Minimizing the electric field near the electrode

Abstract

To provide a catheter assembly. [Solution] The catheter assembly is configured to prevent the occurrence of at least one hot spot during the operation of the catheter assembly. The catheter assembly includes a shaft and an end effector. The shaft is designed to be guided into the lumen through a delivery sheath. The electrodes are printed on a substrate and configured to deliver energy to the ablation site. The bottom surface of the electrodes is bonded to the substrate, and arc-shaped elements are bonded to the top surface of the electrodes. The arc-shaped elements have a curved top surface and extend over their respective locations. The arc-shaped elements reduce the intensity of the electric field at each of their locations to below the arcing level when the electrodes are operated in the blood, thereby preventing the occurrence of hot spots during operation.

Description

[Technical Field]

[0001] The subject matter of this disclosure generally relates to catheter assemblies for tissue ablation, and more specifically to catheter assemblies designed to prevent arcing during tissue ablation. [Background technology]

[0002] Ablation techniques are widely used in a variety of medical procedures, including the treatment of tumors, cardiac arrhythmias, and other conditions where selective tissue destruction is desired.

[0003] One technique for tissue ablation is pulsed-field ablation (PFA). PFA is a process known as electroporation, which uses high-voltage electrical pulses to create pores in cell membranes, leading to cell death without significant heat generation. This mechanism offers precise targeting of tissue, reduced collateral damage to surrounding tissues, and the ability to treat larger and more complex tissue structures than other techniques.

[0004] PFA is typically performed using a catheter assembly that includes an end-effector guided through a shaft to the ablation site. The end-effector contains one or more electrodes printed on a substrate that deliver energy to the ablation site. The structure and design of the end-effector are crucial to ensure that tissue ablation is performed with minimal damage to surrounding tissue. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] One important aspect of electrode design addressed herein is preventing arcing around the electrode during ablation procedures. The high voltage and electric field typical of PFA can lead to the formation of vapor bubbles in the blood. If the electric field is sufficiently strong, arcing occurs, which is undesirable due to its strength and can degrade the materials constituting the electrode and cause damage to surrounding tissue.

[0006] As described herein, according to some aspects of the present invention, the term “hot spot” means a location where an ambient electric field with an intensity exceeding the arcing level is generated when the electrode is operated in blood. [Means for solving the problem]

[0007] Some aspects of this disclosure prevent the occurrence of hot spots by coupling one or more arc-shaped elements to an electrode at locations where hot spots are expected to occur if the electrode is not protected by an arc-shaped element. Such locations are referred to herein as “potential hot spot locations”.

[0008] Potential hotspot locations are typically characterized by angles between materials with significantly different electrical conductivity. For example, the electrical conductivity of a common metal electrode is very high (σ = 6 × 10⁻⁶). 7 S / m Siemens / meter (Siemens is 1 / Ω). Current within a highly conductive electrode flows to the electrode rim virtually without resistance, creating potential hot spots near the edges of one or more electrodes (e.g., the corners of the top surface of the electrodes, the junctions between the electrode edges and the substrate, etc.).

[0009] According to some aspects of the subject matter of this disclosure, one or more arc-shaped elements are coupled to the electrode at each potential hotspot location where a hotspot may occur if the electrode comes into direct contact with blood. The arc-shaped elements reduce the intensity of the electric field at each location, thereby preventing arcing.

[0010] The electrode should remain flexible even when the shaft is housed within the sheath and protected by an arcuate element so as to be inserted through the sheath. This can be achieved by using a relatively thin arcuate element. In some examples, the arcuate element is printed on the electrode with a flexible ink. The elongation ratio λ = l / L (where l is the final length and L is the initial length) of the flexible conductive ink can be about 1,000 times that of a typical metal. Thus, a thin flexible conductive ink can have a 10% elongation with nearly the same performance compared to a metal having a 0.01% elongation.

[0011] Similarly, the substrate should be sufficiently flexible to allow the sheath to pass through with the arcuate element present.

[0012] As will be described in more detail below, the materials used to form the electrode and the arcuate element can have similar or different respective conductivities. The size and shape of the arcuate element are adapted to the difference between these conductivities.

Brief Description of the Drawings

[0013] To better understand the subject matter disclosed herein and to illustrate how the subject matter can actually be carried out, examples will be described here as merely non-limiting examples while referring to the accompanying drawings. [Figure 1] Illustrates a catheter-based electrophysiological mapping and ablation system according to an embodiment of the subject matter of the present disclosure. [Figure 2] Illustrates an electrode having no arcuate element coupled to the substrate. [Figure 3A] Shows the simulation results of a flat electrode having no arcuate element coupled to the substrate. [Figure 3B] Shows the simulation results of a flat electrode having no arcuate element coupled to the substrate. [Figure 4A] Simplified diagrams of catheter assemblies according to respective embodiments of the subject matter of the present disclosure. [Figure 4B] Simplified diagram of a catheter assembly according to each example of the subject matter of the present disclosure. [Figure 5] Simplified illustrative diagram of an end effector having a balloon-shaped substrate according to an example of the subject matter of the present disclosure. [Figure 6A] Simplified cutaway view of an end effector according to an example of the subject matter of the present disclosure. [Figure 6B] Simplified cutaway view of an end effector according to an example of the subject matter of the present disclosure. [Figure 7A] Simplified flowchart of a method of manufacturing a catheter assembly having hot spot protection according to an example of the subject matter of the present disclosure. [Figure 7B] Simplified flowchart of a method of preparing an end effector according to an example of the subject matter of the present disclosure. [Figure 8A] Simplified illustrative diagram of an end effector according to some examples of the subject matter of the present disclosure. [Figure 8B] Simplified illustrative diagram of an end effector according to some examples of the subject matter of the present disclosure. [Figure 8C] Simplified illustrative diagram of an end effector according to some examples of the subject matter of the present disclosure. [Figure 8D] Simplified illustrative diagram of an end effector according to some examples of the subject matter of the present disclosure. [Figure 9A] Simplified illustrative diagram showing a process for manufacturing an end effector according to an example of the subject matter of the present disclosure. [Figure 9B] Simplified illustrative diagram showing a process for manufacturing an end effector according to an example of the subject matter of the present disclosure. [Figure 9C] Simplified illustrative diagram showing a process for manufacturing an end effector according to an example of the subject matter of the present disclosure. [Figure 9D] Simplified illustrative diagram showing a process for manufacturing an end effector according to an example of the subject matter of the present disclosure. [Figure 10A] This is a simplified illustrative diagram of an end effector according to some embodiments of the subject matter of this disclosure. [Figure 10B] This is a simplified illustrative diagram of an end effector according to some embodiments of the subject matter of this disclosure. [Figure 10C] This is a simplified illustrative diagram of an end effector according to some embodiments of the subject matter of this disclosure. [Figure 11A] This is a simplified illustrative diagram illustrating a process for manufacturing an end effector according to an embodiment of the subject matter of the present disclosure. [Figure 11B] This is a simplified illustrative diagram illustrating a process for manufacturing an end effector according to an embodiment of the subject matter of the present disclosure. [Figure 11C] This is a simplified illustrative diagram illustrating a process for manufacturing an end effector according to an embodiment of the subject matter of the present disclosure. [Figure 11D] This is a simplified illustrative diagram illustrating a process for manufacturing an end effector according to an embodiment of the subject matter of the present disclosure. [Figure 12] This is a simplified illustrative diagram of an edge effector according to some embodiments of the subject matter of this disclosure. [Figure 13A] This is a simplified cutaway diagram illustrating a lamination process for manufacturing embedded electrodes according to exemplary embodiments of the subject matter of this disclosure. [Figure 13B] This is a simplified cutaway diagram illustrating a lamination process for manufacturing embedded electrodes according to exemplary embodiments of the subject matter of this disclosure. [Figure 13C] This is a simplified cutaway diagram illustrating a lamination process for manufacturing embedded electrodes according to exemplary embodiments of the subject matter of this disclosure. [Figure 14] This is a simplified cutaway view of an embedded electrode according to an exemplary embodiment of the subject matter of the present disclosure. [Modes for carrying out the invention]

[0014] According to aspects of this disclosure, one or more arc-shaped elements are coupled to the top surface (also called the “upper surface”) of the electrode of the catheter assembly. The arc-shaped elements reduce the intensity of the electric field surrounding each of their respective locations compared to the intensity of the electric field that would be generated for an electrode of similar size, shape, and material but without the arc-shaped elements while operating in the blood.

[0015] The following detailed description includes many specific details to help fully understand the invention. However, it will be understood by those skilled in the art that the subject matter disclosed herein can be carried out without these specific details. In other cases, well-known methods and features are not described in detail so as not to obscure the subject matter disclosed herein.

[0016] Refer to Figure 1, which shows an exemplary catheter-based electrophysiological mapping and ablation system 10. The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 through the patient's vascular system into the lumen or vascular structure of the heart 12. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 12. One or more catheters can then be inserted into the delivery sheath catheter to reach a desired location in the heart 12. The multiple catheters may include a catheter dedicated to sensing intracardiac electrogram (IEGM) signals, a catheter dedicated to ablation, and / or a catheter dedicated to both sensing and ablation. An exemplary catheter 14 configured to sense IEGM is illustrated herein. To sense a target site in the heart 12, the physician 24 may position the distal end 28 of the catheter 14 in contact with the heart wall. For ablation, the physician 24 may similarly position the distal end of an ablation catheter in contact with a target site for tissue ablation.

[0017] The catheter 14 is an exemplary catheter comprising one, preferably multiple, electrodes 26 optionally distributed across a plurality of splines 22 at the distal tip 28 and configured to sense IEGM signals. The catheter 14 may additionally include a position sensor 29 implanted in or near the distal tip 28 to track the position and orientation of the distal tip 28. Optionally and preferably, the position sensor 29 is a magnetic-based position sensor comprising three magnetic coils for sensing three-dimensional (3D) position and orientation.

[0018] A magnetic-based position sensor 29 may operate in conjunction with a location pad 25 which includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predefined working volume. The real-time position of the distal tip 28 of the catheter 14 may be tracked based on the magnetic field generated using the location pad 25 and sensed by the magnetic-based position sensor 29. Details of magnetic-based position sensing technology are described in U.S. Patents No. 5,5391,199, No. 5,443,489, No. 5,558,091, No. 6,172,499, No. 6,239,724, No. 6,332,089, No. 6,484,118, No. 6,618,612, No. 6,690,963, No. 6,788,967, and No. 6,892,091.

[0019] System 10 includes one or more electrode patches 38 positioned for skin contact on a patient 23 to establish a location reference for the location pad 25 and impedance-based tracking of the electrodes 26. In the case of impedance-based tracking, a current is directed to the electrode 26 and sensed in the electrode skin patch 38 so that the location of each electrode can be triangulated through the electrode patch 38. Details of impedance-based location tracking technology are described in U.S. Patents 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182.

[0020] The recorder 11 records and displays the electrophysiological diagram 21 captured by the body surface ECG electrode 18 and the intracardiac electrophysiological diagram (IEGM) captured by the electrode 26 of the catheter 14. The recorder 11 may include pacing capabilities for pacing the rhythm of the heart and / or may be electrically connected to a standalone pacer.

[0021] System 10 may include an ablation energy generator 50 adapted to transmit ablation energy to one or more electrodes located at the distal tip of a catheter configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy, pulsed-field ablation (PFA) energy including unipolar or bipolar high-voltage DC pulses that may be used to perform irreversible electroporation (IRE), or a combination thereof.

[0022] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheter, other electrophysiological devices, a power supply unit, and a workstation 55 for controlling the operation of the system 10. The electrophysiological devices of the system 10 may include, for example, multiple catheters, a location pad 25, a body surface ECG electrode 18, an electrode patch 38, an ablation energy generator 50, and a recorder 11. Optionally, and preferably, the PIU 30 additionally includes processing capabilities for implementing real-time calculation of catheter location and performing ECG calculations.

[0023] The workstation 55 includes memory, a processor unit having memory or storage device internally storing appropriate operating software, and user interface functions. The workstation 55 may optionally provide several functions, including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on a display device 27; (2) displaying activation sequences (or other data) compiled from recorded electrophoresis diagrams 21 on the display device 27 as a representative visual representation or image superimposed on the rendered anatomical map 20; (3) displaying the real-time location and orientation of multiple catheters within the cardiac chambers; and (4) displaying areas of interest, such as the locations where ablation energy has been applied, on the display device 27. A single commercial product embodying each element of the system 10 is available as the CARTO® 3 system, commercially available from Biosense Webster, Inc. (31A Technology Drive, Irvine, CA, 92618).

[0024] While the system described above is intended for catheter assemblies for cardiac tissue ablation, this example is not limiting. Other embodiments of the catheter assembly may be suitable for ablation of tissues of other body organs, such as kidney or lung tissue ablation.

[0025] Here, we refer to Figure 2, a simplified block diagram of an electrode without an arc-shaped element bonded to a substrate. The electrode 210 is printed on an insulating substrate 220 (such as a balloon wall). A metal pad 230 is connected to a wire 240 which is connected to a power source (not shown) that supplies power to the electrode 210.

[0026] There are several locations on electrode 210 where hotspots may occur if the electrode operates directly in the blood. Typical hotspot locations are marked as follows: a) Location A: Surrounding the junction between the insulating substrate 220 (e.g., balloon wall), electrode 210, and blood. b) Location B: Surrounding the corner of electrode 210 in the blood. c) Location C: On the corner joint of the pad 230 (typically copper), electrode 210 and insulating substrate 220.

[0027] Figures 3A and 3B show simulation results for a flat electrode with a typical material thickness of approximately 20 μm. High electric fields can be observed at all three potential hotspot locations A, B, and C.

[0028] I. Catheter Assembly According to several aspects of the disclosed subject matter, a catheter assembly is configured to prevent the occurrence of at least one hotspot during the operation of the catheter assembly. This is achieved by coupling one or more arcuate elements to the electrode at potential hotspot locations that may be surrounded by a high-intensity electric field during the ablation procedure if the electrode is not coupled to an arcuate element.

[0029] For clarity, some aspects of this disclosure describe non-limiting examples of catheter assemblies having a single electrode. Other aspects of the subject matter of this disclosure may include catheter assemblies having multiple electrodes, at least one of which is coupled to an arc-shaped element to prevent a strong electric field from being generated around the electrode during operation of the catheter assembly.

[0030] The catheter assembly includes a shaft and an end effector coupled to the distal portion of the shaft. The shaft is configured to be guided into the lumen through a delivery sheath.

[0031] The end effector includes electrodes printed on a substrate and at least one arc-shaped element.

[0032] The electrodes are configured to deliver energy to the ablation site. The bottom surface of the electrodes is bonded to the substrate. The arc-shaped elements are bonded to the top surface of the substrate.

[0033] According to some aspects of the disclosed subject matter, arc-shaped elements are printed on electrodes.

[0034] The arc-shaped elements extend over each location, reducing the intensity of the electric field at each location to below the arcing level when the electrodes are operating in the blood. In this way, the formation of hot spots around the electrodes during operation in the blood is prevented.

[0035] In some examples, the end effector includes an arc-shaped element that extends over the edge of the upper surface of the electrode.

[0036] In alternative or additional embodiments, the end effector includes an arc-shaped element extending over the exposed connection between the bottom surface of the electrode and the substrate.

[0037] In another alternative or additional embodiment, the end effector includes a conductive pad configured to supply power to an electrode, and the end effector includes an arc-shaped element extending over the location of the conductive pad.

[0038] In some aspects of this disclosure, a single arc-shaped element extends over multiple potential hotspot locations.

[0039] For effective operation, it is desirable that the surface area of ​​the electrode remain as large as possible. In some aspects of this disclosure, the total area covered by the arcuate element is less than 10% of the upper surface of the electrode. In other aspects of this disclosure, the total area covered by the arcuate element is less than 13% of the upper surface of the electrode. In yet another aspect of this disclosure, the total area covered by the arcuate element is less than 15% of the upper surface of the electrode.

[0040] According to one aspect of the present disclosure, the substrate is expandable (e.g., balloon-shaped). The expandable substrate can be folded so that the end effector can be guided through the delivery sheath until it reaches the ablation site. When it reaches the ablation site, the substrate expands.

[0041] In an alternative example, the substrate is non-expandable. In a further example, the substrate has a cylindrical shape.

[0042] I.1. Conductivity One factor that affects the ability of the arcuate element to reduce the electric field is the respective conductivity of the electrode material and the arcuate element material.

[0043] To describe the conductivity level of a material (e.g., electrode material, arcuate element material, etc.), the following terms are used herein. 1. Conductive material (metal) - an electrical conductivity of 6x10 7 S / m, 2. Low conductivity material - an electrical conductivity of 10 4 ~10 6 S / m, 3. Very low conductivity material - an electrical conductivity of 100~5,000 S / m, 4. Extremely low conductivity material - an electrical conductivity of 0.5~5 S / m, and 5. Non-conductive material - an electrical conductivity of 10 -13 S / m.

[0044] In one aspect of the present disclosure, the electrode and the arcuate element are composed of the same material and thus have the same conductivity. In one example, the electrode and the arcuate element have the same conductivity of 10 3 ~10 6 S / m. In a further aspect, the thickness of the arcuate element is within 1.8 to 5.2 times the thickness of the electrode.

[0045] In another aspect of the present disclosure, the electrode and the arcuate element are composed of different materials, and the conductivity of the arcuate element is lower than that of the electrode. In one example, the conductivity of the electrode is 10 3 ~10 6The conductivity is S / m, and the conductivity of the arc-shaped element is within 0.5 to 5 S / m. In a further embodiment, the thickness of the arc-shaped element is within 0.8 to 3.2 times the thickness of the electrode.

[0046] Herein, we refer to Figure 4A, a simplified diagram of a catheter assembly according to an embodiment of the subject matter of the present disclosure. The catheter assembly 400 includes a shaft 410 and an end effector 430. The shaft 410 is configured to be guided into the lumen through a delivery sheath. The end effector 430 is coupled to the proximal end of the shaft 410 and includes an electrode 440 and arcuate elements 450.1-450.3 coupled to the electrode 440.

[0047] The electrode 440 is bonded to the substrate 420 and configured to deliver energy to the ablation site. The electrode 440 is formed as a strip along a portion of the outer periphery of the end effector 430.

[0048] The arc-shaped elements have a curved upper surface and extend over each potential hotspot location. Arc-shaped elements 450.1–450.2 are located at each edge of the electrode 440. Arc-shaped element 450.3 is located above a conductive pad (not shown) that delivers voltage to the electrode 440.

[0049] The arc-shaped elements prevent the formation of hot spots around the electrode 440 during the ablation procedure by reducing the intensity of the electric field at each of their locations to below the arcing level.

[0050] Herein, we refer to Figure 4B, a simplified diagram of a catheter assembly according to an embodiment of the subject matter of the present disclosure. The catheter assembly 460 includes a shaft 410 and an end effector 430. The shaft 410 is configured to be guided into the lumen through a delivery sheath. The end effector 430 is coupled to the proximal end of the shaft 410 and includes an electrode 470 and arcuate elements 480.1-480.3 coupled to the electrode 470. The electrode 470 is coupled to a substrate 420 and is configured to deliver energy to the ablation site.

[0051] The electrode 470 and the arcuate elements 480.1–480.2 surround the end effector 430. The arcuate elements have a curved upper surface and extend over their respective potential hotspot locations. The arcuate elements 480.1–480.2 are located at each edge of the electrode 470. The arcuate element 480.3 is located above a conductive pad (not shown) that delivers voltage to the electrode 470.

[0052] The arc-shaped elements prevent the formation of hot spots around electrode 470 during the ablation procedure by reducing the intensity of the electric field at each of their locations to below the arcing level.

[0053] Herein, we refer to Figure 5, a simplified illustrative diagram of an end effector 500 having a balloon-shaped substrate 510 according to an embodiment of the subject matter of the present disclosure. Electrodes 520.1 to 520.4 are printed on the balloon-shaped substrate 510. In the case of cardiac ablation, the balloon may have a diameter of approximately 30 mm and has a relatively thick catheter that needs to be navigated into the heart using a sheath. The balloon is folded and flexible enough to pass through the sheath. Therefore, it is desirable that the printed electrodes 520.1 to 520.4 and their combined arcuate elements (not shown) be as thin as possible and made of flexible ink so that each layer of printing can harden the balloon.

[0054] Herein, we refer to Figures 6A and 6B, which are simplified cutaway diagrams of end effectors according to embodiments of the subject matter of this disclosure. In Figure 6A, the electrodes and arc elements are made of the same material. In Figure 6B, the electrodes and arc elements are made of different materials having different conductivity properties.

[0055] Referring to Figure 6A, electrode 620 is printed from a material having low to very low conductivity and has a layer thickness t2 of approximately 10 microns (ranging from 5 to 20 microns). Arc elements 640.1, 640.2, and 650 are formed from the same material as electrode 620. Arc element 640.1 covers a small portion of the top surface of electrode 620, the entire height of electrode 620, and a portion that slightly overlaps the top surface of substrate 610 (e.g., balloon), ensuring that potential hotspot locations (e.g., locations A and B in Figure 3B) are completely covered. This arc cover creates a larger radius at the corners, reducing the electric field by at least half. In one example, the width W of the arc element is approximately 0.5 to 1.0 mm (ranging from 0.3 to 2.0 mm) and is applied approximately equally to both sides / ends of the top surface of electrode 620 (or around the rim of a closed shape). The height t1 of the upper arc-shaped element on the surface of electrode 620 is approximately 50 microns (in the range of 20 to 80 microns), and the total thickness above the substrate surface is approximately 60 microns.

[0056] A second arc-shaped element 640.2 of similar shape and size is coupled to the opposite edge of the electrode 620.

[0057] A third arc-shaped element 650 is coupled above the pad 630 that supplies high voltage. The arc-shaped element 650 has a dome shape with a thickness t1 and a diameter Y slightly larger than that of the pad (for example, if the pad diameter is 2 mm, the diameter Y of the arc-shaped element may be 3 mm).

[0058] Referring to Figure 6B, electrode 620 is printed with a material having low to very low conductivity and a layer thickness t2 of approximately 10 microns. The edges of the electrode are covered with arcuate elements 660.1-660.2 made from a material having extremely low conductivity (i.e., electrical conductivity of 0.5-5 S / m). The thickness t3 of the arcuate elements is approximately 20 microns, and the average width W is approximately 0.5-1.0 mm. The arcuate element 670 above pad 630 is also made from a material with extremely low conductivity and has a thickness t3 of approximately 20 microns.

[0059] II. Method for Manufacturing Catheter Assemblies Herein, we refer to Figure 7A, a simplified flowchart of a method for manufacturing a catheter assembly having hotspot protection according to an embodiment of the subject matter of the present disclosure. The catheter assembly includes at least one electrode. The electrode is coupled to at least one arc-shaped element to reduce the intensity of the electric field at each location and to prevent arcing.

[0060] In 710, the end effector is prepared. In one embodiment, the end effector is prepared as described with reference to Figure 7B.

[0061] In the 720, the end effector is coupled to the distal portion of a shaft configured to be guided to the ablation site through a delivery sheath.

[0062] Herein, we refer to Figure 7B, a simplified flowchart of a method for manufacturing an end effector according to an embodiment of the subject matter of this disclosure.

[0063] In 730, electrodes configured to deliver energy to the ablation site are printed on the substrate. The electrodes have a bottom surface bonded to the substrate and a top surface.

[0064] In 740, the bottom surface of at least one arc-shaped element is coupled to the top surface of the electrode. The arc-shaped elements extend above each location to reduce the intensity of the electric field at each location to below the arcing level during the operation of the electrode in the blood.

[0065] According to some embodiments, the term “top surface of the electrode” includes the exposed corners and edges of the electrode that are available for coupling to the arcuate element.

[0066] The combined end effector and shaft provide a catheter assembly having at least one protected area where the arc-shaped element prevents the occurrence of hot spots during electrode operation.

[0067] In one example, the arc-shaped element is coupled to the electrode by printing the arc-shaped element onto the electrode.

[0068] Potential hotspot locations for electrodes without arc-shaped elements include, but are not limited to, the following: a) The area surrounding the junction between the substrate, electrode, and blood, b) The area surrounding the corner of the electrode in the blood, c) The corners of the pads, the electrodes, and the areas above the substrate joints.

[0069] According to one aspect of the present disclosure, at least one arc-shaped element extends over the location of the connection between the electrode and the power supply to the electrode.

[0070] According to one aspect of this disclosure, at least one arc-shaped element extends over the edge of the upper surface of the electrode.

[0071] According to one aspect of the present disclosure, at least one arc-shaped element extends over an exposed connection between the bottom surface of the electrode and the substrate.

[0072] In one aspect of this disclosure, the arc-shaped element covers less than 10% of the upper surface of the electrode. In another aspect of this disclosure, the total area covered by the arc-shaped element is less than 13% of the upper surface of the electrode. In yet another aspect of this disclosure, the total area covered by the arc-shaped element is less than 15% of the upper surface of the electrode.

[0073] In one aspect of this disclosure, the electrode and the arc-shaped element are made of the same material and therefore have the same conductivity. The thickness of the arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode. In one example, the electrode and the arc-shaped element are 10 3 ~10 6 They have the same conductivity in S / m.

[0074] In another aspect of this disclosure, the electrode and the arc-shaped element are composed of different materials, and the conductivity of the arc-shaped element is lower than that of the electrode. The thickness of the arc-shaped element is within 0.8 to 3.2 times the thickness of the electrode. In one example, the conductivity of the electrode is 10 3 ~10 6 The conductivity is S / m, and the conductivity of the arc-shaped element is within 0.5 to 5 S / m.

[0075] Exemplary end effector Herein, we refer to Figures 8A to 8D, which are simplified illustrative diagrams of an end effector according to an embodiment of the subject matter of this disclosure. For simplicity, the electrodes have a round shape and are presented printed on the wall of a balloon-shaped substrate. In alternative embodiments, the electrodes and substrate may have other shapes and dimensions (e.g., the triangular electrodes in Figure 5).

[0076] Figure 8A is a top view of electrodes printed on the wall of a balloon-shaped substrate 810.

[0077] Figure 8B is a cross-sectional view AA showing a printed conductor 813 made of a conductive material covered with an insulating material layer 814. The printed conductor 813 connects the electrode 811 to a high input voltage supplied by a wire routed inside the shaft of the balloon.

[0078] Figure 8C is a cross-sectional view BB showing an extended connection area covered by a layer 16 having a diameter E between the conductor and the electrode. This area is necessary to reduce the high electric field generated at their connection point. The diameter E ranges from 0.5 to 2 mm.

[0079] Figure 8D is a cross-sectional view CC showing an electrode 812 coupled to two arcuate elements 815.1 and 815.2. The width of the arcuate elements is C.

[0080] Herein, we refer to Figures 9A to 9D, which are simplified illustrative diagrams illustrating the process for manufacturing the end effectors shown in Figures 8A to 8D according to embodiments of the subject matter of this disclosure. Printing may be carried out, for example, by spray or pad printing.

[0081] Figure 9A shows a printed conductor 813 made from a conductive material. In one example, the printed conductor 813 has a typical thickness A of 10 microns (in the range of 5 to 20 microns).

[0082] Figure 9B shows insulating material 814 printed on conductor 813 (to insulate conductor 813 from blood). The insulator does not cover the entire conductor 813, leaving a portion of it exposed. In one example, insulating material 814 has a typical thickness B of about 10 microns and a typical width of about 1 mm (ranging from 0.5 to 2 mm).

[0083] Figure 9C shows an electrode printed on the exposed edge of conductor 813. In one example, electrode 812 is made of a material with low to very low conductivity, typically having a thickness of about 10 microns and a diameter D of about 10 mm. An extended connection area 817 with a width E covers the connection between conductor 813 and electrode 812.

[0084] Figure 9D shows protective arc elements 815 printed around the edge of electrode 812 and the extended connection area. In one example, the width C of the arc element 815 is approximately 0.5–1.0 mm, and the diameter F of the protective area 816 on the extended connection area is approximately 4 mm.

[0085] The type of material used to print the arc-shaped element layer can be one of the two approaches described with respect to Figures 6A and 6B. That is, the arc-shaped element 815 can be made from the same material as the electrode 812, or from a material having a much lower conductivity compared to the electrode material.

[0086] Herein, we refer to Figures 10A to 10C, which are simplified illustrative diagrams of an end effector according to an embodiment of the subject matter of this disclosure. Figure 10A is a top view of an electrode printed on the balloon wall. Figure 10B is a cross-sectional view AA. Figure 10C is a cross-sectional view BB.

[0087] The electrode 1032 is printed on the balloon wall 1031. The flexible printed circuit 1033 is made from an insulating base material 1039 (e.g., Kapton) and a metal conductor 1033 (e.g., copper). The metal conductor 1033 faces the electrode 1032 and is bonded to the electrode with a conductive adhesive 1038. As shown in the inset of Figure 10B, the adhesive 1038 fills the gap between the printed circuit 1033 and the electrode 1032, continues to spread to the sides, covers the sidewall of the printed circuit 1033, and extends beyond the corner J.

[0088] Figure 10C shows the arc-shaped elements 1035 and 1037. The arc-shaped element 1035 extends along the entire edge of the electrode 1032, covering both the upper corner of the electrode 1032 and the connection between the electrode 1032 and the printed circuit board 1033. The arc-shaped element 1037 is located above the connection between the conductor 1033 and the electrode 1032. The arc-shaped element 1037, like the arc-shaped element 650 in Figure 6A, reduces the intensity of the electric field at the connection site.

[0089] Herein, we refer to Figures 11A to 11D, which are simplified illustrative diagrams illustrating the process for manufacturing the end effectors shown in Figures 10A to 10C according to embodiments of the subject matter of this disclosure.

[0090] Figure 11A illustrates the printing of the electrode 1032 itself, which has a diameter D, typically about 10 mm. The electrode material has a typical thickness of about 10 microns and low to very low electrical conductivity. Figure 11B illustrates the placement of the flexible printed circuit 1033 and the application of a layer of conductive adhesive 1038 to the bottom of the circuit. The adhesive layer 1038 is positioned on the electrode 1032 so that its edge reaches approximately the center of the electrode, and is pressed so that it spreads out to the sides. The width t4 is typically about 1 mm.

[0091] After the adhesive has dried properly, a protective layer is printed on the electrode edge 1035 with a typical width of approximately 0.5–1.0 mm, as shown in Figure 11C. The arc-shaped element 1036 is dome-shaped and printed with a diameter I of approximately 2–3 mm to protect the edge of the printed circuit from arcing.

[0092] Optionally, the printed circuit 1033 may have one or more holes 1040. The holes 1040 may be used to create arc-shaped elements on the edges of electrodes by injecting conductive adhesive through the holes, for example, as shown in Figure 11D.

[0093] Figure 11D is a cross-sectional view of AA in Figure 11C illustrating an embodiment in which a metal-based adhesive (e.g., platinum or silver) is injected into the gap between the printed circuit (PCB copper) and the pad printed electrodes by using a dispenser from above to inject the adhesive through the holes in the printed circuit.

[0094] The type of material used for the arcuate element can be one of the two approaches described with respect to Figures 6A and 6B. That is, the arcuate element 1035 can be made from the same material as the electrode 1032, or from a material having a much lower conductivity compared to the electrode material.

[0095] Herein, we refer to Figure 12, a simplified illustrative diagram of an edge effector according to an embodiment of the subject matter of the present disclosure. The edge effector 1200 has a cylindrical shape, which is an axially symmetric rotation of a flat end effector illustrated in Figures 6A-6B. The substrate 1271 is a tube having a diameter of 1-3 mm. The tube has electrodes 1272 printed thereon and is made of a material having low to very low electrical conductivity and has a typical thickness of about 10 microns (ranging from 5-50 microns). The thin layer allows for the maintenance of the flexibility of the end effector, in particular for catheters with a small diameter of about 1 mm that need to be inserted into narrow blood vessels. High voltage reaches the electrodes 1272 from a metal pad 1273 to which thin wires are connected and routed inside the catheter toward the catheter handle (and from there through a connector to the generator). Arc-shaped elements 1275 are applied around the edge of the electrodes and have a thickness t of about 10-20 microns. A dome-shaped arc-shaped element 1274 with a diameter I slightly larger than the pad size is applied above the pad area.

[0096] The type of material used for the arcuate elements can be one of the two approaches described with respect to Figures 6A and 6B. That is, the arcuate elements 1275 and 1274 can be made from the same material as electrode 1032, or from a material having a much lower conductivity compared to the electrode material.

[0097] Herein, we refer to Figures 13A–13C, which are simplified cutaway diagrams of implanted electrodes illustrating a distal end laminated manufacturing process of a catheter according to exemplary embodiments of the subject matter of this disclosure.

[0098] The distal end lamination process of the catheter uses the protruding electrode as a "mold" barrier. During lamination, heat and pressure are applied to press the printed circuit board (PCB) into thermoplastic polyurethane (TPU). The TPU flows to the electrode, leaving the metal exposed.

[0099] Figure 13A is a simplified illustrative diagram of the layers stacked in preparation for the lamination process. The layered structure is, i. Upper PCB1300 having printed electrodes, ii.Top TPU layer 1310.1, iii. Nitinol layer 1320, iv. Lower TPU layer 1310.2, and v. Lower PCB1301 having printed electrodes.

[0100] In Figure 13B, heat and pressure are applied to the stacked layers. As a result, the TPU layers fuse into a single TPU element 1310 that encapsulates the nitinol layer 1320.

[0101] In Figure 13C, heat and pressure are continuously applied. The TPU element 1300 covers the sides of PCB 1300 and PCB 1301, leaving the conductive surface of the electrodes substantially exposed.

[0102] Problems can arise if the TPU does not make contact with the edge of the electrode, leaving the edge exposed. This can create a potential hotspot at the interface between the embedded electrode and the TPU.

[0103] Herein, we refer to Figure 14, a simplified cutaway diagram of an embedded electrode according to an exemplary embodiment of the subject matter of this disclosure. Arc-shaped elements 1330.1–1330.4 are printed on the respective interfaces between the electrode and the TPU 1310 so that potential hotspot locations are completely covered.

[0104] In one aspect of this disclosure, the electrode and the arc-shaped element are made of the same material and therefore have the same conductivity. The thickness of the arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode. In one example, the electrode and the arc-shaped element are 10 3 ~10 6 They have the same conductivity in S / m.

[0105] In another aspect of this disclosure, the electrode and the arcuate element are composed of different materials, and the conductivity of the arcuate element is lower than that of the electrode. The thickness of the arcuate element is within 0.8 to 3.2 times the thickness of the electrode. In one example, the conductivity of the electrode is 10 3 ~10 6 The conductivity is S / m, and the conductivity of the arc-shaped element is within 0.5 to 5 S / m.

[0106] In another example, the electrode thickness t5 is approximately 7–15 μm, and the thickness of the conductive printed arc-shaped element is approximately 10–30 μm.

[0107] The following is a non-exclusive list of some exemplary embodiments of the present disclosure. The disclosure also includes embodiments that have fewer features than all of the embodiments, and embodiments that use features from multiple embodiments, even if not listed below.

[0108] Example 1: A catheter assembly (400) is configured to prevent the occurrence of at least one hot spot during the operation of the catheter assembly (400), wherein the hot spot includes a location where the surrounding electric field exceeds the arcing level in the blood, and the catheter assembly (400) A shaft (410) having a defined longitudinal axis extending from the proximal to distal portion of the shaft (410), configured such that the shaft (410) is guided into the lumen through a delivery sheath, An end effector (430) is coupled to the distal portion of the shaft (410), wherein the end effector (430) is An electrode (440) printed on a substrate (420), wherein the electrode (440) has a bottom surface bonded to the substrate (420) and a top surface, and the electrode (440) is configured to deliver energy to the ablation site, A catheter assembly (400) comprising an end effector (430) including at least one arc-shaped element (450) having a bottom surface coupled to the upper surface of an electrode (440) and a curved upper surface, wherein at least one arc-shaped element (450) extends over each of the locations such as to reduce the intensity of the electric field at each location to below the arcing level when the electrode (440) is operating in blood, thereby preventing the occurrence of at least one hot spot during the operation of the electrode (440) in blood.

[0109] Example 2: The catheter assembly according to Example 1 further includes a conductive pad configured to supply power to an electrode (440), wherein at least one of the arc-shaped elements (450) extends over the location of the conductive pad.

[0110] Example 3: The catheter assembly according to Example 1 or Example 2, wherein at least one of the arc-shaped elements (450) extends over the edge of the upper surface of the electrode (440).

[0111] Example 4: A catheter assembly according to any one of Examples 1 to 3, wherein at least one of the arc-shaped elements (450) extends over the exposed connection between the bottom surface of the electrode (440) and the substrate (420).

[0112] Example 5: A catheter assembly according to any one of Examples 1 to 4, wherein the arc-shaped element (450) covers less than 10% of the upper surface of the electrode (440).

[0113] Example 6: A catheter assembly according to any one of Examples 1 to 4, wherein the arc-shaped element (450) covers less than 13% of the upper surface of the electrode (440).

[0114] Example 7: A catheter assembly according to any one of Examples 1 to 4, wherein the arc-shaped element (450) covers less than 15% of the upper surface of the electrode (440).

[0115] Example 8: A catheter assembly according to any one of Examples 1 to 7, wherein the electrode (440) and at least one arc-shaped element are made of the same material, and the thickness of at least one arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode (440).

[0116] Example 9: The electrode (440) and at least one arc-shaped element are made of the same material, and the material is 10 3 ~10 6 A catheter assembly according to any one of Examples 1 to 8, having a conductivity of S / m.

[0117] Example 10: A catheter assembly according to any one of Examples 1 to 7, wherein the conductivity of the arcuate element is lower than that of the electrode (440), and the thickness of at least one arcuate element is within 0.8 to 3.2 times the thickness of the electrode (440).

[0118] Example 11: The conductivity of electrode (440) is 10 3 ~10 6 A catheter assembly according to any one of Examples 1 to 7 and 10, wherein the conductivity of the arc-shaped element is within 0.5 to 5 S / m, and the conductivity of the arc-shaped element is within 0.5 to 5 S / m.

[0119] Example 12: A catheter assembly according to any one of Examples 1 to 11, wherein at least one arc-shaped element is printed on the upper surface of the electrode (440).

[0120] Example 13: A catheter assembly according to any one of Examples 1 to 12, wherein the substrate (420) is balloon-shaped.

[0121] Example 14: A catheter assembly according to any one of Examples 1 to 12, wherein the substrate (420) is cylindrical in shape.

[0122] Example 15: A method for manufacturing a catheter assembly (400) having hotspot protection, wherein the hotspot includes a location where the surrounding electric field exceeds the arcing level in the blood. The end effector (430) is to be prepared. Printing an electrode (440) onto a substrate (420), wherein the electrode (440) has a bottom surface bonded to the substrate (420) and a top surface, and the electrode (440) is configured to deliver energy to the ablation site. Preparing an end effector (430) by coupling at least one arc-shaped element to the electrode (440), wherein the at least one arc-shaped element has a bottom surface coupled to the upper surface of the electrode (440) and a curved upper surface, and the at least one arc-shaped element extends over each location such that, during the operation of the electrode (440) in the blood, the intensity of the electric field at each location is reduced to below the arcing level. The end effector (430) is coupled to the distal portion of the shaft (410), wherein the shaft (410) defines a longitudinal axis extending from the proximal portion to the distal portion of the shaft (410), and the shaft (410) is configured to be guided to the ablation site through the delivery sheath. A method to provide a catheter assembly (400) having at least one protected area for preventing the occurrence of hot spots during the operation of the electrode (440).

[0123] Example 16: The method according to Example 15, wherein bonding at least one arcuate element to the electrode (440) includes printing the arcuate element onto the electrode (440).

[0124] Example 17: The method according to Example 15 or Example 16, wherein at least one of the arc-shaped elements (450) extends over the location of the connection between the electrode (440) and the power supply to the electrode (440).

[0125] Example 18: The method according to any one of Examples 15 to 17, wherein at least one of the arc-shaped elements (450) extends over the edge of the upper surface of the electrode (440).

[0126] Example 19: The method according to any one of Examples 15 to 18, wherein at least one of the arc-shaped elements (450) extends over the exposed connection between the bottom surface of the electrode (440) and the substrate (420).

[0127] Example 20: The method according to any one of Examples 15 to 19, wherein the arc-shaped element (450) covers less than 15% of the upper surface of the electrode (440).

[0128] Example 21: The method according to any one of Examples 15 to 20, wherein the electrode (440) and at least one arc-shaped element are made of the same material, and the thickness of at least one arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode (440).

[0129] Example 22: The conductivity of electrode (440) is 10 3 ~10 6 The method according to any one of Examples 15 to 20, wherein the conductivity of the arc-shaped element is within 0.5 to 5 S / m, and the thickness of at least one arc-shaped element is within 0.8 to 3.2 times the thickness of the electrode (440).

[0130] Those skilled in the art to which this disclosure pertains will understand that, although this disclosure has been described in terms of preferred embodiments, the concepts on which this disclosure is based can be readily used as a basis for designing other structures, systems, and processes to accomplish some of the purposes of this disclosure.

[0131] Furthermore, it should be understood that the expressions and terms used herein are for illustrative purposes only and should not be considered limiting. Note that the words “comprising,” “including,” and “having,” as used throughout the attached claims, should be interpreted as “including but not limited to.” The indefinite articles “a” and “an,” as used herein and in the claims, should be understood as “at least one,” unless explicitly stated otherwise. The phrases “and / or,” as used herein and in the claims, should be understood as “either or both,” of the thus combined elements, that is, elements that exist as a combination in some cases and as separate in others. The term “each” may not be understood exclusively as referring to each and all, and may also refer to “at least some,” where technically relevant.

[0132] All patents and patent applications referenced herein are incorporated herein by reference as in whole, as if each individual patent or patent application were specifically and individually indicated to be incorporated herein by reference. No reference or specification of any reference in this application should be construed as an admission that such documents are available as prior art to this disclosure.

[0133] Therefore, it is important to note that the scope of this disclosure should not be construed as being limited by the illustrative examples described herein. Other modifications are possible within the scope of this disclosure as defined in the appended claims. Other combinations and subcombinations of features, functions, elements, and / or properties may be asserted by modifications to the claims or by presentation of new claims in this application or a related application. Such modifications or new claims, whether they cover different or identical combinations, and whether they differ from, broader, narrower than, or identical to the scope of the original claims, are also considered to be included in the subject matter of the invention described herein.

[0134] [Implementation Method] (1) A catheter assembly, wherein the catheter assembly is configured to prevent the occurrence of at least one hot spot during the operation of the catheter assembly, the hot spot includes a location where the surrounding electric field exceeds the arcing level in the blood, and the catheter assembly A shaft having a defined longitudinal axis extending from the proximal to the distal portion of the shaft, and configured such that the shaft is guided into a lumen through a delivery sheath, An end effector coupled to the distal portion of the shaft, wherein the end effector is An electrode printed on a substrate, wherein the electrode has a bottom surface bonded to the substrate and a top surface, and the electrode is configured to deliver energy to the ablation site, An end effector comprising: at least one arc-shaped element having a bottom surface coupled to the upper surface of the electrode and a curved upper surface, wherein the at least one arc-shaped element extends over each of the locations such that when the electrode is operated in blood, the intensity of the electric field at each location is reduced to below the arcing level; A catheter assembly that thereby prevents the occurrence of the at least one hot spot during the operation of the electrode in the blood. (2) The catheter assembly according to Embodiment 1, further comprising a conductive pad configured to supply power to the electrode, wherein at least one of the arc-shaped elements extends over the location of the conductive pad. (3) The catheter assembly according to Embodiment 1, wherein at least one of the arc-shaped elements extends over the edge of the upper surface of the electrode. (4) The catheter assembly according to Embodiment 1, wherein at least one of the arc-shaped elements extends over the exposed connection between the bottom surface of the electrode and the substrate. (5) The catheter assembly according to Embodiment 1, wherein the arc-shaped element covers less than 10% of the upper surface of the electrode.

[0135] (6) The catheter assembly according to Embodiment 1, wherein the arc-shaped element covers less than 13% of the upper surface of the electrode. (7) The catheter assembly according to Embodiment 1, wherein the arc-shaped element covers less than 15% of the upper surface of the electrode. (8) The catheter assembly according to Embodiment 1, wherein the electrode and the at least one arc-shaped element are made of the same material, and the thickness of the at least one arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode. (9) The electrode and the at least one arc-shaped element are 10 3 ~10 6 A catheter assembly according to Embodiment 1, comprising the same material having conductivity of S / m. (10) The catheter assembly according to Embodiment 1, wherein the conductivity of the arc-shaped element is lower than the conductivity of the electrode, and the thickness of at least one arc-shaped element is within 0.8 to 3.2 times the thickness of the electrode.

[0136] (11) The conductivity of the electrode is 10 3 ~10 6The catheter assembly according to Embodiment 1, wherein the conductivity of the arc-shaped element is within 0.5 to 5 S / m, and the conductivity of the arc-shaped element is within 0.5 to 5 S / m. (12) The catheter assembly according to Embodiment 1, wherein at least one arc-shaped element is printed on the upper surface of the electrode. (13) The catheter assembly according to Embodiment 1, wherein the substrate is balloon-shaped. (14) The catheter assembly according to Embodiment 1, wherein the substrate is cylindrical in shape. (15) A method for manufacturing a catheter assembly having hotspot protection, wherein the hotspot includes a location where the surrounding electric field exceeds the arcing level in the blood, and the method It involves preparing the end effector. Printing electrodes onto a substrate, wherein the electrodes have a bottom surface bonded to the substrate and a top surface, and the electrodes are configured to deliver energy to the ablation site. Preparing an end effector by coupling at least one arc-shaped element to the electrode, wherein the at least one arc-shaped element has a bottom surface coupled to the top surface of the electrode and a curved top surface, and the at least one arc-shaped element extends over each of the locations such that, during the operation of the electrode in the blood, the intensity of the electric field at each location is reduced to below the arcing level. The end effector is coupled to the distal portion of the shaft, wherein the shaft defines a longitudinal axis extending from the proximal portion to the distal portion, and the shaft is configured to be guided to the ablation site through the delivery sheath. A method to provide a catheter assembly having at least one protected area for preventing the occurrence of hot spots during the operation of the electrode.

[0137] (16) The method of embodiment 15, wherein coupling the at least one arcuate element to the electrode includes printing the arcuate element onto the electrode. (17) The method of embodiment 15, wherein at least one of the arc-shaped elements extends over at least one of the following: the location of the connection between the electrode and the power supply to the electrode, the edge of the upper surface of the electrode, and the exposed connection between the bottom surface of the electrode and the substrate. (18) The method according to embodiment 15, wherein the arc-shaped element covers less than 15% of the upper surface of the electrode. (19) The method according to Embodiment 15, wherein the electrode and the at least one arc-shaped element are made of the same material, and the thickness of the at least one arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode. (20) The conductivity of the electrode is 10 3 ~10 6 The method according to Embodiment 15, wherein the conductivity of the arc-shaped element is within 0.5 to 5 S / m, and the thickness of at least one arc-shaped element is within 0.8 to 3.2 times the thickness of the electrode.

Claims

1. A catheter assembly, wherein the catheter assembly is configured to prevent the occurrence of at least one hot spot during the operation of the catheter assembly, the hot spot includes a location where the surrounding electric field exceeds the arcing level in the blood, and the catheter assembly, A shaft having a defined longitudinal axis extending from the proximal to the distal portion of the shaft, and configured such that the shaft is guided into a lumen through a delivery sheath, An end effector coupled to the distal portion of the shaft, wherein the end effector is An electrode printed on a substrate, wherein the electrode has a bottom surface bonded to the substrate and a top surface, and the electrode is configured to deliver energy to the ablation site, An end effector comprising: at least one arc-shaped element having a bottom surface coupled to the upper surface of the electrode and a curved upper surface, wherein the at least one arc-shaped element extends over each of the locations such that, when the electrode is operated in blood, the intensity of the electric field at each location is reduced to below the arcing level; A catheter assembly that thereby prevents the occurrence of the at least one hot spot during the operation of the electrode in the blood.

2. The catheter assembly according to claim 1, further comprising a conductive pad configured to supply power to the electrode, wherein at least one of the arc-shaped elements extends over the location of the conductive pad.

3. The catheter assembly according to claim 1 or 2, wherein at least one of the arc-shaped elements extends over the edge of the upper surface of the electrode.

4. The catheter assembly according to claim 1 or 2, wherein at least one of the arc-shaped elements extends over the exposed connection between the bottom surface of the electrode and the substrate.

5. The catheter assembly according to claim 1 or 2, wherein the arc-shaped element covers less than 10% of the upper surface of the electrode.

6. The catheter assembly according to claim 1 or 2, wherein the arc-shaped element covers less than 13% of the upper surface of the electrode.

7. The catheter assembly according to claim 1 or 2, wherein the arc-shaped element covers less than 15% of the upper surface of the electrode.

8. The catheter assembly according to claim 1 or claim 2, wherein the electrode and the at least one arc-shaped element are made of the same material, and the thickness of the at least one arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode.

9. The electrode and the at least one arc-shaped element are 10 ３ ~10 ６ A catheter assembly according to claim 1 or claim 2, comprising the same material having an electrical conductivity of S / m.

10. The catheter assembly according to claim 1 or claim 2, wherein the conductivity of the arc-shaped element is lower than the conductivity of the electrode, and the thickness of at least one arc-shaped element is within 0.8 to 3.2 times the thickness of the electrode.

11. The conductivity of the electrode is 10 ３ ~10 ６ The catheter assembly according to claim 1 or claim 2, wherein the conductivity of the arc-shaped element is within 0.5 to 5 S / m, and the conductivity of the arc-shaped element is within 0.5 to 5 S / m.

12. The catheter assembly according to claim 1 or 2, wherein the at least one arc-shaped element is printed on the upper surface of the electrode.

13. The catheter assembly according to claim 1 or claim 2, wherein the substrate is balloon-shaped.

14. The catheter assembly according to claim 1, wherein the substrate is cylindrical in shape.

15. A method for manufacturing a catheter assembly having hotspot protection, wherein the hotspot includes a location where the surrounding electric field exceeds the arcing level in the blood, and the method It involves preparing the end effector. Printing electrodes onto a substrate, wherein the electrodes have a bottom surface bonded to the substrate and a top surface, and the electrodes are configured to deliver energy to the ablation site. Preparing an end effector by coupling at least one arc-shaped element to the electrode, wherein the at least one arc-shaped element has a bottom surface coupled to the top surface of the electrode and a curved top surface, and the at least one arc-shaped element extends over each of the locations such that, during the operation of the electrode in the blood, the intensity of the electric field at each location is reduced to below the arcing level. The end effector is coupled to the distal portion of the shaft, wherein the shaft defines a longitudinal axis extending from the proximal portion to the distal portion, and the shaft is configured to be guided to the ablation site through the delivery sheath. A method to provide a catheter assembly having at least one protected area for preventing the occurrence of hot spots during the operation of the electrode.

16. The method according to claim 15, wherein coupling the at least one arc-shaped element to the electrode includes printing the arc-shaped element onto the electrode.

17. The method according to claim 15 or claim 16, wherein at least one of the arc-shaped elements extends over at least one of the following: the location of the connection between the electrode and the power supply unit to the electrode, the edge of the upper surface of the electrode, and the exposed connection portion between the bottom surface of the electrode and the substrate.

18. The method according to claim 15 or claim 16, wherein the arc-shaped element covers less than 15% of the upper surface of the electrode.

19. The method according to claim 15 or claim 16, wherein the electrode and the at least one arc-shaped element are made of the same material, and the thickness of the at least one arc-shaped element is within 1.8 to 5.2 times the thickness of the electrode.

20. The conductivity of the electrode is 10 ３ ~10 ６ The method according to claim 15 or claim 16, wherein the conductivity of the arc-shaped element is 0.5 to 5 S / m, and the thickness of at least one arc-shaped element is 0.8 to 3.2 times the thickness of the electrode.

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