Conduit with a support structure having variable dimensions

Abstract

The present invention is entitled "A conduit with a support structure having variable dimensions." The invention relates to a conduit having a multi-electrode assembly with high electrode density. The multi-electrode assembly can be a basket-shaped electrode assembly or a brush-shaped electrode assembly, each having multiple ridges. Each ridge includes a flexible wire core of shape memory material. The flexible wire may have a variable cross-section to control the movement and stiffness of the ridge.

Description

Technical Field

[0001] This invention relates to electrophysiological (EP) catheters, and more specifically, to EP catheters for cardiac mapping and / or ablation. More specifically, this invention relates to EP catheters with a support structure having variable dimensions. Background Technology

[0002] Electrophysiological catheters are commonly used to map electrical activity in the heart. Various electrode designs for different purposes are known. Specifically, catheters with basket electrode arrays are known and described, for example, in U.S. Patents 5,772,590, 6,748,255, and 6,973,340, the entire disclosure of each of which is incorporated herein by reference.

[0003] A basket catheter typically has an elongated catheter body and a basket electrode assembly mounted at the distal end of the catheter body. The basket assembly has a proximal end and a distal end, and includes multiple ridges connected at its proximal and distal ends. Each ridge includes at least one electrode. The basket assembly has an expanded arrangement in which the ridges are radially outwardly curved; and a collapsed arrangement in which the ridges are generally arranged along the axis of the catheter body.

[0004] It is desirable for multi-electrode assemblies to detect as much electrical function as possible in the area where the assembly is deployed (such as the left or right atrium) with as few heartbeats as possible (including a single heartbeat). By implementing more electrodes on the assembly, a larger and more complete coverage area can be obtained accordingly. Furthermore, with an increased number of electrodes, it may be less necessary or even unnecessary to reposition the assembly to reach the full desired area. Increasing the number of electrodes is typically accompanied by an increase in the number of ridges or other structures supporting the electrodes. One problem with prior art designs with multiple ridges is that the movement of the ridges is not easily controlled when deployed and may cause them to move closer together, potentially resulting in contact or overlap between the ridges and electrodes. Contact or overlap between ridges and electrodes can lead to inaccurate data collection from the tissue or ineffective treatment. Another problem with existing devices is that the ridges may not be robust enough to maintain contact with the tissue to be mapped or treated. Therefore, there is a need for multi-electrode assemblies with improved support members for controlling ridge movement and maintaining contact with the tissue electrodes. The technology disclosed herein addresses this, as well as other needs described in the following materials. Summary of the Invention

[0005] This disclosure relates to a catheter comprising: an elongated catheter body extending along a longitudinal axis, the elongated catheter body having a proximal end and a distal end; and a flexible wire assembly positioned at the distal end of the elongated catheter body, the flexible wire assembly being formed of a shape memory material, the flexible wire assembly having a plurality of flexible wires, each flexible wire having a proximal end and a distal end, and wherein at least one of the flexible wires has a variable cross-section. The catheter also includes a plurality of ridges formed by the plurality of flexible wires and a plurality of electrodes and cables attached to each ridge.

[0006] On one hand, the distal ends of multiple flexible wires are joined at the distal hub to form a basket-shaped multi-electrode device.

[0007] In one aspect, at least one flexible line has a variable thickness, wherein the middle portion of the flexible line has a first thickness and the proximal portion of the flexible line has a second thickness, wherein the second thickness is greater than the first thickness, and wherein at least one flexible line has a distal portion having a third thickness, wherein the third thickness is greater than the first thickness.

[0008] On one hand, the second thickness is equal to the third thickness, wherein the thickness of the flexible line gradually decreases from the distal portion to the middle portion; and wherein the thickness of the flexible line gradually decreases from the proximal portion to the middle portion.

[0009] On one hand, at least one flexible line has a constant width from the proximal portion to the distal portion.

[0010] On one hand, at least one flexible line has a width that tapers from the proximal portion to the middle portion, and wherein the width tapers from the distal portion to the middle portion.

[0011] On one hand, the flexible wire assembly includes a brush-shaped flexible wire assembly, wherein the distal end of each flexible wire is not attached to an adjacent flexible wire.

[0012] On one hand, the multiple flexible lines include at least one flexible line having a first width and at least one flexible line having a second width, wherein the second width is greater than the first width.

[0013] On one hand, the multiple flexible lines include at least one flexible line with a third width, wherein the third width is greater than the second width.

[0014] On one hand, the multiple flexible lines include at least one flexible line with a thickness, wherein the thickness is a constant thickness along the length of the flexible line.

[0015] On one hand, the multiple flexible lines include at least one flexible line with a variable thickness, wherein the variable thickness gradually decreases from a first thickness at the proximal portion of the flexible line to a second thickness at the distal portion of the flexible line.

[0016] On one hand, the plurality of flexible lines includes a proximal portion having a first width and a distal portion having a second width; wherein the first width is greater than the second width; and wherein the width gradually decreases along the length of the plurality of flexible lines from the proximal portion having the first width to the distal portion having the second width.

[0017] On one hand, the plurality of flexible lines includes a proximal portion having a first thickness and a distal portion having a second thickness; wherein the first thickness is greater than the second thickness; and wherein the thickness gradually decreases along the length of the plurality of flexible lines from the proximal portion having the first thickness to the distal portion having the second thickness.

[0018] On one hand, shape memory materials include nickel-titanium alloys.

[0019] This disclosure also relates to a method for forming a catheter, the method comprising: forming an elongated catheter body; forming a flexible wire assembly from a shape memory material, the flexible wire assembly having a plurality of flexible wires having a variable cross-section; heating the flexible wire assembly to heat-set the flexible wire assembly; connecting a plurality of electrodes and cables to each of the plurality of flexible wires to form a multi-electrode assembly; and connecting the multi-electrode assembly to a distal end of the elongated catheter body.

[0020] On one hand, the multi-electrode assembly is a brush electrode assembly.

[0021] On one hand, the multiple flexible lines have a first width at the proximal portion and a second width at the distal portion, wherein the width tapers from the first width at the proximal portion toward the second width at the distal portion.

[0022] On one hand, the plurality of flexible lines have at least one flexible line with a first width and at least one flexible line with a second width; wherein the second width is greater than the first width.

[0023] On one hand, the multiple flexible lines have at least one flexible line with a third width, wherein the third width is greater than the second width. Attached Figure Description

[0024] Further features and advantages will become apparent from the following more detailed description of preferred embodiments of the present disclosure, as illustrated in the accompanying drawings (which are not drawn to scale), wherein similar reference characters generally refer to the same portion or element throughout the view, and wherein:

[0025] Figure 1 This is a schematic diagram of the catheter of the present invention according to one embodiment.

[0026] Figure 2A and Figure 2B This is a schematic diagram of a brush-shaped flexible line assembly according to one implementation scheme.

[0027] Figure 3A and Figure 3B This is a schematic diagram of another flexible line assembly according to one implementation scheme.

[0028] Figure 4 This is a detailed view of a basket-shaped multi-electrode assembly according to another embodiment.

[0029] Figure 5A and Figure 5B It is based on Figure 4 A schematic diagram of a portion of the basket-shaped flexible line assembly of the implementation scheme.

[0030] Figure 6 This is a schematic diagram of an invasive medical procedure using a multi-electrode assembly according to one implementation scheme. Detailed Implementation

[0031] First, it should be understood that this disclosure is not limited to specific exemplary materials, architectures, conventions, methods, or structures, as these are all subject to variation. Therefore, while preferred materials and methods are described herein, many similar or equivalent options may be used in the practice or implementation of this disclosure.

[0032] It should also be understood that the terminology used herein is for the purpose of describing specific embodiments of this disclosure only and is not intended to be limiting.

[0033] The specific embodiments described below, in conjunction with the accompanying drawings, are intended as exemplary embodiments of this disclosure and are not intended to represent the only exemplary embodiments that may be practiced with respect to this disclosure. The term "exemplary" as used throughout this specification means "serving as an example, instance, or illustration" and is not necessarily to be construed as preferred or superior to other exemplary embodiments. The detailed description includes specific details intended to provide a thorough understanding of the exemplary embodiments of this specification. It will be apparent to those skilled in the art that the exemplary embodiments of this specification may be practiced without these specific details. In some instances, well-known structures and apparatuses are shown in the block diagrams to avoid obscuring the novelty of the exemplary embodiments presented herein.

[0034] For the sake of brevity and clarity only, directional terms such as top, bottom, left, right, up, down, above, above, below, under, rear, back, and front may be used relative to the accompanying drawings. These terms and similar directional terms should not be construed as limiting the scope of this disclosure in any way.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0036] Finally, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless otherwise expressly indicated.

[0037] Multi-electrode assemblies are frequently used in cardiac chambers to analyze or map electrical activity. There is a desire to collect this type of data as quickly as possible to reduce procedure time and limit patient stress. Medical devices with multiple electrodes distributed across multiple ridges have been developed to shorten this procedure time. The increased number of ridges used to house the electrodes has created opportunities for better control over their placement and relative stiffness as the ridges are deployed and used at the treatment site. According to the technology disclosed herein, the ridges of a basket-shaped or brush-shaped multi-electrode assembly are configured with different dimensions along the ridge support to control ridge movement during the procedure and maintain electrode contact with tissue.

[0038] For reference Figure 1 The catheter 10 includes an elongated catheter body 12 having a proximal end and a distal end, and a control handle 14 located at the proximal end of the catheter body. The catheter 10 also includes an electrode assembly 16 located at the distal end of the catheter body 12. The electrode assembly 16 is a multi-electrode assembly including multiple ridges. In one embodiment, as... Figure 1 As shown, the electrode assembly 16 is a brush-shaped electrode assembly 16 having multiple ridges 18 (each ridge carrying multiple electrodes 20) and mounted at the distal end of the catheter body 12. In another embodiment, as discussed below and as... Figure 4 As shown, electrode assembly 16 includes a basket-shaped electrode assembly. The catheter body 12 includes an elongated tubular structure having a single axial or central lumen 26, but optionally multiple lumens if desired. To enable accurate mapping of electrical signals, it is desirable to provide an electrode array with a relatively high density. Thus, the number of ridges 18 employed can vary from four to sixteen or any other suitable number. The distal ends of the ridges 18 are separated from adjacent ridges. Each ridge 18 may include multiple electrodes 20, such as at least six and up to approximately 16 electrodes per ridge, or any other number of electrodes to suit a particular application. Similarly, the electrodes may be uniformly distributed along the ridges or may be deflected proximally, centrally, or distally to facilitate the analysis of the measured electrical signals.

[0039] The catheter body 12 is flexible, i.e., it can be bent, but is substantially incompressible along its length. The catheter body 12 can be of any suitable construction and can be made of any suitable material. One construction includes polyurethane or PEBAX. ®The outer wall is formed of polyether block amide. The outer wall includes an embedded braided mesh of stainless steel or the like to increase the torsional stiffness of the catheter body 12, such that the distal end of the catheter body rotates accordingly when the control handle 14 is rotated. The outer diameter of the catheter body 12 is not definitive, but should generally be as small as possible and not greater than about 10 French kilometres, depending on the desired application. In one aspect, the total diameter of the catheter body 12 can be related to the number of electrodes 20 implemented by the electrode assembly 16 to accommodate associated electrical leads. For example, a twelve-ridge design with sixteen electrodes per ridge (a total of 192 electrodes), a ten-ridge design with sixteen electrodes per ridge (a total of 160 electrodes), and an eight-ridge design with sixteen electrodes per ridge (a total of 128 electrodes) can use a catheter body of up to 10.0 French kilometres. Similarly, the thickness of the outer wall is not definitive, but can be thin enough to accommodate leads, sensor cables, and any other wires, cables, or tubes in the central lumen. If desired, the inner surface of the outer wall may be lined with a reinforcing tube (not shown) to provide improved torsional stability. U.S. Patent 6,064,905 describes and depicts examples of catheter body constructions suitable for use in conjunction with the present invention, the entire disclosure of which is incorporated herein by reference.

[0040] The ridge 18 comprises a shape memory material that facilitates an expanded arrangement, as described below. When the brush-shaped electrode assembly 16 is deployed, it takes on an expanded configuration, whereby the ridge 18 expands in a generally planar manner and contacts the wall of a chamber (such as the left atrium) of the deployed brush-shaped electrode assembly 16.

[0041] In one aspect, the electrophysiologist may introduce the guiding sheath 24, guidewire, and dilator into the patient, as is commonly known in the art. For example, a suitable guiding sheath for connecting the catheter of the present invention is the French DiRex 10. ™ Guide sheath (available commercially from BARD, Murray Hill, NJ). Insert guidewire, remove dilator, and introduce catheter through guidewire sheath, whereby guidewire lumen 26 allows catheter to pass through guidewire. In an exemplary procedure, catheter is first introduced into the right atrium (RA) via the inferior vena cava (IVC), whereby catheter passes through septum (S) to reach the left atrium (LA).

[0042] As should be understood, in the collapsed delivery position, the guide sheath 24 covers the ridge 18 of the electrode assembly 16, allowing the entire catheter to traverse the patient's vascular system to reach the desired location. Once the distal end of the catheter reaches the desired location, e.g., the left atrium, the guide sheath is withdrawn to expose the electrode assembly 16. After the guide sheath is withdrawn, the shape memory material of the multi-electrode assembly causes the device to expand within the chamber. With the electrode assembly 16 expanded, the annular electrode 20 contacts the atrial tissue. As those skilled in the art will recognize, the electrode assembly 16 can expand, straighten, or deflect in various configurations, depending on the configuration of the cardiac region being mapped or treated.

[0043] When electrode assembly 16 expands, an electrophysiologist can map the local activation time and / or perform ablation using electrode 20, which can guide the electrophysiologist in diagnosing and providing treatment to the patient. The catheter may include one or more reference ring electrodes mounted on the catheter body, and / or one or more reference electrodes may be placed externally to the patient. By using a catheter with multiple electrodes on a brush electrode assembly, an electrophysiologist can map selected areas of the heart. The embodiments described above utilize multiple ring electrodes. In another embodiment, the multi-electrode assembly uses multiple printed circuit board (PCB) electrodes. In this embodiment, the PCB electrodes may be positioned on any part of the ridge that can access the tissue to be treated. For example, the PCB electrodes may be on the first side, the second side, or both of the first and second sides of the ridge. The placement of the PCB may depend on the application of the specific device.

[0044] like Figure 1 As shown, the brush-shaped electrode assembly 16 is characterized by a total of eight ridges 18, each ridge carrying ten electrodes 20. In other embodiments, different numbers of ridges 18 and / or electrodes 20 may be used, and each ridge or electrode may be uniformly or non-uniformly distributed as needed. The proximal ends of the ridges 18 may be secured to the distal ends 32 of the catheter body 12. The lumen 26 may be used as a guidewire lumen. In some embodiments, the lumen 26 may also be used to supply a suitable flushing fluid (such as heparinized saline) to the electrode assembly 16. Accessories (not shown) in the control handle 14 may be provided to conduct flushing fluid from a suitable source or pump it into the lumen 26.

[0045] Each ridge 18 may include a cable with built-in or embedded leads having electrodes 20 carried by the ridge. The cable has a core and multiple generally similar wires, each wire being covered by an insulating layer that enables each wire to be formed and function as a conductor. The core provides a lumen in which other components, such as a support structure in the form of a flexible wire 28 (as discussed further in detail below), and / or additional leads (one or more), cables, tubing, or other components can pass through. Cables suitable for use with the present invention are described in U.S. Application Serial No. 13 / 860,921, filed April 11, 2013, entitled “HIGH DENSITY ELECTRODE STRUCTURE,” and U.S. Application Serial No. 14 / 063,477, filed October 25, 2013, entitled “CONNECTION OF ELECTRODES TOWIRES COILED ON A CORE,” the entire disclosure of which is incorporated herein by reference. Each cable (with embedded leads) can extend to the control handle 14 for appropriate electrical connection of the wire, thereby allowing detection of the signal measured by the electrodes 20.

[0046] Each ridge 18 may include a flexible wire 28 support having a non-conductive cover 30 on which one or more annular electrodes 20 are mounted. Each annular electrode 20 may be configured as unipolar or bipolar, as known in the art. In embodiments, the flexible wire 28 may be formed of a shape memory material to facilitate transitions between an expanded (unfolded) configuration and a collapsed (delivered) configuration, and the non-conductive cover 30 may each comprise a biocompatible plastic tubing, such as polyurethane or polyimide tubing. Multiple flexible wires 28 may be joined to form a flexible wire assembly. (See below) Figures 2A to 5B The embodiment of the flexible wire assembly 29 shown provides an improved approach to controlling and stabilizing the multi-electrode device when the spinal contact is with tissue to be mapped and / or treated.

[0047] Figure 2A and Figure 2B An embodiment of an improved flexible wire assembly 29 is shown. The flexible wire assembly 29 comprises multiple flexible wires 28. In one embodiment, the flexible wire assembly 29 is made of nitinol (a nickel-titanium alloy). In another embodiment, the flexible wire assembly 29 is manufactured from a single nitinol sheet. In yet another embodiment, the flexible wire assembly 29 is manufactured from a single nitinol tube and formed in a brush shape. The nitinol alloy may be laser-cut and / or drilled to form a brush pattern. In still some embodiments, individual flexible wires 28 are manufactured and then joined together at their proximal ends to form the flexible wire assembly. In each of these embodiments, the proximal ends of the flexible wires 28 are joined to the distal end 32 of the catheter body 12.

[0048] As mentioned above, the flexible wire assembly 29 is made of nitinol (a shape memory material). During manufacturing, the flexible wire assembly is heat-set into a "memorized" shape, also referred to as an unfolded shape or unfolded configuration. At body temperature, nitinol wires are flexible and elastic, and like most shape memory metals, they deform when subjected to minimal force and return to their shape when the force is absent. During manufacturing, the nitinol material is heated and shaped into the desired shape. This shape is then heat-set, as is known in the art. The brush-shaped electrode assembly 16 will have a three-dimensional shape that can collapse (deform) to be placed in a guide sheath and then return to its expanded shape memory configuration upon release from the guide sheath when delivered to the desired area of ​​the patient. Those skilled in the art will recognize that other shape memory materials (e.g., other shape memory metals and shape memory polymers) can be used instead of nitinol.

[0049] As mentioned above, in describing Figure 1 In this configuration, the flexible wire assembly 29 provides a support structure to the ridges 18 and the electrodes 20 supported on those ridges. However, in order to improve the functionality of the multi-electrode device, which is superior to that of the prior art, the inventors determined that varying the size and shape of the cross-section of the flexible wire assembly would provide better tissue contact and control to the ridges supporting the electrodes. Figure 2AA flexible wire assembly with flexible wires 28 of varying widths is shown. In this embodiment, the width W of the flexible wires 28 increases from a first width W1 of flexible wire 28A positioned close to the centerline CL, to an intermediate second width W2 of flexible wire 28B positioned further from the centerline, and then to a maximum width W3 of flexible wire 28C positioned furthest from the centerline. In this embodiment, the specific width (W1, W2, or W3) of each flexible wire is maintained along the length of each flexible wire 28 as the flexible wire extends from the conduit attachment portion 40 to the distal end 42 of the flexible wire 28. Each flexible wire 28 also includes a transition portion 44 extending distally from the conduit attachment portion 40 to the proximal end 46 of each flexible wire. The width of the transition portion 44 of each flexible wire is generally equal to the width of the corresponding flexible wire 28. The length and curvature of the transition portion 44 vary depending on the position of the flexible wire 28. Typically, the length and curvature of the transition portion 44 increase as the flexible lines 28 are positioned further from the centerline CL. For example, those flexible lines 28A closer to the centerline CL have relatively short and straight transition portions 44A, those flexible lines 28B with intermediate distances may be slightly longer and have more pronounced curvature, and the outer flexible lines 28C have longer transition portions that bend substantially from the conduit attachment portion 40. The increased width of the flexible lines and the transition portions of those flexible lines positioned further from the centerline CL increases their stability as the flexible lines bend away from the centerline to form brush-shaped ridges on the periphery of the electrode assembly 16.

[0050] Figure 2B It shows Figure 2A Side view of the flexible line assembly 29 shown. Figure 2B The thickness T of the flexible wire 28 is shown. In this embodiment, the thickness T is consistent for all of the flexible wires 28A to 28C and from the proximal end 46 to the distal end 42 of each flexible wire 28. However, the width-to-thickness ratio of the flexible wire 28 increases from the narrowest flexible wire 28A to the widest flexible wire 28C. The width of the flexible ridge can vary from 0.005 inches to 0.020 inches. The thickness can vary from 0.004" to 0.020". The width-to-thickness ratio can vary from 1:1 to 4:1 or higher, depending on the application of the particular device. As shown, the ridge ratio of flexible wire 28A can be 1.1:1, the ridge ratio of flexible wire 28B can be 1.5:1, and the ridge ratio of flexible wire 28C can be 2:1. The resulting cross-sectional shape of the flexible wires with these ratios will vary from square to rectangular. It should be noted that... Figure 2AThe described embodiments are illustrative only; the device may have more than six flexible wires, and the flexible wire assembly may have a ratio of more or less than the three depicted on the multiple flexible wires. Those skilled in the art will also understand that the width-to-thickness ratio will depend on several factors, such as the specific application of the device and the total number of ridges included on the device. Figure 2A and Figure 2B In the illustrated embodiment, the increased width-to-thickness ratio of the flexible lines 28A, 28B, 28C as the position moves away from the center line CL provides increased stiffness to the flexible lines 28, thereby better stabilizing those ridges 18 further from the center of the deployed electrode assembly 16.

[0051] For reference Figure 3A and Figure 3B , Figure 3A This is another embodiment of the flexible wire assembly 129 with a variable cross-section. In this embodiment, the cross-section tapers from a first width W11 at the proximal end 146 of the flexible wire 128 to a width W12 at the distal end 142 of the flexible wire. The width difference between W11 and W12 can be from 0.001" to 0.015". The increase in the width of W11 provides a more rigid base portion to better support the ridge and electrode covering the flexible wire assembly 129. The narrowest width W12 at the distal end 142 will increase the flexibility of the distal portion of the device and allow the electrode 20 to make better contact with the tissue to be treated. The stiffness of the proximal end 146 and the flexibility of the distal end 142 can be further increased by adjusting the thickness T of the flexible wire 128. Figure 3B A side view of a flexible wire assembly 129 is shown, exhibiting a thickness T. The flexible wire 128 has a variable thickness of approximately 0.004" to 0.020". In one embodiment, the thickness of the flexible wire 128 tapers from a first thickness T1 to a second thickness T2. Similar to the width difference discussed above, the thickness T difference can be approximately 0.001" to approximately 0.015". In another embodiment, the thickness does not vary along the length L, where T1 equals T2. Figures 3A to 3B The embodiment of the flexible line assembly 129 shown is similar to the above in all other respects. Figures 2A to 2B The flexible line assembly 29 is shown.

[0052] For reference Figure 4 , Figure 4 It shows a suitable connection with catheters (such as those mentioned above). Figure 1The basket electrode assembly 216 is used in conjunction with the catheter body 12 shown. The basket electrode assembly 216 is a multi-electrode assembly comprising multiple ridges. In this embodiment, the basket electrode assembly 216 is a basket electrode assembly 216 having multiple ridges 218, each ridge carrying multiple electrodes 220. To enable accurate mapping of electrical signals, it is desirable to provide an electrode array with a relatively high density. Thus, the number of ridges 218 employed can vary from four to sixteen or any other suitable number. The distal ends of the ridges 218 are separated from adjacent ridges. Each ridge 218 may include multiple electrodes 220, such as at least six and up to approximately sixteen electrodes per ridge, or any other number of electrodes to suit a particular application. Similarly, the electrodes may be evenly distributed along the ridges or may be deflected proximally, centrally, or distally to facilitate the analysis of the measured electrical signals. The distal ends of the ridges 218 are joined together at a distal hub 222. The distal hub 222 may take any form to suit a particular application. In one embodiment, the distal hub 222 is generally a circular, flat structure to allow more electrodes 220 to contact the tissue to be mapped or treated. In another embodiment, the distal hub 222 is a cylindrical shape that allows ridges to engage the distal hub at multiple insertion points. Ribs 218 may be radially distributed uniformly or non-uniformly around the distal hub 222. Ribs 218 include shape memory materials, as described above, that facilitate an expanded arrangement. When the basket electrode assembly 216 is deployed, it expands, whereby the ridges 218 bend outward into an arc shape, contacting or being close to the wall of a chamber (such as the left atrium) in which the basket electrode assembly 216 has been deployed.

[0053] Each ridge 218 may include a flexible wire 228 support having a non-conductive cover 230 on which one or more annular electrodes 220 are mounted. Each annular electrode 220 may be configured to be unipolar or bipolar, as known in the art. In embodiments, the flexible wires 228 may be formed of a shape memory material to facilitate transitions between an expanded (unfolded) configuration and a collapsed (delivered) configuration, and the non-conductive covers 230 may each comprise a biocompatible plastic tubing, such as polyurethane or polyimide tubing. Multiple flexible wires 28 may be joined to form a flexible wire assembly, as described below. Figure 5A and Figure 5B To elaborate further.

[0054] As used herein, the term "basket-shaped" to describe the basket electrode assembly 216 is not limited to the depicted configuration, but may include other designs such as spherical or egg-shaped designs, which include multiple expandable arms or ridges connected directly or indirectly at their proximal and distal ends. In one aspect, basket electrode assemblies of different sizes may be used depending on the patient's anatomy to fit closely to the area of ​​the patient being investigated, such as the right or left atrium. Other shapes for the basket electrode assembly 216 are contemplated by the present invention.

[0055] As shown and described in detail above for the brush-shaped multi-electrode assembly, the lower flexible wire assembly support for the basket-shaped multi-electrode assembly will also benefit from improvements in the cross-section of the flexible wires that make up the flexible wire assembly. Furthermore, the cross-sectional shape is typically square or rectangular. This shape also facilitates improved control and movement of the ridges and electrodes.

[0056] For reference Figure 5A and Figure 5B , Figure 5A and Figure 5B A flexible wire 228 with a variable cross-section is shown in a flexible wire assembly 229. In one embodiment, the thickness T of the flexible wire 228 varies from a first thickness T1 near the middle of the flexible wire 228 to a second thickness T2 adjacent to the proximal end 246 of the flexible wire 228. The flexible wire 228 may have a third thickness T3 located near the hub 222. Figure 5B A straightened flexible line 228 is shown to better illustrate the variable thickness. In this embodiment, the thickness of the flexible line 228 tapers from a thickness T3 at the distal end 242 toward the center and also from a thickness T2 at the proximal end 246 toward the center. In one embodiment, thickness T2 is equal to thickness T3. The thickness of the flexible line 228 varies from 0.006" to 0.012". The thickness difference between T1 and T2 / T3 can be from about 0.001" to about 0.006". In one embodiment, the width of the flexible line remains substantially constant from the proximal end 246 to the distal end 242. In another embodiment, the width also varies similarly to the thickness. The width can vary from 0.004" to 0.015".

[0057] Those skilled in the art will understand that the above refers to Figures 2A to 5B Each element in the described embodiments can be combined with other elements in other embodiments, and these combinations are all within the scope of the invention. The following describes... Figure 6 The same argument applies to each of the implementation schemes described above.

[0058] To help illustrate the use of the multi-electrode assembly 16, Figure 6This is a schematic diagram of an invasive medical procedure according to an embodiment of the present invention. An electrode assembly 16 is provided at the distal end (see...). Figure 1 The catheter 10 may have a connector 60 at its proximal end, which can receive electrodes 20 from their respective electrodes (see...). Figure 1 The catheter 10 is wire-coupled to a console 62 for recording and analyzing the detected signals. An electrophysiologist 64 may insert the catheter 10 into the patient 66 to acquire electrode potential signals from the patient's heart 68. The technician uses a control handle 14 attached to the catheter to perform the insertion. The console 62 may include a processing unit 70 that analyzes the received signals and presents the analysis results on a display 72 attached to the console. These results are typically in the form of mappings, digital displays, and / or graphs derived from the signals.

[0059] In another aspect, the processing unit 70 may also receive signals from one or more position sensors 74 disposed near the distal end of the catheter 10, adjacent to the electrode assembly 16. Each of the sensors may include a magnetic field-responsive coil or multiple such coils. Using multiple coils enables the determination of six-dimensional position and orientation coordinates. In response to a magnetic field from an outer coil, the sensor can thus generate an electrical position signal, enabling the processing unit 70 to determine the position (e.g., position and orientation) of the distal end of the catheter 10 within the cardiac cavity. An electrophysiologist can then observe the position of the electrode assembly 16 on an image of the patient's heart on a display 72. By way of example, this position sensing method can use CARTO ™ The system is implemented using a system manufactured by Biosense Webster Inc. (Diamond Bar, Calif.) and specifically described in U.S. Patents 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, PCT Patent Publication WO 96 / 005768, and U.S. Patent Application Publications 2002 / 0065455 A1, 2003 / 0120150 A1, and 2004 / 0068178 A1, the disclosures of which are incorporated herein by reference. Other position sensing techniques may also be employed, as will be appreciated. If desired, at least two position sensors may be positioned proximally and distally on the electrode assembly 16. The coordinates of the distal sensor relative to the proximal sensor can be determined, and other known information relating to the ridge 18 of the electrode assembly 16 is used to locate the position of each of the electrodes 20.

[0060] The above description has been presented with reference to the currently disclosed embodiments of the present invention. Those skilled in the art will recognize that changes and modifications can be made to the structures without intentionally departing from the principles, spirit, and scope of the invention. As will be understood by those skilled in the art, the drawings are not necessarily drawn to scale. Therefore, the specific embodiments described above should not be construed as suitable only for the precise structures shown in the drawings, but should be construed as conforming to and supporting the following claims, which have a full and fair scope of the invention.

Claims

1. A catheter, comprising: An elongated catheter body extending along a longitudinal axis, the elongated catheter body having a proximal end and a distal end; A flexible wire assembly, the flexible wire assembly being positioned at the distal end of the elongated conduit body and formed of a shape memory material, the flexible wire assembly having multiple flexible wires, each flexible wire having a proximal end and a distal end, and wherein at least one of the multiple flexible wires has a variable cross-section; Multiple ridges formed by the aforementioned flexible wires; and Multiple electrodes and cables are attached to each ridge; The flexible wire assembly includes a brush-shaped flexible wire assembly, wherein the distal end of each flexible wire is not attached to an adjacent flexible wire; The plurality of flexible lines include a first flexible line positioned close to the center line and having a first width, and a second flexible line positioned further from the center line than the first flexible line and having a second width, wherein the second width is greater than the first width.

2. The catheter of claim 1, wherein the distal ends of the plurality of flexible wires are joined at a distal hub to form a basket-shaped multi-electrode device.

3. The catheter of claim 2, wherein the at least one flexible wire has a variable thickness, wherein the middle portion of the at least one flexible wire has a first thickness and the proximal portion of the at least one flexible wire has a second thickness, wherein the second thickness is greater than the first thickness.

4. The catheter of claim 3, wherein the at least one flexible wire has a distal portion, the distal portion having a third thickness, wherein the third thickness is greater than the first thickness.

5. The catheter of claim 4, wherein the second thickness is equal to the third thickness, wherein the thickness of the at least one flexible wire tapers from the distal portion to the intermediate portion; and wherein the thickness of the at least one flexible wire tapers from the proximal portion to the intermediate portion.

6. The catheter of claim 4, wherein the at least one flexible wire has a constant width from the proximal portion to the distal portion.

7. The catheter of claim 4, wherein the at least one flexible wire has a width that tapers from the proximal portion to the intermediate portion, and wherein the width tapers from the distal portion to the intermediate portion.

8. The catheter according to claim 1, wherein the plurality of flexible wires includes a third flexible wire positioned further from the centerline than the second flexible wire and having a third width, wherein the third width is greater than the second width.

9. The catheter of claim 1, wherein the at least one flexible wire includes a thickness, wherein the thickness is a constant thickness along the length of the at least one flexible wire.

10. The catheter of claim 1, wherein the at least one flexible wire includes a variable thickness, wherein the variable thickness tapers from a first thickness at a proximal portion of the at least one flexible wire to a second thickness at a distal portion of the at least one flexible wire.

11. The conduit according to claim 1, wherein the shape memory material comprises a nickel-titanium alloy.

12. A method of forming a catheter, comprising: Forming the main body of the elongated catheter; A flexible wire assembly is formed from a shape memory material, the flexible wire assembly having multiple flexible wires, wherein the multiple flexible wires have a variable cross-section; The flexible wire assembly is heated to heat-set the flexible wire assembly; Multiple electrodes and cables are connected to each of the multiple flexible wires to form a multi-electrode assembly; as well as The multi-electrode assembly is connected to the distal end of the elongated catheter body; The multi-electrode assembly is a brush electrode assembly; The plurality of flexible lines include a first flexible line positioned close to the center line and having a first width, and a second flexible line positioned further from the center line than the first flexible line and having a second width; wherein the second width is greater than the first width.

13. The method of claim 12, wherein the plurality of flexible lines includes a third flexible line positioned further from the center line than the second flexible line and having a third width, the third width being greater than the second width.

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