Catheter including a deflection axis and method of assembling the catheter

Abstract

A catheter shaft comprises a slender body extending from a proximal end to a distal end and comprising a proximal portion and a deflectable distal portion. The distal portion can be selectively deflected in at least one direction by actuating a shaft actuator assembly. The slender body defines at least one lumen extending from the proximal end to the distal end. The catheter shaft also comprises a loop actuation wire, which extends through the at least one lumen and can be operated to selectively adjust the diameter of the electrode loop assembly connected to the distal end of the slender body. The catheter shaft also comprises a first coil and a second coil, the first coil being wound around the loop actuation wire along the proximal portion of the slender body, and the second coil being wound around the loop actuation wire along the distal portion of the slender body. The second coil has a more flexible structure than the first coil.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 928,436, filed on October 31, 2019, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention generally relates to medical devices for use within the human body. More particularly, the present invention relates to catheters including deflection axes and methods of assembling such catheters. Background Art

[0004] Medical devices such as mapping and / or electrophysiological catheters are used for various diagnostic and / or therapeutic medical procedures. In some operations, a catheter is manipulated to pass through the patient's vascular system to reach, for example, the patient's heart, and carry one or more electrodes, which can be used for mapping, ablation, diagnosis and / or performing other functions. Common catheters include a catheter shaft connected to a catheter handle at the proximal end and carrying electrodes at the distal end. The catheter shaft is inserted into the patient's vascular system to deliver the electrodes to a specified location. Once in the specified location, treatment may include radio frequency (RF,) ablation, cryoablation, laser, chemicals, high intensity focused ultrasound, electroporation, etc. It is obvious that this treatment requires precise control of the catheter during operation to the mapping and / or treatment position, operation from the mapping and / or treatment position, and operation at the mapping and / or treatment position, which always depends on the user's technical level. Commonly used catheters include an actuator assembly located on the handle, which is used to manipulate the catheter shaft through the patient's vascular system and position the electrodes at the specified location. The actuator assembly can be used to displace the deflectable portion of the catheter shaft toward at least one direction.

[0005] Some catheters include a loop assembly at the distal end of the catheter shaft. The loop assembly can be adjusted and / or positioned using an actuator assembly on a handle. For example, a loop actuation line can extend through the lumen of the catheter shaft and be connected to the actuator assembly to allow a user to adjust the diameter of the loop assembly. However, operating the actuation line extending through the catheter shaft may cause undesirable displacement of the catheter shaft. Summary of the invention

[0006] On the one hand, the catheter shaft includes a slender body, which extends from the proximal end to the distal end and includes a proximal portion and a deflectable distal portion. The distal portion can actuate the shaft actuator assembly to selectively deflect in at least one direction. The slender body defines at least one lumen extending from the proximal end to the distal end. The catheter shaft also includes a loop actuation line, which extends through the at least one lumen and can be operated to selectively adjust the diameter of the electrode loop assembly connected to the distal end of the slender body. The catheter shaft also includes a first coil and a second coil, the first coil is wound around the loop actuation line along the proximal portion of the slender body, and the second coil is wound around the loop actuation line along the distal portion of the slender body. The second coil has a more flexible structure than the first coil.

[0007] On the other hand, the catheter includes a catheter shaft, which includes an elongated body extending from a proximal end to a distal end and including a proximal portion and a deflectable distal portion. The elongated body defines at least one lumen extending from the proximal end to the distal end. The catheter also includes an electrode loop assembly connected to the distal end of the elongated body and a handle attached to the catheter shaft. The handle includes a loop actuator assembly and a shaft actuator assembly, and the shaft actuator assembly is configured to selectively deflect the deflectable portion of the elongated body in at least one direction. The catheter shaft also includes a loop actuator wire, which is connected to the loop actuator assembly and extends through the at least one lumen. The loop actuator wire is operable to selectively adjust the diameter of the electrode loop assembly by actuating the loop actuator assembly. The catheter shaft also includes a first coil and a second coil, the first coil is wound around the loop actuator wire along the proximal portion of the elongated body, and the second coil is wound around the loop actuator wire along the distal portion of the elongated body. The second coil has a more flexible structure than the first coil.

[0008] On the other hand, a method for assembling a catheter includes providing a catheter shaft, the catheter shaft including an elongated body extending from a proximal end to a distal end. The elongated body includes a proximal portion and a deflectable distal portion. The distal portion can be selectively deflected in at least one direction by actuation of a shaft actuator assembly. The elongated body defines at least one lumen extending from the proximal end to the distal end. The method also includes positioning a loop actuation wire in at least one lumen. The loop actuation wire can be operated to selectively adjust the diameter of an electrode loop assembly connected to the distal end of the elongated body. The method also includes positioning a first coil around the loop actuation wire along the proximal portion of the elongated body and positioning a second coil around the loop actuation wire along the distal portion of the elongated body. The second coil has a more flexible structure than the first coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1is a schematic and block diagram of a system including a catheter for performing one or more diagnostic and / or therapeutic functions.

[0010] Figure 2 is with Figure 1 A perspective view of one embodiment of a catheter for use with a system comprising a catheter handle and a catheter shaft.

[0011] Figure 3 yes Figure 2 A perspective view of a deflectable distal portion of a catheter shaft is shown showing the catheter shaft in different positions.

[0012] Figure 4 yes Figure 2 A perspective view of the electrode collar assembly of the catheter shown.

[0013] Figure 5 yes Figure 4 An end view of the electrode collar assembly is shown.

[0014] Figure 6 yes Figure 2 A cross-sectional view of the deflectable distal portion of the catheter shaft is shown taken along line 6-6.

[0015] Figure 7 yes Figure 2 A cross-sectional view of the proximal portion of the catheter shaft shown in FIG. 7 taken along line 7 - 7 .

[0016] Figure 8 yes Figure 2 A top view of a portion of a catheter shaft is shown in , with the body of the catheter shaft removed to show the actuation wire and the coil positioned around the actuation wire.

[0017] Fig. 9 yes Figure 2 and 8 A partial exploded view of a portion of a catheter shaft is shown in FIG.

[0018] Fig.10 is Figure 2 and 8 A cross-sectional view of a portion of the coil assembly and actuation wire of the catheter shaft is shown.

[0019] Fig.11 is a flow chart illustrating one embodiment of a method of assembling a catheter. DETAILED DESCRIPTION

[0020] The present invention relates to a catheter, which includes a deflectable shaft and a coil positioned in the shaft to support the shaft. For example, the catheter may include a catheter shaft, which includes an elongated body. The elongated body includes a proximal portion connected to a catheter handle and a deflectable distal portion. A loop actuation line extends through at least one lumen in the catheter shaft and is operable to selectively adjust the diameter of an electrode loop assembly connected to the distal end of the elongated body. A first coil is wound around the loop actuation line along the proximal portion. When the distal loop assembly is adjusted using the actuation line extending through the catheter shaft, the configuration of the first coil provides increased resistance for the deformation of the catheter shaft (i.e., the shaft swings up and down (nodding)). For example, the stiffness of the first coil absorbs the force that occurs in the distal loop assembly during the adjustment process, without converting the force into displacement or deformation of the catheter shaft.

[0021] The second coil is wound around the loop actuation line along the distal portion. The second coil has a more flexible structure than the first coil. The flexibility of the second coil allows the full range of motion of the deflectable portion. Thus, when the actuator assembly is used to actuate the distal portion, the second coil helps the distal portion to have a consistent deflection profile. For example, due to the support provided by the second coil for the distal portion of the shaft, the distal portion has improved performance in bidirectional flatness and always moves in the desired plane, without moving in the direction outside the desired plane.

[0022] Therefore, the first coil and the second coil achieve an effective balance of shaft performance parameters. For example, the first coil and the second coil reduce shaft up and down swing during adjustment of the distal loop assembly and provide the desired bidirectional flatness of the deflectable distal portion. Thus, the catheter shaft of the present invention facilitates the surgeon's ability to precisely steer and predictably manipulate the catheter during surgery.

[0023] In addition, in some embodiments, the first coil and the second coil are joined by a flexible connector. The flexible connector realizes an operable connection between the first coil and the second coil and resists the stress caused by the different flexible configurations of the coils. Thus, the flexible connector improves the performance reliability of the catheter by preventing the coils from being disengaged or displaced relative to each other during the operation of the catheter. In addition, the flexible connector can simplify the assembly of the catheter because the flexible connector allows the first coil and the second coil to be positioned in the catheter shaft as a single component.

[0024] In some embodiments, the catheter is a unidirectional catheter as described herein. That is, the catheter shaft deflects in only a single direction. In other embodiments, the catheter is a bidirectional catheter. That is, the catheter shaft can deflect in at least two different directions, for example, in the same or common plane.

[0025] Now refer to the attached drawings, Figure 1An example embodiment of a system 100 is shown for use in performing one or more diagnostic and / or therapeutic functions or for use with tissue 102 of a body 104. In the example embodiment, the tissue 102 includes a heart or cardiac tissue within a human body 104. However, it should be understood that the system 100 may be used in conjunction with a variety of other tissues in both the human body and non-human bodies, and thus the present invention is not intended to be limited to use of the system 100 only in conjunction with cardiac tissue and / or the human body.

[0026] System 100 may include a medical device (eg, catheter 106) and a subsystem 108 for observing, navigating, and / or mapping internal body structures (hereinafter referred to as "observation, navigation, and mapping subsystem 108," "subsystem 108," or "mapping system").

[0027] In this embodiment, the medical device includes a catheter 106, such as an electrophysiology catheter. In other example embodiments, the medical device can take a form other than catheter 106, such as, but not limited to, a cannula or catheter guide or a catheter other than an electrophysiology catheter. For simplicity and illustrative purposes only, the following description will be limited to an embodiment of the system 100 in which the medical device is a catheter (catheter 106).

[0028] The catheter 106 is used to examine, diagnose and / or treat tissue in the body, such as tissue 102. The catheter 106 may include a wire connector 110 or interface, a handle 112, a shaft 114 having a proximal end 116 and a distal end 118 (as used herein, "proximal" refers to the direction toward the end of the catheter 106 at the handle 112 and away from the human body 104, and "distal" refers to the direction away from the handle 112 and toward the end of the catheter 106 introduced into the human body 104) and one or more sensors, such as but not limited to a plurality of electrodes 120 (i.e., 1201, 1202, ..., 1203, 1204, 1205, 1206, 1207, 1208, 1209, 1210, 1211, 1212, 1213, 1214, 1215, 1216, 1217, 1218, 1219, 1220, 1221, 1222, 1223, 1224, 1225, 1226, 1227, 1228, 1229, 1230, 1231, 1232, 1233, 1234, 1235, 1236, 1237, 1238, 1239, 1240, 1241, 1242, 1243, 1244, 1245, 1246, 1247, 1248, 1249, 1250, 1251, 1252, 1253, 125 N ). The distal end 118 of the catheter 106 may include an electrode collar assembly, such as the electrode collar assembly 248 (eg, Figure 2 shown).

[0029] In other embodiments, the catheter 106 may also include other conventional components, such as, but not limited to, steering wires and actuators, irrigation lumens and ports, pressure sensors, contact sensors, temperature sensors, additional electrodes and corresponding conductors or leads and / or ablation elements (e.g., ablation electrodes, high-intensity focused ultrasound ablation elements, etc.).

[0030] The handle 112 provides an operator with a location to hold the catheter 106 and may also provide tools for steering or guiding the shaft 114 within the patient. For example, the handle 112 may include a tool for changing the length of a guidewire that extends through the catheter 106 to the distal end 118 of the shaft 114 to steer the shaft 114. Those skilled in the art will appreciate that the configuration of the handle 112 may vary.

[0031] The connector 110 provides mechanical and electronic connections for one or more wires 122, such as extending from the observation, navigation, and mapping subsystem 108 to one or more sensors mounted on the catheter 106. In other embodiments, the connector 110 also provides mechanical, electronic, and / or fluid connections for wires extending from other components in the system 100, such as an ablation system and a fluid source (when the catheter 106 includes an irrigation catheter). The connector 110 is disposed at the proximal end 116 of the catheter 106.

[0032] In another example embodiment, the catheter 106 may be driven or controlled by a machine. Thus, rather than an operator manipulating a handle to steer or guide the catheter 106 and its shaft 114, the catheter 106 may be manipulated robotically.

[0033] The shaft 114 is typically an elongated, tubular flexible member configured to move within the patient's body. The shaft 114 supports, for example, but not limited to, electrodes 120, associated conductors, and other available electronic devices for signal processing or conditioning. The shaft 114 may also allow for the delivery, transmission, and / or removal of fluids (including irrigation fluids, cryoablative fluids, and body fluids), drugs, and / or surgical tools or instruments. The shaft 114 may be made of conventional materials such as polyurethane and define one or more lumens configured to at least accommodate and / or deliver electrical conductors, fluids, or surgical tools. The shaft 114 may be introduced into the heart tissue 102 through a conventional guide. The shaft 114 may then be turned or guided to a desired position within the heart tissue 102 by a guidewire or other tools known in the art.

[0034] As further described herein, catheter 106 may include one or more support coils ( Figure 1 106) which extend through the shaft 114 to provide support for the shaft 114 during operation of the catheter 106. For example, the first coil can provide support near the proximal end 116 of the shaft 114 to prevent displacement or deformation of the shaft 114 during adjustment of the distal electrode collar assembly. In addition, the second coil can provide support near the distal end 118 of the shaft 114 and allow the desired deflection of the distal end 118 to occur using the actuator assembly.

[0035] The observation, navigation, and mapping subsystem 108 can be used to determine the positions of the electrodes 120 or other sensors. These positions can be projected onto a geometric anatomical model. In some embodiments, the observation, navigation, and mapping subsystem 108 includes a magnetic field-based system. For example, the observation, navigation, and mapping subsystem 108 can include an electric field and a magnetic field-based system, such as the ENSITE PRECISION 3D imaging system commercially available from Abbott Laboratories. TM The system is generally shown in reference to U.S. Patent No. 7,263,397 entitled "Method and Apparatus for Intracardiac Catheter Navigation and Positioning and Mapping," the entire disclosure of which is incorporated herein by reference. In such an embodiment, the distal end 118 may include at least one magnetic field sensor, such as a magnetic coil (not shown). If two or more magnetic field sensors are used, a full six-degree-of-freedom registration of magnetic coordinates and spatial coordinates can be completed without the need to determine orthogonal coordinates by solving registration transformations from various positions and orientations. Further benefits of this configuration may include advanced displacement detection and derived dynamic field scaling because they can be self-contained.

[0036] In other example embodiments, the subsystem 108 may employ systems other than electric field based systems. For example, the subsystem 108 may include a magnetic field based system, such as the CARTO TM The system is generally described with reference to one or more of the following patents: U.S. Patent No. 6,498,944, entitled “In Vivo Measurements,” U.S. Patent No. 6,788,967, entitled “Medical Diagnostic, Processing, and Imaging Systems,” and U.S. Patent No. 6,690,963, entitled “System and Method for Determining the Position and Orientation of an Invasive Medical Device,” the contents of which are incorporated herein by reference in their entirety.

[0037] In another example embodiment, the subsystem 108 may include a magnetic field-based system, such as the GMPS system commercially available from MediGuide, LLC, and generally described with reference to one or more of the following patents: U.S. Patent No. 6,233,476, entitled “Medical Positioning System,” U.S. Patent No. 7,197,354, entitled “System for Determining the Position and Orientation of a Catheter,” and U.S. Patent No. 7,386,339, entitled “Medical Imaging and Navigation System,” the contents of which are incorporated herein by reference in their entirety.

[0038] In yet another embodiment, the subsystem 108 may employ a combination of electric-field-based and magnetic-field-based systems, as generally described in U.S. Patent No. 7,536,256, entitled "Hybrid Magnetic-Based and Impedance-Based Position Sensing," the contents of which are incorporated herein by reference in their entirety. In other example embodiments, the subsystem 108 may include or be used in conjunction with other commonly used systems, such as, but not limited to, systems based on fluoroscopy, computed tomography (CT), and magnetic resonance imaging (MRI).

[0039] Although Figure 1 Not shown, but in some embodiments system 100 may include suitable components to perform electroporation and / or ablation (eg, RF ablation). It should be understood that in these embodiments, the type of ablation energy provided may be varied (eg, cryoablation, ultrasound, etc.).

[0040] Figure 2 Shown to be applicable to Figure 1 An example embodiment of a catheter 200 for use with the system 100 is shown in FIG. As used herein, the term catheter includes, but is not limited to, catheters, cannulas, and similar medical devices. Figure 2 As shown, the catheter 200 includes an elongated, flexible, substantially cylindrical hollow shaft 202 and an ergonomically shaped actuation handle 204. In some embodiments, the catheter 200 may include other components, such as but not limited to steering wires and actuators, irrigation lumens and ports, pressure sensors, contact sensors, temperature sensors, other electrodes and corresponding conductors or wires and / or ablation elements (e.g., ablation electrodes, high-intensity focused ultrasound ablation elements, etc.).

[0041] like Figure 2 As shown, the actuation handle 204 includes a housing 206 extending from a proximal end 208 to a distal end 210 along a longitudinal axis 212. The housing 206 includes an upper grip portion 214 and a lower grip portion 216. The upper grip portion 214 and the lower grip portion 216 define an inner cavity 218 extending longitudinally through the actuation handle 204. In some embodiments, a fluid lumen (not shown) can be positioned in the inner cavity 218 for use in a flushing configuration.

[0042] The shaft 202 has a proximal end 220 and a distal end 222 connected to the actuation handle 204. In some embodiments, the distal end 222 of the shaft 202 is deflectable, and the actuation handle 204 is adapted to control the deflection of the deflectable distal end 222. For example, Figure 3 As shown, the distal end 222 of the shaft 202 can be directed in two opposite directions (e.g., Figure 3 The catheter 200 shown is a bidirectional catheter. In other embodiments, the catheter may be a unidirectional catheter (i.e., the tip can only be deflected in one direction).

[0043] Although a variety of materials can be used to construct shaft 202, it is typically made of polyurethane, nylon or any suitable non-conductive material. Shaft 202 serves as at least a portion of the blood contacting section of catheter 200 and is inserted into a patient's body through a blood vessel using methods and means known in the art.

[0044] The shaft 202 includes an elongated body 224 extending from a proximal end 220 to a distal end 222 and includes a proximal portion 226 and a deflectable distal portion 228. In addition, the elongated body 224 defines at least one lumen 230 extending from the proximal end 220 to the distal end 222 (at Figure 6 and 7 ). Ring actuation wire 232 (in Figure 6 and 7 ) extends through the lumen 230 and is operable, for example, to selectively adjust the diameter of an electrode collar assembly 248 connected to the distal end 222 of the shaft 202.

[0045] See also Figure 4 and 5 , the distal end 222 of the shaft 202 includes an electrode collar assembly 248. The electrode collar assembly 248 includes a plurality of catheter electrodes 252, which can be used for various diagnostic and therapeutic purposes, such as but not limited to cardiac mapping and / or ablation. For example, one or more catheter electrodes 252 can perform a positioning or position sensing function. More specifically, one or more catheter electrodes 252 can be configured as a position sensor, which provides information about the positioning (position and orientation) of the electrode collar assembly 248.

[0046] The diameter of the electrode ring assembly 248 may vary in some embodiments. For example, the diameter 250 of the electrode ring assembly 248 (in Figure 5 ) can be in the expanded (also called open) diameter ( Figure 5 In some embodiments, the diameter 250 can vary between an expanded diameter (shown in Figure 250) and a retracted (also referred to as a closed) diameter (not shown). In an embodiment, the expanded diameter is approximately 27 millimeters (mm) and the retracted diameter is approximately 15 mm. In other embodiments, the diameter 250 can vary between any suitable open and closed diameters. Alternatively, in other embodiments of the present invention, the diameter of the electrode ring assembly 248 is fixed.

[0047] See again Figure 2In at least some embodiments where the diameter is variable, the catheter 200 includes a first actuator 256 to allow an operator to adjust the diameter of the electrode collar assembly 248; that is, an assembly or mechanism that increases or decreases the diameter of the electrode collar assembly 248. Further, in at least some embodiments where the shaft 202 includes a deflectable distal portion 228, the catheter 200 includes a second actuator 258 to allow an operator to selectively deflect the distal portion 228 of the shaft 202. For example, in one embodiment where the distal end 222 forms a loop or lasso, actuation of the first actuator 256 causes the distal end 222 to increase or decrease the diameter of the electrode collar assembly 248, and actuation of the second actuator 258 causes the distal end 222 to deflect in at least one direction. In other embodiments, the first actuator 256 causes the distal end 222 to deflect in at least one direction, and the second actuator 258 causes the distal end 222 to increase or decrease the diameter of the electrode collar assembly 248. This diameter adjustment of the electrode loop assembly 248 can be accomplished at any time during the procedure, and can further be accomplished with or without deflection of the distal end 222 of the catheter 200; that is, any deflection of the distal end 222 is independent of any diameter adjustment of the electrode loop assembly 248 according to the present invention. This independent adjustment can be achieved by using multiple pull wires contained within the catheter 200, such as described in U.S. Patent Application Publication No. 2017 / 0291008 entitled "Mapping Variable Annular Catheter Handle", the contents of which are incorporated herein by reference in their entirety. By having the ability to adjust the diameter of the electrode loop assembly 248 before or during the procedure, the operator is able to more effectively navigate the patient's vasculature as described herein and improve patient outcomes.

[0048] See also Figure 6 and 7 , the first actuator 256 and the second actuator 258 can be connected to the deflectable distal end 222 of the shaft 202 via actuation wires 232, 233. For example, the loop actuation wire 232 can be connected to the first actuator 256, and the shaft actuation wire 233 can be connected to the second actuator 258. The actuation wires 232, 233 can be any of the types of actuation wires known in the prior art, such as but not limited to pull wires or tension wires (i.e., actuation wires that are not suitable for supporting compressive loads) and pull / push or tension / compression wires (i.e., actuation wires that are suitable for supporting compressive loads). In embodiments including pull / push actuation wires, when one actuation wire is placed in tension, the other actuation wire will carry a compressive load. The actuation wires can be formed of super elastic nitinol wire or another suitable material.

[0049] like Figure 6 and 7 As shown, the shaft 202 includes a plurality of lumens 230 defined by an elongated body 224 and extending from a proximal end 220 to a distal end 222. In the illustrated embodiment, the distal portion 228 of the shaft 202 includes four Figure 6The proximal portion 226 of the shaft 202 includes a lumen 230 as shown in FIG. Figure 7 20. The single lumen 230 shown. An electrical conductor 260 and actuation wires 232, 233 extend through the lumen 230. Specifically, the electrical conductor 260 extends from the actuation handle 204 through the lumen 230 to the electrode 252 and magnetic sensor of the electrode collar assembly 248. The shaft actuation wire 233 extends from the second actuator 158 through the separate lumen 230 and is operable to deflect the distal end 222 of the shaft 202 when the second actuator 258 is actuated. In addition, at least one actuation wire 232 extends from the first actuator 256 through the lumen 230 and is operable to adjust the diameter 250 of the electrode collar assembly 248 when the first actuator 256 is actuated.

[0050] See again Figure 2 , wire connectors such as in Figure 1 The wire connector 110 shown in FIG. 1 may be located at the proximal end 208 of the actuation handle 204. The actuation handle 204 may also include a strain relief 254 located at the distal end 210. Figure 4 In the embodiment shown in FIG. 2A , each electrode 252 on the electrode collar assembly 248 can be connected to an electrical conductor 260 (in FIG. 2A ) extending through the shaft 202, the strain relief 254, and the actuation handle 204 to a wire connector. Figure 6 and 7 ). The wire connector is suitable for connecting to a device such as a recording, monitoring or RF ablation device.

[0051] See also Figure 8-10 , the shaft 202 also includes a first coil 234 and a second coil 236. The first coil 234 is wound around the loop actuation wire 232 along the proximal portion 226 of the elongated body 224, and the second coil 236 is wound around the loop actuation wire 232 along the distal portion 228 of the elongated body 224. The first coil 234 and the second coil 236 are configured to provide targeted support for the portions 226, 228 of the elongated body 224 to prevent or prevent the shaft 202 from producing undesirable movement and promote the movement of the shaft 202 along the desired movement path. More specifically, the first coil 234 and the second coil 236 are configured and positioned within the shaft 202 to provide a balance between the controllable deflection of the distal portion 228 and the deformation or deflection of the shaft 202. For example, the second coil 236 provides support for the distal portion 228 of the elongated body 224 and has a more flexible structure than the first coil 234 to allow the distal portion 228 to be selectively deflected. The first coil 234 provides support for the proximal portion 226 of the elongated body 224 and has a stiffer or more rigid construction than the second coil 236 to inhibit or prevent the shaft from rocking up and down when the loop actuation wire 232 is actuated.

[0052] Any suitable process and technology that enables the shaft 202 to function as described herein can be used to impart variable flexibility to the coils of the first coil 234 and the second coil 236. In some embodiments, for example, the first coil 234 and the second coil 236 are composed of separate, spirally wound multiple wires having different stiffness properties. More specifically, the first coil 234 can be composed of a first wire and the second coil 236 can be composed of a second wire, and the second wire has at least one characteristic that is different from the characteristic of the first wire. The at least one characteristic may include, for example, but not limited to, the cross-sectional area of ​​the wire, the inherent (i.e., material-related) stiffness of the wire, the tensile strength of the wire, and combinations thereof. For example, the cross-sectional area of ​​the first wire is greater than the cross-sectional area of ​​the second wire so that the first wire has a greater stiffness than the second wire. Additionally or alternatively, the inherent stiffness of the first wire is greater than the inherent stiffness of the second wire. In addition, the tensile strength of the first wire is greater than the tensile strength of the second wire.

[0053] Applicable processing technology can also be used to give the coil variable flexibility of the first coil 234 and the second coil 236. In some embodiments, for example, the first coil 234 and the second coil 236 are constructed to have different flexibility by changing the initial tension of the coil. The term "initial tension" refers to the initial or inherent rigidity given to the coil due to the coil winding process. For example, the coil is given a desired initial tension by controlling the speed and / or the force applied to the coil as the coil is wound. A "tightly" wound coil will have a greater initial tension than a "loosely" wound coil. In some embodiments, the first coil 234 is wound to have an initial tension greater than the initial tension of the second coil 236.

[0054] The first coil 234 and the second coil 236 can be constructed of any suitable coil that allows the shaft 202 to function as described herein. In some embodiments, for example, the first coil 234 and / or the second coil 236 are constructed of wires including, but not limited to, metal wires (e.g., stainless steel, nickel titanium alloys, and / or other metals) and polymer-based materials including thermosets and thermoplastic elastomers (e.g., polyethylene, polyurethane, and acrylonitrile-butadiene-styrene copolymers). The wire can have any cross-sectional shape that allows the first and second coils 234 and 236 to function as described herein, for example, including, but not limited to, round wire, square wire, and rectangular wire. In some embodiments, the first coil 234 is constructed of a first wire having at least one dimension that is greater than the dimension of the second wire used to construct the second coil 236. In a specific embodiment, for example, the first wire has a thickness of approximately 0.005 inches (in.) and a width of approximately 0.08 inches, and the second wire has a thickness of approximately 0.003 inches and a width of approximately 0.007 inches.

[0055] As mentioned above, the first coil 234 is configured to resist deformation or displacement of the proximal portion 226 of the shaft 202 when a force is applied to a component extending through the shaft 202, such as the actuation wire 232. In order to maintain or enhance the performance of the first coil 234, the spacing between adjacent coils of the first coil 234 can be controlled or minimized to reduce the movement of adjacent coils of the first coil 234 relative to each other. For example, in some embodiments, the first coil 234 is wound such that the cumulative spacing between adjacent coils or turns of the first coil 234 is less than about 0.020 inches or less than about 0.002 inches.

[0056] In the illustrated embodiment, the length 244 of the first coil 234 is greater than the length 246 of the second coil 236. In some embodiments, the length 244 of the first coil 234 is at least about 20 inches or at least about 40 inches, and the length 246 of the second coil 236 is in the range of about 2.5 inches to about 5.0 inches. Because the first coil 234 is longer than the second coil 236 and extends along a majority (i.e., greater than 50%) of the shaft 202, the first coil 234 and its associated greater stiffness play a greater role in preventing the shaft from bobbing up and down over substantially the entire shaft 202 than the second coil 236.

[0057] In some embodiments, the third coil 251 is positioned between the loop actuation wire 232 and the shaping wire 253 ( Fig. 9 ), to provide additional support to the loop actuation wire 232 and the electrode loop assembly 248. The third coil 251 can be configured to be smaller and more flexible than the first coil 234 and the second coil 236 to allow the third coil 251 to bend and extend through the elbow.

[0058] In some embodiments, the support 237 is disposed on at least a portion of the second coil 236 along at least the length of the proximal portion 226. For example, the support 237 extends along the distal portion of the second coil 236 in the illustrated embodiment. The support 237 is configured to provide additional support for the second coil 236 and the elongated body 224 at the connection with the electrode collar assembly 248. In some embodiments, the support 237 comprises a thermoplastic elastic material.

[0059] The shaft 202 also includes a flexible connector 238 that connects the first coil 234 and the second coil 236 at a connection location 240 and surrounds the connection location 240. The flexible connector 238 is flexible and accommodates the different flexibility of the first coil 234 and the second coil 236. In addition, the material included by the flexible connector 238 is attached to both the first coil 234 and the second coil 236 and maintains the connection between the first coil 234 and the second coil 236 during bending of the first coil 234 and / or the second coil 236. In some embodiments, the flexible connector 238 includes a thermoplastic resin.

[0060] In other embodiments, the first coil 234 and the second coil 236 can be connected by any means that allows the shaft 202 to function as described above. For example, but not limited to, in some embodiments, the first coil 234 and the second coil 236 are joined by bonding, welding, soldering joints, mechanical fasteners and / or combinations thereof. In the illustrated embodiment, the end of the first coil 234 is joined to the end of the second coil 236 so that the first coil 234 and the second coil 236 do not overlap. In an alternative embodiment, the connecting portions of the first coil 234 and the second coil 236 partially overlap each other. In other embodiments, the first coil 234 and the second coil 236 are constructed from a single wire as a single continuous coil with different properties along its length. For example, in some embodiments, the first coil 234 includes a first section of a continuous coil wound with a first initial tension, and the second coil 236 includes a second section of a continuous coil wound with a second initial tension.

[0061] See again Figure 6 and 7 , the first coil 234 and the second coil 236 are positioned within the lumen 230 and around the actuation wire 232. In the illustrated embodiment, the actuation wire 232 and the lumen 230 are radially offset relative to the longitudinal axis of the shaft 202. Therefore, when the actuation wire 232 is operated, the shaft 202 may be subjected to an eccentric axial force that would cause the shaft to wobble up and down without the first coil 234 and the second coil 236. The first coil 234 is configured to react to the eccentric force and prevent the shaft from wobble up and down when the actuation wire 232 is operated, for example because the first coil 234 has a relatively rigid construction and extends through the proximal portion 226 of the shaft 202 along the actuation wire 232.

[0062] The first coil 234 and the second coil 236 respectively define a middle cavity 290 configured to receive the actuation wire 232. For example, the diameter of each middle cavity 290 is larger than the diameter of the actuation wire 232. The size of the middle cavity 290 is suitable for providing space for the actuation wire 232 to be spaced apart from the coils of the first coil 234 and the second coil 236 and preventing the first coil 234 and the second coil 236 from interfering with the operation of the actuation wire 232.

[0063] In some embodiments, a shell or sleeve is positioned over the actuation wire 232, the first coil 234, and / or the second coil 236. For example, in the illustrated embodiment, the shell 292 extends around the first coil 234 and the second coil 236 to prevent interference between the first coil 234 and the second coil 236 and other components within the shaft 202. The shell 292 may include an elastic polymer material. The shell 292 is configured to maintain the orientation of the first coil 234 and the second coil 236 within the lumen 230. In addition, the shell 292 accommodates first coils 234 and second coils 236 of different diameters. For example, the shell 292 has a greater thickness along the second coil 236 than along the first coil 234 because the first coil 234 is wider than the second coil 236 in the illustrated embodiment.

[0064] Fig.11 is a diagram showing an assembled catheter (eg Figure 2 200 shown in FIG. 1 . The method 1100 includes providing a catheter shaft (e.g., shaft 202) at 1102, the catheter shaft including an elongated body (e.g., elongated body 224) extending from a proximal end to a distal end. The elongated body includes a proximal portion (e.g., proximal portion 226) and a deflectable distal portion (e.g., distal portion 228). The distal portion is selectively deflectable in at least one direction by actuating a shaft actuator assembly (e.g., first actuator 256 and second actuator 258). The elongated body defines at least one lumen extending from a proximal end to a distal end.

[0065] Method 1100 also includes positioning a loop actuation wire (e.g., loop actuation wire 232) in at least one lumen at 1104. The loop actuation wire is operable to selectively adjust a diameter of an electrode loop assembly (e.g., electrode loop assembly 248) connected at the distal end of the elongated body.

[0066] Method 1100 also includes 1106 positioning a first coil (e.g., first coil 234) around the loop actuation line along the proximal portion of the elongated body, and 1108 positioning a second coil (e.g., second coil 236) around the loop actuation line along the distal portion of the elongated body. The second coil has a more flexible configuration than the first coil. Therefore, during the operation of the loop actuation line, the first coil provides support for the shaft and resists deformation of the shaft. In addition, the second coil allows selective displacement of the distal portion.

[0067] In some embodiments, the method 1100 includes connecting the first coil and the second coil at a connection point and surrounding the connection point with a flexible connector, such as the flexible connector 238. In other embodiments, the method 1100 includes attaching a catheter handle, such as the catheter handle 204, to a proximal end of the catheter shaft, such as the proximal end 220, and connecting the electrode loop assembly to a distal end of the elongated body, such as the distal end 222.

[0068] Although certain steps of the example methods are numbered, such numbering does not imply that the steps must be performed in the order listed. Therefore, specific steps do not need to be performed in the exact order in which they are presented unless their description specifically requires such order. The steps may be performed in the order listed, or in another order that is applicable.

[0069] Although the embodiments and examples disclosed herein have been described with reference to specific embodiments, it should be understood that these embodiments and examples are merely illustrations of the principles and applications of the present invention. It should therefore be understood that various modifications may be made to the illustrative embodiments and examples, and other structures may be designed without departing from the spirit and scope of the present invention as defined by the claims. Therefore, the present application is intended to cover modifications and variations of these embodiments and their equivalents.

[0070] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

Claims

1. A catheter shaft, comprising: an elongated body extending from a proximal end to a distal end and including a proximal portion and a deflectable distal portion, wherein the distal portion is selectively deflectable in at least one direction by actuating a shaft actuation wire of a shaft actuator assembly, the elongated body defining at least one lumen extending from the proximal end to the distal end; a loop actuation wire extending through the at least one lumen and operable to selectively adjust a diameter of an electrode loop assembly coupled to a distal end of the elongated body; a first coil wound around the loop actuation wire along a proximal portion of the elongated body; and A second coil is wound around the loop actuation wire along a distal portion of the elongated body, wherein the second coil has a more flexible configuration than the first coil, and wherein the second coil defines a lumen that receives only the loop actuation wire.

2. The catheter shaft of claim 1 , wherein the first coil is joined to the second coil at a connection point, wherein the catheter shaft further comprises a flexible connector connecting the first coil to the second coil at the connection point and encapsulating the connection point.

3. The catheter shaft of claim 2, wherein the flexible connector comprises a thermoplastic resin. The catheter shaft of claim 1 , wherein the length of the distal portion is less than the length of the proximal portion.

5. The catheter shaft of claim 1, wherein an initial tension of the first coil is greater than an initial tension of the second coil.

6. The catheter shaft of claim 1, wherein the first coil and the second coil are constructed from a single continuous wire.

7. The catheter shaft of claim 1, wherein the first coil is constructed from a first wire and the second coil is constructed from a second wire.

8. The catheter shaft of claim 7, wherein the first wire has a cross-section that is greater than a cross-section of the second wire.

9. The catheter shaft of claim 7, wherein the first wire is stiffer than the second wire.

10. The catheter shaft of claim 7, wherein the first wire has a greater tensile strength than the second wire.

11. The catheter shaft of claim 1, wherein the cumulative spacing between adjacent coils of the first coil is less than 0.002 inches.

12. The catheter shaft of claim 1, wherein the distal portion is selectively deflectable in a first direction and an opposite second direction by actuating the shaft actuator assembly.

13. A catheter comprising: a catheter shaft comprising an elongated body extending from a proximal end to a distal end and including a proximal portion and a deflectable distal portion, wherein the distal portion is selectively deflectable in at least one direction by actuating a shaft actuation wire of a shaft actuator assembly, the elongated body defining at least one lumen extending from the proximal end to the distal end; an electrode collar assembly connected to the distal end of the elongated body; and a handle attached to the catheter shaft and including a collar actuator assembly and a shaft actuator assembly configured to selectively deflect the deflectable portion of the elongated body in at least one direction; The catheter shaft further comprises: a loop actuation wire connected to the loop actuator assembly and extending through the at least one lumen, the loop actuation wire being operable to selectively adjust a diameter of the electrode loop assembly by actuating the loop actuator assembly; a first coil wound around the loop actuation wire along a proximal portion of the elongated body; and A second coil is wound around the loop actuation wire along a distal portion of the elongated body, wherein the second coil has a more flexible configuration than the first coil, and wherein the second coil defines a lumen that receives only the loop actuation wire.

14. The catheter of claim 13, wherein the first coil is joined to the second coil at a connection point, wherein the catheter shaft further comprises a flexible connector connecting the first coil to the second coil at the connection point and surrounding the connection point. The catheter of claim 13 , wherein the length of the distal portion is less than the length of the proximal portion.

16. The catheter of Claim 13, wherein the distal portion is selectively deflectable in a first direction and an opposite second direction by actuating the shaft actuator assembly.

17. The catheter of claim 13, wherein the first coil and the second coil are constructed from a single continuous wire.

18. The catheter of claim 13, wherein the first coil is constructed from a first wire and the second coil is constructed from a second wire.

19. A method of assembling a catheter, comprising: Providing a catheter shaft including an elongated body extending from a proximal end to a distal end, the elongated body including a proximal portion and a deflectable distal portion, the distal portion being selectively deflectable in at least one direction by actuating a shaft actuation wire of a shaft actuator assembly, the elongated body defining at least one lumen extending from the proximal end to the distal end; positioning a loop actuation wire in at least one lumen, the loop actuation wire operable to selectively adjust a diameter of an electrode loop assembly coupled to a distal end of the elongated body; positioning a first coil around the loop actuation wire along a proximal portion of the elongated body; and A second coil is positioned around the loop actuation wire along a distal portion of the elongated body, wherein the second coil has a more flexible configuration than the first coil, and wherein the second coil defines a lumen that receives only the loop actuation wire.

20. The method of claim 19, further comprising connecting the first coil and the second coil at a connection point, wherein the catheter shaft further comprises a flexible connector connecting the first coil to the second coil at the connection point and surrounding the connection point.

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