on the inner axis where a given expandable frame of the catheter will fit the cross-sectional shape; Present the one or more identified locations to the user; as well as Using a graphical tool, the user is instructed that the given expandable frame will be aligned, within a pre-specified tolerance, with the corresponding orientation of the cross-sectional shape at an angle to the tangent of the inner axis of the cavity at one or more locations.

2. The method of claim 1, wherein, The one or more identified locations include a continuous range of locations on the inner axis of the cavity.

3. The method according to claim 1, characterized in that, The calculated cross-sectional shape is orthogonal to the inner axis at the corresponding location.

4. The method of claim 1, wherein, The cross-sectional shape is elliptical.

5. The method of claim 4, wherein, Identifying the location includes fitting the cross-sectional shape to the corresponding ellipse, and identifying one or more locations where the ellipse has an ellipticity index greater than a predefined value, wherein the ellipticity index is defined as the maximum value for a circle.

6. The method of claim 1, wherein, The method further includes, for at least one of the identified locations, presenting the user with an indication of the diameter of the given expandable frame that will fit the cross-sectional shape of the lumen of the catheter.

7. The method of claim 1, wherein, Presenting the identified locations includes marking one or more identified locations on an inner cross-sectional view of the cavity.

8. The method of claim 1, wherein, The lumen is a pulmonary vein, and identifying the location includes identifying one or more locations where the given expandable frame of the catheter will completely occlude the pulmonary vein.

9. The method of claim 1, wherein, The method includes identifying the corresponding direction at one or more locations within the said position.

10. The method of claim 9, wherein, The lumen is a pulmonary vein, and identifying the corresponding direction includes identifying the corresponding direction in which the given expandable frame of the catheter will completely occlude the pulmonary vein.

11. The method of claim 1, wherein, Instructing the given expandable frame to be angled aligned includes recoloring the display of the electrodes positioned above the given expandable frame of the catheter.

12. A balloon catheter-based ablation system, comprising: A memory configured to store anatomical data of the cavities of organs within a patient's body; as well as Processor, the processor being configured to: Based on the anatomical data, calculate the cross-sectional shapes of the cavity at multiple corresponding positions on the inner side axis of the cavity; Identify one or more of the locations on the inner axis where a given expandable frame of the catheter will fit the cross-sectional shape; Present the one or more identified locations to the user; as well as Using a graphical tool, the user is instructed that the given expandable frame will be aligned, within a pre-specified tolerance, with the corresponding orientation of the cross-sectional shape at an angle to the tangent of the inner axis of the cavity at one or more locations.

13. The system of claim 12, wherein, The one or more estimated positions include a continuous range of positions on the inner axis of the cavity.

14. The system according to claim 12, characterized in that, The calculated cross-sectional shape is orthogonal to the inner axis at the corresponding location.

15. The system of claim 12, wherein, The cross-sectional shape is elliptical.

16. The system of claim 15, wherein, The processor is configured to fit the cross-sectional shape to a corresponding ellipse and identify one or more locations where the ellipse has an ellipticity index greater than a predefined value, wherein the ellipticity index is defined as the maximum value for a circle.

17. The system of claim 12, wherein, The processor is further configured to, for at least one of the identified locations, present the user with an indication of the diameter of the given expandable frame that will fit the cross-sectional shape of the catheter within the lumen.

18. The system of claim 12, wherein, The processor is configured to present the identified locations by marking one or more identified locations on an inner cross-sectional view of the cavity.

19. The system of claim 12, wherein, The lumen is a pulmonary vein, and the processor is configured to identify the location by recognizing one or more locations along the medial axis at which the given expandable frame of the catheter will completely occlude the pulmonary vein.

20. The system of claim 12, wherein, The processor is further configured to identify the corresponding direction at one or more of the locations along the inner axis.

21. The system of claim 20, wherein, The lumen is a pulmonary vein, and the processor is configured to identify the corresponding direction by recognizing the direction in which the given expandable frame of the catheter will completely occlude the pulmonary vein.

22. The system of claim 12, wherein, The processor is configured to indicate to the user that the given expandable frame is angularly aligned by recoloring a display of electrodes radially positioned above the given expandable frame of the conduit.

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