Controlling irreversible electroporation ablation using focal catheter having contact-force and temperature sensors

Abstract

To provide a catheter.SOLUTION: A catheter 21 includes: an insertion tube configured to insert the catheter into a patient's body; a first electrode 50A and a second electrode 50B coupled to a distal end 22a of the catheter at a predetermined distance from each other, the first electrode 50A and the second electrode 50B configured to (i) receive one or more irreversible electroporation (IRE) pulses through the insertion tube and (ii) apply the one or more IRE pulses to tissue of the patient's body between the first electrode and the second electrode; a contact force sensor disposed between the first electrode and the second electrode; and a temperature sensor disposed between the first electrode and the second electrode at a position different from the contact force sensor, wherein one of the first electrode and the second electrode is located at the distal-most edge of the distal end of the catheter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to irreversible electroporation (IRE) procedures, and more particularly to methods and systems for improving control of IRE pulses applied to tissue. [Background technology]

[0002] Various techniques for controlling the irreversible electroporation (IRE) procedure are known in the art.

[0003] For example, European Patent Application No. 3459480 describes an apparatus for localizing an electric field for electroporation of tissue, the apparatus including a pulsed DC electrical generator and at least one catheter tip and electrode assembly configured for endocardial placement, with electrodes positioned at distinct endocardial locations generating an electric field between the electrodes to achieve electroporation of tissue within the electric field.

[0004] U.S. Patent Application Publication No. 2018 / 0214202 describes methods, systems, and devices for improving the efficiency and effectiveness of energy delivery and tissue mapping. One system includes a processing element having multiple electrodes and an energy generator configured to deliver electrical energy pulses to the electrodes in various patterns. Summary of the Invention [Means for solving the problem]

[0005] One embodiment of the present invention described herein provides a catheter including an insertion tube, a first electrode, a second electrode, and a contact force sensor. The insertion tube is configured to insert the catheter into a patient's body. The first electrode and the second electrode are coupled to a distal end of the catheter at a predetermined distance from each other and configured to (i) receive one or more irreversible electroporation (IRE) pulses through the insertion tube and (ii) apply the IRE pulses to tissue of the patient's body between the first electrode and the second electrode. The contact force sensor is disposed between the first electrode and the second electrode and configured to generate an electrical signal indicative of a contact force applied between the distal end and the tissue.

[0006] In some embodiments, the catheter includes a processor configured to control delivery of one or more IRE pulses to the first electrode and the second electrode based on the electrical signal received from the force sensor. In other embodiments, the catheter includes at least a temperature sensor coupled to the distal end and configured to generate a temperature signal indicative of a measured temperature of at least one of the distal end and the tissue. In yet other embodiments, the temperature sensor includes a thermocouple.

[0007] In one embodiment, the processor is configured to (i) maintain a temperature threshold value and (ii) control delivery of one or more IRE pulses to the first electrode and the second electrode based on a comparison of the measured temperature to the temperature threshold value. In another embodiment, the catheter comprises a focal catheter. In yet another embodiment, the first electrode and the second electrode are coupled along the axis of the catheter.

[0008] According to one embodiment of the present invention, there is provided a method for manufacturing a catheter, the method including: coupling first and second electrodes, spaced a predetermined distance from each other, to a distal end of the catheter for receiving one or more irreversible electroporation (IRE) pulses; and applying the IRE pulses to tissue of a patient's body between the first and second electrodes. A contact force sensor is disposed between the first and second electrodes for generating an electrical signal indicative of a contact force applied between the distal end and the tissue.

[0009] In some embodiments, the method includes connecting to the catheter: (i) an IRE pulse generator (IPG) for delivering one or more IRE pulses; and (ii) a processor for controlling the one or more IRE pulses delivered by the IPG to the first electrode and the second electrode based on electrical signals received from the contact force sensor.

[0010] Also, in accordance with one embodiment of the present invention, there is provided a method including inserting a catheter into a patient's body, wherein first and second electrodes mounted on a distal end of the catheter are coupled to tissue of the patient's body at a predetermined distance from each other, receiving an electrical signal indicative of a contact force exerted between the distal end and the tissue, and applying one or more irreversible electroporation (IRE) pulses to the tissue between the first and second electrodes.

[0011] In some embodiments, applying the one or more IRE pulses includes controlling delivery of the one or more IRE pulses to the first electrode and the second electrode based on the received electrical signal. In other embodiments, the method includes (i) maintaining a temperature threshold; (ii) receiving a temperature signal indicative of a measured temperature of at least one of the distal tip and the tissue; and (iii) controlling delivery of the one or more IRE pulses to the first electrode and the second electrode based on (a) the received electrical signal and (b) a comparison of the measured temperature to the temperature threshold. In yet other embodiments, applying the one or more IRE pulses includes applying one or more IRE pulses along the axis of the catheter. [Brief explanation of the drawings]

[0012] The present invention will be more fully understood from the following detailed description taken in conjunction with the drawings, in which: [Figure 1] 1 is a schematic diagram of a catheter-based position tracking and irreversible electroporation (IRE) ablation system, in accordance with an exemplary embodiment of the present invention. [Figure 2] 1 is a flow chart that schematically illustrates a method for manufacturing an IRE focal catheter with contact force and temperature sensors, in accordance with an exemplary embodiment of the present invention. [Figure 3] 1 is a flow chart that schematically illustrates a method for controlling one or more IRE pulses applied to tissue based on signals indicative of contact force and temperature measured during an IRE ablation procedure, in accordance with an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Overview Irreversible electroporation (IRE) can be used, for example, to treat arrhythmias by ablating tissue cells using high-voltage applied pulses. Cell destruction occurs when the transmembrane potential exceeds a threshold, resulting in cell death and lesion formation. In IRE-based ablation procedures, for example, high-voltage bipolar electrical pulses are applied to a pair of electrodes in contact with the tissue to be ablated, forming lesions between the electrodes, thereby treating the patient's cardiac arrhythmia.

[0014] The embodiments of the present invention described below provide improved techniques for controlling IRE ablation by controlling one or more IRE pulses applied to tissue, also referred to herein as target tissue, at the IRE ablation site.

[0015] In some cases, a focal catheter may be required to perform an ablation procedure. In principle, for monopolar radiofrequency (RF) ablation, a focal catheter may include (i) a contact force sensing device for estimating the contact force applied between the catheter and the target tissue, (ii) a large distal electrode for ablating the target tissue, and (iii) one or more ring electrodes for diagnostic measurements. However, this configuration cannot be used for applying high-voltage bipolar IRE pulses, for example, because (a) the close proximity between the electrodes prevents the application of such high-voltage bipolar pulses, and (b) at least one of the electrodes may overheat in response to the application of high-voltage bipolar pulses.

[0016] In some embodiments, a system configured to perform controlled IRE ablation comprises a catheter, including, but not limited to, a focal catheter having an insertion tube configured to insert the catheter into an ablation site within a patient's heart. The catheter may comprise a pair of similar electrodes, also referred to herein as a first electrode and a second electrode, which are substantially wider than the ring electrodes described above.

[0017] In some embodiments, the first electrode and the second electrode are coupled to the distal end of the catheter at a predetermined distance from each other and are configured to (i) receive one or more IRE pulses generated by an IRE pulse generator (IPG) via an insertion tube, and (ii) apply the IRE pulses to tissue at the ablation site between the first electrode and the second electrode.

[0018] In some embodiments, the catheter comprises a contact force sensor disposed between the first electrode and the second electrode and configured to generate an electrical signal indicative of a contact force applied between the distal end and the tissue.

[0019] In some embodiments, the catheter comprises one or more temperature sensors coupled to the distal end at one or more respective locations, each temperature sensor configured to generate a temperature signal indicative of a measured temperature of at least one of the distal end and the tissue.

[0020] In some embodiments, during an IRE ablation procedure, a physician inserts the distal tip into an ablation site and contacts the first and second electrodes with the target tissue. In some embodiments, during IRE ablation, the system's processor is configured to receive signals indicative of the contact force applied between the distal tip and the target tissue and the measured temperature. Based on the received signals, the processor is configured to assist the physician in controlling the IRE ablation by controlling the contact force applied between the distal tip and the tissue and parameters of one or more pulses applied to the tissue. For example, (i) before applying one or more IRE pulses, the processor may alert the physician if the contact between the distal tip and the tissue is not within a specified range of contact force for the IRE procedure, and (ii) during and after applying one or more IRE pulses, the processor may check whether the temperature measured by the temperature sensor is within a specified temperature range for the IRE procedure.

[0021] In some embodiments, the processor may maintain a temperature threshold and compare the measured temperature with the temperature threshold, and if the measured temperature exceeds the temperature threshold, the processor may control the IPG to stop applying IRE pulses.

[0022] The disclosed techniques improve patient safety by improving control of IRE ablation and reduce IRE ablation procedure times.

[0023] System Description 1 is a schematic diagram of a catheter 21-based position tracking and irreversible electroporation (IRE) ablation system 20, according to one embodiment of the present invention. In some embodiments, catheter 21 comprises a focal IRE ablation catheter, although in other embodiments, the techniques described herein may be used, mutatis mutandis, to generate and apply one or more IRE pulses using any other suitable type of IRE ablation catheter.

[0024] In some embodiments, the system 20 comprises a deflectable or non-deflectable tip 40, with the tip 40 including a plurality of electrodes 50 as shown in inset 25 attached to the distal end 22a of the shaft 22 of the catheter 21.

[0025] In the embodiments described herein, electrode 50 is configured for IRE ablation of tissue in the left atrium of heart 26, such as IRE ablation of pulmonary vein ostia 51 within heart 26. Electrode 50 may also be used to sense intracardiac (IC) electrocardiogram (ECG) signals. It should be noted that the techniques disclosed herein are applicable, mutatis mutandis, to other portions of heart 26 (e.g., atria or ventricles) and other organs of patient 28.

[0026] In some embodiments, the proximal end of catheter 21 is connected to a control console 24 (also referred to herein as console 24) that includes an ablation power source, in this example an IRE pulse generator (IPG) 45 configured to deliver peak power in the tens of kW range. Console 24 includes a switching box 46 configured to switch the power applied by IPG 45 to one or more selected pairs of electrodes 50. A sequenced IRE ablation protocol may be stored in memory 48 of console 24.

[0027] In some embodiments, physician 30 inserts distal end 22 a of shaft 22 using, for example, an insertion tube of shaft 22 configured to insert catheter 21 through sheath 23 and into heart 26 of patient 28 positioned on table 29. Physician 30 navigates distal end 22 a of shaft 22 to a target location within heart 26 by manipulating shaft 22 using manipulator 32 near the proximal end of catheter 21 and / or deflection from sheath 23. During insertion of distal end 22 a, tip 40 is maintained in a straight configuration by sheath 23. By housing tip 40 in a straight configuration, sheath 23 also serves to minimize vascular trauma as physician 30 navigates catheter 21 through the vasculature of patient 28 to a target location, such as an ablation site, within heart 26.

[0028] Once the distal end 22a of the shaft 22 reaches the ablation site, the physician 30 retracts the sheath 23, deflects the tip 40 in the case of a deflectable tip, and further manipulates the shaft 22 to bring the electrode 50 disposed on the tip 40 into contact with the ostium 51 at the ablation site.

[0029] In some embodiments, the electrodes 50 are connected through the aforementioned insertion tube of the shaft 22 to a processor 41 configured to control a switching box 46 of an interface circuit 44 in the console 24 .

[0030] Reference is now made to inset 25. In some embodiments, distal end 22a comprises a position sensor 39 of a position tracking system coupled to distal end 22a, for example, at tip 40. In this example, position sensor 39 comprises a magnetic position sensor, although in other embodiments, any other suitable type of position sensor (e.g., other than magnetic-based) may be used. During navigation of distal end 22a within heart 26, console 24 of processor 41 receives signals from magnetic sensor 39 in response to magnetic fields from external magnetic field generator 36, for purposes of, for example, measuring the position of ablation balloon 40 within heart 26 and, optionally, presenting the tracked position on display 27 of console 24 overlaid on an image of heart 26.

[0031] Referring again to the schematic diagram of Figure 1, a magnetic field generator 36 is positioned at a known location external to the patient 28, for example, beneath a table 29. The console 24 also includes a driver circuit 34 configured to drive the magnetic field generator 36.

[0032] This method of position sensing using an external magnetic field has been implemented in various medical applications, for example, in the CARTO™ system manufactured by Biosense Webster Inc. (Irvine, California), and is described in detail in U.S. Pat. Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, WO 96 / 05768, and U.S. Patent Application Publication Nos. 2002 / 0065455(A1), 2003 / 0120150(A1), and 2004 / 0068178(A1), the disclosures of which are all incorporated herein by reference.

[0033] Typically, processor 41 of console 24 comprises a general-purpose processor of a general-purpose computer, with suitable front-end and interface circuitry 44 for receiving signals from catheter 21 and applying ablation energy via catheter 21 in the left atrium of heart 26, as well as controlling other components of system 20. Processor 41 typically includes software in memory 48 of system 20 that is programmed to perform the functions described herein. The software may be downloaded to the computer in electronic form, for example over a network, or alternatively or additionally, may be provided and / or stored on a non-transitory, tangible medium, such as magnetic, optical, or electronic memory.

[0034] Monitoring and control of irreversible electroporation pulses applied to tissue Irreversible electroporation (IRE), also known as pulsed field ablation (PFA), can be used as a minimally invasive treatment modality for creating lesions (e.g., killing tissue cells) at an ablation site by applying high-voltage pulses to tissue. In this example, IRE pulses can be used to kill myocardial tissue cells for the purpose of treating cardiac arrhythmias within the heart 26. Cell destruction occurs when the transmembrane potential exceeds a threshold, leading to cell death and, ultimately, the development of tissue damage. Therefore, of particular interest is the use of high-voltage bipolar electrical pulses, e.g., using a pair of electrodes 50 in contact with the tissue at the ablation site to generate a high electric field (e.g., above a certain threshold) to kill tissue cells located between the electrodes.

[0035] In the context of this disclosure, a "bipolar" voltage pulse means a voltage pulse applied between two electrodes 50 of a catheter 21 (as opposed to a monopolar pulse applied by a catheter electrode relative to a common ground electrode not located on the catheter, e.g., during radiofrequency ablation).

[0036] To perform IRE ablation on a relatively large tissue region of the heart 26, such as around the ostia of a pulmonary vein (PV) or any other suitable organ, it is necessary to use multiple pairs of electrodes 50 on the catheter 21, or any other suitable type of IRE catheter having multiple electrodes 50 in the tip 40. To make the generated electric field as spatially uniform as possible over a large tissue region, it is best to select pairs of electrodes 50 with overlapping magnetic fields, or at least adjacent magnetic fields. However, a Joule heating component occurs in the IRE-generated field, and this heating can damage the electrodes if multiple pairs of electrodes 50 are used sequentially to deliver a series of IRE pulses.

[0037] In one embodiment, system 20 includes surface electrodes 38, shown in the example of FIG. 1 , attached by wires extending through cable 37 to the chest and shoulders of patient 28. In some embodiments, surface electrodes 38 are configured to sense body surface (BS) ECG signals in response to the beating of heart 26. BSECG signals can be acquired using conductive pads attached to the body surface or any other suitable technique. As shown in FIG. 1 , surface electrodes 38 are attached to the chest and shoulders of patient 28, although additional surface electrodes 38 may be attached to other organs of patient 28, such as the limbs.

[0038] In some embodiments, electrodes 50 are configured to sense intracardiac (IC) ECG signals, and (e.g., simultaneously) surface electrodes 38 sense BSECG signals. In other embodiments, sensing ICECG signals is sufficient to perform IRE ablation, and surface electrodes 38 may be adapted for other uses.

[0039] In some embodiments, physician 30 may couple at least a pair of electrodes 50 to tissue, also referred to herein as target tissue, at an ablation site within heart 26. The target tissue is intended to be ablated by applying one or more IRE pulses via electrodes 50. Note that IRE pulses may be applied to the target tissue multiple times, for example, during different stages of the IRE ablation procedure.

[0040] Referring again to inset 60, in some embodiments, tip section 40 attached to distal end 22a of catheter 21 includes a pair of first and second electrodes 50, referred to herein as electrodes 50A and 50B, respectively. Electrodes 50A and 50B are coupled to tip section 40 at distal end 22a at a predetermined distance from each other.

[0041] In some embodiments, electrodes 50A and 50B are similar to one another and relatively wide, e.g., greater than about 1 mm along axis 62 of tip portion 40 of catheter 21. In this example, electrodes 50A and 50B are positioned along axis 62, which is the longitudinal axis of catheter 21. In other embodiments, electrodes 50A and 50B may be positioned at any suitable location within distal end 22a relative to one another and may have any suitable predetermined distance from one another. For example, at least one of electrodes 50A and 50B may be positioned at the edge of tip portion 40.

[0042] In the context of this disclosure and in the claims, the term "about" or "approximately" used in connection with any numerical value or range of values indicates an appropriate dimensional tolerance that enables a portion of a component or a collection of components to function for its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values of ±20% of the recited value; for example, "about 90%" may refer to a range of values of 71% to 99%.

[0043] In some embodiments, the tip 40 of the distal end 22 a includes a contact force sensor 66 disposed between a first electrode and a second electrode, which in this example are electrodes 50A and 50B, respectively. The contact force sensor 66 is configured to generate an electrical signal indicative of the contact force exerted between the tip 40 of the distal end 22 a and the tissue located at the ablation site of the heart 26.

[0044] In other embodiments, one or more force sensors 66 may be coupled to the tip 40 of the distal end 22a at any other suitable location in addition to or instead of the force sensor 66 shown in inset 60.

[0045] In some embodiments, the tip 40 of the distal end 22a includes at least a temperature sensor 64 coupled to the distal end 22a and configured to generate a temperature signal indicative of a measured temperature of at least one of the distal end 22a and the ablated tissue at the target location. In some embodiments, the tip 40 may include multiple temperature sensors 64 positioned at corresponding locations on the distal end 22a. For example, in addition to the temperature sensor 64 shown in the inset 60 for measuring the temperature of the aforementioned tissue, the tip 40 may include two additional temperature sensors 64 coupled to the distal end 22a proximate electrodes 50A and 50B to measure the temperature of both electrodes 50A and 50B.

[0046] In some embodiments, the temperature sensors 66 may include thermocouples (TCs), although in other embodiments, the at least one temperature sensor 66 may comprise any other suitable type of temperature sensing device.

[0047] Referring again to the schematic diagram of FIG. 1 , in some embodiments, processor 41 is configured to receive the aforementioned electrical signals from contact force sensor 66. Based on the electrical signals, processor 41 is configured to control IPG 45 to deliver one or more IRE pulses to electrodes 50A and 50B. In the context of the present disclosure and claims, processor 41 is configured to control one or more parameters of the IRE pulses applied to tissue based on the received electrical signals. For example, based on the sensed contact force applied between distal end 22 a and tissue during IRE ablation, processor 41 may control the energy, amplitude, and / or frequency of the applied IRE pulses. Furthermore, processor 41 is configured to display a message or any other type of display indicative of the sensed contact force, for example, on display 27, so that physician 30 can adjust the applied contact force by, for example, slightly pushing or retracting distal end 22 a against the tissue at the ablation site.

[0048] In some embodiments, processor 41 is configured to maintain at least a temperature threshold and control the delivery of one or more IRE pulses to electrodes 50A and 50B based on a comparison of the temperature measured by temperature sensor 66 to the temperature threshold.

[0049] This particular configuration of system 20 is provided as an example to explain the particular problems addressed by embodiments of the present invention and to demonstrate the application of these embodiments in improving the performance of such IRE ablation systems, however, embodiments of the present invention are not limited to this particular type of exemplary system, and the principles described herein may be applied to other types of ablation systems as well.

[0050] 2 is a flow chart that schematically illustrates a method for manufacturing an IRE focusing catheter having a contact force sensor 66 and a temperature sensor 64, according to one embodiment of the present invention. The method begins with electrode coupling step 100, in which electrodes 50A and 50B are coupled to the distal end 22a of an IRE catheter, such as catheter 21. In some embodiments, electrodes 50A and 50B are mounted a predetermined distance from each other and are configured to apply IRE pulses to target tissue at an ablation site in heart 26 or tissue of any other organ within the body of patient 28.

[0051] In a force sensor placement step 102, a force sensor 66 is positioned and mounted on the tip 40 of the distal end 22a between the electrodes 50A and 50B. As depicted in inset 60 of FIG. 1 above, the force sensor 66 is configured to sense a contact force applied between the distal end 22a and the target tissue of the heart 26 and generate an electrical signal indicative of the sensed contact force.

[0052] In a temperature sensor coupling step 106, one or more temperature sensors 64 are coupled to the tip 40 of the distal end 22a at predetermined locations to measure temperature and generate temperature signals indicative of the sensed temperature, as described above in FIG. 1.

[0053] In a processor coupling step 108, which concludes the method, distal end 22a is coupled to processor 41 of console 24 via catheter 21. In some embodiments, in step 108, processor 41 is electrically connected to several components of catheter 21, including, but not limited to, force sensor 66, one or more temperature sensors 64, and position sensor 39.

[0054] FIG. 3 is a flow chart that schematically illustrates a method for controlling one or more IRE pulses applied to target tissue of heart 26 based on signals indicative of contact force and temperature measured during an IRE ablation procedure, in accordance with one embodiment of the present invention.

[0055] The method begins with an IRE catheter insertion step 200, in which an insertion tip 40 located at the distal end 22a of the catheter 21 is inserted into an ablation site within the heart 26, bringing a pair of electrodes 50A and 50B into contact with the target tissue. As described in FIG. 1 above, the tip 40 includes at least electrodes 50A and 50B configured to receive IRE pulses from the IPG 45 and apply the IRE pulses to the target tissue of the heart 26. In some embodiments, the tip 40 further includes one or more contact force sensors 66 and one or more temperature sensors 64, such as one or more thermocouples or any other suitable type of temperature sensing device.

[0056] In contact force signal receiving step 202, processor 41 receives an electrical signal indicative of the contact force applied between distal end 22a and target tissue of heart 26. If the measured contact force does not fall within a specified level (e.g., approximately 5 grams-force (grf) to 25 grf), processor 41 may display, for example, on display 27, a message to the physician to adjust the contact force applied between distal end 22a having electrodes 50A and 50B and the target tissue. In other embodiments, if the measured contact force does not fall within the specified contact force level, the processor may prevent the physician from applying an IRE pulse to the tissue.

[0057] After verifying that the applied contact force is within the specified level for the IRE procedure, processor 41 controls IPG 45 to generate one or more IRE pulses in an IRE pulse application step 204. As shown in FIG. 1 above, electrodes 50A and 50B are configured to receive one or more IRE pulses from IPG 45 and apply one or more bipolar IRE pulses between electrodes 50A and 50B to the target tissue. In some embodiments, processor 41 is configured to receive one or more temperature signals from one or more temperature sensors 64 indicative of temperatures measured by temperature sensor 64 during the IRE ablation procedure. The measured temperatures may include tissue temperature, electrode temperature, and the temperature of any other component of catheter 21.

[0058] In a first decision step 206, physician 30 determines whether IRE ablation is complete. If yes, the method proceeds to catheter retraction step 212, where the physician retracts distal end 22a of catheter 21 out of heart 26, completing the IRE procedure.

[0059] If IRE ablation is not complete, in a second decision step 208, processor 41 compares the measured temperature to a temperature threshold maintained by processor 41 in step 204, as shown in FIG. 1 above. Based on the comparison, processor 41 checks whether the measured temperature exceeds the temperature threshold. If the measured temperature exceeds the temperature threshold, the method proceeds to pulse level adjustment step 210, where processor 41 and / or physician 30 can adjust the number of IRE pulses applied to the tissue, reduce the number of pulses in a train, or reduce the temperature at the measured location. For example, the temperature may be reduced by waiting a few milliseconds between trains and / or by applying irrigation (not shown) to cool the ablated tissue and / or electrodes 50A and 50B.

[0060] It should be noted that, based on the disclosed technology, temperature control can be performed without changing the IRE pulse voltage. In contrast to IRE treatment, when applying unipolar RF power, control is typically performed by modifying the signal amplitude. However, in the present invention, since voltage is important for achieving the ablation effect, reducing the amplitude in IRE ablation is not desirable.

[0061] In some embodiments, the overall energy applied to the tissue can be reduced by modifying the number of pulses and / or increasing the time interval between sets of IRE pulses (also referred to herein as trains) and / or controlling the number of trains of IRE pulses applied to the tissue. Using one or any suitable combination of these power control techniques prevents electrode and / or tissue heating without the use of irrigation.

[0062] In step 208, if the measured temperature is less than the temperature threshold, the method returns to step 202 to begin a new set of contact force and temperature measurements and to apply one or more additional IRE pulses to the target tissue until IRE ablation is complete.

[0063] Although the embodiments described herein primarily address IRE ablation of cardiac tissue, the methods and systems described herein may also be used in other applications, such as ablation of other organs in humans or other mammals, and for the treatment of lung and liver cancer.

[0064] It will therefore be understood that the above-described embodiments are cited by way of example, and that the present invention is not limited to what has been particularly shown and described above. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the foregoing specification, as well as variations and modifications thereof that would occur to one skilled in the art upon reading the foregoing description, and that are not disclosed in the prior art. Documents incorporated by reference into this patent application are to be deemed part of this application, except that if any term is defined in such incorporated document in a way that contradicts the definition given herein, either expressly or impliedly, then only the definition given herein shall be considered.

[0065] [Embodiment] (1) A catheter, an insertion tube configured to insert the catheter into a patient's body; a first electrode and a second electrode coupled to a distal end of the catheter at a predetermined distance from each other, the first electrode and the second electrode configured to (i) receive one or more irreversible electroporation (IRE) pulses through the insertion tube and (ii) apply the IRE pulses to tissue of the patient's body between the first electrode and the second electrode; a contact force sensor disposed between the first electrode and the second electrode and configured to generate an electrical signal indicative of a contact force applied between the distal tip and the tissue; A catheter comprising: (2) A catheter as described in embodiment 1, comprising a processor configured to control the supply of the one or more IRE pulses to the first electrode and the second electrode based on the electrical signal received from the contact force sensor. (3) A catheter as described in embodiment 2, comprising at least a temperature sensor coupled to the distal end and configured to generate a temperature signal indicative of a measured temperature of at least one of the distal end and the tissue. (4) A catheter as described in embodiment 3, wherein the temperature sensor comprises a thermocouple. (5) A catheter as described in embodiment 3, wherein the processor is configured to (i) maintain a temperature threshold value, and (ii) control the delivery of the one or more IRE pulses to the first electrode and the second electrode based on a comparison of the measured temperature with the temperature threshold value.

[0066] (6) The catheter of embodiment 1, wherein the catheter comprises a focal catheter. (7) A catheter according to embodiment 1, wherein the first electrode and the second electrode are connected along the axis of the catheter. (8) A method for manufacturing a catheter, comprising: coupling a first electrode and a second electrode at a distal end of the catheter, the first and second electrodes being spaced a predetermined distance from each other, for receiving one or more irreversible electroporation (IRE) pulses; applying the IRE pulse to tissue of a patient's body between the first electrode and the second electrode; and disposing a contact force sensor between the first electrode and the second electrode for generating an electrical signal indicative of a contact force applied between the distal end and the tissue. (9) The method of embodiment 8, comprising connecting to the catheter: (i) an IRE pulse generator (IPG) for supplying the one or more IRE pulses; and (ii) a processor for controlling the one or more IRE pulses supplied by the IPG to the first electrode and the second electrode based on the electrical signal received from the contact force sensor. (10) The method of embodiment 9, comprising coupling a temperature sensor to the distal end for generating a temperature signal indicative of a measured temperature of at least one of the distal end and the tissue.

[0067] (11) The method of embodiment 9, wherein coupling the temperature sensor includes coupling a thermocouple. (12) The method of embodiment 8, wherein the catheter comprises a focal catheter. (13) The method of embodiment 8, wherein connecting the first electrode and the second electrode includes connecting the first electrode and the second electrode along the axis of the catheter. (14) A method comprising: Inserting a catheter into the patient's body; coupling a first electrode and a second electrode mounted at a distal end of the catheter at a predetermined distance from each other to tissue of the patient's body; receiving an electrical signal indicative of a contact force applied between the distal tip and the tissue; applying one or more irreversible electroporation (IRE) pulses to the tissue between the first electrode and the second electrode; A method comprising: (15) The method of embodiment 14, wherein applying the one or more IRE pulses includes controlling the supply of the one or more IRE pulses to the first electrode and the second electrode based on the received electrical signal.

[0068] (16) The method of embodiment 14, comprising: (i) maintaining a temperature threshold; (ii) receiving a temperature signal indicative of a measured temperature of at least one of the distal tip and the tissue; and (iii) controlling the supply of the one or more IRE pulses to the first electrode and the second electrode based on (a) the received electrical signal and (b) a comparison of the measured temperature with the temperature threshold. (17) The method of embodiment 14, wherein inserting the catheter comprises inserting a focal catheter. (18) The method of embodiment 14, wherein applying the one or more IRE pulses includes applying the one or more IRE pulses along the axis of the catheter.

Claims

1. A catheter, an insertion tube configured to insert the catheter into a patient's body; a pair of electrodes, a first electrode and a second electrode, coupled to a distal end of the catheter at a predetermined distance from each other, the first electrode and the second electrode configured to (i) receive one or more irreversible electroporation (IRE) pulses through the insertion tube, and (ii) apply the one or more IRE pulses to tissue of the patient's body between the first electrode and the second electrode; a contact force sensor disposed between the first electrode and the second electrode and configured to generate an electrical signal indicative of a contact force applied between the distal tip and the tissue; a temperature sensor disposed between the first electrode and the second electrode at a position different from the first electrode, the second electrode, and the contact force sensor in the longitudinal direction of the catheter, the temperature sensor being configured to generate a temperature signal indicative of a measured temperature of at least one of the distal tip and the tissue; Equipped with A catheter, wherein one of the first electrode and the second electrode is located at a distal-most edge of the distal end of the catheter.

2. 10. The catheter of claim 1, further comprising a processor configured to control delivery of the one or more IRE pulses to the first electrode and the second electrode based on the electrical signals received from the force sensor.

3. The catheter of claim 1 , wherein the temperature sensor comprises a thermocouple.

4. 3. The catheter of claim 2, wherein the processor is configured to (i) maintain a temperature threshold value and (ii) control delivery of the one or more IRE pulses to the first electrode and the second electrode based on a comparison of the measured temperature to the temperature threshold value.

5. The catheter of claim 1 , wherein the first electrode and the second electrode are spaced apart from each other in the longitudinal direction of the catheter.

6. 2. The catheter of claim 1, wherein the second electrode is located at the distal-most edge of the distal end of the catheter, the temperature sensor is located adjacent to and proximal to the second electrode, the force sensor is located adjacent to and proximal to the temperature sensor, and the first electrode is located adjacent to and proximal to the force sensor.

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