Electrode holding features for catheter devices

Abstract

To provide a catheter assembly. [Solution] The device includes an elongated flexible shaft and an end effector. The shaft has a proximal end and a distal end. The end effector is positioned at the distal end of the shaft. The end effector includes a body, an electrode, and a bonding material. The electrode defines one or more laterally oriented openings. The bonding material secures the electrode to the body. A portion of the bonding material is positioned in at least one of the one or more laterally oriented openings.

Description

Background Art

[0001] Cardiac arrhythmias such as atrial fibrillation occur when regions of cardiac tissue conduct electrical signals abnormally. Treatments for arrhythmias include surgically disrupting such signal conduction pathways. By selectively applying electrical energy to cardiac tissue, it may be possible to stop or modify the propagation of unwanted electrical signals from one part of the heart to another. Some such ablation treatments may include radiofrequency (RF) ablation with alternating current (AC) electrical energy and / or irreversible electroporation (IRE) with pulsed field direct current (DC) electrical energy (e.g., pulsed field ablation (PFA)). The ablation process can provide a barrier to unwanted electrical pathways by forming an electrically insulating lesion or scar tissue that effectively blocks the transmission of abnormal electrical signals across the ablated tissue.

[0002] In some procedures, a catheter having one or more electrodes can be used to provide ablation within a patient's body. The catheter can be inserted into a major vein or artery (e.g., the femoral artery) and then advanced to position the electrodes within the heart or within a structure adjacent to the heart (e.g., the pulmonary vein). One or more electrodes can be placed in contact with cardiac tissue or other vascular tissue and then activated with electrical energy to ablate the contacted tissue (e.g., via RF energy, IRE, etc.). In some cases, the electrodes may be bipolar. In some other cases, monopolar electrodes can be used in conjunction with a ground pad or in conjunction with another reference electrode in contact with the patient. Perfusion can be used to draw heat away from components of the ablation catheter and prevent the formation of blood clots near the treatment site of the tissue.

[0003] Examples of ablation catheters include U.S. Patent No. 8,747,351, issued June 10, 2014, entitled "Catheter with Multi-Functional Control Handle Having Linear Mechanism" (the disclosure thereof is incorporated herein by reference in its entirety); U.S. Patent No. 8,956,353, issued February 17, 2015, entitled "Electrode Irrigation Using Micro-Jets" (the disclosure thereof is incorporated herein by reference in its entirety); U.S. Patent No. 9,220,433, issued December 29, 2015, entitled "Catheter with Variable Arcuate Distal Section" (the disclosure thereof is incorporated herein by reference in its entirety); and "Catheter with Soft Distal Tip for Mapping and Ablating Tubular" issued November 20, 2018. These are described in U.S. Patent No. 10,130,422, titled "Region" (the entire disclosure of which is incorporated herein by reference), U.S. Patent No. 10,702,177, titled "Catheter with Bipole Electrode Spacer and Related Methods," issued on July 7, 2020 (the entire disclosure of which is incorporated herein by reference), U.S. Patent No. 10,743,932, titled "Integrated Ablation System using Catheter with Multiple Irrigation Lumens," issued on August 18, 2020 (the entire disclosure of which is incorporated herein by reference), and U.S. Patent No. 11,559,349, titled "Ablation Catheter with a Flexible Printed Circuit Board," issued on January 24, 2023 (the entire disclosure of which is incorporated herein by reference).

[0004] Some catheter ablation procedures may be performed after identifying the tissue area to be targeted for ablation using electrophysiological (EP) mapping. Such EP mapping may include the use of a sensing electrode on a catheter (e.g., the same catheter used to perform the ablation, or a dedicated mapping catheter). Such a sensing electrode can monitor electrical signals emanating from conductive endocardial tissue to pinpoint the location of abnormal conductive tissue sites causing arrhythmias. An example of an EP mapping system is described in U.S. Patent No. 5,738,096, entitled "Cardiac Electromechanics," issued on April 14, 1998 (the disclosure thereof is incorporated herein by reference in its entirety). Examples of EP mapping catheters are described in U.S. Patent No. 9,907,480, entitled "Catheter Spine Assembly with Closely-Spaced Bipole Microelectrodes," issued on March 6, 2018 (the disclosure thereof is incorporated herein by reference in its entirety); U.S. Patent No. 10,130,422, entitled "Catheter with Soft Distal Tip for Mapping and Ablating Tubular Region," issued on November 20, 2018 (the disclosure thereof is incorporated herein by reference in its entirety); and U.S. Patent No. 10,702,177, entitled "Catheter with Bipole Electrode Spacer and Related Methods," issued on July 7, 2020 (the disclosure thereof is incorporated herein by reference in its entirety).

[0005] Some catheter ablation procedures may be performed using image-guided surgery (IGS) systems. IGS systems can enable physicians to visually track the position of the catheter within the patient in real time in relation to images of anatomical structures within the patient. Several systems, including the CARTO 3® system by Biosense Webster, Inc. of Irvine, California, can offer a combination of EP mapping and IGS capabilities. Examples of catheters configured for use with IGS systems are disclosed in U.S. Patent No. 9,480,416, “Signal Transmission Using Catheter Braid Wires,” published November 1, 2016, and in various other references cited herein, the entire disclosure of which is incorporated herein by reference.

[0006] Although several catheter systems and methods have been implemented and used, it is believed that no one prior to the present inventors has implemented or used the invention described, illustrated, and claimed herein. [Brief explanation of the drawing]

[0007] The following drawings and detailed description are intended to be illustrative only and are not intended to limit the scope of the invention as envisioned by the inventors. [Figure 1] This is a schematic diagram of a medical procedure in which a catheter assembly catheter is inserted into a patient. [Figure 2] Figure 1 shows a top view of the catheter assembly, where the intermediate section of the catheter is in a straight configuration shown by a solid line, and the intermediate section of the catheter is in a deflected configuration shown by a dashed line. [Figure 3] Figure 1 shows perspective views of the end effector of the catheter assembly and the distal portion of the catheter. [Figure 4]Figure 3 is a top view of the end effector, where the first helical configuration is shown by a solid line and the second helical configuration is shown by a dashed line. [Figure 5] Figure 3 is a perspective view of the electrodes of the end effector. [Figure 6] Figure 5 shows the fixing between the electrode and the body of the end effector, and is a cross-sectional side view of a portion of the end effector shown in Figure 3. [Figure 7] Figure 3 is a perspective view of an example of an alternative electrode that could be incorporated into the end effector. [Figure 8] This is a cross-sectional side view of a modified version of the end effector shown in Figure 3, illustrating the fixation between the electrode in Figure 7 and the body of the end effector. [Modes for carrying out the invention]

[0008] The following description of specific embodiments of the present invention should not be used to limit the scope of the invention. The drawings are not necessarily to scale, illustrate selected embodiments, and are not intended to limit the scope of the invention. The detailed description is illustrative, not limiting, illustrating the principles of the invention as an example. Other embodiments, features, aspects, forms, and advantages of the invention will become apparent to those skilled in the art from the following description, which is one of the best modes intended to carry out the invention as an example. As will be recognized, the invention can be made into other different or equivalent embodiments without departing from the invention. Accordingly, the drawings and description should be considered illustrative, not limiting.

[0009] Any one or more of the teachings, expressions, modifications, or examples described herein may be combined with any one or more of the other teachings, expressions, modifications, or examples described herein. Therefore, the teachings, expressions, modifications, or examples described below should not be considered in isolation. Various preferred ways in which the teachings herein may be combined will be readily apparent to those skilled in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[0010] Where used herein, the terms “about” or “approximately” for any numerical value or range of numerical values ​​indicate a preferred dimensional tolerance that enables some or a set of components to function for the intended purpose described herein. More specifically, “about” or “approximately” may refer to a range of values ​​within ±20% of the enumerated values; for example, “about 90%” may refer to a range of values ​​between 71% and 99%. In addition, where used herein, the terms “patient,” “host,” “user,” and “subject” refer to any human or animal subject, and while the use of the present invention in a human patient represents a preferred embodiment, it is not intended to limit the system or method to human use.

[0011] I. Examples of catheter systems Figure 1 shows an example of a medical procedure and associated components of a cardiac catheter system that may be used to provide EP mapping and / or cardiac ablation as described above. Specifically, Figure 1 shows a physician (PH) grasping the handle assembly (110) of a catheter assembly (100), and the end effector (130) (Figures 2-4) of the catheter (120) (Figure 2) of the catheter assembly (100) is positioned within the patient (PA) to map the potentials of tissues within or near the patient's (PA) heart (H) and / or ablate the tissues. The catheter assembly (100) is coupled to a guided drive system (10) via a cable (30). The catheter assembly (100) is also coupled to a fluid source (42) via a fluid conduit (40). A pair of field generators (20) are positioned below the patient (PA) and coupled to the guided drive system (10) via another cable (22).

[0012] The induction drive system (10) of this embodiment includes a console (12) and a display (18). The console (12) includes a first driver module (14) and a second driver module (16). The first driver module (14) is coupled to a catheter assembly (100) via a cable (30). In some variations, the first driver module (14) is operable to receive EP mapping signals acquired via electrodes of an end effector (130). The console (12) includes a processor (not shown) that processes such EP mapping signals and thereby performs EP mapping known in the art. In some other variations, the end effector (130) does not provide EP mapping.

[0013] The first driver module (14) of this embodiment is further operable to supply power to the electrodes (140) of the end effector (130), as will be described in more detail below, thereby ablating tissue. In yet another modification, the end effector (130) does not provide ablation.

[0014] A second driver module (16) is coupled to a field generator (20) via a cable (22). The second driver module (16) is operable to activate the field generator (20) to generate an alternating magnetic field around the patient's (PA) heart (H). For example, the field generator (20) may include a coil that generates an alternating magnetic field within a predetermined working volume including the heart (H).

[0015] The first driver module (14) is also operable to receive position indication signals from one or more navigation sensors (not shown) in the end effector (130) and / or catheter (120). In such a variation, the console (12) processor is also operable to process the position indication signals from one or more navigation sensors and thereby determine the position of the end effector (130) in the patient (PA). In some variations, each navigation sensor includes one or more coils operable to generate signals indicating the position and orientation of the end effector (130) in the patient (PA). The coils are configured to generate electrical signals in response to the presence of an alternating electromagnetic field generated by a field generator (20). Other components and techniques that may be used to generate real-time position data associated with the end effector (130) include radio triangulation, acoustic tracking, optical tracking, and inertial tracking. In some other variations, the end effector (130) and / or catheter (120) lack navigation sensors.

[0016] The display (18) is coupled to the processor of the console (12) and is operable to render images of the patient's anatomical structure. Such images may be obtained based on a set of images (e.g., CT scan or MRI scan, 3D map, etc.) acquired before or during surgery. The diagram of the patient's anatomical structure provided through the display (18) may also change dynamically based on signals from the navigation sensor assembly of the end effector (130). For example, as the end effector (130) of the catheter (120) moves within the patient (PA), the processor of the console (12) may update the diagram of the patient's anatomical structure in the display (18) in real time based on corresponding position data from one or more navigation sensors, and depict the area of ​​the patient's anatomical structure around the end effector (130) as the end effector (130) moves within the patient (PA). Furthermore, the console (12) processor may drive the display (18) to indicate the location of abnormal conductive tissue sites, as to be detected by electrophysiological (EP) mapping using an end effector (130) or by other means (e.g., by using a dedicated EP mapping catheter). As just one example, the console (12) processor may drive the display (18) to superimpose the location of abnormal conductive tissue sites onto an image of the patient's anatomical structure, such as by superimposing illumination dots, crosshairs, or some other form of visual representation of abnormal conductive tissue sites.

[0017] The console (12) processor can also drive the display (18) to superimpose the current position of the end effector (130) onto an image of the patient's anatomical structure, for example, by superimposing illumination dots, crosshairs, a graphic representation of the end effector (130), or some other form of visual display. Such superimposed visual indications can also move in real time within the image of the patient's anatomical structure on the display (18) as the physician moves the end effector (130) within the patient (PA), thereby providing the operator with real-time visual feedback on the position of the end effector (130) within the patient (PA) as the end effector (130) moves within the patient (PA). Thus, the images provided via the display (18) can effectively provide video tracking the position of the end effector (130) within the patient (PA) without necessarily having any optical instrument (i.e., a camera) to observe the end effector (130). In the same view, the display (18) can simultaneously visually indicate the location of abnormal conductive tissue sites detected by EP mapping. Thus, the physician (PH) can look at the display (18) and observe the real-time positioning of the end effector (130) in relation to the mapped abnormal conductive tissue sites and images of adjacent anatomical structures within the patient (PA).

[0018] The fluid source (42) in this embodiment includes a bag containing saline solution or several other suitable irrigation fluids. The conduit (40) includes a flexible tube further coupled to a pump (44) that is operable to selectively drive fluid from the fluid source (42) to the catheter assembly (100). Such irrigation fluid may be discharged through an opening (not shown) of the end effector (130). Such irrigation can be carried out in any preferred manner that is apparent to those skilled in the art in light of the teachings herein.

[0019] II. Examples of Catheter Assemblies Figures 2 to 4 show the catheter assembly (100) in more detail. In the illustrated example, as described above, the catheter assembly (100) includes a handle assembly (110), a catheter (120) extending distally from the handle assembly (110), and an end effector (130) located at the distal end of the catheter (120).

[0020] The handle assembly (110) of this embodiment includes a handle housing (112) that houses the components of the deflection control assembly, the operation of which will be described in more detail below. The deflection control assembly includes a rotary actuator (114) that can be directly operated by an operator by rotating the actuator (114) around an axis (116). The axis (116) is substantially transverse or perpendicular to the longitudinal axis of the handle housing (112). A deflection tension adjustment dial (118) is opposed to the actuator (114) along the axis (115). The deflection tension adjustment dial (118) is coupled to and indirectly engaged with the actuator (114) by various mechanisms and components, thereby allowing the operator to adjust the ease with which the actuator (114) can be rotated. The actuator (114) is operated by rotation and its resistance is adjustable by an adjustment dial (118), but control of the deflection control assembly of the handle assembly (110) can be provided using other preferred features, as will become apparent to those skilled in the art by considering the teachings herein.

[0021] The catheter (120) of this embodiment includes an elongated catheter body (122), a deflectable intermediate section (124) at the distal end of the catheter body (122), and a tip section (126) at the distal end of the intermediate section (124). An end effector (130) is provided at the tip section (126). As described above, the handle assembly (110) includes components of a deflection control assembly. This deflection control assembly is further coupled to the intermediate section (124) of the catheter (120) via one or more pull wires, cables, bands, and / or other components. The deflection control assembly is operable to deflect the catheter (120) laterally in the intermediate section (124) in response to rotation of the actuator (114). An example of such deflection is shown in FIG. 2, where the intermediate section (124) is shown by a solid line in a straight configuration and by a dashed line in an example of a deflected configuration. Such controllable deflection in the intermediate section (124) can facilitate positioning of the end effector (130) in the target tissue region.

[0022] By way of example only, the controlled deflection of the catheter (120) in the intermediate section (124) can be provided in accordance with at least some of the teachings of U.S. Patent No. 8,747,351, entitled "Catheter with multi-functional control handle having linear mechanism", issued on June 10, 2014, the disclosure of which is incorporated herein by reference. In some other variations, the catheter assembly (100) lacks features that provide controlled deflection of the catheter (120) in the intermediate section (124). [[ID=??]]

[0023] The end effector (130) of this embodiment includes a substantially linear proximal region (132) and a substantially circular major region (134). The substantially circular major region (134) may form a flat circle or be at least slightly helical, as will be described in more detail below. The end effector (130) includes a body (136) in the form of an electrically insulating pipe having a circular cross-sectional shape or any other suitable cross-sectional shape. By way of example only, the body (136) may include a poly(ether urethane) material (e.g., PELLETHANE thermoplastic polyurethane by Lubrizol Corporation (Wickliffe, Ohio)) and / or any other suitable material(s). A series of electrodes (140) are mounted on the body (136) along the substantially circular major region (134) in a longitudinally spaced configuration. In this embodiment, the substantially circular major region (134) defines a substantially helical form when unrestrained. In some variations or situations, this helical form is centered along the longitudinal axis (125) of the intermediate section (124). In some other variations or situations, this helical form is oriented obliquely with respect to the longitudinal axis (125) of the intermediate section (124).

[0024] In this embodiment, the catheter assembly (100) is operable to provide a controlled contraction of the helical form defined by the circular major region (134), thereby providing a controlled variation of the radius and / or pitch of the helical form. An example of a controlled variation of the helical form of the circular major region (134) is shown in FIG. 3. Specifically, FIG. 4 shows the circular major region (134) having a coarser pitch in solid lines and a finer pitch in dashed lines. In some variations, this control is provided via an actuator (not shown) of a handle assembly (110) operable to drive the longitudinal movement of a mandrel (138) (FIG. 4) slidably disposed within the body (136) of the end effector (130). By way of further example only, control over the helical form defined by the circular major region (134) may be provided via one or more pull wires and / or via any other suitable components.

[0025] In some variations, controlled contraction of a helical shape defined by a circular main region (134) may be provided in accordance with at least some of the teachings of U.S. Patent No. 9,220,433, “Catheter with Variable Arcuate Distal Section,” issued December 29, 2015, the disclosure of which is incorporated herein by reference in its entirety. In some other variations, the catheter assembly (100) lacks the feature that provides controlled contraction of a helical shape defined by a circular main region (134).

[0026] Figure 5 shows the electrode (140) in more detail. The electrode (140) in this embodiment is substantially ring-shaped or barrel-shaped. The electrode (140) includes a conductive material so that it is operable to apply electrical energy to tissue, as described above and in the various references cited herein. For example, the electrode (140) may include noble metals such as gold, platinum, ruthenium, rhodium, palladium, silver, osmium, and iridium. Alternatively, any other suitable conductive material (one or more) may be used. In some modifications, the electrode (140) is also operable to pick up potentials within tissue (for example, as part of an EP mapping process), as also described above and in the various references cited herein. The electrode (140) in this embodiment includes an annular end (142), a central portion (144), and a transitional portion (146). Each end (142) has a first inner diameter and a first outer diameter. The central portion (144) has a second inner diameter and a second outer diameter. The second inner diameter is larger than the first inner diameter. Similarly, the second outer diameter is larger than the second outer diameter. The transition portion (146) provides a substantially smooth transition from these different diameters of the end portion (142) and the central portion (144). In some modifications, each transition portion provides a straight, angled / tapered surface transition between the central portion (144) and each end portion (142). In some other modifications, each transition portion (146) provides a curved or contoured surface transition between the central portion (144) and each end portion (142).

[0027] The electrode (140) of this embodiment further includes a plurality of irrigation openings (148) formed through a central portion (148). The irrigation openings (148) are oriented laterally in this embodiment. In some modifications, a transition portion (146) also defines the irrigation openings (148). The irrigation openings (148) can be used to communicate an irrigation fluid outward from the electrode (140), as described above and in various references cited herein. Such an irrigation fluid can prevent overheating of the electrode (140), prevent the accumulation of lumps on the electrode (140), promote the conductivity of the electrode (140), and / or provide other effects.

[0028] As shown in Figure 6, the irrigation fluid can communicate with the electrode (140) via a lumen (138) defined within the body (136) of the end effector (130). The lumen (138) is in fluid communication with the interior of the electrode (140) via one or more lateral ports (139), so that the irrigation fluid can flow through the lumen (138) into the interior of the electrode (140) via the lateral ports (139) and then out of the electrode (140) via the irrigation opening (148). The lumen (138) is shown in Figure 6 as extending along the entire inner diameter of the body (136), but this is merely a schematic diagram. The lumen (138) may actually be substantially smaller than that shown in Figure 6, and various other components or structures may be located within the body (136). Furthermore, some modifications of the electrode (140) may lack the irrigation opening (148). In some variations, the lumen (138) is omitted.

[0029] As shown in Figure 6, the electrode (140) is fixed to the body (136) via a binder (160). As an example, the binder (160) may include polyurethane and / or any other suitable material. The binder (160) is applied to each end (142) of the electrode (140) along the adjacent region of the body (136). The binder (160) may be applied to the electrode (140) and the body (136) while the binder (160) is in a flowable form (e.g., a liquid), and then the binder (160) may later harden into a solid form. As shown in Figure 6, the inner diameter of each end (142) is larger than the outer diameter of the body (136), so the binder (160) flows into the gap (150) defined between the inner diameter of each end (142) and the outer diameter of the body (136).

[0030] The binding material (160) also covers the entire inner and outer surfaces of each end (142). In addition, the binding material (160) covers at least a portion of each transition portion (146). In some modifications, the binding material (160) covers more than 50% of the outer surface area of ​​each transition portion (146). Nevertheless, the binding material (160) leaves the central portion (144) exposed, and as a result, the binding material (160) does not substantially impede the electrical communication and irrigation functions of the electrode (140).

[0031] In addition to providing structural fixation of the electrode (140) to the body (136), the binding material (160) also provides a fluid sealing seal at the end (142) of the electrode (140), thereby ensuring that the irrigation fluid communicating with the interior of the electrode (140) exits the electrode (140) only through the irrigation opening (148). In this embodiment, the binding material (160) extends longitudinally along the first width (W1) at each end of the electrode (140), and as a result, the binding material (160) does not extend along the body (136) from one end (142) of the electrode (140) to the other end (142) of the electrode (140). In some other variations, each region of the bonding material (160) extends along the body (136) from one end (142) of one electrode (140) to the other end (142), while still exposing the central portion (144) of each electrode (140).

[0032] III. Examples of alternative electrodes and fixation During the operation of the catheter assembly (100), the end effector (130) may bend multiple times in many different ways. For example, the end effector (130) may bend multiple times in many different ways as it traverses a meandering passage on its way to the target site in the patient (PA). The end effector (130) may also bend multiple times in many different ways as the physician (PH) drives the end effector (130) to change the radius and / or pitch of the helical shape defined by the circular main region (134), as described above with reference to Figure 4. In some examples, the bending of the end effector (130) may generate stress (e.g., tensile stress, compressive stress, torsional stress, etc.) in the margin between the binding material (160) and the body (136), and / or in the margin between the binding material (160) and the electrode (140). Such stress can ultimately lead to delamination of the binding material (160) from the body (136) and / or the electrode (140). Such delamination of the binding material can ultimately lead to the intrusion of blood into the internal region of the electrode (140), which in turn can ultimately lead to the formation of a mass within the electrode (140), which in turn can adversely affect the electrical communication and / or irrigation capacity of the electrode (140).

[0033] To strengthen the fixation between the electrode (140) and the body (136) and / or to reduce the risk of delamination of the bonding material (160) in other ways, there may be a tendency to simply use more bonding material (160) to fix the electrode (140) to the body (136). However, this solution may have several drawbacks. For example, providing more bonding material (160) along the body (136) may increase the rigidity of the end effector (130), which may make it more difficult to navigate the end effector (130) along a meandering passage and / or to achieve the desired helical shape within the circular main region (134). Providing more bonding material (160) along the electrode (140) may reduce the electrically active surface of the electrode (140), which may increase the current density of the electrode (140), which may increase the risk of arc generation, charring, agglomeration, and / or other undesirable results.

[0034] Therefore, it may be desirable to provide an alternative fastening between the electrode (140) and the body (136) that reduces the risk of delamination while avoiding adverse effects such as increasing the rigidity of the end effector (130) and / or adversely affecting the electrical performance of the electrode.

[0035] Figures 6 and 7 show an example of an alternative electrode (240) and an alternative mounting of the electrode (240) to the body (136) that can provide the advantages described above while avoiding the adverse effects described above. The electrode (240) in this embodiment may be configured and operate in the same way as the electrode (140), except for the differences described below. Therefore, the electrode (240) may be incorporated into the end effector (130) instead of the electrode (140).

[0036] The electrode (240) in this embodiment is substantially ring-shaped or barrel-shaped, and the electrode (240) constitutes a substantially cylindrical member extending from one annular end (242) to the other annular end (242). The electrode (240) includes a conductive material so that it is operable to apply electrical energy to tissue, as described above and in the various references cited herein. For example, the electrode (240) may include noble metals such as gold, platinum, ruthenium, rhodium, palladium, silver, osmium, and iridium. Alternatively, any other suitable conductive material (one or more) may be used. In some modifications, the electrode (240) is also operable to pick up potentials within tissue (for example, as part of an EP mapping process), as also described above and in the various references cited herein. The electrode (240) of this embodiment includes an annular end (242), a central portion (244), and a longitudinally extending pair of transition portions (246), the central portion (244) being located longitudinally in the center between the end (242) and the transition portion (246). Each end (242) has a first inner diameter defined by its inner surface around a central longitudinal axis (LA) and a first outer diameter. The central portion (244) has a second inner diameter defined by its inner surface around a central longitudinal axis (LA) and a second outer diameter defined by its outer surface around a central longitudinal axis (LA). The second inner diameter is larger than the first inner diameter. Similarly, the second outer diameter is larger than the second outer diameter.

[0037] As merely an example, the second inner diameter may be in the range of approximately 1.50 mm to approximately 3.50 mm, approximately 2.00 mm to approximately 3.00 mm, or more specifically, approximately 2.62 mm. Alternatively, the second inner diameter may be any other suitable size. As yet another example, the electrode (240) may have a length in the range of approximately 1.00 to approximately 5.00 mm (along the central longitudinal axis (LA)), a length in the range of approximately 2.00 mm to approximately 4.00 mm, or more specifically, a length of approximately 3.00 mm. Alternatively, the electrode (240) may have any other suitable length.

[0038] The transition portion (246) provides a substantially smooth transition from these different diameters of the end portion (242) and the central portion (244). In some modifications, each transition portion provides a straight, angled / tapered surface transition between the central portion (244) and each end portion (242). In some other modifications, each transition portion (246) provides a curved or contoured surface transition between the central portion (244) and each end portion (242).

[0039] The electrode (240) of this embodiment further includes a plurality of irrigation openings (248) formed through a central portion (248). The irrigation openings (248) are oriented laterally in this embodiment. In some modifications, a transition portion (246) also defines the irrigation openings (248). The irrigation openings (248) can be used to communicate an irrigation fluid outward from the electrode (240), as described above and in various references cited herein. Such an irrigation fluid can prevent overheating of the electrode (240), prevent the accumulation of lumps on the electrode (240), promote the conductivity of the electrode (240), and / or provide other effects.

[0040] As shown in Figure 8, the irrigation fluid can be communicated to the electrode (240) via the lumen (138) and one or more lateral ports (139) of the body (136) of the end effector (130). As described above with reference to Figure 6, the lumen (138) is shown in Figure 8 as extending along the entire inner diameter of the body (136), but this is merely a schematic diagram. In practice, the lumen (138) may be substantially smaller than that shown in Figure 8, and various other components or structures may be located within the body (136). Furthermore, some modifications of the electrode (240) may lack the irrigation opening (248). In some modifications, the lumen (138) is omitted.

[0041] Unlike electrode (140), electrode (240) in this embodiment further includes a pair of laterally oriented openings (243) formed along each end (242). Each opening (243) is elongated and extends circumferentially along a portion of the end (242) such that the opening (243) constitutes a circumferential notch. Each pair of openings (243) are equidistant and angled from each other along the end (242) with respect to the central longitudinal axis (LA). In this embodiment, the openings (243) are formed only within the end portions (242) such that the openings (243) do not extend into the transition portions (246). In some other modifications, at least a portion of one or more openings (243) extends into adjacent transition portions (246).

[0042] As a further example, each opening (243) may have a width in the range of approximately 0.05 mm to approximately 0.35 mm (measured along the dimension parallel to the central longitudinal axis (LA)), a width in the range of approximately 0.10 mm to approximately 0.30 mm, or more specifically, a width of approximately 0.20 mm. Alternatively, each opening (243) may have any other suitable width. In addition, each opening (243) may have a length in the range of approximately 0.20 mm to approximately 0.60 mm (measured along the circumferential dimension extending at an angle around the central longitudinal axis (LA)), or a length in the range of approximately 0.30 mm to approximately 0.50 mm, or more specifically, a length of approximately 0.40 mm. Alternatively, each opening (243) may have any other suitable length.

[0043] Figure 8 shows how the opening (243) of the electrode (240) facilitates the fixation of the electrode (240) to the body (136). The electrode (240) is fixed to the body (136) via a binder (260). As an example, the binder (260) may include polyurethane and / or any other suitable material. The binder (260) is applied to each end (242) of the electrode (240) along the adjacent area of ​​the body (136). The binder (260) may be applied to the electrode (240) and the body (136) while the binder (260) is in a flowable form (e.g., liquid), and then the binder (260) may later cure into a solid form. As shown in Figure 8, the inner diameter of each end (242) is larger than the outer diameter of the main body (136), and therefore the bonding material (260) flows into the gap (250) defined between the inner diameter of each end (242) and the outer diameter of the main body (136).

[0044] The binding material (260) also covers the entire inner and outer surfaces of each end (242). In addition, the binding material (260) flows through each opening (243), and as a result, portions of the binding material (260) effectively wrap around the entire outer region of each end (242) adjacent to the opening (243). In some cases, some portions of the binding material (260) may also cover portions of the transition portions (246) adjacent to the openings (243). In some other variations, the binding material (260) does not cover any portion of the transition portions (246) adjacent to the openings (243). In any case, the binding material (260) may leave the central portion (244) completely exposed so that the binding material (260) does not substantially interfere with the electrical communication and irrigation functions of the electrode (240).

[0045] In addition to providing structural fixation of the electrodes (240) to the body (136), the binding material (260) also provides a fluid sealing seal at the ends (242) of the electrodes (240), thereby ensuring that the irrigation fluid communicating with the interior of the electrodes (240) exits the electrodes (240) only through the irrigation opening (248). In this embodiment, the binding material (260) extends longitudinally along the second width (W2) at each end of the electrodes (240), and as a result, the binding material (260) does not extend along the body (136) from one end (242) of one electrode (240) to the other end (242) of the electrode (240). In some other variations, each region of the bonding material (260) extends along the body (136) from one end (242) of one electrode (240) to the other end (242), while still exposing the central portion (244) of each electrode (240).

[0046] When comparing the fixation of the electrode (240) to the body (136) via a binder (260) with the fixation of the electrode (140) to the body (136) via a binder (160), it should be noted that the presence of an opening (243) and the flow of the binder (260) through the opening (243) can reduce the risk of delamination. This may be partly due to the tendency of the binders (160, 260) to adhere better to the material of the body (136) (e.g., polymer material) than to the material of the electrodes (140, 240) (e.g., metallic material). In the context of the electrode (140), the entire interface between the electrode (140) and the binder (160) may be vulnerable to shear stresses that may be periodically encountered during normal use of the end effector (130). In contrast, in the context of the electrode (240), the formation of loops by the binder material (260) flowing through the adjacent regions of each opening (243) and end (242) can substantially reduce, if not eliminate, vulnerability to shear stress. In other words, the binder material (260) completely encloses the region of end (242) between the opening (243) and the adjacent outer edge of end (242). Using an analogy of gripping the electrodes (140, 240), the fixation between the binder material (260) and the electrode (240) is similar to the fingers of a hand completely wrapping around a portion of the electrode (240) to fully grip it, while the fixation between the binder material (160) and the electrode (140) is similar to the fingers of a hand simply pinching a portion of the electrode (140). The strengthening of the fixation between the bonding material (260) and the electrode (240) allows the bonding material (260) to withstand more stress than would otherwise be applied to the interface between the bonding material (160) and the electrode (140), and to redistribute more stress to the main body (136).

[0047] By enhancing fixation due to the flow of binder material (260) through the opening (134), the configuration shown in Figure 8 also allows the use of less binder material (260) than the amount used in the configuration shown in Figure 6. This is indicated by the second width (W2) being smaller than the first width (W1). The smaller second width (W2) allows a larger surface area of ​​the electrode (240) to be exposed to the binder material (260) compared to the surface area of ​​the electrode (140) that is left exposed to the binder material (160). This may allow the electrode (240) to provide better electrical communication with the tissue than the electrode (140). Thus, the configuration shown in Figure 8 can provide a combination of (i) a reduced risk of delamination of the binder material (260) and (ii) enhanced electrical communication between the tissue and the electrode (240), two results that might otherwise seem contradictory to a person skilled in the art.

[0048] In summary, the invention described herein may provide one or more of the following advantages: (i) providing a riveting effect that enhances the attachment of the electrodes (240) to the body (136); (ii) partially redistributing the stress on the binder material (260) (e.g., polyurethane) toward the opening (243) and away from the margin, thereby reducing the stress on the binder material (260) margin, thereby reducing the possibility of delamination; and / or (iii) the opening (243) may be used as a visual guide to improve the consistency of the binder material (260) margin. In addition, if the use of the opening (243) reduces the possibility of delamination, the width of the binder material (260) margin can be reduced, and therefore the active electrode surface of each electrode (240) can be made larger. As a result, this can reduce the applied current density and therefore reduce the possibility of arc generation and charring on the ablated structure.

[0049] IV. Examples of combinations The following examples relate to various non-exclusive ways in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to limit any claims that may be presented at any point in this application or any subsequent application. No waiver of rights is intended. The following examples are provided solely for illustrative purposes. Various teachings herein are intended to be arranged and applied in many other ways. Furthermore, some modifications may omit certain features mentioned in the following examples. Therefore, none of the aspects or features mentioned below should be considered important unless they are subsequently explicitly indicated as such by the inventors or their heirs. If claims presented in this application or any subsequent application relating to this application include additional features other than those mentioned below, those additional features should not be considered added for any patentability reason. [Examples]

[0050] A ring electrode for pulsed field ablation, comprising: (a) a substantially cylindrical member extending from one annular end to the other annular end, the central portion including a first transition portion positioned between the central portion and the one annular end, and a second transition portion positioned between the central portion and the other annular end, the central portion including an inner diameter defining an inner surface about a longitudinal axis and an outer diameter defining an outer surface about a longitudinal axis, and each of the annular ends including an inner diameter smaller than the inner diameter of the central portion; and (b) a plurality of circumferential notches positioned in one of the annular ends or transition portions. [Examples]

[0051] The ring electrode according to Example 1, wherein multiple circumferential notches are located on the annular end. [Examples]

[0052] The ring electrode according to Example 1, wherein multiple circumferential notches are located on the annular end and a portion of the transition section. [Examples]

[0053] The ring electrode according to Example 1, wherein each of the notches defines a circumferential slot having a width of approximately 0.20 mm and a length of approximately 0.40 mm. [Examples]

[0054] Apparatus comprising (a) an elongated flexible shaft having a proximal end and a distal end, and (b) an end effector positioned at the distal end of the shaft, wherein the end effector comprises (i) a body, (ii) an electrode, the electrode defining one or more laterally oriented openings, and a bonding material for fixing the electrode to the body, the bonding material having a portion positioned in at least one of the one or more laterally oriented openings. [Examples]

[0055] The apparatus according to Example 5, wherein the electrode includes a pair of outer portions and a central portion interposed longitudinally between the outer portions. [Examples]

[0056] The apparatus according to Example 7, wherein the bonding material is positioned on at least a portion of each of the pair of outer portions. [Examples]

[0057] The apparatus according to any one of Examples 6 to 7, wherein at least one of one or more laterally oriented openings in which the bonding material is placed is located on one of a pair of outer portions. [Examples]

[0058] The apparatus according to Example 8, wherein each of the pair of outer portions includes a plurality of laterally oriented openings, and one or more laterally oriented openings of the electrode include a plurality of laterally oriented openings of the outer portion. [Examples]

[0059] The apparatus according to any one of Examples 6 to 9, wherein each of the pair of outer parts defines a gap with the outer surface of the main body. [Examples]

[0060] The apparatus according to Example 10, wherein a portion of the bonding material is placed within the gap. [Examples]

[0061] The apparatus according to any one of Examples 10 to 11, wherein the gap is located adjacent to at least one of one or more laterally oriented openings in which the bonding material is placed. [Examples]

[0062] The apparatus according to any one of Examples 6 to 12, wherein each of the pair of outer portions has a first outer diameter and the central portion has a second outer diameter. [Examples]

[0063] The apparatus according to Example 13, wherein the second outer diameter is larger than the first outer diameter. [Examples]

[0064] The apparatus according to any one of Examples 13 to 14, wherein the electrodes further include a pair of transition portions, each transition portion being longitudinally interposed between a central portion and each of the outer portions of a pair of outer portions. [Examples]

[0065] The apparatus according to Example 15, wherein the transition portion provides a smooth transition from the first outer diameter to the second outer diameter. [Examples]

[0066] The apparatus according to any one of Examples 13 to 16, wherein the transitional portion and the central portion do not contain a binding material. [Examples]

[0067] The central portion is the apparatus according to any one of Examples 6 to 16, which does not contain a binding material. [Examples]

[0068] The apparatus according to any one of Examples 5 to 18, further comprising one or more laterally oriented openings, at least one of which is configured to discharge irrigation fluid from the electrodes. [Examples]

[0069] The apparatus according to Example 19, wherein the main body defines a lumen and a lateral port, and the lumen and lateral port are configured to communicate an irrigation fluid to an electrode for discharge through at least one irrigation opening. [Examples]

[0070] The apparatus according to any one of Examples 5 to 20, wherein the end effector further comprises a plurality of additional electrodes, the additional electrodes being spaced longitudinally apart from one another along the body, each of the plurality of additional electrodes defining one or more laterally oriented openings, and the bonding material of the end effector further secures the additional electrodes to the body, with each portion of the bonding material positioned in at least one of the one or more laterally oriented openings of each additional electrode. [Examples]

[0071] The apparatus according to Embodiment 21, further comprising an actuator capable of operating to drive the body between a first helical configuration and a second helical configuration. [Examples]

[0072] The apparatus according to any one of Examples 5 to 22, further comprising a handle assembly, wherein the shaft extends distally from the handle assembly. [Examples]

[0073] The apparatus according to any one of Examples 5 to 23, wherein the shaft includes a steerable section, and the apparatus further includes an actuator that is operable to drive lateral deflection of the steerable section of the shaft. [Examples]

[0074] The apparatus according to any one of Examples 5 to 24, wherein the electrodes are operable to apply electrical energy to tissue. [Examples]

[0075] The apparatus according to any one of Examples 5 to 25, wherein the binding material includes polyurethane. [Examples]

[0076] The apparatus according to any one of Examples 5 to 26, wherein the main body contains poly(ether urethane). [Examples]

[0077] The apparatus according to any one of Examples 5 to 27, wherein the electrodes contain a precious metal. [Examples]

[0078] Apparatus comprising (a) an elongated flexible shaft having a proximal end and a distal end, and (b) an end effector positioned at the distal end of the shaft, the end effector comprising (i) a body, and (ii) a plurality of electrodes spaced longitudinally apart from each other along the body, each of the plurality of electrodes including (A) a first outer portion, (B) a second outer portion, (C) a central portion interposed longitudinally between the outer portions, (D) a first set of laterally oriented openings formed through the first outer portion, and (E) a second set of laterally oriented openings formed through the second outer portion, and (iii) a plurality of discrete regions of a binding material for fixing the plurality of electrodes to the body, wherein at least some of the discrete regions of the binding material are located within the first set of laterally oriented openings, and at least some of the discrete regions of the binding material are located within the second set of laterally oriented openings, the plurality of discrete regions of the binding material. [Examples]

[0079] A method for coaxially positioning an electrode around an elongated body, wherein the electrode has a pair of longitudinally opposed outer portions, each of which defines an inner diameter, and the elongated body has an outer diameter, the inner diameter being larger than the outer diameter such that each of which defines a gap between itself and the elongated body, and each of which further defines a plurality of laterally oriented openings; pouring a bonding material into the plurality of laterally oriented openings and gaps; and curing the bonding material to fix the electrode to the elongated body.

[0080] V. Others Any of the instruments described herein may be cleaned and sterilized before and / or after a procedure. One sterilization technique involves placing the device in a sealed container, such as a plastic or TYVEK bag. The container and device may then be placed in a radiation field that can penetrate the container, such as gamma rays, X-rays, or high-energy electron beams. The radiation may kill bacteria on the device and within the container. The sterilized device may then be stored in a sterilized container for later use. The device may also be sterilized using any other technique known in the art, including, but not limited to, beta or gamma rays, ethylene oxide, hydrogen peroxide, peracetic acid, and gas-phase sterilization with or without gas plasma or water vapor.

[0081] It should be understood that any of the embodiments described herein may include a variety of other features in addition to or instead of those described above. For example, any of the embodiments described herein may include one or more of the various features disclosed in any of the various references incorporated herein by reference.

[0082] It should be understood that one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with one or more of the other teachings, expressions, embodiments, examples, etc. described herein. Therefore, the above teachings, expressions, embodiments, examples, etc. should not be considered in isolation from one another. Various preferred ways in which the teachings herein may be combined will be readily apparent to those skilled in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

[0083] Any patent, publication, or other disclosure material that is said to be incorporated herein by reference will be incorporated herein only to the extent that the incorporated material, in whole or in part, does not contradict any existing definitions, views, or other disclosure material contained herein. Any disclosure expressly contained herein, either by itself or to the extent necessary, shall take precedence over any conflicting statements incorporated herein by reference. Any material, or any part thereof, that is said to be incorporated herein by reference but contradicts any existing definitions, views, or other disclosure material contained herein will be incorporated only to the extent that there is no conflict between the incorporated material and the existing disclosure material.

[0084] While various modifications of the present invention have been illustrated and described, further adaptations of the methods and systems described herein can be achieved by appropriate modifications by those skilled in the art without departing from the scope of the invention. Some of these possible modifications have been mentioned, but others will be obvious to those skilled in the art. For example, the embodiments, modifications, geometric shapes, materials, dimensions, proportions, processes, etc., discussed above are illustrative and not essential. Therefore, it should be understood that the scope of the invention is considered with respect to the following claims and is not limited to the structural and operational details shown and described herein and in the drawings.

[0085] [Implementation Method] (1) A ring electrode for pulsed-field ablation, (a) A substantially cylindrical member extending from one annular end to the other annular end, wherein the central portion includes a first transition portion positioned between the central portion and the one annular end, and a second transition portion positioned between the central portion and the other annular end, the central portion includes an inner diameter defining the inner surface about the longitudinal axis and an outer diameter defining the outer surface about the longitudinal axis, and each of the annular ends includes an inner diameter smaller than the inner diameter of the central portion, (b) A plurality of circumferential notches located in one of the annular end or the transition portion, A ring electrode equipped with a ring electrode. (2) The ring electrode according to Embodiment 1, wherein the plurality of circumferential notches are arranged on the annular end. (3) The ring electrode according to Embodiment 1, wherein the plurality of circumferential notches are arranged on the annular end and a portion of the transition portion. (4) The ring electrode according to Embodiment 1, wherein each of the notches defines a circumferential slot having a width of about 0.20 mm and a length of about 0.40 mm. (5) A device, (a) an elongated flexible shaft having a proximal end and a distal end, (b) an end effector positioned at the distal end of the shaft, the end effector is (i) The main unit and (ii) an electrode, the electrode defining one or more transversely oriented openings, the electrode comprising a pair of outer portions and a central portion interposed longitudinally between the outer portions, the bonding material positioned on at least a portion of each of the pair of outer portions, and at least one of the one or more transversely oriented openings on which the bonding material is positioned is positioned on one of the outer portions of the pair of outer portions, (iii) A device comprising a bonding material for fixing the electrode to the main body, wherein a portion of the bonding material is located in at least one of the one or more laterally oriented openings.

[0086] (6) The apparatus according to Embodiment 5, wherein each of the pair of outer portions includes a plurality of laterally oriented openings, and the one or more laterally oriented openings of the electrode include the plurality of laterally oriented openings of the outer portion. (7) The apparatus according to Embodiment 5, wherein each of the pair of outer portions defines a gap with the outer surface of the main body, and a portion of the bonding material is disposed within the gap. (8) The apparatus according to Embodiment 6, wherein the gap is located adjacent to at least one of the one or more laterally oriented openings in which the bonding material is arranged. (9) The apparatus according to Embodiment 5, wherein each of the pair of outer portions has a first outer diameter and the central portion has a second outer diameter. (10) The apparatus according to Embodiment 9, wherein the second outer diameter is larger than the first outer diameter.

[0087] (11) The apparatus according to Embodiment 9, wherein the electrode further includes a pair of transition portions, each transition portion being longitudinally interposed between the central portion and each of the outer portions of the pair of outer portions. (12) The apparatus according to embodiment 11, wherein the transition portion provides a smooth transition from the first outer diameter to the second outer diameter. (13) The apparatus according to Embodiment 9, wherein the transition portion and the central portion do not include the binding material. (14) The apparatus according to Embodiment 5, wherein the central portion does not include the binding material. (15) The apparatus according to Embodiment 5, wherein the one or more laterally oriented openings further include at least one irrigation opening configured to discharge irrigation fluid from the electrode.

[0088] (16) The apparatus according to embodiment 15, wherein the body defines a lumen and a lateral port, and the lumen and the lateral port are configured to communicate an irrigation fluid with the electrode for discharge through the at least one irrigation opening. (17) The apparatus according to Embodiment 5, wherein the end effector further comprises a plurality of additional electrodes, the additional electrodes being spaced apart from each other longitudinally along the body, each of the plurality of additional electrodes defining one or more laterally oriented openings, the bonding material of the end effector further fixing the additional electrodes to the body, and each portion of the bonding material is positioned in at least one of the one or more laterally oriented openings of each of the additional electrodes. (18) The apparatus according to embodiment 17, further comprising an actuator capable of operating to drive the body between a first helical configuration and a second helical configuration. (19) The apparatus according to Embodiment 5, wherein the binding material includes polyurethane, the main body includes poly(ether urethane), and the electrodes include a noble metal. (20) A device, (a) an elongated flexible shaft having a proximal end and a distal end, (b) an end effector positioned at the distal end of the shaft, wherein the end effector is (i) The main unit and (ii) A plurality of electrodes spaced apart from each other in the longitudinal direction along the main body, wherein each of the plurality of electrodes is (A) First outer portion, (B) The second outer part, (C) A central portion interposed longitudinally between the outer portions, (D) A first set of laterally oriented openings formed through the first outer portion, (E) A plurality of electrodes including a second set of laterally oriented openings formed through the second outer portion, (iii) an apparatus comprising a plurality of discrete regions of a binding material for fixing the plurality of electrodes to the main body, wherein at least some of the discrete regions of the binding material are located within the laterally oriented openings of the first set, and at least some of the discrete regions of the binding material are located within the laterally oriented openings of the second set.

Claims

1. A ring electrode for pulsed-field ablation, (a) A substantially cylindrical member extending from one annular end to the other annular end, wherein the central portion includes a first transition portion disposed between the central portion and the one annular end, and a second transition portion disposed between the central portion and the other annular end, the central portion includes an inner diameter defining the inner surface about the longitudinal axis and an outer diameter defining the outer surface about the longitudinal axis, and each of the annular ends includes an inner diameter smaller than the inner diameter of the central portion, (b) A plurality of circumferential notches located in one of the annular end or the transition portion, A ring electrode equipped with a ring electrode.

2. The ring electrode according to claim 1, wherein the plurality of circumferential notches are arranged on the annular end.

3. The ring electrode according to claim 1, wherein the plurality of circumferential notches are arranged on the annular end and a portion of the transition portion.

4. The ring electrode according to claim 1, wherein each of the notches defines a circumferential slot having a width of about 0.20 mm and a length of about 0.40 mm.

5. It is a device, (a) an elongated flexible shaft having a proximal end and a distal end, (b) an end effector positioned at the distal end of the shaft, the end effector is (i) The main unit and (ii) an electrode, wherein the electrode defines one or more transversely oriented openings, the electrode includes a pair of outer portions and a central portion interposed longitudinally between the outer portions, the bonding material is positioned on at least a portion of each of the pair of outer portions, and at least one of the one or more transversely oriented openings on which the bonding material is positioned is positioned on one of the pair of outer portions, (iii) A device comprising a bonding material for fixing the electrode to the main body, wherein a portion of the bonding material is located in at least one of the one or more laterally oriented openings.

6. The apparatus according to claim 5, wherein each of the pair of outer portions includes a plurality of laterally oriented openings, and the one or more laterally oriented openings of the electrode include the plurality of laterally oriented openings of the outer portion.

7. The apparatus according to claim 5, wherein each of the pair of outer portions defines a gap with the outer surface of the main body, and a portion of the bonding material is disposed within the gap.

8. The apparatus according to claim 6, wherein the gap is located adjacent to at least one of the one or more laterally oriented openings in which the bonding material is arranged.

9. The apparatus according to claim 5, wherein each of the pair of outer portions has a first outer diameter, and the central portion has a second outer diameter.

10. The apparatus according to claim 9, wherein the second outer diameter is larger than the first outer diameter.

11. The apparatus according to claim 9, wherein the electrode further includes a pair of transition portions, each transition portion being longitudinally interposed between the central portion and each of the outer portions of the pair of outer portions.

12. The apparatus according to claim 11, wherein the transition portion provides a smooth transition from the first outer diameter to the second outer diameter.

13. The apparatus according to claim 9, wherein the transition portion and the central portion do not include the binding material.

14. The apparatus according to claim 5, wherein the central portion does not include the binding material.

15. The apparatus according to claim 5, wherein the one or more laterally oriented openings further include at least one irrigation opening configured to discharge irrigation fluid from the electrode.

16. The apparatus according to claim 15, wherein the main body defines a lumen and a lateral port, and the lumen and the lateral port are configured to communicate with the electrode for discharging an irrigation fluid through the at least one irrigation opening.

17. The apparatus according to claim 5, wherein the end effector further comprises a plurality of additional electrodes, the additional electrodes being spaced apart from each other longitudinally along the body, each of the plurality of additional electrodes defining one or more laterally oriented openings, the bonding material of the end effector further fixing the additional electrodes to the body, and each portion of the bonding material is positioned in at least one of the one or more laterally oriented openings of each of the additional electrodes.

18. The apparatus according to claim 17, further comprising an actuator capable of operating to drive the main body between a first helical configuration and a second helical configuration.

19. The apparatus according to claim 5, wherein the bonding material includes polyurethane, the main body includes poly(ether urethane), and the electrode includes a noble metal.

20. It is a device, (a) an elongated flexible shaft having a proximal end and a distal end, (b) an end effector positioned at the distal end of the shaft, wherein the end effector is (i) The main unit and (ii) A plurality of electrodes spaced apart from each other in the longitudinal direction along the main body, wherein each of the plurality of electrodes is (A) The first outer part and (B) The second outer part, (C) A central portion interposed longitudinally between the outer portions, (D) A first set of laterally oriented openings formed through the first outer portion, (E) A plurality of electrodes including a second set of laterally oriented openings formed through the second outer portion, (iii) an apparatus comprising a plurality of discrete regions of a binding material for fixing the plurality of electrodes to the main body, wherein at least some of the discrete regions of the binding material are arranged in laterally oriented openings of the first set, and at least some of the discrete regions of the binding material are arranged in laterally oriented openings of the second set.

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