Modular ring electrodes

Abstract

To provide an improved electrode assembly that can facilitate manufacture of an end effector of a catheter.SOLUTION: The disclosed technology includes an end effector for a catheter shaft. The end effector comprises a plurality of ring electrode assemblies, each ring electrode comprising a ring electrode disposed around an insert. Collars can be attached to each end of the ring electrode to fix the ring electrode to the insert. Multiple ring electrode assemblies can be coupled to one another with bridge tubes to form a length of an end effector.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present technology relates generally to minimally invasive medical devices, and more particularly to cardiac mapping catheters having flexible end effectors. [Background technology]

[0002] Cardiac arrhythmias, such as atrial fibrillation, occur when electrical signals are abnormally conducted from an area of ​​cardiac tissue to adjacent tissue, disrupting the normal cardiac cycle and causing an asynchronous rhythm. The source of the unwanted signals may be located in the atrial or ventricular tissue. The unwanted signals may be conducted through the cardiac tissue to other locations and cause or perpetuate the arrhythmia.

[0003] Treatments for arrhythmias include surgically disrupting the source of the signals that cause the arrhythmia and interrupting the conduction pathways of such signals. More recently, it has been discovered that by mapping the electrical properties and volume of the endocardium and selectively ablating cardiac tissue through the application of energy, it is possible to interrupt or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process disrupts the unwanted electrical pathways through the creation of non-conductive lesions.

[0004] In this two-step procedure, which involves mapping followed by ablation, electrical activity at points within the heart is sensed and measured, typically by advancing a catheter equipped with one or more electrical sensors or electrodes into the heart and acquiring data at multiple points, which are then used to select a target area where ablation will be performed.

[0005] It may be desirable to provide an end effector with as small a footprint as possible to prevent undesired damage to the area surrounding the target anatomical structure. It may also be desirable to provide multiple electrodes on the end effector to collect a large amount of data signals and / or to maximize the use of the available surface area provided by the end effector. However, assembling such an end effector with small components can prove to be a tedious and difficult task. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, there is a need for an improved electrode assembly that can facilitate the manufacture of catheter end effectors. [Means for solving the problem]

[0007] In accordance with the techniques of the present disclosure, there is provided a ring electrode assembly comprising: an insert having at least one lumen extending along a longitudinal axis; a ring electrode disposed around a middle portion of the insert and having two ends; and two collars, each coupled to one of the two ends of the ring electrode and to the insert to secure the ring electrode to the insert.

[0008] The ring electrode may taper inward from the central portion toward each of the two ends. The inner circumference of the two ends of the ring electrode may be approximately equal to the outer circumference of the intermediate portion of the insert. Each of the collars may taper inward from the first end toward the second end, and the inner circumference of the first end of each collar may be approximately equal to the outer circumference of the two ends of the ring electrode. Each end of the insert may include a first ledge, the first ledge having an outer circumference approximately equal to the inner circumference of the second end of each collar. Each end of the insert may further include a second ledge, the first ledge being provided at each end of the insert between the second ledge and the intermediate portion of the insert, and the outer circumference of the intermediate portion of the insert may be larger than the outer circumference of the first ledge, which may be larger than the outer circumference of the second ledge. The length of the second ledge may be approximately 0.5 mm. The ring electrode may include a plurality of irrigation holes. The inner circumference of the central portion of the ring electrode can be larger than the outer circumference of the intermediate portion of the insert, and the resulting gap between the inner circumference of the central portion of the ring electrode and the outer circumference of the intermediate portion of the insert can provide an irrigation reservoir.

[0009] According to the disclosed technology, a catheter end effector is provided that includes two or more ring electrode assemblies. Each ring electrode assembly may include an insert having at least one lumen extending along a longitudinal axis. The insert may further include a middle portion, second ledges provided at each end of the insert, and a first ledge provided between each second ledge and the middle portion. A ring electrode is provided, the ring electrode having two ends and disposed around the middle portion of the insert. The ring assembly may further include two collars, each collar coupled to each of the two ends of the ring electrode. The end effector may further include at least one bridge tube connecting adjacent ring electrode assemblies. The bridge tube may include at least one lumen corresponding to the at least one lumen of the insert. The end effector may further include a frame provided through at least one lumen of each ring electrode assembly and through at least one lumen of the at least one bridge tube.

[0010] The frame may comprise nitinol. The at least one bridge tube may include two ends, and the two ends of the at least one bridge tube may have an inner diameter approximately equal to the outer diameter of the second ledge. The ring electrode may taper inward from its center toward each of its two ends. The inner diameter of each of the two ends of the ring electrode may be approximately equal to the outer diameter of the middle portion of the insert. The collars may taper inward from the first end to the second end, and the inner diameter of the first end of each collar may be approximately equal to the outer diameter of the two ends of the ring electrode. The inner diameter of the second end of each collar may be approximately equal to the outer diameter of the first ledge. The end effector may further comprise an overmold between each collar and each first ledge of the insert. At least one lumen of the insert may comprise a lead wire lumen. The lead wire hole may extend from the lead wire lumen to the outer surface of the insert.

[0011] According to the techniques of the present disclosure, there is provided a method for assembling a catheter end effector, the method including assembling one or more ring electrode assemblies, where assembling each ring electrode assembly includes providing an insert, sliding a ring electrode onto a middle portion of the insert, and sliding a collar onto each end of the ring electrode. Each collar can slide over a respective first ledge of the insert. Each insert includes at least one lumen extending along a longitudinal axis, a middle portion, second ledges provided at each end of the insert, and first ledges provided between each second ledge and the middle portion.

[0012] Assembling the end effector can further include sliding each ring electrode assembly onto a frame such that the frame is provided through at least one lumen of the insert. The method can further include assembling at least two ring electrode assemblies and connecting adjacent ring electrode assemblies together with a bridge tube. Connecting the bridge tube to each ring assembly can include sliding an end of the bridge tube over a second ledge of each insert. Each end of the bridge tube can have an inner circumference approximately equal to the outer circumference of the second ledge. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic, pictorial illustration of a medical system including a catheter with multiple ring electrodes in accordance with the techniques of the present disclosure; [Figure 2A] 1 is a schematic, pictorial illustration of an insert component of a modular ring electrode assembly in accordance with the disclosed technology; [Figure 2B] FIG. 2B is an end view of the insert component shown in FIG. 2A of the modular ring electrode assembly in accordance with the technology of the present disclosure. [Figure 3] 1 is a schematic, pictorial illustration of a ring electrode component of a modular ring electrode assembly in accordance with the disclosed technology; [Figure 4] FIG. 1 is a schematic, pictorial illustration of a ring electrode component disposed over an insert component of a modular ring electrode assembly in accordance with the disclosed technology; [Figure 5A] 1 is a schematic, pictorial illustration of a modular ring electrode assembly in accordance with the disclosed technology; [Figure 5B] FIG. 6 is a cross-sectional view of the modular ring electrode assembly taken along line AA of FIG. 5 in accordance with the techniques of the present disclosure. [Figure 6] 1 is a schematic, pictorial illustration of a modular ring electrode assembly in accordance with the disclosed technology; [Figure 7] FIG. 10 is a flow diagram illustrating a method for assembling a modular ring electrode assembly in accordance with the disclosed technique. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict selected examples and are not intended to limit the scope of the present disclosure. The detailed description illustrates, by way of example, but not by way of limitation, the principles of the disclosed technology. This description will clearly enable any person skilled in the art to make and use the disclosed technology and describes several embodiments, adaptations, variations, alternatives, and uses of the disclosed technology, including what is currently contemplated to be the best mode for carrying out the disclosed technology.

[0015] As used herein, the terms "about," "approximately," or "generally" in connection with any numerical value or range indicate suitable dimensional tolerances that enable a portion or collection of components to function for the intended purpose described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value. For example, "about 90%" may refer to a range of values ​​of 71% to 110%. Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and while use of the subject technology in human patients represents a preferred embodiment, it is not intended to limit the systems or methods to human use. Similarly, the term "proximal" refers to a location closer to the operator or physician, while "distal" refers to a location farther from the operator or physician.

[0016] As discussed herein, the vascular system of a "patient," "host," "user," and "subject" may be that of a human or any animal. It should be understood that the animal may be of any of a variety of applicable types, including, but not limited to, mammals, veterinary animals, livestock animals, or companion animals. As an example, the animal may be a laboratory animal (e.g., rat, dog, pig, monkey, etc.) specifically selected to have certain characteristics similar to humans. It should be understood that the subject may be, for example, any applicable human patient.

[0017] As discussed herein, an "operator" may include a physician, surgeon, technician, scientist, or any other individual or delivery instrument associated with the delivery of a multi-electrode catheter for the treatment of drug-refractory atrial fibrillation to a subject.

[0018] As discussed herein, the term "ablate" or "ablation," when referring to the devices and corresponding systems of the present disclosure, refers to components and structural features configured to reduce or prevent the generation of irregular cardiac signals within cells by utilizing non-thermal energy, such as irreversible electroporation (IRE), which is interchangeably referred to as pulsed electric field (PEF) and pulsed field ablation (PFA) throughout this disclosure. When referring to the devices and corresponding systems of the present disclosure, ablation or ablation is used throughout this disclosure to refer to non-thermal ablation of cardiac tissue for specific conditions, including, but not limited to, arrhythmias, atrial flutter ablation, pulmonary vein isolation, supraventricular tachycardia ablation, and ventricular tachycardia ablation. The term "ablate" or "ablation" also includes known methods, devices, and systems for achieving various forms of body tissue ablation, as will be understood by those skilled in the art.

[0019] As discussed herein, the terms "bipolar" and "monopolar," when used to refer to ablation schemes, describe different ablation schemes with respect to current path and electric field distribution. "Bipolar" refers to an ablation scheme that utilizes a current path between two electrodes, both positioned at the treatment site. The current density and electric flux density are typically approximately equal at each of the two electrodes. "Monopolar" refers to an ablation scheme that utilizes a current path between two electrodes, where one electrode with a high current density and high electric flux density is positioned at the treatment site and a second electrode with a relatively low current density and lower electric flux density is positioned remotely from the treatment site.

[0020] As discussed herein, the terms "tubular" and "tube" are intended to be broadly construed and are not limited to right cylindrical structures, or structures that are strictly circular in cross section, or structures that are uniform in cross section throughout their length. For example, a tubular / shaft structure is generally illustrated as a substantially right cylindrical structure. However, a tubular / shaft structure may have a tapered or curved outer surface without departing from the scope of the present disclosure.

[0021] The present disclosure relates to systems, methods, or uses and devices for IRE ablation of cardiac tissue to treat cardiac arrhythmias. Ablation energy is typically delivered to cardiac tissue by a distal portion of a catheter capable of delivering the ablation energy along the tissue to be ablated. Some exemplary catheters include a three-dimensional structure at the distal portion and are configured to administer the ablation energy from various electrodes positioned on the three-dimensional structure. Ablation procedures incorporating such exemplary catheters can be visualized using fluoroscopy.

[0022] Ablation of cardiac tissue using radiofrequency (RF) energy and thermal techniques, such as cryoablation, to improve cardiac function is a well-known procedure. Successful ablation using thermal techniques typically requires measuring cardiac potentials at various locations in the myocardium. Additionally, temperature measurements during ablation provide data that enables assessment of ablation effectiveness. Typically, ablation procedures using thermal techniques involve measuring electrode potentials and temperatures before, during, and after the actual ablation. RF approaches can pose risks that can lead to tissue charring, burning, steam popping, phrenic nerve paralysis, pulmonary vein stenosis, and esophageal fistulas. Cryoablation is an alternative approach to RF ablation that can reduce some of the thermal risks associated with RF ablation. However, operating a cryoablation device and selectively applying cryoablation are generally more difficult than RF ablation. Therefore, cryoablation is not feasible in certain anatomical shapes that can be reached by electrical ablation devices.

[0023] The present disclosure may include electrodes configured for irreversible electroporation (IRE), RF ablation, and / or cryoablation. IRE may be referred to interchangeably throughout this disclosure as pulsed electric field (PEF) ablation and pulsed field ablation (PFA). IRE, as discussed in this disclosure, is a non-thermal cell death technique that can be used to ablate atrial arrhythmias. To ablate using IRE / PEF, biphasic voltage pulses are applied to destroy myocardial cellular structures. The biphasic pulses are non-sinusoidal waveforms that can be tailored to target cells based on the electrophysiology of the cells. In contrast, to ablate using RF, a sinusoidal voltage waveform is applied to generate heat in the treatment area, indiscriminately heating all cells within the treatment area. Therefore, IRE has the ability to spare adjacent heat-sensitive structures or tissues, which may be beneficial in reducing potential complications known with ablation or isolation modalities. Additionally or alternatively, monophasic pulses may be utilized.

[0024] Electroporation can be induced by applying a pulsed electric field to biological cells to cause the reversible (temporary) or irreversible (permanent) creation of pores in the cell membrane. Cells have a transmembrane electrostatic potential that increases above their resting potential upon application of the pulsed electric field. While the transmembrane electrostatic potential remains below a threshold potential, electroporation is reversible, meaning that the pores can close when the applied pulsed electric field is removed, allowing the cell to self-repair and survive. If the transmembrane electrostatic potential increases above the threshold potential, electroporation is irreversible and the cell becomes permanently permeable. As a result, the cell dies due to loss of homeostasis, typically by apoptosis. Generally, different types of cells have different threshold potentials. For example, cardiac cells have a threshold potential of approximately 500 V / cm, while bone has a threshold potential of 3000 V / cm. These differences in threshold potential allow IRE to selectively target tissues based on their threshold potential.

[0025] The disclosed technology includes systems and methods for applying electrical signals from catheter electrodes positioned near myocardial tissue to generate ablation energy for ablating the myocardial tissue. In some examples, the systems and methods may be effective for ablating target tissue by inducing irreversible electroporation. In some examples, the systems and methods may be effective for inducing reversible electroporation as part of a diagnostic procedure. Reversible electroporation occurs when electricity applied at the electrodes falls below the electric field threshold of the target tissue, allowing cells to repair. Reversible electroporation does not kill cells but allows a physician to see the effect of reversible electroporation on the electrical activation signal near the target location. Exemplary systems and methods for reversible electroporation are disclosed in U.S. Patent Application Publication No. 2021 / 0162210, which is incorporated herein by reference in its entirety.

[0026] The pulsed electric field and its effectiveness in inducing reversible and / or irreversible electroporation can be affected by the physical parameters of the system and the biphasic pulse parameters of the electrical signal. Physical parameters can include electrode contact area, electrode spacing, electrode shape, etc. Examples presented herein generally include physical parameters adapted to effectively induce reversible and / or irreversible electroporation. Biphasic pulse parameters of the electrical signal can include voltage amplitude, pulse duration, interpulse delay, interpulse delay, total application time, delivered energy, etc. In some examples, the parameters of the electrical signal can be adjusted to induce both reversible and irreversible electroporation given the same physical parameters. Examples of various systems and methods for ablation, including IRE, are provided in U.S. Patent Application Publication Nos. 2021 / 0169550(A1), 2021 / 0169567(A1), 2021 / 0169568(A1), 2021 / 0161592(A1), 2021 / 0196372(A1), 2021 / 0177503(A1), and 2021 / 0186604(A1), the entire contents of each of which are incorporated herein by reference.

[0027] Refer to FIG. 1 , which illustrates an exemplary catheter-based electrophysiology mapping and ablation system 10. The system 10 includes multiple catheters that are percutaneously inserted by a physician 24 through the vascular system of a patient 23 and into a chamber or vasculature of a heart 12. Typically, a delivery sheath catheter is inserted into the left or right atrium near a desired location in the heart 12. Multiple catheters can then be inserted into the delivery sheath catheter to reach the desired location. The multiple catheters may include catheters dedicated to sensing intracardiac electrogram (IEGM) signals, catheters dedicated to ablation, and / or catheters dedicated to both sensing and ablation. An exemplary catheter 14 configured to sense IEGMs is illustrated herein. To sense a target site within the heart 12, the physician 24 brings a catheter shaft 90 (i.e., end effector 100) having a distal tip of the catheter 14 into contact with the heart wall. For ablation, the physician 24 similarly delivers the distal end of an ablation catheter to the target site for ablation.

[0028] The catheter 14 is an exemplary catheter that includes one, and preferably multiple, electrodes 26 configured to sense IEGM signals, optionally distributed over an end effector 100 coupled to a catheter shaft 90, as described in more detail below. The catheter 14 may additionally include a position sensor embedded in or near the end effector 100 to track the position and orientation of the end effector 100. Optionally and preferably, the position sensor is a magnetic-based position sensor including multiple magnetic coils for sensing three-dimensional (3D) position and orientation.

[0029] The magnetic-based position sensor may operate in conjunction with a location pad 25 that includes a plurality of magnetic coils 32 configured to generate a magnetic field within a predetermined working volume. The real-time position of the end effector 100 of the catheter 14 may be tracked based on the magnetic field generated by the location pad 25 and sensed by the magnetic-based position sensor. Details of magnetic-based position sensing technology are described in U.S. Patent Nos. 5,391,199; 5,443,489; 5,558,091; 6,172,499; 6,239,724; 6,332,089; 6,484,118; 6,618,612; 6,690,963; 6,788,967; and 6,892,091, each of which is incorporated herein by reference.

[0030] System 10 includes one or more electrode patches 38 positioned for skin contact on patient 23 to establish a position reference for location pads 25 and impedance-based tracking of electrodes 26. For impedance-based tracking, current is directed to electrodes 26 and sensed at electrode skin patches 38, allowing the position of each electrode to be triangulated via electrode patches 38. Details of impedance-based position tracking techniques are described in U.S. Patent Nos. 7,536,218, 7,756,576, 7,848,787, 7,869,865, and 8,456,182, each of which is incorporated herein by reference.

[0031] Recorder 11 displays electrograms 21 captured by body surface ECG electrodes 18 and intracardiac electrograms (IEGMs) captured by electrodes 26 on catheter 14. Recorder 11 may include pacing capability for pacing the cardiac rhythm and / or may be electrically connected to a stand-alone pacer.

[0032] The system 10 may include an ablation energy generator 50 adapted to conduct ablation energy to one or more of the electrodes 26 at the distal tip 28 of the catheter configured for ablation. The energy generated by the ablation energy generator 50 may include, but is not limited to, radiofrequency (RF) energy or pulsed-field ablation (PFA) energy, including unipolar or bipolar high-voltage DC pulses, such as may be used to effect irreversible electroporation (IRE), or a combination thereof.

[0033] The patient interface unit (PIU) 30 is an interface configured to establish electrical communication between the catheters, electrophysiology equipment, a power source, and a workstation 55 that controls the operation of the system 10. The electrophysiology equipment of the system 10 may include, for example, multiple catheters, location pads 25, body surface ECG electrodes 18, electrode patches 38, an ablation energy generator 50, and a recorder 11. Optionally and preferably, the PIU 30 additionally includes processing capabilities for implementing real-time calculations of catheter position and performing ECG calculations.

[0034] The workstation 55 includes a processor unit having memory, memory or storage loaded with appropriate operating software, and user interface functionality. The workstation 55 may optionally provide multiple functions, including: (1) modeling the endocardial anatomical structure in three dimensions (3D) and rendering the model or anatomical map 20 for display on the display device 27; (2) displaying activation sequences (or other data) compiled from recorded electrograms 21 in a representative visual representation or image superimposed on the rendered anatomical map 20 on the display device 27; (3) displaying the real-time position and orientation of multiple catheters within the cardiac chambers; and (4) displaying sites of interest, such as where ablation energy is being applied, on the display device 27. One commercially available product embodying elements of the system 10 is available as the CARTO™ 3 system, commercially available from Biosense Webster, Inc., 31 Technology Drive, Suite 200, Irvine, CA 92618.

[0035] 5 shows a ring electrode assembly 100 according to some examples of the disclosed technology. The ring electrode assembly can include an insert 110, a ring electrode 130 disposed on the insert 110, and two collars 150 coupled to the ends of the ring electrode 130 and the insert 110 to secure the ring electrode to the insert 110.

[0036] 2A and 2B illustrate an insert component 110 of a modular ring assembly 100, according to some examples of the disclosed technology. FIG. 2A is a perspective view, and FIG. 2B is an end view of the insert component 110. The insert 110 can extend along a longitudinal axis 180 and can include an intermediate portion 115 having a first diameter or circumference D1. A first ledge 112 can be provided at each end of the insert 110, having a second diameter D2 or circumference slightly smaller than the first diameter or circumference of the intermediate portion 115 of the insert 110. A second ledge 114 can be provided at each end of the insert 110, having a third diameter D3 or circumference slightly smaller than the second diameter or circumference of the first ledge 112. This arrangement is such that the ends of the insert 110 can have a two-stage taper provided by the first ledge 112 and the second ledge 114. A second ledge 114 is provided at an end of the insert 110, and a first ledge 112 is provided between the second ledge 114 and an intermediate portion 115 of the insert 110. In some examples, the first ledge 112 has a length of about 0.5 millimeters (mm). In some examples, the second ledge 114 has a length of about 0.5 millimeters (mm).

[0037] The insert 110 can further comprise one or more lumens 122, 124, 126, 128. In some examples, the insert 110 comprises a lead lumen 122 for providing a lead (e.g., lead 105 shown in FIG. 4) for providing an electrical signal to a ring electrode of the end effector. The insert 110 can further include a lead hole 118 for providing a lead to the ring electrode when the ring electrode is disposed around the insert (as shown in FIG. 4). The insert 110 can further comprise a lead recess 116 that provides space for a lead between the insert 110 and the ring electrode.

[0038] Insert 110 can further include pull lead lumen 124. In some embodiments, the end effector is a helical end effector (as shown in FIG. 1 ). The helical end effector can change its shape, for example, from a straight configuration to a helical configuration (as shown in FIG. 1 ), by engaging a pull lead, which can be provided through pull lead lumen 124.

[0039] The insert 110 may further comprise an irrigation lumen 126. In some examples, irrigation fluid is provided through an irrigation tube, which may be disposed within the irrigation lumen 126. In some examples, the irrigation lumen 126 functions as an irrigation tube and provides a channel for the irrigation fluid to flow.

[0040] The insert 110 can further include a frame lumen 128. The frame lumen 128 can be provided to receive a frame that forms the shape of the end effector. In some embodiments, the frame is formed from a flexible, elastic material. By way of example, the frame can be formed from a shape memory alloy, such as nickel-titanium, also known as nitinol, cobalt chromium, stainless steel, and / or other alloys that exhibit pseudoelastic properties. In some examples, the frame lumen 128 can be shaped to correspond to the cross-section of the frame. For example, the frame lumen 128 can include an elongated slot that corresponds to the oval cross-section of the frame.

[0041] The insert may comprise a single, integrated part. The insert may be molded. The insert may be formed by injection molding. In some examples, the insert comprises a plastic or elastomeric material. The insert may further comprise an insulating material or be coated with an insulator.

[0042] 3 illustrates a ring electrode 130 of a modular ring electrode assembly, according to some examples. The ring electrode 130 can include an annular body extending along a longitudinal axis 180. The ring electrode 135 can include one or more irrigation holes 132 for delivering irrigation fluid to the target anatomical region. The irrigation fluid can be used to facilitate cooling of the target anatomical region and the ring electrode 130 during operation of the catheter, for example, during an ablation procedure. The ring electrode 130 further includes two tapered ends 134. The ends of the ring electrode 130 are tapered such that at least the outer diameter / circumference of a middle portion 135 of the ring electrode 130 is greater than the outer diameter / circumference 138 of the tapered ends 134.

[0043] FIG. 4 illustrates a ring electrode 130 disposed on an insert 110, according to some examples. As shown in FIG. 5B, which is a cross-sectional view of the ring electrode 130 and insert 110 taken along line AA in FIG. 5A, the inner diameter / circumference 136 (D4) of the electrode's tapered end 134 can be approximately equal to the outer diameter / circumference D1 of the intermediate portion 115 of the insert 110. By disposing the ring electrode 130 on the insert 110, an interference fit can be formed between the inner diameter / circumference 136 of the tapered end 134 and the outer diameter / circumference D1 of the intermediate portion 115 of the insert 110, forming a seal at the interface between the tapered end 134 of the ring electrode 130 and the outer circumference of the intermediate portion 115 of the insert 110. In some examples, the intermediate portion of the ring electrode 130 has an inner diameter / circumference D5 that is larger than the outer diameter / circumference (D1) of the intermediate portion of the insert 110, thereby providing a space 131 between the intermediate portion of the insert 110 and the intermediate portion of the ring electrode 130. This provided space 131 can be utilized as a reservoir for the introduction of irrigation fluid. In other examples, the lead wire hole (hole 118 shown in FIG. 2 ) can also be used to accommodate irrigation fluid tubing and introduce irrigation fluid into the space 131 provided between the intermediate portion 115 of the insert 110 and the intermediate portion of the ring electrode 130. In some examples, one or more additional holes 127 are provided through the intermediate portion 115 of the insert 110 from the irrigation fluid lumen 126 to the outer periphery / surface of the intermediate portion 115 of the insert 110 to provide irrigation tubing or irrigation fluid to the irrigation reservoir provided by the space 131 between the intermediate portion 115 of the insert 110 and the intermediate portion of the ring electrode 130.

[0044] 5A , an exemplary modular ring electrode assembly 100 is shown in which a ring electrode 130 is disposed on an insert 110 and a collar 150 is coupled to each end of the ring electrode 130, thereby securing the ring electrode 130 to the insert 110. The collars 150 may be connected to the ring electrode 130 and / or the insert 110 by press-fitting, adhesive, shrink tubing, crimping, or other suitable methods of attaching the collar to the ring electrode 130 and / or the insert 110. In some examples, each of the collars 150 is tapered from a first end 152 to a second end 154. The first end 152 of each collar 150 may include an inner diameter / circumference approximately equal to the outer diameter / circumference of the tapered end 134 of the ring electrode 130. The second end 154 of each collar 150 may include an inner diameter / circumference approximately equal to the outer diameter / circumference of the first ledge 112 of the insert 110. In some examples, when the collar 150 is coupled to the tapered end 134 of the ring electrode 130 and the first ledge 112 of the insert 110, the ring electrode 130 is secured in place relative to the insert 110. The collar 150 may also provide a seal to prevent fluid from passing between the tapered end 134 of the ring electrode 130 and the insert 110. In some examples, after the collar 150 is coupled to the end 134 of the ring electrode 130, the second ledge 114 of the insert 110 protrudes outward from the collar 150. In some examples, an overmold may be provided on or in the collar 150 to secure the collar to the ring electrode 130, thereby securing the ring electrode to the insert 110. In some examples, the outer diameter of the insert 110 is roughened or provided with a surface texture to facilitate adhesion of the overmold. In some examples, a space is provided between the inner diameter of the collar 150 and the first ledge 112 and filled with an overmold material. The collar 150 can include slots or through-holes for injecting the overmolding material. In some examples, a mandrel is placed within the lumen of the insert during injection of the overmolding material. The collar 150 can also be swaged onto the electrode 130 and / or insert 110.

[0045] As shown in FIG. 6 , in some examples, two or more ring electrode assemblies 100 can be connected by one or more bridge tubes 160. In some examples, a bridge tube 160 is provided between two adjacent ring electrode assemblies 100. An end of the bridge tube 160 can include an inner diameter / circumference approximately equal to the outer diameter / circumference of the second ledge 114 of the insert 100. In some embodiments, the bridge tube 160 can fit over the second ledges 114 of two adjacent ring electrode assemblies, thereby connecting the two adjacent ring electrode assemblies 100. Multiple ring electrode assemblies can connect multiple bridge tubes 160 to provide an end effector of a desired length.

[0046] In some examples, the bridge tube 160 can have multiple lumens corresponding to the lumens of the insert 110. For example, the bridge tube 160 can have four lumens corresponding to the lead wire lumen 122, the pull wire lumen 124, the irrigation lumen 126, and the frame lumen 128 of the insert 110 shown in FIG. 2 . In some examples, the lumens of the bridge tube 160 are aligned with the lumens of the insert 110. In some examples, the bridge tube 160 can have a single lumen for accommodating components of the end effector (e.g., the pull wire, the frame, the irrigation tubing, and / or the lead wire). In some examples, the bridge tube 160 is secured to the ring assembly 100 after being fitted and glued onto the second ledge 114 of the insert 110. A suitable adhesive may include polyurethane. In some examples, a mandrel is utilized to prevent blockage of the lumens of the bridge tube 160 and / or the insert 110 during application of the adhesive. In some instances, through holes may be provided in bridge tube 110 by trepanning or another suitable method to facilitate application of adhesive.

[0047] FIG. 7 illustrates an exemplary method 700 for forming an end effector using the modular ring assembly disclosed herein. In some examples, the method 700 begins in a first step 705 by providing an insert (e.g., the insert 110 shown in FIG. 2). In a second step 710, a ring electrode can be slid onto the insert (as shown in FIG. 4). As described herein, the ring electrode can be sized so that an interference fit is provided between the insert and the ring electrode to temporarily hold the ring electrode in place. In a third step 715, a collar can be coupled to the end of the ring electrode. In some examples, the collar is further coupled to the end of the insert during coupling to the end of the ring electrode (e.g., the first ledge 112). Coupling the collar to the end of the ring electrode and the end of the insert can secure the ring electrode to the insert. In a fourth step 720, an overmold can be provided over or within the collar and insert to secure the ring electrode and collar to the insert. In a fifth step 725, a ring electrode assembly (e.g., ring electrode assembly 100 shown in FIG. 5) is slid onto the frame of the end effector. As an optional sixth step 730, a bridge tube (e.g., bridge tube 160 shown in FIG. 6) is slid onto the frame, and then an additional ring electrode assembly can be slid onto the frame at the other end of the bridge tube, thereby connecting the ring electrode assemblies. Multiple ring electrode assemblies can be connected by bridge tubes to form an end effector of a desired length. Optionally, in addition to or instead of the overmold in the fourth step 720, an overmold can be provided on or in a collar that extends over the end of the bridge tube to secure the ring electrode assemblies to the bridge tube.

[0048] The techniques of the present disclosure described herein can be further understood in accordance with the following clauses.

[0049] Clause 1. A ring electrode assembly comprising: an insert including at least one lumen extending along a longitudinal axis; a ring electrode disposed around a middle portion of the insert and having two ends; and two collars, each coupled to each of the two ends of the ring electrode and to the insert to secure the ring electrode to the insert.

[0050] Clause 2. A ring electrode assembly as described in clause 1, wherein the ring electrode tapers inward from a central portion to each of the two ends.

[0051] Clause 3. A ring electrode assembly as described in clause 2, wherein the inner circumference of each of the two ends of the ring electrode is approximately equal to the outer circumference of the middle portion of the insert.

[0052] Clause 4. A ring electrode assembly as described in clause 2 or 3, wherein each of the two collars tapers inward from the first end to the second end, and the inner circumference of the first end of each collar is approximately equal to the outer circumference of the two ends of the ring electrode.

[0053] Clause 5. The ring electrode assembly of clause 4, wherein each end of the insert comprises a first ledge, the first ledge having an outer periphery approximately equal to the inner periphery of the second end of each collar.

[0054] Clause 6. A ring electrode assembly as described in Clause 5, wherein each end of the insert further comprises a second ledge, and a first ledge is provided at each end of the insert between the second ledge and an intermediate portion of the insert, the outer periphery of the intermediate portion of the insert being larger than the outer periphery of the first ledge, and the outer periphery of the first ledge being larger than the outer periphery of the second ledge.

[0055] Clause 7. The ring electrode of clause 6, wherein the length of the second ledge is about 0.5 mm.

[0056] Clause 8. A ring electrode as described in any one of clauses 2 to 7, wherein the ring electrode is provided with a plurality of irrigation holes, the inner circumference of the central portion of the ring electrode being greater than the outer circumference of the intermediate portion of the insert, and the resulting gap between the inner circumference of the central portion of the ring electrode and the outer circumference of the intermediate portion of the insert provides an irrigation reservoir.

[0057] Clause 9. A catheter end effector comprising: two or more ring electrode assemblies, each ring assembly comprising an insert having at least one lumen extending along a longitudinal axis, the insert further comprising an intermediate portion, a second ledge provided at each end of the insert, and a first ledge provided between each second ledge and the intermediate portion; two or more ring electrode assemblies, the two or more ring electrode assemblies being disposed around the intermediate portion of the insert and having two ends; and two collars, each collar coupled to each of the two ends of the ring electrode; at least one bridge tube connecting adjacent ring electrode assemblies and having at least one lumen corresponding to the at least one lumen of the insert; and a frame provided through at least one lumen of each ring electrode assembly and through at least one lumen of the at least one bridge tube.

[0058] Clause 10. The end effector of clause 9, wherein the frame comprises nitinol.

[0059] Clause 11. An end effector as described in clause 9 or 10, wherein at least one bridge tube has two ends, and the two ends of the at least one bridge tube have an inner diameter approximately equal to the outer diameter of the second ledge.

[0060] Clause 12. An end effector described in any one of clauses 9 to 11, wherein the ring electrode tapers inward from a central portion to each of the two ends, and the inner diameter of each of the two ends is approximately equal to the outer diameter of the intermediate portion of the insert.

[0061] Clause 13. An end effector described in any one of clauses 9 to 12, wherein each of the two collars tapers inward from the first end to the second end, and the inner diameter of the first end of each collar is approximately equal to the outer diameter of the two ends of the ring electrode.

[0062] Clause 14. The end effector of clause 13, wherein an inner diameter of the second end of each collar is approximately equal to an outer diameter of the first ledge.

[0063] Clause 15. An end effector as described in clauses 9-14, further comprising an overmold between each collar of the insert and each first ledge.

[0064] Clause 16. An end effector described in any one of clauses 9 to 15, wherein at least one lumen of the insert includes a lead wire lumen, and the insert further includes a lead wire hole extending from the lead wire lumen to the outer surface of the insert.

[0065] Clause 17. A method of assembling a catheter end effector, the method comprising assembling one or more ring electrode assemblies, wherein assembling each ring electrode assembly includes: providing an insert having at least one lumen extending along a longitudinal axis, the insert further comprising a middle portion, a second ledge provided at each end of the insert, and a first ledge provided between each second ledge and the middle portion; sliding a ring electrode onto the middle portion of the insert; and sliding a collar onto each end of the ring electrode, wherein each collar slides onto a respective first ledge of the insert.

[0066] Clause 18. The method of clause 17, wherein assembling the end effector further comprises sliding each ring electrode assembly onto a frame such that the frame is provided through at least one lumen of the insert.

[0067] Clause 19. The method of clause 17 or 18, wherein at least two ring electrode assemblies are assembled, and the method further comprises connecting adjacent ring electrode assemblies to each other with a bridge tube.

[0068] Clause 20. The method of clause 19, wherein coupling the bridge tube to each ring assembly includes sliding an end of the bridge tube over a second ledge of each insert, each end of the bridge tube including an inner circumference approximately equal to the outer circumference of the second ledge.

[0069] The above-described embodiments are cited as examples, and the technology of the present disclosure is not limited to what has been specifically shown and described in the above specification. Rather, the scope of the technology of the present disclosure includes both combinations and subcombinations of the various features described above, as well as variations and modifications thereof that would occur to one skilled in the art upon reading the foregoing description and that are not disclosed in the prior art.

[0070] [Embodiment] (1) A ring electrode assembly comprising: an insert having at least one lumen extending along a longitudinal axis; a ring electrode disposed around a middle portion of the insert and having two ends; a ring electrode assembly comprising: two collars, each collar coupled to each of the two ends of the ring electrode and the insert to secure the ring electrode to the insert; (2) A ring electrode assembly as described in embodiment 1, wherein the ring electrode tapers inward from a central portion toward each of the two ends. (3) A ring electrode assembly as described in embodiment 2, wherein the inner circumference of each of the two ends of the ring electrode is approximately equal to the outer circumference of the middle portion of the insert. (4) A ring electrode assembly as described in embodiment 2, wherein each of the two collars tapers inward from the first end to the second end, and the inner circumference of the first end of each collar is approximately equal to the outer circumference of the two ends of the ring electrode. (5) A ring electrode assembly as described in embodiment 4, wherein each end of the insert comprises a first ledge, the first ledge having an outer periphery approximately equal to the inner periphery of the second end of each collar.

[0071] (6) A ring electrode assembly as described in embodiment 5, wherein each end of the insert further comprises a second ledge, the first ledge is provided at each end of the insert between the second ledge and the intermediate portion of the insert, the outer periphery of the intermediate portion of the insert is larger than the outer periphery of the first ledge, and the outer periphery of the first ledge is larger than the outer periphery of the second ledge. (7) A ring electrode as described in embodiment 6, wherein the length of the second ledge is about 0.5 mm. (8) The ring electrode of embodiment 2, wherein the ring electrode comprises a plurality of irrigation holes, the inner circumference of the central portion of the ring electrode is greater than the outer circumference of the intermediate portion of the insert, and the resulting gap between the inner circumference of the central portion of the ring electrode and the outer circumference of the intermediate portion of the insert provides an irrigation reservoir. (9) An end effector for a catheter, Two or more ring electrode assemblies, each ring electrode assembly comprising: an insert having at least one lumen extending along a longitudinal axis, the insert further comprising a middle portion, a second ledge provided at each end of the insert, and a first ledge provided between each second ledge and the middle portion; a ring electrode disposed around the middle portion of the insert and having two ends; two or more ring electrode assemblies comprising two collars, each collar coupled to one of the two ends of the ring electrode; at least one bridge tube connecting adjacent ring electrode assemblies and having at least one lumen corresponding to the at least one lumen of the insert; a frame provided through the at least one lumen of each ring electrode assembly and through the at least one lumen of the at least one bridge tube. (10) An end effector as described in embodiment 9, wherein the frame comprises Nitinol.

[0072] (11) An end effector as described in embodiment 9, wherein the at least one bridge tube has two ends, and the two ends of the at least one bridge tube have an inner diameter approximately equal to the outer diameter of the second ledge. (12) An end effector as described in embodiment 9, wherein the ring electrode tapers inward from a central portion toward each of the two ends, and the inner diameter of each of the two ends is approximately equal to the outer diameter of the intermediate portion of the insert. (13) An end effector as described in embodiment 9, wherein each of the two collars tapers inward from the first end to the second end, and the inner diameter of the first end of each collar is approximately equal to the outer diameter of the two ends of the ring electrode. (14) An end effector as described in embodiment 13, wherein the inner diameter of the second end of each collar is approximately equal to the outer diameter of the first ledge. (15) An end effector as described in embodiment 9, further comprising an overmold between each collar and each first ledge of the insert.

[0073] (16) An end effector as described in embodiment 9, wherein the at least one lumen of the insert includes a lead wire lumen, and the insert further includes a lead wire hole extending from the lead wire lumen to an outer surface of the insert. (17) A method of assembling an end effector of a catheter, comprising: Assembling one or more ring electrode assemblies, wherein assembling each ring electrode assembly includes: providing an insert having at least one lumen extending along a longitudinal axis, the insert further comprising a middle portion, a second ledge provided at each end of the insert, and a first ledge provided between each second ledge and the middle portion; sliding a ring electrode onto the intermediate portion of the insert; and assembling one or more ring electrode assemblies, the method including: sliding a collar onto each end of the ring electrodes, each collar sliding onto a first ledge of each of the inserts. (18) The method of embodiment 17, wherein assembling the end effector further comprises sliding each ring electrode assembly onto a frame such that the frame is provided through the at least one lumen of the insert. (19) The method of embodiment 17, wherein at least two ring electrode assemblies are assembled, and the method further comprises connecting adjacent ring electrode assemblies to each other with a bridge tube. (20) The method of embodiment 19, wherein coupling the bridge tube to each ring assembly includes sliding an end of the bridge tube over the second ledge of each insert, and each end of the bridge tube includes an inner circumference approximately equal to the outer circumference of the second ledge.

Claims

1. 1. A ring electrode assembly comprising: an insert having at least one lumen extending along a longitudinal axis; a ring electrode disposed around a middle portion of the insert and having two ends; a ring electrode assembly comprising: two collars, each collar coupled to each of the two ends of the ring electrode and the insert to secure the ring electrode to the insert;

2. The ring electrode assembly of claim 1 , wherein the ring electrode tapers inwardly from a central portion toward each of the two ends.

3. 3. The ring electrode assembly of claim 2, wherein an inner circumference of each of the two ends of the ring electrode is approximately equal to an outer circumference of the middle portion of the insert.

4. 3. The ring electrode assembly of claim 2, wherein each of the two collars tapers inward from a first end to a second end, and the inner circumference of the first end of each collar is approximately equal to the outer circumferences of the two ends of the ring electrode.

5. 5. The ring electrode assembly of claim 4, wherein each end of the insert comprises a first ledge, the first ledge having an outer periphery approximately equal to an inner periphery of the second end of each collar.

6. 6. The ring electrode assembly of claim 5, wherein each end of the insert further comprises a second ledge, the first ledge being provided at each end of the insert between the second ledge and the intermediate portion of the insert, the outer periphery of the intermediate portion of the insert being larger than the outer periphery of the first ledge, and the outer periphery of the first ledge being larger than the outer periphery of the second ledge.

7. The ring electrode of claim 6 , wherein the second ledge has a length of about 0.5 mm.

8. 3. The ring electrode of claim 2, wherein the ring electrode comprises a plurality of irrigation holes, the inner circumference of the central portion of the ring electrode being greater than the outer circumference of the intermediate portion of the insert, the resulting gap between the inner circumference of the central portion of the ring electrode and the outer circumference of the intermediate portion of the insert providing an irrigation reservoir.

9. 1. A catheter end effector, comprising: Two or more ring electrode assemblies, each ring electrode assembly comprising: an insert having at least one lumen extending along a longitudinal axis, the insert further comprising an intermediate portion, a second ledge provided at each end of the insert, and a first ledge provided between each second ledge and the intermediate portion; a ring electrode disposed around the intermediate portion of the insert and having two ends; two or more ring electrode assemblies comprising two collars, each collar coupled to one of the two ends of the ring electrode; at least one bridge tube connecting adjacent ring electrode assemblies and having at least one lumen corresponding to the at least one lumen of the insert; a frame provided through the at least one lumen of each ring electrode assembly and through the at least one lumen of the at least one bridge tube.

10. The end effector of claim 9 , wherein the frame comprises nitinol.

11. The end effector of claim 9 , wherein the at least one bridge tube comprises two ends, the two ends of the at least one bridge tube having an inner diameter approximately equal to an outer diameter of the second ledge.

12. 10. The end effector of claim 9, wherein the ring electrode tapers inward from a central portion to each of the two ends, an inner diameter of each of the two ends being approximately equal to an outer diameter of the intermediate portion of the insert.

13. 10. The end effector of claim 9, wherein each of the two collars tapers inward from a first end to a second end, and an inner diameter of the first end of each collar is approximately equal to an outer diameter of the two ends of the ring electrode.

14. The end effector of claim 13 , wherein an inner diameter of the second end of each collar is approximately equal to an outer diameter of the first ledge.

15. The end effector of claim 9 , further comprising an overmold between each collar and each first ledge of the insert.

16. The end effector of claim 9 , wherein the at least one lumen of the insert includes a lead wire lumen, and the insert further includes a lead wire hole extending from the lead wire lumen to an outer surface of the insert.

17. 1. A method of assembling a catheter end effector, comprising: Assembling one or more ring electrode assemblies, wherein assembling each ring electrode assembly includes: providing an insert having at least one lumen extending along a longitudinal axis, the insert further comprising a middle portion, a second ledge provided at each end of the insert, and a first ledge provided between each second ledge and the middle portion; sliding a ring electrode onto the intermediate portion of the insert; and assembling one or more ring electrode assemblies, the method including: sliding a collar onto each end of the ring electrodes, each collar sliding onto a first ledge of each of the inserts.

18. 18. The method of claim 17, wherein assembling the end effector further comprises sliding each ring electrode assembly onto a frame such that the frame is provided through the at least one lumen of the insert.

19. 20. The method of claim 17, wherein at least two ring electrode assemblies are assembled, the method further comprising connecting adjacent ring electrode assemblies to each other with a bridge tube.

20. 20. The method of claim 19, wherein coupling the bridge tube to each ring assembly includes sliding an end of the bridge tube over the second ledge of each insert, each end of the bridge tube including an inner circumference approximately equal to an outer circumference of the second ledge.

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