Cardiac Ablation Systems and Software Products

Abstract

The present invention is entitled "Cardiac Map Segmentation". The present invention discloses an embodiment, which includes a cardiac ablation system, which includes: an ablation probe, the ablation probe including at least one ablation application element, the at least one ablation application element being used to ablate tissue in a chamber of the heart of a living subject; a tracking module, the tracking module being used to track the position of the at least one ablation application element within the heart; a memory, the memory being used to store a map of the chamber of the heart and storing different corresponding default ablation parameter sets for each different area of ​​the chamber; and a processing circuit, the processing circuit being configured to segment the map of the chamber into different areas, receive user input indicating the start of an ablation procedure, identify an area of ​​the chamber in contact with the at least one ablation application element in response to the tracked position, retrieve the corresponding default ablation parameter set assigned to the identified area, and apply the retrieved default ablation parameter set to control the ablation procedure.

Description

Technical Field

[0001] The present invention relates to ablation systems and, in particular, to ablation parameters. Background Art

[0002] Minimally invasive intracardiac ablation is a treatment option for various types of arrhythmias. To perform such treatment, a physician typically inserts a catheter into the heart through the vascular system, brings the distal end of the catheter into contact with myocardial tissue in an area of ​​abnormal electrical activity, and then energizes one or more electrodes at or near the distal end to produce tissue necrosis.

[0003] Many systems for intracardiac ablation therapy are commercially available, such as those provided by Biosense Webster Inc. (Irvine, California). 3 system. CARTO tracks the position and operating parameters of the distal tip of the catheter and electronically displays this information on a three-dimensional (3D) anatomical map of the heart. CARTO enables the system operator to electronically mark the ablated locations on the map and thus track the progress of the procedure.

[0004] US Patent Publication 2015 / 0294082 to Passerini et al. describes a method and system for image-based patient-specific guidance of arrhythmia treatment. A patient-specific anatomical heart model is generated from medical image data of a patient. A patient-specific cardiac electrophysiology model is generated based on the patient-specific anatomical heart model and electrophysiological measurements of the patient. One or more virtual electrophysiological interventions are performed using the patient-specific cardiac electrophysiology model. One or more pacing targets or ablation targets based on the one or more virtual electrophysiological interventions are displayed.

[0005] U.S. Patent Publication 2015 / 0065836 to Thakur et al. describes a system and method for mapping anatomical structures, the system and method comprising sensing activation signals of physiological activity using a plurality of mapping electrodes disposed in or near the anatomical structure. Patterns in the sensed activation signals are identified based on similarity measures generated between each pair of uniquely identified patterns, which are classified into groups based on correlations between corresponding pairs of similarity measures. A feature representation is determined for each group of similarity measures and is displayed as a summary graph of the feature representations.

[0006] U.S. Patent 6,317,631 to Ben-Haim et al. describes a method for modifying the contractile force of at least a portion of a cardiac chamber, the method comprising: providing a subject having a heart, the heart including at least a portion having activation; and applying a non-excitation electric field of a given duration to the portion with a delay after the activation, which results in an increase in the contractile force of at least 5%. Summary of the invention

[0007] According to an embodiment of the present disclosure, a cardiac ablation system is provided, which includes: an ablation probe, which includes at least one ablation application element, and the at least one ablation application element is configured to ablate tissue in a chamber of the heart of a living subject; a tracking module, which is configured to track the position of the at least one ablation application element within the heart; a memory, which is configured to store a map of the chamber of the heart and store different corresponding default ablation parameter sets for each of a plurality of different regions of the chamber; and a processing circuit, which is configured to segment the map of the chamber into different regions, receive user input indicating the start of an ablation procedure, identify a region of the chamber in contact with the at least one ablation application element in response to the tracking position, retrieve the corresponding default ablation parameter set assigned to the identified region in response to the user input, and apply the retrieved default ablation parameter set to control the ablation procedure.

[0008] Additionally, in accordance with an embodiment of the present disclosure, the processing circuit is configured to apply the segmentation model of the cardiac chamber to the map of the chamber, thereby generating the segmentation map of the chamber.

[0009] Furthermore, according to an embodiment of the present disclosure, the processing circuit is configured to receive at least one user correction to a segmentation of the segmentation map, and to modify the segmentation map in response to the received at least one user correction.

[0010] Additionally, according to an embodiment of the present disclosure, the processing circuit is configured to receive a user marking of the map of the chamber that divides the map into different regions, and segment the map of the chamber into different regions in response to the received user marking.

[0011] Furthermore, according to an embodiment of the present disclosure, the processing circuit is configured to receive a user-defined default ablation parameter set for each of the different regions, and in response to the region designation of each of the received user-defined default ablation parameter sets, assign the user-defined default ablation parameter sets to the different regions.

[0012] Additionally, according to an embodiment of the present disclosure, the processing circuit is configured to control the ablation probe to ablate tissue at the identified region according to the retrieved default ablation parameter set.

[0013] Furthermore, according to an embodiment of the present disclosure, the processing circuit is configured to receive a user update to the retrieved default ablation parameter set, thereby generating an updated ablation parameter set, and to control the ablation probe to ablate tissue at the identified region according to the updated ablation parameter set.

[0014] Additionally, according to an embodiment of the present disclosure, the processing circuit is configured to assign probe-specific default ablation parameter sets to each of the different regions for a plurality of different probe types, and in response to user input, retrieve probe-specific default ablation parameter sets assigned to the identified regions for the probe type of the ablation probe.

[0015] In addition, according to an embodiment of the present disclosure, the ablation probe includes multiple ablation application elements, and the processing circuit is configured to: identify a first area of ​​a cavity in contact with at least a first ablation application element among the multiple ablation application elements in response to a tracking position; identify a second area of ​​the cavity in contact with at least a second ablation application element among the multiple ablation application elements in response to the tracking position; retrieve a default ablation parameter set assigned to the first area and a default ablation parameter set assigned to the second area; and apply the retrieved default ablation parameter sets for the first area and the second area to perform an ablation procedure using the first ablation application element and the second ablation application element among the multiple ablation application elements at the first area and the second area, respectively.

[0016] In addition, according to an embodiment of the present disclosure, a default ablation parameter set for one of the different regions includes any one or more of the following: tissue thickness of a region, whether to track temperature during an ablation procedure, an ablation mode used during an ablation procedure, an irrigation rate used during an ablation procedure, a power level applied during an ablation procedure, a force applied during an ablation procedure, an ablation duration of an ablation procedure, an ablation index used during an ablation procedure, a target power, and a target temperature.

[0017] In addition, according to an embodiment of the present disclosure, the ablation mode is selected from any one or more of the following: ablation index mode, controlling ablation power according to measured temperature, applying alternating current to at least one ablation application element, applying direct current to at least one ablation application element, laser ablation, electroporation, cryoablation, and radiofrequency power ablation.

[0018] According to another embodiment of the present disclosure, a cardiac ablation method is also provided, the method comprising: tracking the position of at least one ablation application element of an ablation probe, the at least one ablation application element being configured to ablate tissue in a chamber of the heart of a living subject; storing a map of the chamber of the heart; storing different corresponding default ablation parameter sets for each of a plurality of different regions of the chamber; segmenting the map of the chamber into different regions; receiving user input indicating the start of an ablation procedure; identifying a region of the chamber in contact with the at least one ablation application element in response to the tracked position; retrieving a corresponding default ablation parameter set assigned to the identified region in response to the user input; and applying the retrieved default ablation parameter set to control the ablation procedure.

[0019] Additionally, in accordance with an embodiment of the present disclosure, the method includes applying a segmentation model of the cardiac chamber to a map of the chamber, thereby generating a segmentation map of the chamber.

[0020] Furthermore, according to an embodiment of the present disclosure, the method includes receiving at least one user correction to a segmentation of the segmentation map, and in response to receiving the at least one user correction, revising the segmentation map.

[0021] Additionally, according to an embodiment of the present disclosure, the method includes receiving a user marking of the map of the chamber that divides the map into different regions, and segmenting the map of the chamber into different regions in response to receiving the user marking.

[0022] Furthermore, according to an embodiment of the present disclosure, the method includes receiving a user-defined default ablation parameter set for each of the different regions, and assigning the user-defined default ablation parameter set to the different regions in response to the region designation of each of the received user-defined default ablation parameter sets.

[0023] Additionally, according to an embodiment of the present disclosure, the method includes controlling the ablation of the tissue at the identified region by the ablation probe according to the retrieved default ablation parameter set.

[0024] Furthermore, according to an embodiment of the present disclosure, the method includes receiving a user update to the retrieved default ablation parameter set, thereby generating an updated ablation parameter set, and controlling the ablation of tissue at the identified region by the ablation probe according to the updated ablation parameter set.

[0025] Additionally, according to an embodiment of the present disclosure, the method includes assigning a probe-specific default ablation parameter set to each of the different regions for a plurality of different probe types, and in response to user input, retrieving the probe-specific default ablation parameter set assigned to the identified region for the probe type of the ablation probe.

[0026] In addition, according to an embodiment of the present disclosure, the ablation probe includes multiple ablation application elements, and the method also includes: identifying a first area of ​​a cavity in contact with at least a first ablation application element among the multiple ablation application elements in response to the tracking position; identifying a second area of ​​a cavity in contact with at least a second ablation application element among the multiple ablation application elements in response to the tracking position; retrieving a default ablation parameter set assigned to the first area and a default ablation parameter set assigned to the second area; and applying the retrieved default ablation parameter sets for the first area and the second area to perform an ablation procedure using the first ablation application element and the second ablation application element among the multiple ablation application elements at the first area and the second area, respectively.

[0027] In addition, according to an embodiment of the present disclosure, a default ablation parameter set for one of the different regions includes any one or more of the following: tissue thickness of a region, whether to track temperature during an ablation procedure, an ablation mode used during an ablation procedure, an irrigation rate used during an ablation procedure, a power level applied during an ablation procedure, a force applied during an ablation procedure, an ablation duration of an ablation procedure, an ablation index used during an ablation procedure, a target power, and a target temperature.

[0028] In addition, according to an embodiment of the present disclosure, the ablation mode is selected from any one or more of the following: ablation index mode, controlling ablation power according to measured temperature, applying alternating current to at least one ablation application element, applying direct current to at least one ablation application element, laser ablation, electroporation, cryoablation, and radiofrequency power ablation.

[0029] According to another embodiment of the present disclosure, a software product is also provided, which includes a non-transitory computer-readable medium storing program instructions therein, which, when read by a central processing unit (CPU), causes the CPU to: track the position of at least one ablation application element of an ablation probe, the at least one ablation application element being configured to ablate tissue in a chamber of the heart of a living subject; store a map of the chamber of the heart; store different corresponding default ablation parameter sets for each of a plurality of different regions of the chamber; segment the map of the chamber into different regions; receive user input indicating the start of an ablation procedure; identify a region of the chamber in contact with the at least one ablation application element in response to the tracked position; retrieve a corresponding default ablation parameter set assigned to the identified region in response to the user input; and apply the retrieved default ablation parameter set to control the ablation procedure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0031] Figure 1is a schematic diagram of an invasive medical procedure using a device according to an embodiment of the present invention;

[0032] Figure 2 For use in the embodiment according to the present invention Figure 1 A schematic diagram of a distal end of a probe in a device;

[0033] Figure 3 To include Figure 1 A flowchart of exemplary steps in a method of preparing a device for use with the device;

[0034] Figure 4 For Figure 1 Schematic diagram of map segmentation for use with a device;

[0035] Figure 5 For Figure 1 Schematic diagram specifying the area in which the equipment is to be used;

[0036] Figure 6 To include Figure 1 A flowchart of exemplary steps in a segmentation and region designation method for use with a device;

[0037] Figure 7 To include Figure 1 A flowchart of exemplary steps in an alternative segmentation and region designation method for use with a device;

[0038] Figure 8 To include Figure 1 A flowchart of exemplary steps in an ablation method for use with a device;

[0039] Fig. 9 For Figure 1 Schematic diagram of a balloon catheter used with the device;

[0040] Fig.10 For Figure 1 a cross-sectional view of a balloon catheter disposed in a chamber of the heart for use with the device; and

[0041] Fig.11 To include the use of Figure 1 Flow chart of exemplary steps in a method of ablation using a multi-ablation element probe for use with the device. DETAILED DESCRIPTION

[0042] Overview

[0043] During an ablation procedure, the physician may set ablation parameters such as, by way of example only, power, duration of ablation, flushing rate of cooling fluid, contact force between the ablation catheter and the tissue being ablated. To set the parameters, the physician has to mentally manage the necessary parameter settings without guidance from the ablation device and complete the settings manually.

[0044] This parameter setting process is time consuming and requires the physician to make decisions regarding the medical issue and the control of the ablation device before, during, and after each ablation.

[0045] This process can lead to errors due to the number of decisions that need to be taken. Additionally, time is often of the essence in cardiac procedures.

[0046] The above problems can be magnified as ablation devices become more diverse. For example, the catheters can be focal ablation catheters or balloon-type catheters, each with its own specific electrodes. In such cases, the setting of ablation parameters (which can include consideration of the individual patient's anatomical structure) becomes more cumbersome and prone to error.

[0047] Embodiments of the present invention provide a default set of ablation parameters to be used in an ablation procedure based on the tracked location of the ablation probe. Thus, for example, if the ablation probe is in contact with one region of cardiac tissue, a default set of ablation parameters for that region is retrieved for use with the ablation procedure in that region. When the ablation probe is in contact with a second region of cardiac tissue, a different set of ablation parameters for the second region is retrieved for use with the ablation procedure in that second region.

[0048] The physician may be provided with an option to modify one or more settings in the retrieved default ablation parameter set prior to performing ablation with the ablation probe.

[0049] Prior to initiating an ablation procedure, a map of the chambers of the patient's heart is acquired from an image of the heart (eg, from CT or MRI) or from mapping performed using a mapping tool inserted into the patient's heart chambers.

[0050] The map of the chambers of the heart can be automatically segmented by applying the segmentation model of the heart chambers to the map of the chambers of the patient's heart, thereby generating a segmented map of the chambers of the patient's heart. The segmented map can also include labels marking various regions of the heart (e.g., posterior wall, anterior wall, etc.).

[0051] The segmentation map may be reviewed by a physician and optionally corrected by the physician prior to use. In some embodiments, the segmentation map may be used without prior review.

[0052] In other embodiments, a map of chambers of the patient's heart may be segmented based on user markings and labels of the map provided by a physician using a suitable user interface.

[0053] The default ablation parameter sets may be assigned to various different regions of the segmented map based on the labels of the various regions. For example, a default ablation parameter set for the posterior wall is assigned to the region labeled as the posterior wall. Alternatively, the default ablation parameter sets may be manually assigned to the different regions by the physician. In other embodiments, the default ablation parameter sets may be automatically assigned by the system, wherein the physician is provided with the option of reviewing and correcting the various automatically assigned settings.

[0054] The default set of ablation parameters for a region may include any one or more of the following: tissue thickness of the region; whether to track temperature during an ablation procedure; an ablation mode used during an ablation procedure; an irrigation rate used during an ablation procedure; a power level applied during an ablation procedure; a force applied during an ablation procedure; an ablation duration for an ablation procedure; an ablation index used during an ablation procedure (see Figure 1 ), a target power, and / or a target temperature, by way of example only.

[0055] The ablation mode may be selected from any one or more of the following: an ablation index mode; controlling ablation power based on measured temperature; applying alternating current to at least one ablation application element; applying direct current to at least one ablation application element; laser ablation; electroporation; cryoablation; and / or radiofrequency power ablation, by way of example only.

[0056] For example, a lower power setting may be recommended for the posterior wall compared to the anterior wall because the posterior wall is located near the esophagus, which may be damaged by heat during ablation. Similarly, it may be recommended to perform ablation while adjusting the ablation power based on monitored tissue temperature for the posterior wall, while an ablation index may be recommended for the anterior wall. Other factors and examples are described in more detail with reference to the system description included below.

[0057] The default ablation parameter set may be probe-specific to account for the different characteristics and capabilities of different ablation probe types. Thus, when retrieving a default ablation parameter set for a region, a probe-specific default ablation parameter set for that region may be retrieved. For example, a focal catheter may default to using an ablation index threshold or temperature-guided ablation setting for that region, while for a balloon catheter, the power settings for the individual electrodes may be set based on the region and the current position of each electrode within that region.

[0058] In some embodiments, two or more default ablation parameter sets may be retrieved based on a multi-electrode catheter. For example, if some of the electrodes of the multi-electrode catheter are in contact with a first area of ​​tissue, but other electrodes of the multi-electrode catheter are in contact with a second area of ​​tissue, the default ablation parameter set for the multi-electrode catheter for the first area and the default ablation parameter set for the multi-electrode catheter for the second area are retrieved for ablation of the electrodes in contact with tissue in the first area and the second area, respectively. The multi-electrode catheter described herein may be generalized to a multi-ablation application element catheter using any suitable ablation method, such as, but not limited to, laser ablation, electroporation, and / or cryoablation. Similarly, the probe described above may utilize any suitable ablation method, such as, but not limited to, laser ablation, electroporation, cryoablation, and / or radiofrequency ablation.

[0059] The default ablation parameter set may also be customized for different ablation modes used by the ablation probe. For example, if the probe is using an ablation index, one default ablation parameter set may be retrieved, and if the probe is using another ablation mode, another default ablation parameter set may be retrieved. Alternatively, the default ablation parameter set for each region may be a global parameter set that includes default ablation parameters for multiple ablation modes and / or probes, such that relevant default ablation parameters may be extracted from the global parameter set depending on the ablation mode and / or probe type being used.

[0060] While physicians can override the default settings, embodiments of the present invention automatically add an extra layer of security without manual intervention.

[0061] System Description

[0062] Documents incorporated herein by reference are to be considered an integral part of this application, except that, to the extent any term is defined in these incorporated documents in a manner that contradicts a definition explicitly or implicitly made in this specification, only the definition in this specification shall prevail.

[0063] Reference Figure 1 , which is a schematic diagram of an invasive medical procedure using a cardiac ablation device 12 according to an embodiment of the present invention. Figure 2 , which is a schematic diagram of a distal end 22 of a probe 20 used in an apparatus 12 according to an embodiment of the present invention. The procedure is performed by a physician 14, and in the following description, it is assumed that the procedure includes ablation of a portion of tissue 15 of a myocardium 16 of a heart of a human patient 18.

[0064] To perform the procedure, the physician 14 inserts the probe 20 into a sheath 21 that has been pre-positioned in the lumen of the patient 18 so that the probe 20 is inserted into a chamber of the heart. The sheath 21 is positioned so that the distal end 22 of the probe 20 enters the heart of the patient 18. The distal end 22 includes a position sensor 24 that enables the position and orientation of the distal end 22 to be tracked, a force sensor 26 that measures the force applied by the distal end 22 when contacting the myocardium 16, and one or more temperature sensors 28 that measure the temperature at the corresponding position of the distal end 22. The distal end 22 also includes one or more electrodes 30 for applying radiofrequency power to the myocardium 16 in the chamber so as to ablate the myocardium 16. The one or more electrodes 30 can also be used to collect electrical potentials from the myocardium 16.

[0065] The device 12 is controlled by a system processor 46, which is located in an operating console 48 of the device. The operating console 48 includes controls for at least one user input device 49 used by the physician 14 to communicate with the processor 46. Software for the processor 46 may be downloaded to the processor 46 in electronic form, for example, over a network. Alternatively or additionally, the software may be provided via non-transitory tangible media such as optical, magnetic or electronic storage media.

[0066] The processor 46 may include a real-time noise reduction circuit 45, which is typically configured as a field programmable gate array (FPGA), and a subsequent analog-to-digital (A / D) signal conversion integrated circuit 47. The processor 46 may pass signals from the A / D signal conversion integrated circuit 47 to another processor, and / or may be programmed to execute at least one algorithm disclosed herein, which includes the steps described below. The processor 46 uses the noise reduction circuit 45 and the A / D signal conversion integrated circuit 47 and the features of the modules described in more detail below to execute the algorithm. The memory 43 is configured to store data used by the processor 46.

[0067] To operate the device 12, the algorithm of the processor 46 communicates with a module library 50 having a plurality of modules used by the processor 46 to operate the device 12. Thus, the module library 50 includes an electrocardiogram (ECG) module 56 that is coupled to receive signals from the body surface electrodes 31 and / or electrodes 30 so as to provide an ECG signal to the processor 46. The body surface electrodes 31 and / or one or more electrodes 30 are configured to be applied to the body of a subject (e.g., patient 18) and are configured to output signals in response to the electrical activity of the heart of the subject. The one or more electrodes 30 are applied to the heart of the body via the probe 20. The module library 50 also includes a tracking module 58 that receives and analyzes signals from the position sensor 24 and uses the signal analysis to generate the position and orientation of the distal end 22. In some embodiments, the position sensor 24 includes one or more coils that provide sensor signals in response to a magnetic field passing through the coils. In these embodiments, in addition to receiving and analyzing signals from the sensor 24, the tracking module 58 also controls the radiators 32, 34 and 36 that radiate the magnetic field that passes through the position sensor 24. The radiators 32, 34, 36 are positioned close to the myocardium 16 and are configured to radiate the alternating magnetic field into the area close to the myocardium 16. A plurality of wire connections 35 connect the operating console 48 with the surface electrodes 31 and other components (such as the radiators 32, 34, 36 and the sensor 24) so ​​that the tracking module 58 can measure the position and orientation coordinates of the probe 20. In some embodiments, the tracking module 58 is configured to calculate the relative position and relative orientation of the probe 20 relative to the heart. Magnetic position and orientation tracking is described in U.S. Patents 7,756,576 and 7,536,218, which are hereby incorporated by reference. The CARTO system manufactured by Biosense Webster (33 Technology Drive, Irvine, CA 92618 USA) uses such a magnetic tracking system. Tracking module 58 is not limited to using magnetic-based position and orientation tracking. Any suitable position and orientation tracking may be used, such as impedance-based or image-based tracking.

[0068] The device 12 may receive image data from an external imaging modality (such as an MRI unit, a CT unit, etc.) and include an image processor that may be incorporated into or called by the processor 46 to generate and display images. The image data may be registered with the tracking module 58, and a user interface screen 20 combining the received data with the position of the probe 70 may be displayed to the physician 14 on the display 61. For example, the trajectory of the distal end 22 of the probe 20 may be shown on a three-dimensional (3D) representation of the heart of the patient 18 displayed on the display 61. In some embodiments, the 3D representation of the heart may be calculated at least in part based on the mapping performed by the probe 20.

[0069] One or more electrodes 30 and body surface electrodes 31 may be used to measure tissue impedance at the ablation site as taught in US Pat. No. 7,536,218 to Govari et al., which is incorporated herein by reference.

[0070] The module library 50 also includes a force module 60, a power module 62, a flushing module 64, and a temperature module 66. The functions of these modules are explained below. The modules in the module library 50 and the processor 46 are referred to herein as processing circuitry 51.

[0071] The force module 60 receives the signal from the force sensor 26 and generates, based on the signal, a magnitude of the contact force applied by the distal end 22 on the tissue 15 (herein assumed to be measured in grams). In some embodiments, the force sensor 26 is configured so that the signal it provides to the force module 60 enables the force module 60 to assess the direction of the force applied by the distal end 22 on the tissue 15.

[0072] The power module 62 includes a radio frequency (RF) signal generator 63 that generates RF power applied by the one or more electrodes 30 to ablate tissue 15 of the myocardium 16. The processor 46 and the power module 62 are capable of regulating the power level delivered by the one or more electrodes 30 (herein assumed to be measured in watts), as well as the length of time during which the power is delivered (measured in seconds).

[0073] The irrigation module 64 controls the flow rate (herein assumed to be measured in mL / min) of the irrigation fluid (typically saline) provided to the distal end 22 by the pump 65 disposed in the operating console 48. The probe 20 includes an irrigation channel through which the myocardium 16 is irrigated. The irrigation fluid is discharged from the irrigation hole 69 in the distal end 22. The pump 65 is configured to selectively pump the irrigation fluid into the irrigation channel at an idle rate and one or more non-idle rates (higher than the idle rate) according to the state of the ablation procedure.

[0074] The temperature module 66 receives a temperature signal provided by the temperature sensor 28 (or by each temperature sensor 28). The temperature signal indicates the temperature of the myocardium at a plurality of different times. The temperature module 66 determines the temperature recorded by each of the sensors 28. Typically, in the case of multiple sensors 28, the temperature module 66 determines an average temperature of the distal end 22. In addition, in the case of multiple sensors, the temperature module 66 may generate a map of the temperature distribution of the distal end 22.

[0075] Ablation can be performed according to any suitable ablation mode, such as, but not limited to, an ablation index mode, or a mode in which the ablation power and / or irrigation rate is modified based on the temperature or rate of temperature change measured by the temperature sensor 28 or another temperature sensor disposed in any suitable location. Both modes are described in more detail below. In addition to RF ablation, the device 12 can also be modified to perform non-RF ablation or another type of ablation, such as, but not limited to, laser ablation, electroporation, and / or cryoablation.

[0076] As is known in the art, the ablation index is a function having a value that changes as ablation proceeds, and provides an estimate of the size of a lesion produced by ablating a known type of tissue. The estimate provided by the index depends on the values ​​of the contact force CF and power P measured during ablation, as well as the time period of ablation. The ablation index is described in an article entitled "Ablation Index-guided Pulmonary Vein Isolation for Atrial Fibrillation may Improve Clinical Outcomes in Comparison to Contact Force-guided Ablation" presented by Hussein et al. at the 2016 Heart Rhythm Congress, and in U.S. Patent Application 2017 / 0014181 by Bar-Tal et al. Both of these documents are incorporated herein by reference.

[0077] The following formula (1) gives the expression of the ablation index:

[0078]

[0079] where C is a constant that has a value that depends on the type of tissue being ablated; in one embodiment, C has an approximate value of 0.002,

[0080] α is an exponent which has a value typically in the range of 0.6-0.8,

[0081] β is an exponent that has a value typically in the range of 1.4-1.8,

[0082] δ is an exponent with an approximate value of 0.35, and

[0083] D is an estimate of the lesion depth obtained by ablation time t using the instantaneous contact force CF(τ) and the instantaneous power P(τ), and where τ represents the available time.

[0084] If the contact force and power are assumed to be constant, they have corresponding values ​​during the ablation procedure taking time t and Then formula (1) can be rewritten as formula (2):

[0085]

[0086] If the value on the left side of equation (2) (tissue thickness D) is known (from estimation, scanning, or other calculations), processor 46 can therefore use the right side of equation (2) to provide physician 14 with suggested values ​​of power P and time t for ablation using the measured value of force CF and the estimated value of C. Physician 14 can select one of the suggested values ​​of power P and time t to ablate tissue 15 and end ablation of tissue 15 at these values.

[0087] The ablation index serves as an aid for the physician to decide the values ​​of parameters, such as power and ablation time period, to be used during an ablation procedure.

[0088] Co-pending patent application Ser. No. 16 / 196,255 filed Nov. 20, 2018 by Govari et al. describes adjusting power and flushing based on measured temperature and rate of temperature change. Now follows an exemplary function for calculating flushing rate and power change for each of a plurality of cycles.

[0089] New flushing rate (flow) = currentFlow + ΔFlow(Temp) + ΔFlow(Power) (Formula 1), where

[0090] currentFlow is the current flushing rate,

[0091] ΔFlow(Temp)=At*ΔT+Bt*TempSlope+Ct*∫ΔT+Dt*avg(ΔT), and

[0092] ΔFlow(Power)=Ap*ΔP+Bp*PowerSlope+Cp*∫ΔP+Dp*avg(ΔP),

[0093] ΔT is the difference between TargetTemp (target temperature) and Temp (sampled temperature, which can be the average value of several sampling cycles),

[0094] TempSlope is equal to the rate of change of the sampled temperature and can be calculated from the average sample,

[0095] ∫ΔT is an integer of ΔT, and the integration time range can be varied,

[0096] avg(ΔT) is the average value of ΔT,

[0097] At is the tuning parameter of ΔT,

[0098] Bt is the tuning parameter of TempSlope,

[0099] Ct is the tuning parameter of ∫ΔT,

[0100] Dt is the tuning parameter of avg(ΔT),

[0101] ΔP is the difference between TargetPower (target power) and power (sampled power, which can be the average value of several sampling periods),

[0102] PowerSlope is the rate of change of the sampled power and can be calculated from the average samples,

[0103] ∫ΔP is an integer of ΔP, and the integration time range can be varied,

[0104] avg(ΔP) is the average value of ΔP,

[0105] Ap is the tuning parameter of ΔP,

[0106] Bp is the tuning parameter of PowerSlope,

[0107] Cp is the tuning parameter of ∫ΔP,

[0108] Dp is the tuning parameter of avg(ΔP).

[0109] The initial flushing rate (flow rate) can be calculated as follows:

[0110] Flow=FlowLow+(FlowHigh-FlowLow) / (PowerHigh-PowerLow)*(TargetPower–PowerLow)(Formula 2), where

[0111] FlowLow is the lowest flushing rate provided by the system.

[0112] FlowHigh is the highest flushing rate provided by the system.

[0113] PowerLow is the lowest power provided by the system, and

[0114] PowerHigh is the highest power provided by the system.

[0115] Example ranges and values ​​for various parameters are given below. However, it should be noted that these values ​​may be any suitable values ​​even outside the ranges given below.

[0116] parameter Example Range Example Value ∫ΔT 0.5sec to 2sec 1sec Avg(ΔT) 1sec to 5sec 2sec At -0.9 to -0.1 -0.5 Bt -0.9 to -0.1 -0.3 Ct 0 to 0.1 0.015 Dt -0.9 to 0 -0.05 ∫ΔP 0.5sec to 2sec 1sec Avg(ΔP) 1sec to 5sec 2sec Ap 0.1 to 0.9 0.3 B 0.1 to 0.9 0.2 Cp -0.1 to 0 0 Dp 0 to 0.9 0

[0117] The example ranges and values ​​above assume that ΔT is equal to TargetTemp (target temperature) minus Temp (sampled temperature), and ΔP is TargetPower (target power) minus Power (sampled power). The example ranges and values ​​given above for integration refer to example upper limits for integration, where the lower limit for integration is 0 seconds. The example ranges and values ​​for Avg(ΔT) and Avg(ΔP) refer to example sampling time ranges for calculating averages.

[0118] It should be noted that the parameters may be floating point numbers, and any of the parameters may optionally be averaged over a period of time which may vary. The new flush rate may be a floating point number with a limited range.

[0119] In some embodiments, the ablation power may be varied such that a target temperature measured by one or more temperature sensors is maintained. Varying different ablation parameters based on the measured temperature may be referred to as "temperature-guided ablation."

[0120] References below Figure 3-11 The description of describes various exemplary methods for providing a default set of ablation parameters for use in an ablation procedure. The ablation procedure may be performed using the default set of ablation parameters described above with reference to Figure 1 and Figure 2 The apparatus 12 and probe 20 described above, or various modifications of the apparatus 12 and probe 20 and an operating console 48 (e.g., using different types of ablation probes including one or more ablation electrodes, or using different ablation methods in addition to or in lieu of RF ablation) are performed. By way of example only, additional ablation methods may include laser ablation, electroporation, and / or cryoablation. The ablation probe 20 may include at least one ablation application element configured to ablate tissue 15 in a chamber of the heart of a living subject (e.g., patient 18). By way of example only, one or more ablation application elements may include an ablation electrode, a laser device, and / or a cryotube. The ablation probe 20 may optionally include one or more of the following: a force sensor, a temperature sensor, a position sensor, and an irrigation system, as described above with reference to Figure 1 and Figure 2 In other embodiments, in addition to or in place of the above reference Figure 1 and Figure 2 In addition to the sensors described above, the ablation probe 20 may also include other sensors. In some embodiments, the ablation probe 20 may not include an irrigation system.

[0121] Reference Figure 3 , which includes Figure 1 Flowchart 70 of exemplary steps in a preparation method for use with device 12 .

[0122] Processor 46 is configured to store a map of the chambers of the heart in memory 43 ( Figure 1 ) (block 72). The map may be derived from CT, MRI or other imaging techniques, or may be provided using a mapping probe within a chamber of the heart.

[0123] Processor 46 is configured to segment the map of the chamber into different regions (block 74). Segmenting the map may be performed automatically, semi-automatically, or manually. Figure 4-7 Let's describe the segmentation map in more detail.

[0124] The processor 46 is configured to assign a default ablation parameter set to each of the different regions (box 76). In some embodiments, each default ablation parameter set may include default ablation parameters for different probe types and / or different ablation modes used by the ablation probe 20. In other embodiments, the processor 46 is configured to assign probe-specific default ablation parameter sets to each of the different regions for a plurality of different probe types. The default ablation parameter sets may also be customized for different ablation modes used by the ablation probe. For example, if the probe is using an ablation index, one default ablation parameter set may be retrieved, and if the probe is using another ablation mode, another default ablation parameter set may be retrieved. Reference Figure 6 The assignment of default ablation parameter sets to different regions is described in more detail.

[0125] By way of example only, a default set of ablation parameters for one of the different regions may include any one or more of: tissue thickness of the region; whether temperature is tracked during an ablation procedure; an ablation mode used during an ablation procedure; an irrigation rate used during an ablation procedure; a power level applied during an ablation procedure; a force applied during an ablation procedure; an ablation duration of the ablation procedure; an ablation index used during an ablation procedure; a target power; and / or a target temperature.

[0126] By way of example only, the ablation mode may be selected from any one or more of the following: an ablation index mode; controlling ablation power based on measured temperature; applying alternating current to at least one ablation application element; applying direct current to at least one ablation application element; laser ablation; electroporation; cryoablation; and / or radiofrequency power ablation.

[0127] By way of example, the ablation power applied near the posterior wall may be adjusted based on a measured temperature measured by a probe or using a sensor disposed near the esophagus. Thus, a temperature-driven ablation mode may be more suitable for the posterior wall, while other ablation methods, such as ablation indices, may be used in other areas of the cavity. As another example, ablation of appendages should be avoided as much as possible, so the power or ablation index in this area may be set to a low value. As another example, the ablation index value may be set higher for the anterior wall and lower for the posterior wall. Typically, the ablation index value may be set based on the estimated or actual thickness of the tissue in the corresponding area. By way of example only, the flushing rate may also be set to a higher value for the posterior wall compared to other areas. In general, the ablation technique may depend on the region, so that the ablation mode that is most effective for a particular region is included in the default ablation parameter set for that region.

[0128] For example, different default settings for the back wall, front wall, and top areas could be as follows:

[0129] Posterior wall—90 W ablation power, 4 s ablation duration, 2 g or more contact force;

[0130] Anterior wall—35W ablation power, 550 unit ablation index threshold, 15 ml / sec irrigation rate, and 5 g or more contact force; and

[0131] Top - 45W ablation power, 450 unit ablation index threshold, 15 ml / sec irrigation rate, 5 g or more contact force.

[0132] Default ablation parameters may be customized for different probe types as described above, since some probes may be able to perform a given ablation mode (e.g., temperature-guided ablation) while other probes may not. Some probes may include elements (e.g., irrigation systems, lasers, or cryotubes) while other probes may not.

[0133] Default ablation parameters for a multi-ablation administration element (e.g., a balloon catheter with multiple electrodes) may provide default settings that are different from different default ablation parameters used in the ablation administration element. In some embodiments, the default settings for different ablation administration elements may include different ablation administration elements that perform ablation using different ablation modes. Fig.11 Let me provide another example.

[0134] The processor 46 is configured to store in the memory 43 (box 78) a different corresponding set of default ablation parameters for each of a plurality of different regions of the chamber (and optionally for each probe type), thereby providing an association between the default ablation parameter sets and the regions (and probe types).

[0135] Reference Figure 4, which is Figure 1 Schematic diagram of a map segmentation method for use with the device 12 . Figure 4 Anterior and posterior views 80, 82 of a map 84 of a chamber of the heart are shown before and after being divided into different regions 88 (only some regions are labeled for simplicity). Anterior and posterior views 80, 82 may be drawn for display by processor 46 on display 61 ( Figure 1 ) or any other suitable display. The front view 80 and the rear view 82 of the map 84 can be drawn as two separate two-dimensional (2D) images, or as part of a rotatable three-dimensional (3D) image that includes both the front view 80 and the rear view 82. The processor 46 displays the map 84 via the input device 49 ( Figure 1 ) receives user markings 86 and updates map 84 using user markings 86. User markings 86 divide map 84 into different regions 88 having region boundaries 90 (for simplicity, only some regions are marked).

[0136] Reference Figure 5 , which is Figure 1 The segmentation map 84 is then drawn for display by the processor 46 on the display 61. The physician 14 ( Figure 1 ) may then use input device 49 to add labels (e.g., apex, septum, mitral, etc.) to each of regions 88, thereby providing region designations 92. Labels may be selected from a preset list (e.g., a drop-down list) and / or based on free-form text. By way of example only, Figure 5 The area 88 listed in FIG. 1 is for the left atrium. The chamber can be divided into Figure 5 The number of regions 88 shown may be greater or lesser than that of regions 88 . Figure 4 and Figure 5 The method has been described with reference to the left atrium. The method may also be used in any suitable heart chamber.

[0137] Reference Figure 6 , which includes Figure 1 100 of exemplary steps in a segmentation and region designation method for use with the device 12.

[0138] Processor 46 ( Figure 1 ) is configured to display the map 84 on the display 61 ( Figure 1 ) (block 102). The processor 46 is configured to receive, via the input device 49 ( Figure 1 ) receiving the user mark 86 of the map 84 of the chamber ( Figure 4 )(box 104), thereby dividing the map 84 into different regions 88 ( Figure 4 and Figure 5). Processor 46 is configured to segment the map 84 of the chamber into different regions 88 in response to the received user markings 86 (block 106). Processor 46 is configured to display the segmented map 84 (block 108). If the map requires correction, physician 14 may re-enter the corrected markings at step 104 (arrow 110). Processor 46 is configured to receive region designations 92 of different regions 88 of map 84 designated by physician 14 ( Figure 5 ) (block 112 ). Processor 46 is configured to assign region designation 92 to region 88 of map 84 (block 114 ).

[0139] Default ablation parameters may be automatically, semi-automatically, or manually assigned to each of the regions 88, as will now be described below.

[0140] In the automatic mode, the processor 46 is configured to automatically assign a default ablation parameter set to the regions 88 (block 116) based on the region designations 92 for each of the regions 88. For example, a default ablation parameter set previously stored for the septum may be assigned to the septum region, or a default ablation parameter set previously stored for the LUPV region for a balloon catheter may be assigned to the LUPV region for use with the balloon catheter.

[0141] In the semi-automatic mode, the processor 46 is configured to display to the display 61 (box 118) the default ablation parameter set that has been automatically assigned to the regions 88 based on the region designations 92 for each of the regions 88, as described with reference to the steps of box 116. The physician 14 can then review the automatically assigned default ablation parameter set and update the default ablation parameter set using the input device 49. The processor 46 is configured to receive user updates to the default ablation parameter set (box 120) and to modify the default ablation parameter set based on the user updates (box 122).

[0142] In the manual mode, the processor 46 is configured to receive a user-defined default ablation parameter set for each of the different regions 88 as defined by the physician 14 (block 124). The processor 46 is configured to assign the user-defined default ablation parameter set to the different regions 88 in response to the region designation of each of the received user-defined default ablation parameter sets.

[0143] Reference Figure 7 , which includes Figure 1 Flowchart 130 of exemplary steps in an alternative segmentation and region designation method for use with device 12. Figure 7 A method for segmenting a map 84 based on a segmentation model of a cardiac chamber is described. Figure 4 and Figure 5 ) of automatic and semi-automatic methods. Processor 46 ( Figure 1) is configured to apply a segmented model of the cardiac chamber to the map 84 of the chamber (box 132), thereby generating a segmented map 84 of the chamber. The segmented model typically includes a segmented and labeled cardiac chamber map that was previously prepared by a medical professional or based on a correction of a previously segmented and labeled cardiac chamber map prepared by one or more medical professionals. The processor 46 may use image processing techniques that include scaling the model vertically and horizontally and optionally moving the perimeter of the cardiac chamber model until the model matches the map 84. The processor 46 then applies the region boundaries of the model to the map 84, thereby generating a segmented map 84 of the chamber. The processor 46 is configured to apply the region designations of the regions included in the model to corresponding regions 88 of the map 84 (box 134).

[0144] According to some embodiments, the processor 46 is optionally configured to display the segmented map 84 with the region designations (box 136). The physician 14 may then examine the map 84 to determine whether corrections to the region boundaries 90 and / or the region designations 92 are required. The processor 46 is configured to receive at least one user correction to the segmentation and / or region designations 92 from the input device 49 (box 138). The processor 46 is configured to modify the segmentation of the map 84 and / or the region designations 92 in response to one or more user corrections (box 140). The processor 46 is configured to display the corrected segmented map 84 (box 142). The steps of boxes 138-142 may be repeated (arrow 144) to provide subsequent user corrections.

[0145] Default ablation parameters may be automatically, semi-automatically, or manually assigned to each of the regions 88, as described above with reference to Figure 6 The steps of blocks 116-126 are described above.

[0146] Reference Figure 8 , which includes Figure 1 Flowchart 150 of exemplary steps in a method of ablation for use with the device 12. Figure 3 Describe and reference Figure 4-7 Following the preparation methods described in more detail, the ablation procedure can begin. Figure 1 The preparation and insertion of ablation probe 20 into a chamber of the heart of patient 18 is described in detail.

[0147] Tracking module 58 is configured to track the location of one or more ablation application elements of ablation probe 20 within the heart (block 152). Figure 1 The tracking module 58 is described in detail.

[0148] The processor 46 is configured to receive user input indicating the start of an ablation procedure (via, for example, the input device 49) (box 154). The processor 46 is configured to identify, in response to the tracked position, an area 88 of a chamber in contact with one or more ablation application elements (box 156). For example, one or more ablation application elements may be in contact with the septum of the left atrium. In response to the user input of the step of box 154, the processor 46 is configured to retrieve a corresponding default ablation parameter set assigned to the identified area (box 158). For example, a default ablation parameter set for the septum of the left atrium is retrieved. In some embodiments, in response to the user input of the step of box 154, the processor 46 is configured to retrieve a probe-specific default ablation parameter set assigned to the identified area for a probe type of the ablation probe. For example, a default ablation parameter set for the septum of the left atrium of a balloon catheter is retrieved.

[0149] The processor 46 is configured to apply the retrieved default ablation parameter set to control the ablation procedure (box 160). The step of box 160 may include automatically accepting the retrieved default ablation parameter set to control the ablation procedure, or allowing a user (e.g., physician 14) to review the retrieved settings and modify them before using the settings in the ablation procedure, as described in more detail with reference to the steps of boxes 162 and 164 below.

[0150] Thus, in some embodiments, the processor 46 is configured to display the retrieved default ablation parameter set on the display 61 (box 162) and receive a user update to the retrieved default ablation parameter set via the input device 49 (box 164), thereby generating an updated ablation parameter set. The processor 46 is configured to control ablation of tissue at the identified area by the ablation probe 20 according to the retrieved default ablation parameter set (or according to the updated ablation parameter set if the steps of box 164 are performed) (box 166).

[0151] Reference Fig. 9 , which is Figure 1 Schematic diagram of a balloon catheter 168 for use with the device 12 of FIG. The balloon catheter 168 is an ablation probe that includes a plurality of ablation application elements 170 (e.g., ablation electrodes) disposed about the equator of an expandable balloon 172 of the balloon catheter 168. The balloon catheter 168 is particularly effective for performing ablations at more than one site in a chamber of the heart simultaneously.

[0152] Reference Fig.10 , which is Figure 1A cross-sectional view of a balloon catheter 168 disposed in a chamber of the heart for use with the device 12 of the present invention. Some of the ablation application elements 170-1 are in contact with a first tissue surface 174 of the chamber, and some of the ablation application elements 170-2 are in contact with a second tissue surface 176 of the chamber, while some of the ablation application elements 170-3 are not in contact with any tissue. In addition, the tissue 178 of the first tissue surface 174 is thicker than the tissue 180 of the second tissue surface 176. Therefore, when the balloon catheter 168 is actuated to perform ablation, the ablation application element 170-1 should be set to have a higher power and / or a longer ablation duration than the ablation application element 170-2, while the ablation application element 170-3 should not be activated at all. Applying the above-described settings can be extremely challenging for the physician 14.

[0153] According to some embodiments of the present invention, based on the tracked position of each of the ablation application elements 170, different default ablation parameter sets are retrieved for the ablation application element 170-1 in contact with the first tissue surface 174 and the ablation application element 170-2 in contact with the second tissue surface 176. The ablation application element 170-3 that is not currently in contact with any tissue is typically not actuated to prevent additional heat from being generated in the heart chamber. Fig.11 The above method is described in more detail.

[0154] Reference Fig.11 , which includes the use of Figure 1 A multi-ablation element probe (e.g., Fig. 9 Flowchart 182 of exemplary steps in a method of ablation using a balloon catheter 168 or any other suitable multi-ablation element probe.

[0155] Tracking module 58 is configured to track the position of each of the ablation application elements of the multi-ablation element probe within the heart (block 184).Processor 46 is configured to receive user input (via, for example, input device 49) indicating the start of an ablation procedure (block 186).

[0156] The processor 46 is configured to identify, in response to the tracked position of each of the ablation application elements, a region 88 of the lumen in contact with the ablation application elements (block 188 ).

[0157] For example, processor 46 is configured to identify, in response to the tracked position, at least a first ablation application element (eg, Fig.10 The processor 46 is configured to identify, in response to the tracked position, at least a second ablation application element (e.g., Fig.10The ablation application element 170-2 contacts a second area of ​​the chamber (e.g., a second tissue surface 176).

[0158] The processor 46 is configured to retrieve a default ablation parameter set assigned to each of the identified regions (eg, a default ablation parameter set assigned to the first region and a default ablation parameter set assigned to the second region) (block 190).

[0159] The processor 46 is configured to apply a retrieved default ablation parameter set (e.g., a retrieved default ablation parameter set for the first region and the second region) (box 192) to perform an ablation procedure at the identified regions (e.g., the first region and the second region) using corresponding ablation application elements (e.g., using a first ablation application element and a second ablation application element among a plurality of ablation application elements, respectively).

[0160] The steps of box 194 and box 196 generally correspond to the steps of box 194 and box 196 respectively described above with reference to Figure 8 The steps of blocks 162 and 164 are described above. Processor 46 is configured to control ablation according to the retrieved (or updated) default ablation parameter set (block 198).

[0161] For the sake of clarity, various features of the present invention described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, for the sake of simplicity, various features of the present invention are described in the context of a single embodiment and may also be provided separately or in any suitable sub-combination.

[0162] The above embodiments are cited by way of example, and the present invention is not limited by what is specifically shown and described above. On the contrary, the scope of the present invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which should occur to those skilled in the art when reading the above description, and which are not disclosed in the prior art.

Claims

1. A cardiac ablation system, comprising: an ablation probe comprising at least one ablation application element configured to ablate tissue in a chamber of a heart of a living subject; a tracking module configured to track a position of the at least one ablation administration element within the heart; a memory configured to store a map of the chamber of the heart and to store a different corresponding set of default ablation parameters for each of a plurality of different regions of the chamber; as well as A processing circuit, the processing circuit being configured to: prior to ablation, segmenting the map of the chamber into the plurality of distinct regions, each region having a region designation; receiving user input indicating initiation of an ablation procedure; identifying one of the plurality of different regions with which the at least one ablation application element is in contact responsive to the tracked location; in response to the user input, retrieving a corresponding stored set of default ablation parameters assigned to the identified region based on the region designation of the identified region; as well as The retrieved default ablation parameter set is applied to control the ablation procedure. 2 . The system of claim 1 , wherein the processing circuit is configured to apply a segmentation model of a cardiac chamber to the map of the chamber, thereby generating a segmentation map of the chamber.

3. The system of claim 2, wherein the processing circuit is configured to: receiving at least one user correction to a segmentation of the segmentation map; and In response to the received at least one user correction, the segmented map is modified.

4. The system of claim 1 , wherein the processing circuit is configured to: receiving a user marking of the map of the chamber dividing the map into the different regions; and In response to the received user markings, the map of the chamber is segmented into the different regions.

5. The system of claim 1 , wherein the processing circuit is configured to: receiving a user-defined set of default ablation parameters for each of the different regions; and Responsive to the region designation of each of the received user-defined default ablation parameter sets, the user-defined default ablation parameter sets are assigned to the different regions. 6 . The system of claim 1 , wherein the processing circuit is configured to control the ablation of the tissue at the identified region by the ablation probe according to the retrieved default ablation parameter set.

7. The system of claim 1 , wherein the processing circuit is configured to: receiving a user update to the retrieved default ablation parameter set, thereby generating an updated ablation parameter set; and The ablation probe is controlled to ablate the tissue at the identified region according to the updated ablation parameter set.

8. The system of claim 1, wherein the processing circuit is configured to: assigning a probe-specific default ablation parameter set to each of the different regions for a plurality of different probe types; and In response to the user input, the probe-specific default ablation parameter set assigned to the identified region for a probe type of the ablation probe is retrieved.

9. The system of claim 1, wherein: The ablation probe includes a plurality of ablation application elements; and The processing circuit is configured to: identifying, responsive to the tracked location, a first region of the lumen with which at least a first ablation application element of the plurality of ablation application elements is in contact; identifying, responsive to the tracked location, a second region of the lumen with which at least a second ablation application element of the plurality of ablation application elements is in contact; retrieving the default ablation parameter set assigned to the first region and the default ablation parameter set assigned to the second region; as well as The retrieved default ablation parameter sets for the first region and the second region are applied to perform the ablation procedure at the first region and the second region using the first ablation application element and the second ablation application element of the plurality of ablation application elements, respectively.

10. The system of claim 1, wherein the default set of ablation parameters for one of the different regions comprises any one or more of: tissue thickness of the one region; whether to track temperature during the ablation procedure; an ablation mode used during the ablation procedure; an irrigation rate used during the ablation procedure; a power level applied during said ablation procedure; the force applied during said ablation procedure; the ablation duration of the ablation procedure; an ablation index used during said ablation procedure; a target power; and target temperature.

11. A system according to claim 10, wherein the ablation mode is selected from any one or more of the following: ablation index mode; controlling ablation power according to measured temperature; applying alternating current to the at least one ablation application element; applying direct current to the at least one ablation application element; laser ablation; electroporation; cryoablation; radiofrequency power ablation.

12. A software product comprising a non-transitory computer readable medium having program instructions stored therein, the instructions, when read by a central processing unit, causing the central processing unit to: tracking a position of at least one ablation application element of an ablation probe, the at least one ablation application element configured to ablate tissue in a chamber of a heart of a living subject; storing a map of the chamber of the heart; storing a different respective set of default ablation parameters for each of a plurality of different regions of the chamber; prior to ablation, segmenting the map of the chamber into the plurality of distinct regions, each region having a region designation; receiving user input indicating initiation of an ablation procedure; identifying one of the plurality of different regions with which the at least one ablation application element is in contact responsive to the tracked location; in response to the user input, retrieving a corresponding stored set of default ablation parameters assigned to the identified region based on the region designation of the identified region; as well as The retrieved default ablation parameter set is applied to control the ablation procedure.

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