catheter with pulsed-field ablation electrode

Abstract

To provide a catheter system and method. [Solution] The apparatus includes an elongated shaft assembly and a processor. The elongated shaft assembly includes a distal portion having an end effector and a tip member. The end effector has a flexible circuit having multiple electrodes that extend at an angle around the distal portion of the shaft assembly and are longitudinally spaced apart from each other along the distal portion of the shaft assembly. The tip member is positioned distal to the end effector and is more flexible than the distal portion of the shaft assembly. The processor is electrically coupled to the flexible circuit and configured to select one or more electrodes from the multiple electrodes to be activated. The processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue.

Description

Technical Field

[0001] (Priority) This application claims priority to U.S. Provisional Patent Application No. 63 / 739,156, filed on December 27, 2024, entitled "Ablation Catheter with Longitudinally Spaced Electrodes", the disclosure of which is hereby incorporated by reference in its entirety.

Background Art

[0002] Cardiac arrhythmias, such as atrial fibrillation, occur when regions of heart tissue conduct electrical signals abnormally. Treatments for treating arrhythmias include surgically disrupting the conduction pathways of such signals. By selectively applying electrical energy to heart 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 creating an electrically insulating lesion or scar tissue that effectively blocks the transmission of abnormal electrical signals across the ablated tissue.

[0003] In some procedures, ablation can be delivered into the patient's body using a catheter with one or more electrodes. 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 a structure adjacent to the heart (e.g., the pulmonary veins). 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, a unipolar electrode may be used in conjunction with a grounding pad or with another reference electrode in contact with the patient. Irrigation can be used to draw heat from the components of the ablation catheter and prevent the formation of a blood clot near the treatment site of the tissue.

[0004] 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" (its disclosure 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" (its disclosure 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" (its disclosure 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 disclosure is incorporated in its entirety by reference), U.S. Patent No. 10,702,177, titled "Catheter with Bipole Electrode Spacer and Related Methods," issued on July 7, 2020 (the disclosure is incorporated in its entirety 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 disclosure is incorporated in its entirety 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 disclosure is incorporated in its entirety by reference).

[0005] 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 involve the use of sensing electrodes on a catheter (e.g., the same catheter used to perform the ablation, or a dedicated mapping catheter). Such sensing electrodes can monitor electrical signals emanating from conductive endocardial tissue to precisely 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, “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, “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, “Catheter with Bipole Electrode Spacer and Related Methods,” issued on July 7, 2020 (the disclosure thereof is incorporated herein by reference in its entirety).

[0006] Some catheter ablation procedures can be performed using image-guided surgery (IGS) systems. IGS systems can allow physicians to visually track the position of the catheter within the patient in real time against images of the patient's anatomical structures. Several systems, including the CARTO 3® system by Biosense Webster, Inc. (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 (the disclosure of which is incorporated herein by reference in its entirety), and in various other references cited herein.

[0007] Although several catheter systems and methods have been fabricated and used, it is believed that no one prior to the inventors had fabricated or used the invention described, illustrated, and claimed herein. [Brief explanation of the drawing]

[0008] 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 diagram shows a schematic representation of the medical procedure in which a catheter assembly catheter is inserted into a patient. [Figure 2] Figure 1 shows a perspective view of an example of a catheter assembly that can be used in the medical procedure. [Figure 3] Figure 2 shows a perspective view of the distal portion of the shaft assembly of the catheter assembly. [Figure 4] Figure 2 shows a perspective view of the distal portion of the flex circuit of the catheter assembly. [Figure 5]Figure 4 shows a perspective view of the proximal portion of the flex circuit. [Figure 6] Figure 2 shows a cross-sectional side view of the distal portion of the catheter assembly, with the outer layer omitted from the shaft assembly. [Figure 7] Figure 3 shows a cross-sectional end view of the shaft assembly. [Figure 8] Figure 4 shows a bottom view of the flex circuit, which has a flat configuration. [Figure 9] Figure 4 shows a top view of the distal portion of the flex circuit, which has a flat configuration. [Figure 10] Figure 4 shows a bottom view of the proximal portion of the flex circuit, which has a flat configuration. [Figure 11] Figure 4 shows a side and elevation view of the flex circuit, which is configured with a flex circuit wrapped around it. [Figure 12] Figure 4 shows a side elevation view of the distal portion of the flex circuit, which is configured with a flex circuit wrapped around it. [Figure 13] Figure 4 shows a top view of the distal portion of the flex circuit, which is configured with a flex circuit wrapped around it. [Figure 14] Figure 4 shows a side elevation view of the proximal portion of the flex circuit, which is configured with a flex circuit wrapped around it. [Figure 15] Figure 4 shows a top view of the proximal portion of the flex circuit, which is configured with a flex circuit wrapped around it. [Figure 16A] A schematic diagram of a catheter shaft having a first example of an elongated position sensor arrangement is shown, with the position sensor loop in an unbent state. [Figure 16B] A schematic diagram of the position sensor loop in the example of a bent state is shown in Figure 16A. [Figure 16C] Figure 16A shows a schematic top view of the position sensor loop in the non-bent state. [Figure 16D] Figure 16B shows a schematic top view of the position sensor loop in Figure 16A in the bent state. [Figure 17]A schematic diagram of a catheter shaft having a second example of an elongated position sensor arrangement is shown. [Figure 18] A bottom view of an example of a flex circuit that can be used to provide the elongated position sensor arrangement of FIG. 17 is shown. [Figure 19] A bottom view of an intermediate portion of the flex circuit of FIG. 18 is shown. [Figure 20] A schematic diagram of a catheter shaft having a third example of an elongated position sensor arrangement is shown. [Figure 21] A schematic diagram of a catheter shaft having a fourth example of an elongated position sensor arrangement is shown. [Figure 22] A schematic diagram of the end effector of the catheter assembly of FIG. 2 is shown, where the electrodes of the end effector are used with a ground pad in a first example of an electrical path. [Figure 23] A schematic diagram of the end effector of the catheter assembly of FIG. 2 is shown, where the electrodes of the end effector are used in a second example of an electrical path. [Figure 24] A schematic diagram of the end effector of the catheter assembly of FIG. 2 is shown, where the electrodes of the end effector are used in a third example of an electrical path. [Figure 25] A schematic diagram of the end effector of the catheter assembly of FIG. 2 is shown, where the electrodes of the end effector are used in a fourth example of an electrical path. [Figure 26] A schematic diagram of the end effector of the catheter assembly of FIG. 2 is shown, where the electrodes of the end effector are used in a fifth example of an electrical path. [Figure 27] A schematic diagram of the end effector of the catheter assembly of FIG. 2 is shown, where the electrodes of the end effector are used in a sixth example of an electrical path. [Figure 28] A schematic diagram of the end effector of the catheter assembly of FIG. 2 is shown, where the electrodes of the end effector are used with a guide wire in a seventh example of an electrical path. [Figure 29]Figure 2 shows a schematic diagram of the end effector of the catheter assembly, where the end effector electrode is used together with the guidewire in the eighth example of the electrical path. [Figure 30] Figure 2 shows a schematic diagram of the end effector of the catheter assembly, where the end effector electrodes are used together with the irrigation fluid from the catheter assembly in the ninth example of the electrical pathway. [Figure 31] Figure 2 shows a schematic diagram of the end effector of the catheter assembly, where the end effector electrode is used together with the irrigation fluid from the sheath in the tenth example of the electrical pathway. [Figure 32] Figure 2 shows a side elevation view of a modified end effector of the catheter assembly. [Figure 32A] Figure 32 shows a schematic cross-sectional side view of a portion of the end effector. [Figure 33] Figure 2 shows a schematic diagram of the end effector of the catheter assembly, where the end effector electrodes are used together with another ablation device in the 11th example of the electrical pathway. [Figure 34] Figure 2 shows a schematic diagram of the end effector of the catheter assembly, where the end effector electrodes are used together with another ablation device in the twelfth example of the electrical pathway. [Modes for carrying out the invention]

[0009] 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 and depict selected embodiments, and are not intended to limit the scope of the invention. The detailed description is illustrative of the principles of the invention, not limiting, but 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 forms without departing from the invention. Accordingly, the drawings and description should be considered illustrative and not limiting.

[0010] Any one or more of the teachings, expressions, modifications, examples, etc., described herein may be combined with any one or more of the other teachings, expressions, modifications, examples, etc., described herein. Therefore, the teachings, expressions, modifications, examples, etc., described below should not be considered as independent of each other. 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 claims.

[0011] 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 ​​from 71% to 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.

[0012] 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 the EP mapping and / or cardiac ablation described above. Specifically, Figure 1 shows a physician (PH) grasping the handle assembly (110) of a catheter assembly (100), and the end effector of the catheter (not shown) of the catheter assembly (100) is positioned inside the patient (PA) to map the potentials of tissues within or near the patient's (PA) heart (H) and / or ablate the tissue. The catheter assembly (100) is coupled to a guide and 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 guide and drive system (10) via another cable (22).

[0013] The induction and driving system (10) in this example 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 modifications, the first driver module (14) is operable to receive EP mapping signals acquired via the electrodes of the end effector. In such modifications, the console (12) includes a processor (not shown) that processes such EP mapping signals and thereby provides EP mapping, as is known in the art. In some other modifications, the end effector does not provide EP mapping. In addition to receiving EP mapping signals acquired via the electrodes of the end effector, or instead of receiving EP mapping signals acquired via the electrodes of the end effector, the first driver module (14) may be operable to power the electrodes of the end effector and thereby ablate tissue. In such modifications, the console (12) includes a processor (not shown) that drives the generation of an appropriate electrical signal to provide ablation, as is well known in the art. In yet another modification, the end effector 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) may also be operable to receive position indicator signals from one or more position sensors (not shown) in the end effector and / or other locations within the catheter. In such modifications, the console (12) processor may be operable to process the position indicator signals from one or more position sensors and thereby determine the position of the end effector within the patient (PA). In some modifications, each position sensor includes one or more coils operable to generate signals indicating the position and orientation of the end effector within 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 include wireless triangulation, acoustic tracking, optical tracking, and inertial tracking. In some other modifications, the end effector and / or catheter lack position 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 are obtained based on a set of images (e.g., CT scan or MRI scan, 3D map, etc.) acquired preoperatively or during surgery. The view of the patient's anatomical structure provided through the display (18) may also change dynamically based on signals from the end effector and / or catheter position sensor assembly. For example, as the catheter's end effector moves within the patient (PA), corresponding position data from one or more position sensors may cause the processor of the console (12) to update the view of the patient's anatomical structure on the display (18) in real time to depict the area of ​​the patient's anatomical structure around the end effector as the end effector moves within the patient (PA). Furthermore, the processor of the console (12) may drive the display (18) to indicate the location of abnormal conductive tissue sites, as detected by electrophysiological (EP) mapping using the end effector, or as detected by other means (e.g., using a dedicated EP mapping catheter). As just one example, the processor of the console (12) may drive the display (18) to superimpose the location of abnormal conductive tissue areas onto an image of the patient's anatomical structure by superimposing an illuminated dot, crosshair, or some other form of visual representation of the abnormal conductive tissue areas.

[0017] The console (12) processor can also drive the display (18) to superimpose the current position of the end effector onto an image of the patient's anatomical structure, such as by superimposing an illuminated dot, crosshairs, a graphic representation of the end effector, or any other form of visual display. Such superimposed visual display 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 within the patient (PA), thereby providing the operator with real-time visual feedback on the position of the end effector within the patient (PA) as the end effector moves within the patient (PA). Thus, the images provided through the display (18) can effectively provide video tracking the position of the end effector within the patient (PA) body, even without necessarily having optical equipment (i.e., a camera) to view the end effector. In the same view, the display (18) can simultaneously visually indicate the location of abnormal conductive tissue sites detected by EP mapping. Therefore, the physician (PH) can observe the real-time positioning of the end effector relative to the mapped abnormal conductive tissue area and to images of adjacent anatomical structures within the patient (PA) by looking at the display (18).

[0018] The fluid source (42) in this example includes a bag containing saline solution or any other suitable irrigation fluid. 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 can be discharged through an opening (not shown) of the end effector. Such irrigation may be provided in any preferred form that will be apparent to those skilled in the art in light of the teachings herein.

[0019] II. Examples of Catheter Assemblies As described above, the catheter assembly (100) may be used to perform diagnostic functions (e.g., EP mapping) and / or therapeutic functions (e.g., ablation) within the patient's cardiovascular system. In some cases, the end effector of the catheter assembly (100) may be positioned in anatomical spaces such as the cardiac chambers or pulmonary veins of the heart to provide diagnostic and / or therapeutic functions in those spaces. In addition, or instead, it may be desirable to advance the end effector into smaller anatomical spaces such as the Marshall's vein and / or other small vessels branching from the coronary sinus to provide diagnostic and / or therapeutic functions in those smaller spaces.

[0020] While some conventional EP mapping and / or ablation end effectors can be fitted into larger anatomical spaces such as the cardiac chambers and pulmonary veins, such end effectors may not be able to fit into smaller anatomical spaces such as Marshall's veins and other small vessels branching from the coronary sinus. Furthermore, simply reducing the size of such conventional end effectors to fit them into such smaller spaces may not be practical, and therefore size reduction is not merely a design choice. For example, simply reducing the size of the electrodes and / or position sensors of such conventional end effectors to fit into smaller spaces may be physically impossible. Even if it is theoretically and physically possible to simply reduce the size of the electrodes and / or position sensors of such conventional end effectors to fit into smaller spaces, the reduction in size of the electrodes and / or position sensors may negatively affect the function of the electrodes and / or position sensors. For example, a reduced electrode may not be able to provide sufficient EP mapping and / or ablation function, and a reduced position sensor may not be able to provide sufficient position indication signal and accuracy. Therefore, it may be necessary to provide novel configurations and / or arrangements of electrodes and / or position sensors to provide desired functionality in relatively small spaces, such as other small vessels branching from the Marshall vein and / or coronary sinus.

[0021] Figure 2 shows an example of a catheter assembly (200) having an end effector (350) capable of providing desired EP mapping, ablation, and / or position-sensing functions within relatively small anatomical spaces, such as other small vessels branching from the Marshall vein and / or coronary sinus. The catheter assembly (200) in this example includes a handle assembly (210) and a shaft assembly (220) extending distally from the handle assembly (210).

[0022] The handle assembly (210) includes a body (212), a port (214), and a cable (216). The body (212) is configured to be grasped by the hand of a physician (PH). In some modifications, the body (212) includes one or more actuators that can operate to drive movement (e.g., rotation, joint movement, helical contraction, etc.) and / or other functions of the shaft assembly (220). In some alternative modifications, the body (212) is configured to engage with a robotic arm or other automated assembly rather than being operated by the hand of a physician (PH). The port (214) is positioned and configured to provide access to the lumen (236) (Figures 6-7) of the shaft assembly (220), thereby enabling the insertion of other components (e.g., a guidewire (250), etc.) into the shaft assembly (220) and / or communication of fluids (e.g., irrigation fluids such as saline, ethanol, or contrast agents) through the shaft assembly (220). For example, in some scenarios, a fluid conduit such as the fluid conduit (40) described above may be connected to the port (214). The cable (216) is configured to provide electrical communication between the electrical components of the catheter assembly (200) (e.g., the flexible circuit (300) described later) and the induction and drive system (10). Thus, the cable (216) may represent a modification of the cable (30) described above with reference to Figure 1.

[0023] The shaft assembly (220) in this example includes a proximal portion (222) and a distal portion (224), with the end effector (350) provided on the distal portion (224). The proximal portion (222) comprises a rigid shaft (223) in this example. For example, the proximal portion (222) may comprise a metal hypotube. Alternatively, the proximal portion (222) may comprise any other suitable material. The distal portion (224) comprises a flexible catheter body (230). In some variations, the distal region of the proximal portion (222) comprises laser cutting and / or other mechanisms that provide a gradual transition of rigidity between the proximal portion (222) and the distal portion (224). Examples of materials and configurations that may be used to form the distal portion (224) are described in more detail below.

[0024] The tip member (226) is fixed to the distal end of the distal portion (224) of the catheter body (230), distal to the end effector (350). As shown in Figure 2, the guidewire (250) may be slidably positioned within the lumen (236) of the catheter body (230) and extend distally from the tip member (226). In some modifications, the guidewire (250) includes a non-ferrous material (e.g., nitinol, SS316, etc.), but the guidewire (250) may be formed using any suitable material. The guidewire (250) may be inserted into the catheter assembly (200) via the port (214). Similarly, the guidewire (250) may be removed from the catheter assembly (200) via the port (214). In some variations, at least a portion of the guidewire (250) has a predetermined shape, and the distal portion (224) of the shaft assembly (220) conforms to this predetermined shape of the guidewire (250) when the guidewire (250) is positioned in the lumen (236). Alternatively, the guidewire (250) may be flexible without having a predetermined shape, and as a result, the positioning of the guidewire (250) in the lumen (236) does not impart a predetermined shape to the distal portion (224) of the shaft assembly (220).

[0025] The shaft assembly (220) may have any suitable dimensions. As just one example, the shaft assembly (220) may have an outer diameter in the range of approximately 2 French (e.g., approximately 0.67 mm) to approximately 4 French (e.g., approximately 1.33 mm), or more specifically, approximately 3 French (e.g., approximately 1.00 mm), or any other suitable outer diameter. As just another example, the shaft assembly (220) may have an inner diameter in the range of approximately 0.25 mm to approximately 0.45 mm, or any other suitable inner diameter. The shaft assembly (220) may also have any suitable length. For example, the shaft assembly (220) may have a length in the range of approximately 150 cm to approximately 200 cm, or more specifically, approximately 173 cm, or any other suitable length. As just another example, the distal portion (224) may have a length in the range of approximately 30 cm to approximately 75 cm, or more specifically, approximately 46 cm, or any other suitable length.

[0026] In some modifications, the distal portion (224) region is maneuverable or operable to articulate so that the end effector (350) can be controllably deflected laterally away from the central longitudinal axis. In some such modifications, such maneuverability is provided in accordance with at least some of the teachings of U.S. Patent No. 8,747,351, issued June 10, 2014, entitled “Catheter with multi-functional control handle having linear mechanism,” the disclosure of which is incorporated herein by reference. In some other modifications, the catheter assembly (200) lacks a mechanism to provide controlled deflection of the shaft assembly (220). As another example, the distal portion (224) region may be configured to deform controllably into a helical shape, with radius and / or pitch controllable by the physician (PH). In some variations, such controllable contraction of the distal portion (224) is provided in accordance with at least some of the teachings of 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. In some other variations, the catheter assembly (100) lacks a mechanism to provide controlled contraction of the helical shape defined by the distal portion (224).

[0027] As shown in Figure 7, the catheter body (230) in this example includes a first layer (234), a second layer (232) positioned around the first layer (234), and a flexible circuit board (302) and a third layer (238) positioned around the second layer (232). The lumen (236) is defined by the first layer (234). The first layer (234) in this example includes a braided structure formed of fibers or wires (e.g., non-ferromagnetic material), but the first layer (234) may alternatively have any other suitable composition and / or configuration. In some modifications, the inner sidewall of the first layer (234) (i.e., the sidewall of the lumen (236)) includes a lubricating coating or otherwise includes a low-friction material. This can facilitate the sliding of the guidewire (250) through the catheter body (230).

[0028] The second layer (232) in this example comprises a polymer material bonded around the first layer (234). As a mere example, the second layer (232) may include thermoplastic polyurethane (e.g., poly(ether urethane)) and / or any other suitable material. In some variations, the second layer (232) is omitted. For example, in some modifications, the second layer (232) may be omitted if the first layer (234) has sufficient thickness or if there is sufficient structural integrity in the absence of the second layer (232) (e.g., due to material properties, etc.). In some modifications, a flexible circuit board (302) effectively functions as the second layer (232).

[0029] In this example, the tip member (226) comprises a separate component fixed to the distal end of the distal portion (224) of the catheter body (230), but several other modifications may include the tip member (226) as an integrally formed mechanism of the catheter body (230). For example, the tip member (226) may comprise a distal extension of the first layer (234), and the second layer (232) may or may not extend further into this distal extension of the first layer (234) to form the tip member (226). In such modifications, the tip member (226) may (or may not) be formed in the same tapered shape as shown in Figure 6.

[0030] In this example, the flexible circuit board (302) effectively extends around the second layer (232) to an angular range of approximately 270 degrees around the central longitudinal axis. Alternatively, the flexible circuit board (302) may effectively extend around the second layer (232) to any other suitable angular range around the central longitudinal axis. For example, in some modifications, the flexible circuit board (302) may be wrapped around the entire perimeter of the second layer (232). The flexible circuit board (302) may even overlap itself due to the angular range of the wrapping. It should also be understood that different regions of the flexible circuit board (302) may extend to different angular ranges at different longitudinal positions along the length of the distal portion (224) of the shaft assembly (220). In this example, the third layer (238) is applied around the outside of the flexible circuit board (302) through the reflow process, while the area of ​​the second layer (232) is left exposed to the flexible circuit board (302). As just a further example, the third layer (238) may include thermoplastic polyurethane (e.g., poly(ether urethane)), silicone, and / or any other suitable material that can be heated during the reflow process to provide the desired performance. Alternatively, the third layer (238) may include any suitable material and may be applied in any other suitable manner. In this example, the layers (232, 238) have substantially strong bonding properties with the first layer (234), with each other, and with the flexible circuit board (302). In some cases, such bonding may be achieved by the use of adhesives. In some other cases, such bonding is achieved by the application of heat and pressure (e.g., hot air reflow) and / or molding. Alternatively, any other suitable type of bonding may be used.

[0031] In Figure 7, the third layer (238) and the second layer (232) are depicted as being made of different materials, but in some variations, the third layer (238) and the second layer (232) may contain the same material. In other words, the layers (232, 238) may effectively contain a single layer in which the flexible circuit board (302) is embedded.

[0032] As shown in Figures 2-4 and 6, the tip member (226) in this example includes a lumen (227) and an open distal end (228). As a mere example, the openings of the lumen (227) and / or distal end (228) may have a diameter of about 0.3 mm or any other suitable diameter. The lumen (227) of the tip member (226) is aligned with the lumen (236) of the catheter body (230), allowing the guidewire (250) to pass through the catheter body (230) and the tip member (226). The lumens (236, 227) may also allow a fluid (e.g., an irrigation fluid such as saline, ethanol, or contrast agent) to be discharged through the open distal end (228). Although the tip member (226) has a tapered configuration in this example, the tip member (226) may alternatively have any other suitable configuration. Like the catheter body (230), the tip member (226) is flexible. In this example, the tip member (226) is more flexible than the catheter body (230). Increased flexibility of the tip member (226) may facilitate the navigation of the shaft assembly (220) into a narrow, meandering anatomical passage. In some variations, the tip member (226) is more flexible than the catheter body (230) because it lacks a braided core like the first layer (234) of the catheter body (230). In addition, or instead, the tip member (226) may contain a material that is more flexible than the material used to form the second layer (232) and / or third layer (238) of the catheter body (230). As merely an example, the tip member (226) may include any other polymer, including polyether block amides (e.g., PEBAX by Arkema (Colombes, France)), thermoplastic polyurethanes (e.g., TECOTHANE by Lubrizol Advanced Materials, Inc. (Cleveland, Ohio)), silicones, or combinations thereof. Alternatively, the tip member (226) may include any other suitable material.

[0033] The flex circuit (300) is positioned along the distal portion (224) of the shaft assembly (220) and forms part of the end effector (350), while extending proximal to the end effector (350). As shown in Figures 3 to 6, the flex circuit (300) in this example has a proximal portion (310), an intermediate portion (320), and a distal portion (330). Figures 8 to 10 show a flat configuration of the flex circuit (300), which is a configuration the flex circuit (300) may have before it is fixed to the catheter body (230). Figures 11 to 15 show a wrapped configuration of the flex circuit (300), which is a configuration the flex circuit (300) may have after it is fixed to the catheter body (230).

[0034] The flex circuit (300) comprises a flexible substrate (302), traces (304), and electrodes (352). It should be understood that the flex circuit (300) may have substantially more traces (304) than those shown in the drawings, as the number of traces (304) depicted is minimized in the drawings for clarity. Where used herein, the singular term “trace” should be understood to include the plural term “trace.” In other words, the depiction of a single trace (304) in the drawings, and the description of “trace (304)” herein, are intended to include scenarios in which two or more traces are provided. Therefore, this disclosure should not be read as intended to mean that in each instance where the drawings show a single trace (304) and the specification refers to “trace,” only a single trace is provided. The term “trace,” and the corresponding depiction of a single trace, are merely used as an abbreviation for one or more traces. The claims should also be understood so that the term "trace" can include "multiple traces."

[0035] The flexible substrate (302) may comprise polyimide and / or any other suitable material. The trace (304) may comprise any suitable conductive material. The trace (304) may be positioned on either or both surfaces of the flexible substrate (302). At least some of the traces (304) may be covered by the third layer (238) of the catheter body (230) as described above. The traces (304) may also be covered by another electrically insulating layer of plastic (e.g., polyimide) in front of the third layer (238) as part of the manufacturing process of the flexible circuit (300) before the third layer (238) is applied to the flexible circuit (300). In some such variations, the layers of the flexible circuit (300) may comprise a polyimide cover film, adhesive, conductive traces (e.g., traces (304)), a polyimide substrate (e.g., flexible substrate (302)), conductive traces (e.g., traces (304)), adhesive, and a polyimide cover film. Therefore, the traces (304) may be provided on both sides of the flexible substrate (302), and the adhesive and cover film layers are also provided on both sides of the flexible substrate (302) along both layers of the traces (304) and along the areas that remain exposed to the traces (304).

[0036] The electrodes (352) may remain uncovered by the third layer (238) of the catheter body (230), and as a result, the electrodes (352) may come into direct contact with tissue, conductive fluid, etc. The electrodes (352) may include a conductive material so that each electrode (352) is operable to apply electrical energy to tissue, as described above and in the various references cited herein. As mere examples, each electrode (352) may include a precious metal such as gold, platinum, ruthenium, rhodium, palladium, silver, osmium, or iridium. Alternatively, any other suitable conductive material may be used. In some modifications, each electrode (352) is also operable to pick up potentials within tissue (e.g., as part of an EP mapping process), as described above and in the various references cited herein.

[0037] As also shown in Figures 3-6 and 8-15, the structural configuration of the flex circuit (300) differs between the proximal portion (310), the intermediate portion (320), and the distal portion (330). As best seen in Figures 4, 6, 9, and 12-13, the flexible substrate (302) in the distal portion (330) includes a circumferentially extending portion (332) and a longitudinally extending portion (334), the circumferentially extending portions (332) being longitudinally separated from each other by their respective pairs of longitudinally extending portions (334). Each circumferentially extending portion (332) has its own electrode (352) applied to it. The trace (304) extends along the longitudinally extending portion (334). A portion of the trace (304) may also extend along the circumferentially extending portion (332). The flex circuit (300) in this example has six circumferentially extending portions (332) and their respective electrodes (352), but other modifications may have any other suitable number of circumferentially extending portions (332) and their respective electrodes (352). Just as an example, some modifications may have a number of electrodes (352) ranging from 2 to 20, or any other suitable number of electrodes (352).

[0038] As is most commonly seen in Figures 3, 5, and 8–15, the flexible substrate (302) within the proximal portion (320) has a circumferentially extending portion (312), a tail portion (314), and a plurality of contact pads (316). The circumferentially extending portion (312) may extend around the catheter body (230) along an angular range of about 270 degrees. Alternatively, the circumferentially extending portion (312) may extend around the catheter body (230) along any other preferred angular range. In the arrangements shown in Figures 3 and 5, the electrode (354) is positioned around the circumferentially extending portion (312). In some modifications, the electrode (354) is used as a reference electrode. In some such modifications, the electrode (354) is used during EP mapping procedures to pick up a reference potential from blood or saline passing along the end effector (350). Such reference potentials can be used to reduce noise or far-field signals, as is well known in the art. In addition, or instead, the electrode (354) can be used as an active or return electrode during ablation procedures such as RF ablation or PFA. In yet another modification, the electrode (354) may be omitted, as shown in Figures 14-15.

[0039] As is most commonly seen in Figures 8-10, when the flexible circuit (300) is in a flat configuration, the tail (314) extends obliquely outward with respect to the central longitudinal axis (LA). As is most commonly seen in Figures 11-15, when the flexible circuit (300) is in a wound configuration, the tail (314) is wound spirally around the catheter body (230). In this example, the underside of the tail (314) includes a contact pad (316). The contact pad (316) is in electrical communication with the trace (304) and the electrode (352). The contact pad (316) is configured to couple with a wire, a trace of another flexible circuit, and / or other conductive mechanisms on or within the rigid shaft (223). In some variations, the tail section (314) may be located inside the rigid shaft (223), so that the contact pad (316) is coupled to a wire, a trace of another flexible circuit, and / or other conductive mechanism located inside the rigid shaft (223). Such wires, flexible circuits, and / or other conductive mechanisms on or inside the rigid shaft (223) may be further electrically coupled to the cable (216). The tail section (314) may be incorporated into the shaft (230) via a third layer (238) which may be arranged around the outer surface of the tail section (314) along the entire length of the tail section (314). In some other variations, the tail section (314) may extend into the interior of the rigid shaft (223) and into the handle assembly (210). Furthermore, it should be understood that, in addition to the contact pad (316) being positioned on the underside of the tail portion (314), or instead, the contact pad (316) may be positioned on the upper side of the tail portion (314). Alternatively, the flex circuit (300) may be electrically coupled to the mechanism of the cable (216) in any other preferred manner.

[0040] As best seen in Figures 3, 5, and 8-15, the intermediate portion (320) of the flexible substrate (302) has two legs (302a, 302b) that extend longitudinally and define a wavy or meandering configuration. As best seen in Figures 8-10, when the flex circuit (300) is in a flat configuration, the first meandering leg (302a) of the flexible substrate (302) is located on the first side of the central longitudinal axis (LA) (oriented along the x-dimension in Figures 8-10), while the second meandering leg (302b) of the flexible substrate (302) is located on the second side of the central longitudinal axis (LA). The meandering legs (302a, 302b) are spaced apart from each other along the y-dimension. The meandering legs (302a, 302b) are positioned relative to each other along the x-dimensional such that their respective peaks (303a, 303b) are aligned along the horizontal axis (TA) (oriented along the y-dimensional in Figures 8-10). In other words, if the meandering legs (302a, 302b) were viewed as waveforms plotted along the xy-plane in Figures 8-10, these waveforms would be 180 degrees out of phase with each other when the flex circuit (300) is in a flat configuration.

[0041] As is most clearly seen in Figures 11-15, when the flex circuit (300) is in a winding configuration, the meandering legs (302a, 302b) are positioned relative to each other along the x-dimensional such that the respective peaks (303a, 303b) of the meandering legs (302a, 302b) are aligned with each other along another horizontal axis (TA) (oriented along the z-dimensional in Figures 11-15). In other words, if the meandering legs (302a, 302b) are viewed as their respective waveforms plotted along the xz-plane in Figures 11-12 and 14, these waveforms are in phase with each other when the flex circuit (300) is in a winding configuration.

[0042] In this example, the trace (304) (which may actually include two or more traces, as described above) extends along the entire length of the meandering configuration of the flexible substrate (302), at least over the entire intermediate portion (320). This trace (304) continues along both meandering legs (302a, 302b), connecting them. For example, the trace may span the circumferentially extending portion (332) of the distal portion (330) of the flex circuit (300), thereby connecting the meandering legs (302a, 302b). The trace (304) may also span the circumferentially extending portion (312) of the proximal portion (320) of the flex circuit (300), thereby connecting the meandering legs (302a, 302b). By extending along both the meandering legs (302a, 302b) and the circumferentially extending portion (332), the trace (304) forms a loop configuration. If the trace (304) also straddles the circumferentially extending portion (312) of the proximal portion (320) of the flex circuit (300), thereby connecting the meandering legs (302a, 302b), the trace (304) may form a multi-winding coil loop configuration.

[0043] In some variations, the loop formed by the trace (304) extends only along the most proximal circumferential portion (332) of the distal portion (330) of the flexible circuit (300), and as a result, the loop does not extend along the length of the distal portion (330) of the flexible circuit, but only along the length of the intermediate portion (320) of the flexible circuit (300). In some other variations, the loop formed by the trace (304) extends along the most distal circumferential portion (332) of the distal portion (330) of the flexible circuit (300), and as a result, the loop extends along the length of the distal portion (330) of the flexible circuit, in addition to the length of the intermediate portion (320) of the flexible circuit (300).

[0044] In this example, the loop formed by the trace (304) along the intermediate portion (320) (and optionally along the distal portion (330)) provides a position sensor as described above. In other words, the loop formed by the trace (304) along the intermediate portion (320) (and optionally along the distal portion (330)) functions as an induction coil that provides electrical signals in response to the presence of an alternating electromagnetic field generated by the field generator (20). These electrical signals can indicate the real-time position and orientation of the end effector (350) within the patient (PA). The processor in the console (12) can receive these position indicator signals via the cable (216) and process them to determine the real-time position and orientation of the end effector (350) within the patient (PA). Accordingly, the processor of the console (12) may drive the display (18) to show the real-time position and orientation of the end effector (350) within the patient (PA), such as against preoperative images of the patient's anatomical structure or against a digital model of the patient's anatomical structure, as described above and in the various references cited herein.

[0045] In some modifications, the legs (302a, 302b) of the flexible substrate (302) along both sides of the central longitudinal axis (LA) are linear (for example, simply extending longitudinally) rather than having a meandering configuration. In such modifications, the loop formed by the trace (304) can still effectively provide a position sensor. In this example, the meandering configuration of the legs (302a, 302b) of the flexible substrate (302) along both sides of the central longitudinal axis (LA) allows the loop formed by the trace (304) to also effectively provide a position sensor; however, the meandering configuration of the legs (302a, 302b) of the flexible substrate (302) can further facilitate the bending of the flex circuit (300) along the intermediate portion (320). In some cases, the meandering configuration of the legs (302a, 302b) of the flexible substrate (302) does not affect the performance of the loop formed by the trace (304) as a position sensor, compared to the performance of the loop formed by the trace (304) as a position sensor in a modified example in which the legs (302a, 302b) are linear. Also, in some cases, the meandering configuration of the legs (302a, 302b) of the flexible substrate (302) does not generate or enhance bending bias in the distal portion (224) of the shaft assembly (220). In other words, the meandering configuration of the legs (302a, 302b) of the flexible substrate (302) does not provide an elastic bias that biases the distal portion (224) of the shaft assembly (220) toward a linear configuration along the central longitudinal axis (LA).

[0046] To the extent that some conventional catheter devices include a position sensor at the distal end of the shaft assembly in an end effector or otherwise, the catheter assembly (200) in this example may differ substantially from such conventional catheter devices in that the position sensor provided by a loop formed by a trace (304) along the middle portion (320) (and possibly along the distal portion (330)) extends along a substantial portion of the entire length of the shaft assembly (220). For example, the position sensor provided by the loop formed by the trace (304) may have a length of at least about 5 cm, at least about 10 cm, in the range of about 5 cm to about 20 cm, in the range of about 10 cm to about 15 cm, or about 13 cm. Alternatively, the position sensor provided by the loop formed by the trace (304) may have any other preferred length.

[0047] With respect to the entire length of the shaft assembly (220), the position sensor provided by the loop formed by the trace (304) may extend along at least about 2.5% of the total length of the shaft assembly (220), along at least about 3% of the total length of the shaft assembly (220), along at least about 5% of the total length of the shaft assembly (220), along at least about 6.5% of the total length of the shaft assembly (220), along at least about 7.5% of the total length of the shaft assembly (220), along at least about 8.5% of the total length of the shaft assembly (220), along at least about 10% of the total length of the shaft assembly (220), along at least about 11.5% of the total length of the shaft assembly (220), along at least about 13% of the total length of the shaft assembly (220), along at least about 15% of the total length of the shaft assembly (220), or along at least about 20% of the total length of the shaft assembly (220). Alternatively, the length of the position sensor provided by the loop formed by the trace (304) may have any other preferred relationship with the total length of the shaft assembly (220).

[0048] With respect to the outer diameter of the shaft assembly (220), the length of the position sensor provided by the loop formed by the trace (304) may be more than 10 times the outer diameter of the shaft assembly (220), more than 20 times the outer diameter of the shaft assembly (220), more than 25 times the outer diameter of the shaft assembly (220), more than 50 times the outer diameter of the shaft assembly (220), more than 75 times the outer diameter of the shaft assembly (220), more than 100 times the outer diameter of the shaft assembly (220), more than 125 times the outer diameter of the shaft assembly (220), more than 145 times the outer diameter of the shaft assembly (220), more than 200 times the outer diameter of the shaft assembly (220), more than 250 times the outer diameter of the shaft assembly (220), or more than 300 times the outer diameter of the shaft assembly (220). Alternatively, the length of the position sensor provided by the loop formed by the trace (304) may have any other preferred relationship with the outer diameter of the shaft assembly (220).

[0049] Regardless of whether the length of the position sensor provided by the loop formed by the trace (304) is compared to the total length of the shaft assembly (220) or the outer diameter of the shaft assembly (220), the relative length of the position sensor provided by the loop formed by the trace (304) may be considered substantial, particularly compared to a similar relative length provided by a conventional position sensor. This substantial relative length of the position sensor may be counterintuitive, as conventional fixture design considerations may tend to focus on minimizing the size of the components. In other words, conventional position sensors may tend to be as compact as possible, and as a result, the position sensor provided by the loop formed by the trace (304) may be substantially larger than that of a conventional position sensor. Similarly, the surface area bounded by the trace (304) may be substantially larger than the surface area bounded by a conventional position sensor. Conventional position sensor designs may also indicate that the position sensor should not bend during use. On the other hand, the position sensor provided by the loop formed by the trace (304) may be substantially prone to bending during use, and this bending is more likely to be due to the substantial length of the position sensor provided by the loop formed by the trace (304). In other words, the substantial length of the position sensor provided by the loop formed by the trace (304) may promote bending of the position sensor during use.

[0050] In another respect, the catheter assembly (200) in this example may differ substantially from conventional catheter instruments having a position sensor in that the position sensor provided by the loop formed by the trace (304) may be substantially bent during the operation of the catheter assembly (200). This bending may be facilitated by the meandering configuration of the flexible substrate (302) along the middle portion (320) of the flex circuit (300). This bending of the position sensor may be partially attributable to the substantial length of the position sensor in this example. In contrast, conventional position sensors may be substantially shorter and / or be longitudinally constrained to components of a catheter assembly that do not bend. In other words, conventional position sensors may be substantially impervious to bending during use, or bend minimally during use, and as a result, conventional position sensors may be substantially impervious to bending as much as the position sensor provided by the loop formed by the trace (304).

[0051] III. Example of a long, narrow position sensor configuration As described above, the loop formed by the trace (304) along the intermediate portion (320) (and possibly along the distal portion (330)) can provide a position sensor that provides a position indicator signal in the presence of an alternating electromagnetic field. Also, as described above, the loop formed by the trace (304) can be considered to form a substantially rectangular shape that extends longitudinally along a portion of the length of the catheter body (230) and covers the periphery of the catheter body (230). This arrangement is schematically shown in Figure 16A. Specifically, Figure 16A shows a first example of an elongated position sensor arrangement (400) in which the loop (404) covers the upper part of the catheter body (402). Thus, the loop (404) schematically represents the loop formed by the trace (304) within the flex circuit (300). The length of the rectangle defined by the loop (404) is determined by the length of the flexible circuit into which the loop (404) is incorporated, and the width of the rectangle defined by the loop is determined by the diameter of the catheter body (402).

[0052] The arrow (405) indicates the direction of any current that may be generated within the loop (404) by an alternating electromagnetic field (e.g., one generated by the field generator (20)). The direction indicated by the arrow (405) in Figure 16A is illustrative only, and the current may actually flow in the opposite direction depending on the orientation of the field. In the example shown in Figure 16A, each circumferential segment of the loop (404) has an angular range of approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (402), and as a result, the longitudinal segments of the loop (404) are angularly offset from each other by approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (402). This relative positioning of the longitudinal segments of the loop (404) may tend to maximize the sensitivity of the position sensor provided by the loop (404). Alternatively, the segments extending circumferentially from the loop (404) may have any other preferred angular range, and the segments extending longitudinally from the loop (404) may be angularly offset from each other by any other preferred angular distance.

[0053] In the operating state shown in Figure 16A, the catheter body (402) is in an unbent state, as is the loop (404). During normal operation, the catheter body (402) may bend in a number of different directions as it traverses a meandering anatomical passage, as described herein. The loop (404) bends together with the catheter body (402). Figure 16B shows an example of the loop (404) in such a bent state. As shown, the loop (404) is bent along the xz plane in this example, and the loop (404) extends longitudinally along the x direction. Also as shown, when the loop (404) is bent in this manner, it defines a saddle-shaped plane or extends along a saddle-shaped plane. In some other scenarios (for example, when the catheter body (402) and loop (404) are bent along the xy-plane), the loop (404) may define different shapes when it is in a bent state.

[0054] As schematically shown in Figure 16C, the loop (404) may have a first effective length (L1) and a first effective width (W1) when the loop (404) is in an unbent state (e.g., the state shown in Figure 16A). In this unbent state, the loop (404) may effectively boundary a first region (i.e., L1 × W1) along a particular two-dimensional plane (e.g., the xy-plane as shown in Figure 16C). As schematically shown in Figure 16D, the loop (404) may have a second effective length (L2) while maintaining the first effective width (W1) when the loop (404) is in a bent state (e.g., the state shown in Figure 16B). In this bent state, the loop (404) may effectively boundary a second region (i.e., L2 × W1) along the same two-dimensional plane (e.g., the xy-plane as shown in Figure 16D). In this example, the second effective length (L2) is smaller than the first effective length (L1). As a result, the second region along the two-dimensional plane (i.e., L2 × W1) is smaller than the first region along the two-dimensional plane (i.e., L1 × W1). In other words, the region defined by the effective length (L) and effective width (W) of the loop (404) along the two-dimensional reference plane may tend to become smaller when the catheter body (402) and loop (404) are bent, especially when the catheter body (402) and loop (404) are bent.

[0055] In some other scenarios, the effective width (W) of the loop (404) may change when the catheter body (402) and loop (404) are bent, and in addition, or instead, the effective length (L) of the loop (404) may change when the catheter body (402) and loop (404) are bent. This may depend on the direction in which the catheter body (402) and loop (404) are bent. In any of these cases, the area defined by the effective length and width of the loop (404) along a given two-dimensional plane may change when the catheter body (402) and loop (404) are bent, for example, by becoming smaller when the catheter body (402) and loop (404) are bent. In some modifications, the catheter assembly (200) has an area defined by the effective length (L) and effective width (W) of the loop (404) along a two-dimensional reference plane (including when the catheter body (402) and loop (404) are bent) of at least about 150 mm 2 at least approximately 175mm 2 , at least about 200mm 2 , at least about 225mm 2 , at least about 250mm 2 , at least about 275mm 2 , or at least about 300 mm 2 It is constructed in such a manner. Alternatively, the loop (404) may define any other suitable region along the two-dimensional reference plane when the loop (404) is in an unbent or bent state.

[0056] Figure 17 shows a second example of an elongated position sensor arrangement (410). In this arrangement (410), the first loop (414) covers the top of the catheter body (412) at a first angular position and a first longitudinal position, and the second loop (416) covers the side of the catheter body (412) at a second angular position and a second longitudinal position. In this example, the loops (414, 416) are electrically insulated from each other. The second angular position is angularly offset by approximately 90 degrees from the first angular position with respect to the central longitudinal axis (LA) of the catheter body (412). The second longitudinal position is distal to the first longitudinal position. The arrangement of the loops (414, 416) is such that no part of loop (414) overlaps with any part of loop (416). This longitudinal spacing of the loops (414, 416) can maximize the flexibility of the arrangement (410).

[0057] The arrow (415) indicates the direction of any current that may be generated within the loop (414) by an alternating electromagnetic field (e.g., one generated by the field generator (20)). In the example shown in Figure 17, each circumferential segment of the loop (414) has an angular range of approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (412), and as a result, the longitudinal segments of the loop (414) are angularly offset from each other by approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (412). This relative positioning of the longitudinal segments of the loop (414) may tend to maximize the sensitivity of the position sensor provided by the loop (414). Alternatively, the circumferential segments of the loop (414) may have any other preferred angular range, and the longitudinal segments of the loop (414) may be angularly offset from each other by any other preferred angular distance.

[0058] The arrow (417) indicates the direction of any current that may be generated within the loop (416) by an alternating electromagnetic field (e.g., one generated by the field generator (20)). In the example shown in Figure 17, each circumferential segment of the loop (416) has an angular range of approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (412), and as a result, the longitudinal segments of the loop (416) are angularly offset from each other by approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (412). This relative positioning of the longitudinal segments of the loop (416) may tend to maximize the sensitivity of the position sensor provided by the loop (416). Alternatively, the circumferential segments of the loop (416) may have any other preferred angular range, and the longitudinal segments of the loop (416) may be angularly offset from each other by any other preferred angular distance.

[0059] The presence of two loops (414, 416) and an angular offset of approximately 90 degrees between them can provide a position-sensitive arrangement (410) with two degrees of freedom, and thus can provide enhanced real-time position information compared to the real-time position information provided by arrangement (400). Although only two loops (414, 416) are provided for arrangement (410), variations of arrangement (410) may include three or more loops, each providing its own respective position indicator signal.

[0060] Figures 18-19 show an example of a flexible circuit (500) that may be used to provide the arrangement (410) of Figure 17. Although the flexible circuit (500) is shown in a flat configuration, it should be understood that the flexible circuit (500) may be wrapped around the catheter body, as described above in the context of the flexible circuit (300). The flexible circuit (500) in this example comprises a flexible substrate (502) having a proximal portion (510), a first intermediate portion (520), a transition portion (530), a second intermediate portion (540), and a distal portion (550). The proximal portion (510) of the flexible circuit (500) may be configured and operable in the same way as the proximal portion (310) of the flexible circuit (300) described above. Similarly, the distal portion (550) of the flex circuit (500) may be configured and operable in the same way as the distal portion (330) of the flex circuit (300) described above.

[0061] Similar to the intermediate portion (320) of the flexible circuit (300), the first intermediate portion (520) of the flexible circuit (500) has two legs, each defining a wavy or meandering configuration. Also similar to the intermediate portion (320) of the flexible circuit (300), the second intermediate portion (540) of the flexible circuit (500) has two legs, each defining a wavy or meandering configuration. Unlike the intermediate portion (320) of the flexible circuit (300), each intermediate portion (520, 540) of the flexible circuit (500) includes a plurality of transversely oriented webs (508) that join the meandering legs of the flexible substrate (502). The webs (508) are spaced longitudinally apart from each other along the length of each intermediate portion (520, 540). The web (508) can prevent the meandering legs of the flexible substrate (502) from moving further away from each other along the transverse axis, so that the web (508) can provide consistent spacing between the meandering legs of the flexible substrate (502) along the length of each intermediate portion (520, 540). In this example, there are no electrical traces extending across the web (508), but in other modifications, electrical traces spanning the web (508) may be provided.

[0062] The transition portion (530) of the flexible substrate (502) is joined together with the intermediate portions (520, 540). In the flat configuration shown in Figures 18-19, the transition portion (530) is oriented laterally, but in the wrapped configuration (when the flexible circuit (500) is wrapped around the catheter body), the transition portion extends along a circumferential path.

[0063] The first intermediate portion (520) includes a trace (504) that extends along both meandering legs of the flexible substrate (502) along the entire length of the first intermediate portion (520). The trace (504) also straddles the transition portion (530). Thus, the trace (504) forms a loop that provides a position sensor, as schematically represented by the first loop (414) in the position sensor arrangement of Figure 17. The second intermediate portion (540) includes a trace (506) that extends along both meandering legs of the flexible substrate (502) along the entire length of the second intermediate portion (540). The trace (506) also straddles the transition portion (530). Thus, the trace (506) forms a loop that provides a position sensor, as schematically represented by the second loop (416) in the position sensor arrangement of Figure 17. In this example, the traces (504, 506) are electrically isolated from each other. Nevertheless, it should be understood that a portion of the trace (506) extends along the first intermediate portion (520) to reach a corresponding pair of contact pads on the proximal portion (510), thereby enabling the communication of position indicator signals from the loop formed by the trace (506) to a processor (e.g., the processor of console (12)).

[0064] As described above with respect to the loops (414, 416) of arrangement (410), the intermediate portions (520, 540) are positioned relative to each other such that when the flex circuit (500) is wrapped around the catheter body, the loops formed by the traces (504, 506) are angularly offset from each other by approximately 90 degrees around the central longitudinal axis of the catheter body. This offset is provided in this example by the configuration of the transition portion (530). If three or more loops are provided, the flex circuit may include modified variations of the transition portion (530) and / or two or more transition portions to accommodate any desired number of angular offsets corresponding to the number of loops.

[0065] Figure 20 shows a third example of an elongated position sensor arrangement (600). In this arrangement (600), the first loop (604) covers the top of the catheter body (602) at a first angular position and a first longitudinal position, and the second loop (606) covers the top of the catheter body (602) at a second angular position and a first longitudinal position. In this example, the loops (604, 606) are electrically insulated from each other. The second angular position is angularly offset by approximately 90 degrees from the first angular position with respect to the central longitudinal axis (LA) of the catheter body (602). In this example, the loops (604, 606) have the same longitudinal spread relative to each other. The arrangement of the loops (604, 606) is such that the angular segment of loop (604) overlaps with the angular segment of loop (606). In this example, this angular overlap extends along approximately 90 degrees of the angular range of each loop (604, 606). This relative spacing of loops (604, 606) can minimize the overall length of arrangement (600).

[0066] The arrow (605) indicates the direction of any current that may be generated within the loop (604) by an alternating electromagnetic field (e.g., one generated by the field generator (20)). In the example shown in Figure 20, each circumferential segment of the loop (604) has an angular range of approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (602), and as a result, the longitudinal segments of the loop (602) are angularly offset from each other by approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (602). This relative positioning of the longitudinal segments of the loop (604) may tend to maximize the sensitivity of the position sensor provided by the loop (604). Alternatively, the circumferential segments of the loop (604) may have any other preferred angular range, and the longitudinal segments of the loop (604) may be angularly offset from each other by any other preferred angular distance.

[0067] The arrow (607) indicates the direction of any current that may be generated within the loop (606) by an alternating electromagnetic field (e.g., one generated by the field generator (20)). In the example shown in Figure 20, each circumferential segment of the loop (606) has an angular range of approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (602), and as a result, the longitudinal segments of the loop (606) are angularly offset from each other by approximately 180 degrees around the central longitudinal axis (LA) of the catheter body (602). This relative positioning of the longitudinal segments of the loop (606) may tend to maximize the sensitivity of the position sensor provided by the loop (606). Alternatively, the circumferential segments of the loop (606) may have any other preferred angular range, and the longitudinal segments of the loop (606) may be angularly offset from each other by any other preferred angular distance.

[0068] The presence of two loops (604, 606) and an angular offset of approximately 90 degrees between them can provide a position-sensitive arrangement (600) with two degrees of freedom, and thus can provide enhanced real-time position information compared to the real-time position information provided by arrangement (400). Although only two loops (604, 606) are provided for arrangement (600), variations of arrangement (600) may include three or more loops, each providing its own respective position indicator signal.

[0069] Figure 21 shows a fourth example of an elongated position sensor arrangement (610). In this arrangement (610), a pair of first loop segments (614a, 614b, 614c) cover the top of the catheter body (612) at a first angular position around the central longitudinal axis (LA). A pair of second loop segments (616a, 616b, 616c) cover the sides of the catheter body (612) at a second angular position around the central longitudinal axis (LA). The second angular position is angularly offset by approximately 90 degrees from the first angular position around the central longitudinal axis (LA) of the catheter body (412). The combination of angular and longitudinal positioning of loop segments (614a, 614b, 614c) relative to loop segments (616a, 616b, 616c) is such that the regions of loop segments (614a, 614b, 614c) alternate with those of loop segments (616a, 616b, 616c). However, no portion of any loop segment (614a, 614b, 614c) from the first set overlaps with any portion of any loop segment (616a, 616b, 616c) from the second set.

[0070] In this example, the first set of loop segments (614a, 614b, 614c) are joined together in series (e.g., by a shared set of traces). Similarly, the second set of loop segments (616a, 616b, 616c) are joined together in series (e.g., by a shared set of traces). In this example, the first set of loop segments (614a, 614b, 614c) are electrically isolated from the second set of loop segments (616a, 616b, 616c). Figure 21 does not include arrows indicating the direction of currents that may be generated in each loop segment (614a, 614b, 614c, 616a, 616b, 616c) by an alternating electromagnetic field (e.g., generated by a field generator (20)), but such currents may be generated in the same way as described above with respect to the arrangement (400, 410, 600).

[0071] With the first set of loop segments (614a, 614b, 614c) joined together in series, the first set of loop segments (614a, 614b, 614c) cooperate to effectively provide a first single loop, thereby providing a real-time position indication signal with a first degree of freedom. Similarly, with the second set of loop segments (616a, 616b, 616c) joined together in series, the second set of loop segments (616a, 616b, 616c) cooperate to effectively provide a second single loop, thereby providing a real-time position indication signal with a second degree of freedom. Thus, arrangement (610) can provide enhanced real-time position information compared to the real-time position information provided by arrangement (400). Only active loops are provided by the loop segments (614a, 614b, 614c, 616a, 616b, 616c) within arrangement (610), however, variations of arrangement (610) may include additional loop segments that effectively provide three or more active loops, each active loop providing its own position indicator signal.

[0072] IV. Examples of Electrical Paths As described above, the electrodes (352) of the end effector (350) can be used in a number of ways. For example, the electrodes (352) can be used to provide EP mapping and / or other diagnostic functions. In addition, or instead, the electrodes (352) may be used to provide ablation and / or other therapeutic functions. In the context of ablation, the electrodes (352) can be used to apply RF energy to tissue to ablate the tissue. In addition, or instead, the electrodes (352) may be used to ablate tissue by applying PFA or any other form of electrical energy. Whether the electrodes (352) are used to provide RF ablation, PFA, or any other form of electrical ablation, there are a number of permutations in which one or more different electrodes (352) can be operated with different polarities to apply electrical energy to tissue. Various examples of how the electrodes (352) can be used to apply electrical energy to tissue, either through direct or indirect contact with the tissue, are described in more detail below.

[0073] A. Example of an electrical path between an electrode and a grounding pad Figure 22 shows the electrodes (352) of an end effector (350) used with a grounding pad (700) to provide a first example of an electrical pathway. In this example, the end effector (350) is used as a unipolar instrument, so that one or more of the electrodes (352) may be activated, while the grounding pad (700) provides a return pathway. The grounding pad (700) can take any preferred form, including, but not limited to, a pad on which the patient (PA) lies, or a patch adhered to the patient's (PA) skin. Once the end effector (350) is positioned within the anatomical space of the target (e.g., Marshall's vein or other small vessels branching from the coronary sinus), one or more of the electrodes (352) may be positioned in contact with the tissue and then activated with unipolar electrical energy. The electrical energy can flow through the adjacent tissue between the activated electrode (352) and the grounding pad (700), which may result in tissue ablation.

[0074] B. Example of an electrical path between electrode combinations In some scenarios, the use of a grounding pad (700) may be undesirable, and therefore, it may be more desirable to apply bipolar electrical energy to the tissue using electrodes (352). This may allow the physician (PH) to ablate the tissue in a more precisely targeted manner. While a variant of the end effector (350) with only one electrode (352) can apply bipolar electrical energy to the tissue, a variant of the end effector (350) with three or more electrodes (352) can provide even better control over the formation of damage and / or other ablation outcomes by allowing the physician (PH) to make ad hoc individual combinations of which electrodes (352) act as active electrodes and which electrodes (352) act as return electrodes at a given point in time during the ablation procedure. Such control over the bipolar assignment between electrodes (352) may allow the physician to fine-tune the shape, gradient, and / or other characteristics of the damage formed by the ablation process (and / or other outcomes of the ablation process). This, in turn, can minimize the risk of undesirable gaps remaining between or within the ablated areas of the tissue.

[0075] Figures 23–27 provide examples of different cases in which electrodes (352) can function as the active electrode and which electrodes (352) can function as the return electrode at a given point in time during an ablation procedure. The examples shown in Figures 23–27 are illustrative examples only. One or more of the electrodes (352) can be used to establish an electrical bipolarity with any other electrode (352) or any other group of electrodes (352) to deliver electrical energy. The following examples are not intended to be exhaustive.

[0076] Figure 23 shows the electrodes (352) of an end effector (350) used together to provide a second example of an electrical path. In this example, the most distal electrodes (352, 352e, 352f) function as active electrodes, while the nearest electrodes (352a, 352b, 352c) function as return electrodes. In some such variations, the most distal electrodes (352d, 352e, 352f) are acted simultaneously, while the nearest electrodes (352a, 352b, 352c) function simultaneously as return electrodes. In some other variations, the most distal electrodes (352d, 352e, 352f) are acted sequentially, while the nearest electrodes (352a, 352b, 352c) function sequentially as return electrodes. In some such variations, electrode (352a) acts as a return electrode while electrode (352d) is activated, electrode (352b) acts as a return electrode while electrode (352e) is activated, and electrode (352c) acts as a return electrode while electrode (352f) is activated. Such sequences can occur in any suitable order or arrangement. Furthermore, a pair of bipolars can be formed at any point in time between any suitable electrode pairs (352a, 352b, 352c, 352d, 352e, 352f).

[0077] Figure 24 shows the electrodes (352) of an end effector (350) used together to provide a third example of an electrical path. In this example, the most distal electrode (352f) functions as the active electrode, while the nearest electrode (352a) functions as the return electrode.

[0078] Figure 25 shows the electrodes (352) of an end effector (350) used together to provide a fourth example of an electrical path. In this example, electrodes (352e, 352f) function together / simultaneously as the active electrode, while electrodes (352a, 352b, 352c) function together / simultaneously as the return electrode. Therefore, there does not need to be a 1:1 parity between the number of electrodes (352) functioning as active electrodes and the number of electrodes (352) functioning as return electrodes at a given time.

[0079] Figure 26 shows the electrodes (352) of the end effector (350) used together to provide a fifth example of an electrical path. In this example, electrodes (352e, 352f) function together / simultaneously as the active electrode, while electrodes (352a, 352b) function together / simultaneously as the return electrode.

[0080] Figure 27 shows the electrodes (352) of an end effector (350) used together to provide a sixth example of an electrical path. In this example, electrodes (352d, 352e, 352f) function together / simultaneously as the active electrode, while electrodes (352a, 352b) function together / simultaneously as the return electrode.

[0081] The bipolar assignments between electrodes (352) shown in Figures 23 to 27 and described above are not intended to be exhaustive, as any other suitable bipolar assignments may be used. It should also be understood that the bipolar assignments may be changed during the ablation procedure. For example, the bipolar assignment shown in Figure 23 may be used at some point during the ablation procedure, and then the bipolar assignment shown in Figure 24 may be used at another point during the same ablation procedure on the same area of ​​tissue. Alternatively, the bipolar assignments of electrodes (352) may be changed in any other suitable way during the same ablation procedure on the same area of ​​tissue. In some cases, the bipolar assignments of electrodes (352) may be changed during the same ablation procedure according to a predetermined assignment sequence. In some other cases, the bipolar assignments of electrodes (352) may be changed on an ad-hoc basis during the same ablation procedure based on real-time feedback. For example, the electrode (352) may provide tissue impedance sensing, and a control algorithm may be used to change the bipolar assignment of the electrode (352) on an ad-hoc basis based on real-time tissue impedance data. In addition, or alternatively, the end effector (350) may include one or more thermocouples and / or other temperature sensing mechanisms, and a control algorithm may be used to change the bipolar assignment of the electrode (352) on an ad-hoc basis based on real-time temperature data. Alternatively, the bipolar assignment of the electrode (352) may be changed on an ad-hoc basis during the same ablation procedure based on any other preferred criteria. In any of the above scenarios, additional factors that may influence the bipolar assignment of the electrode (352) include, among other things, the intended tissue target (e.g., the anatomical structure to be targeted), the intended depth or shallowness of the injury, the geometric configuration of the injury, and / or other factors.

[0082] C. Example of an electrical path between an electrode and a guide wire As described above with respect to the grounding pad (700) in the electrical path shown in Figure 22, it is possible to use a second device to provide a return to the electrical path including the active electrode (352). Also as described above, the use of the grounding pad (700) may come at the cost of reduced precision and control of the damage provided via ablation using the electrode (352). This may be partly due to the distance the current must travel from the electrode (352) to the grounding pad (700).

[0083] Therefore, it may be desirable to use a second device to provide a return path within the electrical path including the active electrode (352), the second device being substantially closer to the electrode (352), thereby reducing the distance the current must travel. For this purpose, Figure 28 shows the electrode (352) of an end effector (350) used with a guidewire (250) to provide a seventh example of an electrical path. In this example, the guidewire (250) is positioned within the lumen (236, 227) and protrudes distally from the open distal end (228) of the tip member (226). The guidewire (250) is also conductive in this example. Thus, the guidewire (250) can provide a return path while one or more electrodes (352) are actuated with unipolar electrical energy. The electrical energy can flow between the actuated electrode (352) and the guidewire (250) through adjacent tissue, which may result in tissue ablation. Although Figure 28 shows only the electrode (352a) that functions as the active electrode, an active electrode that works in cooperation with the guide wire (250) as a return electrode can be provided using any suitable number or position of electrodes (352).

[0084] Figure 29 shows the electrodes (352) of an end effector (350) used with a guidewire (250) to provide an eighth example of an electrical pathway. In this example, the guidewire (250) is not located within a lumen (236, 227) but instead located elsewhere within the patient (PA). For example, the guidewire (250) may be located within any other blood vessel, a cardiac chamber of the heart (H), or any other suitable location within the patient (PA). Nevertheless, the guidewire (250) may be used to provide a return pathway while one or more electrodes (352) are activated with unipolar electrical energy. The electrical energy can flow between the activated electrode (352) and the guidewire (250) through adjacent tissue, which may result in tissue ablation.

[0085] D. Example of an electrical path between an electrode and an irrigation fluid. In some scenarios, it may be beneficial to introduce an irrigation fluid (e.g., saline solution) into communication with the ablation device and / or ablation site during the ablation procedure. For example, the irrigation fluid may prevent arc discharge during ablation, prevent the accumulation of lumps, promote conductivity, prevent overheating, and / or provide other benefits. The irrigation fluid may also function as a virtual electrode. When saline solution is used as the irrigation fluid providing a virtual electrode, the salt content of the saline solution can be varied to alter its conductivity, which in turn can affect the performance of the irrigation fluid as a virtual electrode.

[0086] Figures 30-31 illustrate an example of how irrigation fluid may be used to provide a virtual electrode that serves as a return path for one or more activated electrodes (352) of an end effector (350). Specifically, Figure 30 shows an electrode (352) of an end effector (350) used with irrigation fluid (700) to provide a ninth example of an electrical path. In this example, the end effector (350) is located within a lumen (L) defined by tissue (T). As a mere example, the lumen (L) may be within some other small vessel branching from Marshall's vein or coronary sinus. The irrigation fluid (700) is discharged into the lumen (L) through the open distal end (228) of the tip member (226) via the lumen (236, 227). As described above, the irrigation fluid (700) can be supplied from the fluid source (42) to the lumens (236, 227) via the pump (44), conduit (40), and port (214).

[0087] As a mere example, the irrigation fluid (700) may be discharged through the open distal end (228) at a flow rate of approximately 3 mL / min, at a flow rate greater than approximately 3 mL / min, or at any other suitable flow rate. Discharge of the irrigation fluid (700) into the lumen (L) may ultimately result in a backflow of the irrigation fluid (700) toward the electrodes (352). When the irrigation fluid (700) has sufficiently reached the electrodes (352), one or more electrodes (352) may be activated to provide an active electrode, while the irrigation fluid (700) acts as a virtual return electrode. The resulting flow of electrical energy may result in ablation of the adjacent region of tissue (T) defining the lumen (L).

[0088] The irrigation fluid (700) can be communicated to the lumen (L) via the tubular lumen (236, 227) and the open distal end (228) of the tip member (226), but it may be preferable to communicate the irrigation fluid (700) to the lumen (L) via some other route. For example, this may be desirable if the physician (PH) wishes to maintain some other device (e.g., a guidewire (250)) inside the lumen (236, 227), in which case the presence of the other device inside the lumen (236, 227) may negatively affect the ability of the irrigation fluid (700) to communicate adequately through the lumen (236, 227). Figure 31 shows the electrodes (352) of an end effector (350) used with an irrigation fluid (700) to provide a tenth example of an electrical path, the irrigation fluid (700) being communicated through an open distal end (712) of a sheath (710) in which a shaft assembly (220) is located. In this example, the open distal end (712) is located proximal to the end effector (350). In some modifications, the sheath (710) is in fluid communication with a fluid source (42) via a pump (44) and a conduit (40).

[0089] As a mere example, the irrigation fluid (700) may be discharged through the open distal end (712) at a flow rate of approximately 10 mL / min, at a flow rate greater than approximately 10 mL / min, or at any other suitable flow rate. Discharge of the irrigation fluid (700) into the lumen (L) may ultimately result in a backflow of the irrigation fluid (700) toward the electrodes (352). When the irrigation fluid (700) has sufficiently reached the electrodes (352), one or more electrodes (352) may be activated to provide an active electrode, while the irrigation fluid (700) acts as a virtual return electrode. The resulting flow of electrical energy may result in ablation of the adjacent region of tissue (T) defining the lumen (L). Figures 30 and 31 show the irrigation fluid (700) being discharged through either the open distal end (228) of the tip member (226) or the open distal end (712) of the sheath (710), although some modifications may provide discharge of the irrigation fluid (700) through both the open distal end (228) of the tip member (226) and the open distal end (712) of the sheath (710) (for example, simultaneously).

[0090] Furthermore, in addition to discharging the irrigation fluid (700) through the open distal end (228) of the tip member (226) or through the open distal end (712) of the sheath (710), or as an alternative to discharging the irrigation fluid (700) through the open distal end (228) of the tip member (226) or through the open distal end (712) of the sheath (710), it may be desirable to discharge the irrigation fluid (700) through the end effector (350). For this purpose, Figure 32 shows an end effector (720) representing a modification of the end effector (350), so that the end effector (720) may be provided as a substitute for the end effector (350). The end effector (720) in this example is configured and operable in the same way as the end effector (350), except for the differences described below. The end effector (720) is configured as the tip member (226) described above and is positioned proximal to the movable tip member (724). The end effector (720) includes a flexible circuit (730) having a flexible substrate (732) wrapped around the catheter body (722). The flexible circuit (730) also includes a plurality of electrodes (740) on the flexible substrate (732).

[0091] Unlike the electrode (352) of the end effector (350), the electrode (740) of the end effector (720) includes an irrigation opening (742). Similarly, unlike the flexible substrate (302) of the flex circuit (300), the flexible substrate (732) of the flex circuit (730) includes an irrigation opening (734) positioned between the electrodes (740). An irrigation opening (723) is also formed through the catheter body (722) in this example. The irrigation opening (723) may be provided in addition to, or instead of, the irrigation openings (734, 742). Similarly, the irrigation opening (734) and the irrigation opening (742) are optional. If irrigation openings (723) and / or irrigation openings (734) are provided, such irrigation openings (723, 734) may be positioned adjacent to the electrode (740) to facilitate contact between the irrigation fluid discharged through the irrigation openings (723, 734) and the electrode (740). Any suitable number of irrigation openings (723, 734, 742) may be provided, such as 70 irrigation openings (723, 734, 742) or any other suitable number of irrigation openings (723, 734, 742).

[0092] The irrigation openings (723, 734, 742) can be in fluid communication with a lumen (not shown) within the catheter body (722). This lumen within the catheter body (722) can be further in fluid communication with a fluid source (42) via a pump (44), a conduit (40), and a port (214).

[0093] As a mere example, the irrigation fluid (700) may be discharged through the irrigation openings (723, 734, 742) at a flow rate of approximately 3 mL / min, at a flow rate greater than approximately 3 mL / min, or at any other suitable flow rate. As a mere further example, the irrigation openings (723, 734, 742) may have a diameter of approximately 0.1 mm, or any other suitable diameter. When the discharged irrigation fluid (700) comes into contact with the electrodes (740), one or more electrodes (740) may be activated to provide an active electrode, while the irrigation fluid (700) acts as a virtual return electrode. The resulting flow of electrical energy may result in ablation of the adjacent region of tissue (T) defining the lumen (L).

[0094] It should be understood that the irrigation fluid (700) can also be discharged through the open distal end of the tip member (724) while also being discharged through the irrigation openings (723, 734, 742). In addition, or alternatively, the irrigation fluid (700) can also be discharged through the open distal end (712) of the sheath (710) while also being discharged through the irrigation openings (723, 734, 742). Some variations of the end effector (720) may include one or more types of irrigation openings (723, 734, 742), while omitting one or more other types of irrigation openings (723, 734, 742).

[0095] In some variations, the material defining the irrigation openings (723, 734, 742) is configured such that the irrigation fluid discharged through the irrigation openings (723, 734, 742) is discharged along a path oriented obliquely to the central longitudinal axis (LA). This example is schematically shown in Figure 32A. As shown, the irrigation openings (723) adjacent to the electrode (740) are oriented obliquely to the central longitudinal axis (LA) along their respective axes oriented toward each other, such that one irrigation opening (723) discharges a jet of irrigation fluid (J1) along a path having a distal side, while the other irrigation opening (723) discharges a jet of irrigation fluid (J2) along a path having a proximal side. The jets (J1, J2) converge to form a vortex (V) of irrigation fluid, which is adjacent to the electrode (740). Although only one pair of irrigation openings (723) and adjacent electrodes (740) are shown, a similar arrangement can be provided between additional electrodes (740) (if not all) of the same end effector (720) so that each electrode (740) receives its own local vortex (V) of the irrigation fluid. Such local vortices (V) of the irrigation fluid can promote the cooling of the electrodes, particularly at the edges of the electrodes (740). In some other modifications, the irrigation fluid at each electrode (740) is discharged only in the direction of jet (J1) or jet (J2) so that the jets (J1, J2) do not converge. Alternatively, the irrigation fluid may be discharged in any other preferred manner.

[0096] E. Example of an electrical path between electrodes and other ablation devices There may be several scenarios in which two different types of ablation devices are positioned simultaneously in the same patient (PA). This may include a catheter assembly (200) and another device having at least one ablation electrode. In such scenarios, it may be desirable to provide a bipolar coupling between at least one electrode (352) of an end-effector (350) and at least one electrode of the other ablation device. For this purpose, Figure 33 shows the electrode (352) of an end-effector (350) used with another ablation device (750) to provide an eleventh example of an electrical pathway. In this example, the end-effector (350) is positioned in a lumen (L) defined by tissue (T). As a mere example, the lumen (L) may be in some other small vessel branching from the Marshall vein or coronary sinus.

[0097] The other ablation device (750) is positioned within a larger cavity (C), such as a cardiac chamber of the heart (H) or a space outside the heart (H). The device (750) may comprise a sheath or some other delivery device, another catheter, and / or any other suitable type of device. In this example, the device (750) includes a shaft (752) with a distal tip electrode (754). Alternatively, the device (750) may have any other suitable type of conductive mechanism at any other suitable position along the shaft (752). In the example shown in Figure 33, the electrode (754) of the device (750) is used to provide a return path, while one or more electrodes (352) are actuated with unipolar electrical energy. The electrical energy can flow between the actuated electrode (352) and electrode (754) through adjacent tissue (T), which may result in ablation of the tissue (T). Although not shown in Figure 33, the irrigation fluid (700) may be provided intraluminal (L) and / or intracardiac chamber (C) during this process. In some cases, the instrument (750) may also be used to ablate tissue and / or to provide EP mapping via electrodes (754) and / or via other mechanisms in intracardiac chamber (C). Such ablation by the intracardiac instrument (750) may be provided within the same procedure in which an ablation is provided intraluminal (L) using an end effector (350).

[0098] Figure 34 shows the electrodes (352) of an end effector (350) used with another ablation device (760) to provide a twelfth example of an electrical pathway. In this example, the shaft assembly (220) is positioned within the lumen of the device (760), and the end effector (350) is positioned distal to the device (760). The device (760) may comprise a sheath or any other delivery device, another catheter, and / or any other suitable type of device. The device (760) in this example includes a shaft (762) having a pair of ring electrodes (764). Alternatively, the device (760) may have any other suitable type of conductive mechanism at any other suitable position along the shaft (762). In the example shown in Figure 33, one or more electrodes (764) of the device (760) are used to provide a return pathway, while one or more electrodes (352) are actuated with unipolar electrical energy. Electrical energy can flow between the activated electrode (352) and electrode (764) through adjacent tissue, which can result in tissue ablation.

[0099] In some cases, the instrument (760) is advanced along a larger lumen (e.g., within the coronary sinus) and used to ablate tissue defining the larger lumen (e.g., via the action of an electrode (764)). While the instrument (760) is held in place within its larger lumen, the end effector (350) may be advanced into a smaller lumen branching off from the larger lumen (e.g., within Marshall's vein). One or more electrodes (352) are then used together with one or more electrodes (764) to form a bipolar pair, thereby ablating tissue defining the smaller lumen. Alternatively, the end effector (350) may be used with another instrument (760) in any other preferred manner.

[0100] V. Examples of Combinations The following embodiments relate to various non-exclusive forms in which the teachings herein may be combined or applied. It should be understood that the following embodiments 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 embodiments are provided for illustrative purposes only. Various teachings herein are intended to be composed of and applied in many other forms. Furthermore, some modifications may omit certain features mentioned in the following embodiments. Therefore, none of the embodiments or features mentioned below should be considered essential unless explicitly indicated thereafter 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.

[0101] Example 1 The apparatus comprises (a) an elongated shaft assembly having a proximal portion and a distal portion, the distal portion having a distal end, the distal portion being flexible, and the shaft assembly having an outer diameter; (b) an end effector positioned at the distal end of the shaft assembly, the end effector including one or more electrodes; and (c) a flexible circuit comprising (i) a flexible substrate, (A) a proximal portion of the flexible substrate positioned proximal to the end effector, and (B) extending along the distal portion of the shaft assembly and positioned proximal to the end effector. Apparatus comprising: a flexible substrate including (c) an intermediate portion and (i) a distal portion; and a flexible circuit including (ii) a first trace extending along at least the intermediate portion of the flexible substrate, wherein a portion of the first trace defines a first position sensor having a first position sensor length extending along the first portion of the length of the distal portion of the shaft assembly, the first position sensor being configured to generate a signal in the presence of an alternating magnetic field and further configured to bend together with the distal portion of the shaft assembly, the first position sensor length being at least about 10 times greater than the outer diameter of the shaft assembly.

[0102] Example 2 The proximal portion of the shaft assembly is rigid, as described in Example 1.

[0103] Example 3 The apparatus according to Example 2, further comprising an intermediate portion that provides a gradual transition from a rigid proximal portion to a flexible distal portion.

[0104] Example 4 The apparatus according to any one of Examples 1 to 3, wherein the end effector includes multiple electrodes, the electrodes being spaced longitudinally apart from one another along the distal end of the shaft assembly.

[0105] Example 5 The apparatus according to Example 4, wherein the electrodes are operable to apply electrical energy to tissue, thereby ablating the tissue.

[0106] Example 6 The apparatus according to Example 5, wherein the electrodes are operable to deliver pulsed-field ablation to the tissue.

[0107] Example 7 The apparatus according to any one of Examples 1 to 6, wherein one or more electrodes are positioned on the distal portion of a flexible substrate.

[0108] Example 8 The apparatus according to any one of Examples 1 to 7, wherein the intermediate portion comprises a segment extending in a first longitudinal direction and a segment extending in a second longitudinal direction, and the segment extending in the first longitudinal direction is angularly spaced apart from the segment extending in the second longitudinal direction.

[0109] Example 9 The apparatus according to Example 8, wherein the first longitudinally extending segment is angularly separated from the second longitudinally extending segment by approximately 180 degrees about the central longitudinal axis.

[0110] Example 10 The apparatus according to any one of Examples 8 to 9, wherein the first longitudinally extending segment has a meandering configuration.

[0111] Example 11 The apparatus according to Example 10, wherein the second longitudinally extending segment has a meandering configuration.

[0112] Example 12 The apparatus according to any one of Examples 8 to 11, wherein a portion of the first trace defines a first position sensor extending along a first longitudinally extending segment and along a second longitudinally extending segment.

[0113] Example 13 The apparatus according to Embodiment 12, wherein the flexible substrate further comprises an angled segment that joins a first longitudinally extending segment with a second longitudinally extending segment, and a portion of the first trace defining the first position sensor further extends along the angled segment.

[0114] Example 14 An apparatus according to any one of Examples 1 to 13, wherein a portion of the first trace defines a first position sensor that defines the coil shape.

[0115] Example 15 The apparatus according to any one of Examples 1 to 14, wherein the proximal portion of the flexible substrate includes a tail portion configured to spirally wrap around the distal portion of the shaft assembly.

[0116] Example 16 The apparatus according to any one of Examples 1 to 15, further comprising one or more electrical contact pads positioned on the proximal portion of the flexible substrate.

[0117] Example 17 The apparatus according to any one of Examples 1 to 16, wherein a portion of the first trace defines a position sensor that further extends along the distal portion of the flexible substrate.

[0118] Example 18 The apparatus according to any one of Examples 1 to 16, wherein a portion of the first trace defines a position sensor that further extends along the end effector.

[0119] Example 19 The apparatus according to any one of Examples 1 to 18, further comprising a tip member fixed to the distal portion of the shaft assembly at the distal end of the end effector.

[0120] Example 20 The apparatus according to Example 19, wherein the tip member has higher flexibility than the distal portion of the shaft assembly.

[0121] Example 21 The apparatus according to Example 21, wherein the distal portion of the shaft assembly includes a braided internal structure, while the tip member lacks a braided internal structure, and as a result, the absence of the braided internal structure provides greater flexibility to the tip member compared to the flexibility of the distal portion of the shaft assembly.

[0122] Example 22 The apparatus according to any one of Examples 19 to 21, wherein the shaft assembly and tip member together define a lumen, and the lumen terminates distally at the open distal end of the tip member.

[0123] Example 23 The apparatus as described in Example 22, wherein the lumen is sized to receive a guidewire.

[0124] Example 24 The apparatus according to any one of Examples 22 to 23, wherein the lumen is configured to allow fluid to flow outward through an elongated shaft assembly and through the open distal end of the tip member.

[0125] Example 25 The apparatus according to any one of Examples 1 to 24, wherein the shaft assembly has a total length extending from the proximal end to the distal end of the shaft assembly, and the first position sensor is defined by a portion of the first trace and has a total length extending from the proximal end to the distal end of the first position sensor, and the total length of the first position sensor is at least about 5% of the total length of the shaft assembly.

[0126] Example 26 The apparatus according to any one of Examples 1 to 25, wherein the flexible circuit further includes a second trace extending along at least the middle portion of the flexible substrate, a portion of which defines a second position sensor extending along a second portion of the length of the distal portion of the shaft assembly, and the second position sensor is configured to generate a signal in the presence of an alternating magnetic field.

[0127] Example 27 The apparatus according to Example 26, wherein the second position sensor is positioned distal to the first position sensor.

[0128] Example 28 The apparatus according to Example 26, wherein the second position sensor has the same longitudinal extent as the first position sensor.

[0129] Example 29 The apparatus according to any one of Examples 26 to 28, wherein the second position sensor is angularly offset from the first position sensor with respect to the central longitudinal axis.

[0130] Example 30 The apparatus according to Example 29, wherein the second position sensor is angularly offset by approximately 90 degrees from the first position sensor with respect to the central longitudinal axis.

[0131] Example 31 The apparatus according to any one of Examples 26 to 30, wherein the first position sensor comprises a first set of loop segments, and the second position sensor comprises a second set of loop segments.

[0132] Example 32 The apparatus according to Example 31, wherein the first set of loop segments of the loop segments are arranged alternately with the second set of loop segments.

[0133] Example 33 The apparatus according to any one of Examples 26 to 32, wherein the second trace is electrically insulated from the first trace.

[0134] Example 34 The apparatus according to any one of Examples 26 to 33, further comprising a flexible substrate with angled segments that provide an angular offset and a longitudinal offset between a first position sensor and a second position sensor.

[0135] Example 35 The apparatus according to any of Examples 1 to 34, wherein the outer diameter of the shaft assembly is in the range of approximately 0.67 mm to approximately 1.33 mm.

[0136] Example 36 The apparatus is one of the apparatuses described in any of Examples 1 to 35, having an inner diameter in the range of approximately 0.25 mm to approximately 0.45 mm.

[0137] Example 37 The apparatus according to any of Examples 1 to 36, wherein the shaft assembly has a length ranging from approximately 150 cm to approximately 200 cm.

[0138] Example 38 The distal portion of the shaft assembly has a length ranging from approximately 30 cm to approximately 75 cm, as described in any of Examples 1 to 37.

[0139] Example 39 The end effector is sized to fit into a blood vessel branching from the patient's coronary sinus, as described in any of Examples 1 to 28.

[0140] Example 40 The apparatus according to Example 39, wherein the end effector is sized to fit into the patient's Marshall vein.

[0141] Example 41 Apparatus comprising: (a) an elongated shaft assembly having a total length extending from the proximal end to the distal end of the shaft assembly; (b) an end effector positioned at the distal end of the shaft assembly, including one or more electrodes; (c) a flexible circuit comprising: (i) a flexible substrate, including (A) a proximal portion of the flexible substrate positioned proximal to the end effector; (B) an intermediate portion extending along the distal portion of the shaft assembly and positioned proximal to the end effector; and (C) a distal portion; and (ii) a trace extending along at least the intermediate portion of the flexible substrate, defining a position sensor having a position sensor length extending along a portion of the length of the distal portion of the shaft assembly, the position sensor being configured to generate a signal in the presence of an alternating magnetic field, and further configured to bend together with the distal portion of the shaft assembly, the position sensor length being at least about 5% of the total length of the shaft assembly.

[0142] Example 42 The apparatus according to Example 41, wherein the shaft assembly has an outer diameter, and the position sensor length is at least about 25 times greater than the outer diameter of the shaft assembly.

[0143] Example 43 The apparatus comprises: (a) an elongated shaft assembly having a total length extending from the proximal end to the distal end of the shaft assembly; (b) an end effector positioned at the distal end of the shaft assembly, including one or more electrodes; (c) a flexible circuit comprising: (i) a flexible substrate, including (A) a proximal portion of the flexible substrate positioned proximal to the end effector, (B) an intermediate portion extending along the distal portion of the shaft assembly and positioned proximal to the end effector, and (C) a distal portion; and (ii) a trace extending along at least the intermediate portion of the flexible substrate. A portion of the position sensor defines a position sensor having an effective position sensor length that extends along a portion of the length of the distal portion of the shaft assembly, the position sensor having an effective position sensor width that extends transversely with respect to the length of the distal portion of the shaft assembly, the position sensor is configured to generate a signal in the presence of an alternating magnetic field, and is further configured to bend together with the distal portion of the shaft assembly, the effective position sensor length and effective position sensor width together define a region along a two-dimensional plane, the region is configured to change along with either or both the effective position sensor length or effective position sensor width as the position sensor bends together with the distal portion of the shaft assembly, and the region is approximately 150 mm when the position sensor bends together with the distal portion of the shaft assembly 2 A device comprising a flexible circuit including a trace, which is further configured so as not to become smaller than a certain size.

[0144] Example 44 The apparatus according to Example 43, wherein the effective length of the position sensor is at least about 5% of the total length of the shaft assembly.

[0145] Example 45 The apparatus according to any one of Examples 43 to 44, wherein the shaft assembly has an outer diameter, and the effective length of the position sensor is at least about 25 times greater than the outer diameter of the shaft assembly.

[0146] Example 46 The apparatus comprises: (a) an elongated shaft assembly having a proximal portion and a distal portion, wherein the distal portion has a distal end and the distal portion is flexible; (b) an end effector positioned at the distal end of the shaft assembly, comprising one or more electrodes; and (c) a flexible circuit comprising: (i) a flexible substrate, wherein (A) a proximal portion of the flexible substrate positioned proximal to the end effector, and (B) an intermediate portion extending along the distal portion of the shaft assembly, positioned proximal to the end effector, and extending in a first longitudinal direction. A flexible substrate comprising (i) a segment and a second longitudinally extending segment, the first longitudinally extending segment being angularly separated from the second longitudinally extending segment, the intermediate portion and (c) a distal portion; and a flexible circuit comprising (ii) a trace extending along the first longitudinally extending segment and the second longitudinally extending segment, the trace defining a position sensor extending along a portion of the length of the distal portion of the shaft assembly, the position sensor being configured to generate a signal in the presence of an alternating magnetic field.

[0147] Example 47 The apparatus according to Embodiment 79, wherein the position sensor is further configured to bend together with the distal portion of the shaft assembly.

[0148] Example 48 The apparatus according to any one of Examples 79 to 80, wherein the first longitudinally extending segment is angularly separated by approximately 180 degrees from the second longitudinally extending segment with respect to the central longitudinal axis.

[0149] Example 49 The apparatus according to any one of Examples 79 to 81, wherein the first longitudinally extending segment has a meandering configuration.

[0150] Example 50 The apparatus according to Example 82, wherein the second longitudinally extending segment has a meandering configuration.

[0151] Example 51 The apparatus according to Example 83, wherein the meandering configuration of the first longitudinally extending segment defines a first plurality of peaks, and the meandering configuration of the first longitudinally extending segment defines a second plurality of peaks.

[0152] Example 52 The apparatus according to Example 84, wherein the peaks of the first set of peaks are positioned to coincide with the peaks of the second set of peaks along a dimension oriented transversely with respect to the longitudinal dimension.

[0153] Example 53 The apparatus according to any one of Examples 79 to 85, wherein the flexible substrate further comprises an angled segment that joins a segment extending in a first longitudinal direction with a segment extending in a second longitudinal direction, and a portion of the trace defining the first position sensor further extends along the angled segment.

[0154] Example 54 The apparatus according to any one of Examples 79 to 86, wherein a portion of the trace defines a position sensor that defines the coil shape.

[0155] Example 55 The apparatus according to any one of Examples 79 to 87, wherein the intermediate portion further comprises a plurality of web segments, the web segments being spaced apart from each other in the longitudinal direction, and the web segments joining a segment extending in a first longitudinal direction with a segment extending in a second longitudinal direction.

[0156] Example 56 A method comprising inserting an elongated shaft assembly into an anatomical structure within the cardiovascular system of a patient, wherein the elongated shaft assembly has a distal portion with an end effector, the end effector having a plurality of electrodes that extend at an angle around the distal portion of the shaft assembly and are longitudinally spaced apart from one another along the distal portion of the shaft assembly, and the shaft assembly further includes a tip member positioned distal to the end effector, the tip member being more flexible than the distal portion of the shaft assembly, the method comprising insertion, selecting one or more electrodes from the plurality to be activated, and activating the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue.

[0157] Example 57 The method according to Example 56, wherein the anatomical passage includes blood vessels branching from the coronary sinus.

[0158] Example 58 The method according to Example 57, wherein the anatomical passage includes the Marshall vein.

[0159] Example 59 Inserting an elongated shaft assembly into an anatomical structure involves advancing the elongated shaft assembly along a guide wire, the guide wire being slidably positioned within the elongated shaft assembly, as described in any of Examples 56-58.

[0160] Example 60 The method according to Example 59, wherein activating one or more selected electrodes to apply electrical energy to tissue and thereby ablate the tissue includes utilizing a guidewire as a return path for the electrical energy.

[0161] Example 61 The method according to any one of Examples 56 to 60, which includes activating one or more selected electrodes to apply electrical energy to tissue and thereby ablate the tissue, and utilizing a grounding pad as a return path for the electrical energy.

[0162] Example 62 The method according to Example 61, wherein the contact pad comprises a patch adhered to the patient.

[0163] Example 63 The method according to any one of Examples 56 to 62, wherein selecting one or more electrodes from a plurality of electrodes includes selecting a first single electrode from the plurality of electrodes to function as an active electrode.

[0164] Example 64 The method according to any of Examples 56 to 62, wherein selecting one or more electrodes from a plurality of electrodes includes selecting a first set of electrodes from a plurality of electrodes so that they function collectively as an active electrode.

[0165] Example 65 The method according to any one of Examples 56 to 64, wherein selecting one or more electrodes from a plurality of electrodes includes selecting a first single electrode from a plurality of electrodes to function as a return electrode.

[0166] Example 66 The method according to any of Examples 56 to 64, wherein selecting one or more electrodes from a plurality of electrodes includes selecting a first set of electrodes from a plurality of electrodes so that they function collectively as a return electrode.

[0167] Example 67 The method according to any one of Examples 56 to 66, comprising activating one or more selected electrodes to apply electrical energy to tissue and thereby ablate the tissue, utilizing a separate instrument to provide a return pathway for the electrical energy, the separate instrument being positioned within the patient.

[0168] Example 68 The method according to Example 67, wherein a separate device includes a guide wire.

[0169] Example 69 The method according to Example 68, wherein the guidewire is positioned at different locations within the patient so that the guidewire is not positioned within an anatomical structure where the elongated shaft assembly is located.

[0170] Example 70 The method of Example 67, wherein the separate instrument includes an ablation instrument having electrodes.

[0171] Example 71 The method according to Example 70, wherein the ablation device is positioned at different locations within the patient so that the ablation device is not positioned within an anatomical structure where the elongated shaft assembly is located.

[0172] Example 72 The method according to Example 71, wherein the ablation device is positioned within the cardiac chambers or pulmonary veins of the heart.

[0173] Example 73 The ablation device defines a lumen, and the elongated shaft assembly is slidably positioned within the lumen of the ablation device, according to any one of Examples 71 to 72.

[0174] Example 74 The method according to Example 73, wherein the ablation device is positioned within the coronary sinus and the elongated shaft assembly is positioned within a blood vessel branching from the coronary sinus.

[0175] Example 75 The method according to any one of Examples 56 to 74, further comprising communicating the irrigation fluid with an anatomical structure.

[0176] Example 76 The method according to Example 75, further comprising activating one or more selected electrodes to apply electrical energy to tissue and thereby ablate the tissue, and using an irrigation fluid to provide a return pathway for the electrical energy.

[0177] Example 77 The method according to any one of Examples 74 to 76, wherein the irrigation fluid is connected to an anatomical structure, and the irrigation fluid is discharged through the open distal end of the tip member.

[0178] Example 78 The method according to any one of Examples 76-77, wherein an elongated shaft assembly is positioned within a sheath, and the irrigation fluid is communicated with an anatomical structure, and the irrigation fluid is discharged through the open distal end of the sheath.

[0179] Example 79 The method according to Example 78, wherein the open distal end of the sheath is positioned proximal to the end effector.

[0180] Example 80 Communicating the irrigation fluid to an anatomical structure is the method according to any one of Examples 76-79, which includes draining the irrigation fluid through a lateral opening formed in the end effector.

[0181] Example 81 The method according to Example 75, wherein at least one of the lateral openings is located within at least one electrode of a plurality of electrodes.

[0182] Example 82 The method according to any one of Examples 80 to 81, wherein the lateral opening is oriented obliquely to the central longitudinal axis of the shaft assembly, so that the discharged irrigation fluid is discharged in a jet oriented obliquely to the central longitudinal axis of the shaft assembly.

[0183] Example 83 The method according to Example 82, wherein at least some of the jets form vortices of the irrigation fluid adjacent to multiple electrodes.

[0184] Example 84 The method according to Example 83, wherein at least some of the jets are oriented toward each other to form vortices of the irrigation fluid adjacent to multiple electrodes.

[0185] Example 85 The method according to any one of Examples 56 to 84, wherein activating one or more selected electrodes to apply electrical energy to tissue and thereby ablate the tissue includes applying high-frequency energy to the tissue.

[0186] Example 86 The method according to any one of Examples 56 to 84, which includes activating one or more selected electrodes to apply electrical energy to tissue and thereby ablate the tissue, thereby providing pulsed-field ablation to the tissue.

[0187] Example 87 The method according to any of Examples 56 to 86, further comprising processing a signal from a position sensor, the signal indicating the real-time position of the end effector.

[0188] Example 88 The position sensor comprises a coil formed by a portion of a flexible circuit, the coil bending together with the distal portion of the elongated shaft assembly while the elongated shaft assembly is inserted into an anatomical structure, as described in Example 87.

[0189] Example 89 Apparatus comprising: (a) an elongated shaft assembly having a proximal portion and a distal portion, wherein the distal portion has a distal end and the distal portion is flexible; (b) an end effector positioned at the distal end of the shaft assembly; (c) a flexible circuit including (i) a flexible substrate; (ii) at least one position sensor supported by the flexible substrate and configured to provide a signal indicating the position of the end effector; and (iii) a plurality of electrodes supported by the flexible substrate, wherein the electrodes of the plurality are spaced apart from each other longitudinally along the end effector; and (d) a processor electrically coupled to the flexible circuit, configured to (i) determine the arrangement of a pair of bipolar electrodes based on one or more criteria; (ii) select one or more electrodes from the plurality based on the determination; and (iii) activate the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue.

[0190] Example 90 The apparatus according to Example 89, wherein one or more criteria include one or more criteria selected from the group consisting of a targeted anatomical structure, the depth of the intended injury, and the geometric configuration of the intended injury.

[0191] Example 91 A method comprising inserting an elongated shaft assembly of a first instrument into a first anatomical structure in the cardiovascular system of a patient, wherein the elongated shaft assembly has a distal portion having an end effector, the end effector having a plurality of electrodes that extend at an angle around the distal portion of the shaft assembly and are longitudinally spaced apart from each other along the distal portion of the shaft assembly, and the shaft assembly further includes a tip member positioned distal to the end effector, the tip member being more flexible than the distal portion of the shaft assembly; inserting a second instrument having at least one conductive mechanism into a second anatomical structure in the patient; selecting one or more electrodes from a plurality of electrodes to be activated; and activating the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue, wherein at least one conductive mechanism of the second instrument provides a return path for the electrical energy.

[0192] Example 92 The second anatomical structure is located within the patient's cardiovascular system, as described in Example 91.

[0193] Example 93 The method according to Example 92, wherein the second anatomical structure includes the cardiac chambers of the patient's heart.

[0194] Example 94 The first anatomical structure includes blood vessels branching from the patient's coronary sinus, as described in any of Examples 91-93.

[0195] Example 95 The second apparatus is the method according to any of Examples 91 to 94, including a guide wire.

[0196] Example 96. The method according to any one of Examples 91 to 94, wherein the second device includes an ablation catheter.

[0197] Example 97 The method according to any one of Examples 91 to 96, wherein at least one conductive mechanism of the second instrument includes a distal tip electrode.

[0198] Example 98 The method according to any one of Examples 91 to 97, wherein the first and second instruments are separated by tissue between the first and second anatomical structures.

[0199] Example 99 The method according to any one of Examples 91 to 98, wherein the first anatomical structure includes a first blood vessel, the second anatomical structure includes a second blood vessel, and the first blood vessel branches off from the second blood vessel.

[0200] Example 100 The method according to Example 99, wherein the first apparatus is slidably positioned within the second apparatus.

[0201] Example 101 Apparatus comprising: (a) an elongated shaft assembly including a distal portion, the distal portion including (i) an end effector having a flex circuit having a plurality of electrodes that extend at an angle around the distal portion of the shaft assembly and are longitudinally spaced apart from each other along the distal portion of the shaft assembly, and (ii) a tip member positioned distal to the end effector and being more flexible than the distal portion of the shaft assembly; and (b) a processor electrically coupled to the flex circuit, the processor configured to perform the steps of (i) selecting one or more electrodes from a plurality of electrodes to be activated, and (ii) activating the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue via pulsed-field ablation.

[0202] Example 102 The device described in Example 101, wherein the distal portion is sized to fit into a blood vessel branching from the coronary sinus.

[0203] Example 103 The apparatus according to Example 102 includes a blood vessel, Marshall's vein.

[0204] Example 104 The apparatus according to any one of Examples 101 to 103, further comprising a guide wire, the guide wire being configured to be slidably fitted within an elongated shaft assembly.

[0205] Example 105 The apparatus according to Example 104, wherein the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing a guidewire as a return path for the electrical energy.

[0206] Example 106 The apparatus according to any one of Examples 101 to 105, wherein the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing a grounding pad as a return path for the electrical energy.

[0207] Example 107 The apparatus according to any one of Examples 101 to 106, wherein the processor is further configured to select a single electrode from among several electrodes to function as the active electrode.

[0208] Example 108 The apparatus according to any one of Examples 101 to 107, wherein the processor is further configured to select a set of electrodes from among a plurality of electrodes that collectively function as an active electrode.

[0209] Example 109 The apparatus according to any one of Examples 101 to 108, wherein the processor is further configured to select a single electrode from among several electrodes to function as a return electrode.

[0210] Example 120 The apparatus according to any one of Examples 101 to 109, wherein the processor is further configured to select a set of electrodes from among a plurality of electrodes that collectively function as return electrodes.

[0211] Example 121 The apparatus according to any one of Examples 101 to 120, further comprising a separate instrument, wherein the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing the separate instrument as a return path for the electrical energy.

[0212] Example 122 The apparatus according to Example 121, wherein a separate instrument includes a guidewire, and the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue when the guidewire is positioned in an anatomical structure different from the anatomical structure in which the distal portion of the elongated shaft assembly is positioned, thereby ablating the tissue while utilizing the guidewire as a return path for the electrical energy.

[0213] Example 123 The apparatus described in Example 121 includes an ablation device having electrodes.

[0214] Example 124 The apparatus according to Example 123, wherein the ablation instrument defines a lumen, and the elongated shaft assembly is configured to slidably fit into the lumen of the ablation instrument.

[0215] Example 125 The apparatus according to any one of Examples 101 to 124, wherein the elongated shaft assembly is further configured to communicate the irrigation fluid with an anatomical structure.

[0216] Example 126 The apparatus according to Example 125, wherein the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing the irrigation fluid as a return pathway for the electrical energy.

[0217] Example 127 The apparatus according to any one of Examples 124 to 125, wherein the end effector further includes a lateral opening, the lateral opening being configured to release an irrigation fluid.

[0218] VI. 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 inside the container. The sterilized device may then be stored in a sterile 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 steam.

[0219] 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 also include one or more of the various features disclosed in any of the various references incorporated herein by reference.

[0220] 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 each other. 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 claims.

[0221] Any patent, publication, or other disclosure material that is said to be incorporated herein by reference shall be incorporated herein only to the extent that the incorporated material does not contradict existing definitions, views, or other disclosure materials contained herein, in whole or in part. To that extent, disclosures expressly stated herein shall take precedence over any contradictory material incorporated herein by reference. Any material, or any part thereof, that is said to be incorporated herein by reference but contradicts existing definitions, views, or other disclosure materials contained herein shall be incorporated only to the extent that there is no contradiction between the incorporated material and the existing disclosure materials.

[0222] 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, steps, etc., discussed above are illustrative and not essential. Therefore, it should be understood that the scope of the invention should be considered with respect to the following claims and not be limited to the details of structure and operation shown and described herein and in the drawings.

[0223] [Implementation Method] (1) A device, (a) An elongated shaft assembly including a distal portion, wherein the distal portion is (i) an end effector having a flex circuit that extends angularly about the distal portion of the shaft assembly and has a plurality of electrodes longitudinally spaced from each other along the distal portion of the shaft assembly, and (ii) a tip member positioned distally of the end effector, the tip member being more flexible than the distal portion of the shaft assembly, the elongated shaft assembly comprising, (b) A processor electrically coupled to the flex circuit, (i) selecting one or more electrodes to activate among the plurality of electrodes; and (ii) activating the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue via pulsed field ablation, a processor configured to perform. A device comprising. (2) The device according to embodiment 1, wherein the distal portion is sized to fit into a blood vessel branching from the coronary sinus. (3) The device according to embodiment 2, wherein the blood vessel includes the Marshall vein. (4) The device according to embodiment 1, further comprising a guide wire, the guide wire being configured to slidably fit within the elongated shaft assembly. (5) The device according to embodiment 4, wherein the processor is further configured to activate the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing the guide wire as a return path for the electrical energy.

[0224] (6) The device according to embodiment 1, wherein the processor is further configured to activate the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing a ground pad as a return path for the electrical energy. (7) The apparatus according to Embodiment 1, wherein the processor is further configured to select a single electrode that functions as an active electrode from among the plurality of electrodes. (8) The apparatus according to Embodiment 1, wherein the processor is further configured to select a set of electrodes that collectively function as active electrodes from among the plurality of electrodes. (9) The apparatus according to Embodiment 1, wherein the processor is further configured to select a single electrode that functions as a return electrode from among the plurality of electrodes. (10) The apparatus according to Embodiment 1, wherein the processor is further configured to select a set of electrodes that collectively function as return electrodes from among the plurality of electrodes.

[0225] (11) The apparatus according to Embodiment 1, further comprising a separate instrument, wherein the processor is further configured to activate the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing the separate instrument as a return path for the electrical energy. (12) The separate instrument includes a guide wire, and the processor is configured to activate the one or more selected electrodes to apply electrical energy to tissue when the guide wire is positioned within an anatomical structure different from the anatomical structure where the distal portion of the elongated shaft assembly is positioned, thereby ablating the tissue while utilizing the guide wire as a return path for the electrical energy. The apparatus according to Embodiment 11. (13) The apparatus according to Embodiment 11, wherein the separate instrument includes an ablation instrument having an electrode. (14) The ablation instrument defines a lumen, and the elongated shaft assembly is configured to slidably fit within the lumen of the ablation instrument. The apparatus according to Embodiment 13. (15) The apparatus according to Embodiment 1, wherein the elongated shaft assembly is further configured to communicate a perfusion fluid to an anatomical structure.

[0226] (16) The apparatus according to Embodiment 15, wherein the processor is further configured to activate the one or more selected electrodes to apply electrical energy to the tissue, thereby ablating the tissue while utilizing the irrigation fluid as a return path for the electrical energy. (17) The apparatus according to embodiment 15, wherein the end effector further includes a lateral opening, the lateral opening being configured to release the irrigation fluid. (18) A device, (a) An elongated shaft assembly having a proximal portion and a distal portion, wherein the distal portion has a distal end and the distal portion is flexible, (b) an end effector positioned at the distal end of the shaft assembly, (c) Flexible circuit, (i) Flexible substrate, (ii) at least one position sensor supported by the flexible substrate, configured to provide a signal indicating the position of the end effector, and (iii) A flexible circuit comprising a plurality of electrodes supported by the flexible substrate, wherein the electrodes among the plurality of electrodes are spaced apart from each other in the longitudinal direction along the end effector, (d) A processor electrically coupled to the flex circuit, (i) Determining the arrangement of the electrode bipolar pair based on one or more criteria, (ii) Selecting one or more electrodes from the plurality of electrodes based on the above decision, (iii) A device comprising a processor configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue. (19) The apparatus according to Embodiment 18, wherein the one or more criteria include one or more criteria selected from the group consisting of an anatomical structure to be targeted, the depth of the intended injury, and the geometric configuration of the intended injury. (20) A method, Inserting an elongated shaft assembly of a first device into a first anatomical structure within the patient's cardiovascular system, wherein the elongated shaft assembly has a distal portion having an end effector, the end effector having a plurality of electrodes that extend at an angle around the distal portion of the shaft assembly and are longitudinally spaced apart from each other along the distal portion of the shaft assembly, and the shaft assembly further includes a tip member positioned distal to the end effector, the tip member being more flexible than the distal portion of the shaft assembly, Inserting a second instrument having at least one conductive mechanism into a second anatomical structure within the patient, Selecting one or more electrodes from the aforementioned plurality of electrodes to be activated, A method comprising activating one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue, wherein the at least one conductive mechanism of the second instrument provides a return path for the electrical energy.

Claims

1. It is a device, (a) An elongated shaft assembly including a distal portion, wherein the distal portion is (i) an end effector having a flexible circuit having a plurality of electrodes that extend at an angle around the distal portion of the shaft assembly and are spaced apart from each other longitudinally along the distal portion of the shaft assembly, and (ii) An elongated shaft assembly including a tip member positioned distal to the end effector, which is more flexible than the distal portion of the shaft assembly, (b) A processor electrically coupled to the flex circuit, (i) The step of selecting one or more electrodes from the plurality of electrodes to be activated, (ii) a device comprising a processor configured to perform the steps of activating one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue via pulsed-field ablation.

2. The apparatus according to claim 1, wherein the distal portion is sized to fit into a blood vessel branching from the coronary sinus.

3. The apparatus according to claim 2, wherein the blood vessel includes the Marshall vein.

4. The apparatus according to claim 1, further comprising a guide wire, wherein the guide wire is configured to be slidably fitted within the elongated shaft assembly.

5. The apparatus according to claim 4, wherein the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing the guidewire as a return path for the electrical energy.

6. The apparatus according to claim 1, wherein the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing a grounding pad as a return path for the electrical energy.

7. The apparatus according to claim 1, wherein the processor is further configured to select a single electrode from among the plurality of electrodes to function as an active electrode.

8. The apparatus according to claim 1, wherein the processor is further configured to select a set of electrodes from among the plurality of electrodes that collectively function as active electrodes.

9. The apparatus according to claim 1, wherein the processor is further configured to select a single electrode from among the plurality of electrodes to function as a return electrode.

10. The apparatus according to claim 1, wherein the processor is further configured to select a set of electrodes from among the plurality of electrodes that collectively function as return electrodes.

11. The apparatus according to claim 1, further comprising a separate instrument, wherein the processor is further configured to activate the one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing the separate instrument as a return path for the electrical energy.

12. The apparatus according to claim 11, wherein the separate instrument includes a guidewire, and the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue when the guidewire is positioned in an anatomical structure different from the anatomical structure in which the distal portion of the elongated shaft assembly is positioned, thereby ablating the tissue while utilizing the guidewire as a return path for the electrical energy.

13. The apparatus according to claim 11, wherein the separate instrument includes an ablation instrument having electrodes.

14. The apparatus according to claim 13, wherein the ablation device defines a lumen, and the elongated shaft assembly is configured to be slidably fitted into the lumen of the ablation device.

15. The apparatus according to claim 1, wherein the elongated shaft assembly is further configured to communicate the irrigation fluid with an anatomical structure.

16. The apparatus according to claim 15, wherein the processor is further configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue while utilizing the irrigation fluid as a return path for the electrical energy.

17. The apparatus according to claim 15, wherein the end effector further includes a lateral opening, the lateral opening being configured to discharge the irrigation fluid.

18. It is a device, (a) An elongated shaft assembly having a proximal portion and a distal portion, wherein the distal portion has a distal end and the distal portion is flexible, (b) an end effector positioned at the distal end of the shaft assembly, (c) A flexible circuit, (i) Flexible substrate, (ii) at least one position sensor supported by the flexible substrate, configured to provide a signal indicating the position of the end effector, and (iii) A flexible circuit comprising a plurality of electrodes supported by the flexible substrate, wherein the electrodes among the plurality of electrodes are spaced apart from each other in the longitudinal direction along the end effector, (d) A processor electrically coupled to the flex circuit, (i) Determining the arrangement of the electrode bipolar pair based on one or more criteria, (ii) Selecting one or more electrodes from the plurality of electrodes based on the above decision, (iii) A device comprising a processor configured to activate one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue.

19. The apparatus according to claim 18, wherein the one or more criteria include one or more criteria selected from the group consisting of an anatomical structure to be targeted, the depth of the intended injury, and the geometric configuration of the intended injury.

20. It is a method, Inserting an elongated shaft assembly of a first device into a first anatomical structure within the patient's cardiovascular system, wherein the elongated shaft assembly has a distal portion having an end effector, the end effector having a plurality of electrodes that extend at an angle around the distal portion of the shaft assembly and are longitudinally spaced apart from each other along the distal portion of the shaft assembly, and the shaft assembly further includes a tip member positioned distal to the end effector, the tip member being more flexible than the distal portion of the shaft assembly, and inserting... Inserting a second instrument having at least one conductive mechanism into a second anatomical structure within the patient, Selecting one or more electrodes from the aforementioned plurality of electrodes to be activated, A method comprising activating one or more selected electrodes to apply electrical energy to tissue, thereby ablating the tissue, wherein the at least one conductive mechanism of the second instrument provides a return path for the electrical energy.

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