Composite catheter with single-axis sensor and ring electrode and related methods

Abstract

The present invention is entitled "Composite Catheter with Uniaxial Sensors and Ring Electrodes and Related Methods." The present invention relates to an electrophysiology catheter comprising a first composite component, an elongated support member having shape memory, and a second composite component, an elongated outer tube. The support member defines a longitudinal axis of the catheter, the support member includes a distal portion having a plurality of uniaxial sensors, and the elongated outer tube is substantially coextensive with the elongated support member. The tube includes a sidewall surrounding an inner lumen, the support member extends through the inner lumen and is joined to the outer tube to form the catheter. The tube includes a conductive wire embedded in the sidewall and ring electrodes on an outer surface of the sidewall, each ring electrode being in conductive contact with a corresponding conductive wire.

Description

Technical Field

[0001] The present invention relates to a catheter, in particular to an electrophysiological catheter with a position sensor and an electrical sensor. Background Art

[0002] Electrode catheters have been commonly used in medical practice for many years. They are used to stimulate and map electrical activity in the heart, as well as to ablate sites of abnormal electrical activity. Atrial fibrillation is a common sustained cardiac arrhythmia and a leading cause of stroke. The condition is perpetuated by reentrant wavelets that propagate in an abnormal atrial tissue matrix. Various methods have been developed to interrupt the wavelets, including surgical or catheter-mediated atrial cuts. Before the condition can be treated, the location of the wavelets must first be determined. Various techniques have been proposed for making such a determination, including the use of a catheter with a mapping assembly adapted to measure activity within a pulmonary vein, coronary sinus, or other tubular structure about the inner periphery of the structure. One such mapping assembly has a distal "lasso" structure comprising a generally circular main region generally transverse to and distal to the catheter body, wherein the tubular structure comprises a non-conductive cover over at least the main region of the mapping assembly. A support member comprising shape memory is disposed within at least the circular main region of the mapping assembly. The generally circular main area of ​​the mapping assembly carries a plurality of electrode pairs, each pair comprising two ring electrodes.

[0003] More recently, balloon catheters have been used to ablate pulmonary vein ostia. A balloon with electrodes on its outer surface is advanced into the left atrium, where it is inflated and positioned to nest within the ostia, making circumferential tissue contact around the ostia. However, depending on the size of the balloon and the ostia, the balloon can become dislodged from the ostia during the ablation procedure.

[0004] Conventional methods of assembling catheters, particularly those with sensing components such as ring electrodes and position sensors, can be labor intensive. Furthermore, such components are often susceptible to damage and breakage during assembly.

[0005] Applicants have recognized a need for a catheter having a distal "lasso" assembly that can serve as a guidewire and support a balloon nested within an opening, while also being capable of sensing electrical signals from tissue in the tubular region of the opening and providing position signals for 3-D mapping. Applicants have also recognized a need for a method of constructing or assembling a catheter that provides composite components that are easily assembled. Summary of the Invention

[0006] In some embodiments, an electrophysiology catheter includes an elongated support member having shape memory and defining a longitudinal axis of the catheter, the support member including a distal portion constructed to have a generally circular portion generally transverse to the longitudinal axis; a uniaxial sensor located on the generally circular portion; and an elongated outer tube generally coextensive with the support member, the tube including a side wall surrounding an inner cavity, the support member extending through the inner cavity, the tube including a conductive wire embedded in the side wall and an annular electrode on an outer surface of the side wall.

[0007] In some embodiments, the elongated support member comprises a nitinol wire.

[0008] In some embodiments, the generally circular portion is configured for circumferential contact with tissue in the tubular region.

[0009] In some embodiments, the support member includes a linear portion located proximal to the generally circular portion and configured to support a balloon of a second catheter in contact with an opening of a pulmonary vein.

[0010] In some embodiments, the support member includes a generally linear portion proximal to the generally circular portion, and the generally linear portion is configured to support a balloon of a second catheter to contact an opening of a pulmonary vein while the generally circular portion is in circumferential contact with tissue in the pulmonary vein.

[0011] In some embodiments, the ring electrodes on the outer tube include electrically conductive contacts with embedded conductive wires.

[0012] In some embodiments, the outer tube includes a groove in which the ring electrode includes an electrically conductive contact with the conductive wire.

[0013] In some embodiments, an electrophysiology catheter comprises an elongated support member having shape memory and defining a longitudinal axis of the catheter, the support member comprising a distal portion having a plurality of uniaxial sensors; and an elongated outer tube substantially coextensive with the elongated support member, the tube comprising a sidewall surrounding an inner cavity, the support member extending through the inner cavity, the tube comprising a conductive wire embedded in the sidewall and an annular electrode on an outer surface of the sidewall, each annular electrode being in conductive contact with a corresponding conductive wire.

[0014] In some embodiments, the distal portion includes a generally circular portion transverse to the longitudinal axis.

[0015] In some embodiments, the elongated support member comprises a nitinol wire.

[0016] In some embodiments, a method of constructing a catheter includes providing an elongated support member having shape memory and a first length, the elongated support member defining a longitudinal axis of the catheter, the support member comprising a uniaxial sensor; providing an elongated outer tube having a second length coextensive with the first length, the tube comprising a sidewall surrounding an inner cavity, the support member extending through the inner cavity, the tube comprising a conductive wire embedded in the sidewall and an annular electrode on an outer surface of the sidewall; and inserting the elongated support member through the inner cavity of the outer tube.

[0017] In some embodiments, a method of constructing a catheter includes providing an elongated support member having shape memory and a first length as a first composite component, the elongated support member defining a longitudinal axis of the catheter, the support member including a distal portion, the distal portion being constructed to have a generally circular portion generally transverse to the longitudinal axis, the generally circular portion including a uniaxial sensor; providing an elongated outer tube having a second length coextensive with the first length as a second composite component, the tube including a side wall surrounding an inner cavity, the support member extending through the inner cavity, the tube including a conductive wire embedded in the side wall and an annular electrode on an outer surface of the side wall; and inserting the elongated support member through the inner cavity of the outer tube when assembling the first composite component and the second composite component.

[0018] In some embodiments, providing the elongated support member includes forming the uniaxial sensor as a wire coil at a location on the generally circular portion; and wrapping a wire connected to the wire coil around the generally circular portion proximal to the location.

[0019] In some embodiments, providing the elongated support member includes expanding the wire connected to the wire coil prior to securing the wire to the curved tubular portion proximal to the generally circular portion of the elongated support member.

[0020] In some embodiments, the guide wire is secured to an inner surface of the curved tube portion.

[0021] In some embodiments, providing the elongated outer tube includes extruding the sidewall, wherein the conductive wire is braided into the sidewall.

[0022] In some embodiments, providing the elongated outer tube includes removing a portion of the sidewall to expose the conductive wire and forming a ring electrode in conductive contact with the exposed conductive wire.

[0023] In some embodiments, forming the ring electrode includes applying a conductive epoxy, including applying the conductive epoxy to a tape area on the outer surface of the outer tube or mounting a conductive tape on the outer tube.

[0024] In some embodiments, the generally circular portion has a length spanning at least 360 degrees.

[0025] In some embodiments, the generally circular portion has a length spanning approximately 450 degrees.

[0026] In some embodiments, the center of the generally circular portion is offset from the longitudinal axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and other features and advantages of the present invention will be better understood by referring to the following detailed description when considered in conjunction with the accompanying drawings. It should be understood that selected structures and features are not shown in some of the drawings in order to provide a better view of the remaining structures and features.

[0028] Figure 1 is a perspective view of a catheter of the present disclosure supporting a balloon catheter according to one embodiment.

[0029] Figure 2 An end perspective view of an assembled preformed support member of a distal "lasso" assembly according to one embodiment.

[0030] Figure 3 A side perspective view of the distal "lasso" assembly positioned in a pulmonary vein while supporting a balloon nested in the opening of the pulmonary vein.

[0031] Figure 4 is a side cross-sectional view of a distal assembly including an elbow segment according to one embodiment.

[0032] Figure 5A Taken along line AA Figure 4 End cross-sectional view of the distal assembly.

[0033] Figure 5B Taken along line BB Figure 4 End cross-sectional view of the distal assembly.

[0034] Figure 6 is a side cross-sectional view of a distal assembly including a generally circular segment according to one embodiment. DETAILED DESCRIPTION

[0035] The following detailed description should be read in conjunction with the accompanying drawings, in which the same elements are numbered the same in different drawings. The accompanying drawings (not necessarily drawn to scale) illustrate selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention by way of example and not by way of limitation. This description will clearly enable those skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is currently believed to be the best mode of carrying out the invention.

[0036] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows the part or collection of elements to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of ±20% of the value of the recited value, for example, "about 90%" can refer to a range of values ​​from 71% to 99%. In addition, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject and are not intended to limit the systems or methods to human use, although use of the subject invention in human patients represents a preferred embodiment.

[0037] refer to Figure 1 and Figure 2Embodiments disclosed herein include a catheter 10 configured for use with a balloon catheter 100, comprising an elongated support shaft 12 and a 3-D distal or "lasso" assembly 15. Distal assembly 15 carries one or more uniaxial sensors ("SAS") 13 configured to generate a signal indicative of the position of distal assembly 15 in response to an external magnetic field generator (not shown), and one or more ring electrodes 11 configured to sense electrical signals from tissue. Distal assembly 15 includes a preformed support member 16 having a shape memory, such as a nitinol wire, that provides the 3-D or annular configuration of distal assembly 15. In this regard, it should be understood that when describing distal assembly 15, shape memory elongated support member 16 includes portions that impart shape to corresponding segments of distal assembly 15, including a curved portion 16C corresponding to curved segment 15C of distal assembly 15 and a curved portion 16E located proximal to curved portion 16C corresponding to curved segment 15E of distal assembly 15. In some embodiments, the curved (e.g., circular, spiral, or annular, all terms used interchangeably herein) portion 16C of the support member 16 is generally transverse to the shaft 12, which defines the longitudinal axis L of the catheter, and the curved portion 16C has a curved arc or length that spans at least 360 degrees (if not approximately 450 degrees) with the distal overlapping tail portion 16T. Furthermore, the curved portion 16C is configured relative to the shaft 12 such that the longitudinal axis L defined by the shaft 12 intersects the curved portion 16C and is offset from approximately the center of the circle defined by the curved portion 16C.

[0038] The elongated support shaft 12 of the catheter has a less flexible proximal portion 12P and a more flexible distal portion 12D. The shaft 12 is configured to pass through the lumen of the balloon catheter 14 and appropriately support the balloon 140 in the opening 110 of the pulmonary vein 130, as shown in FIG. Figure 3 , wherein the distal lasso assembly 15 extends into the pulmonary vein to circumferentially contact the tubular tissue of the pulmonary vein. Advantageously, the proximal portion 12P of the shaft is constructed to have sufficient rigidity to transmit axial thrust and torque applied by a user, for example, by manipulating the connector handle 27 ( Figure 1 ) and a torque device 17 ( Figure 1 ), while the distal portion 12D of the shaft is constructed to be sufficiently flexible to accommodate the indirect approach angle between the distal lasso assembly 15 and the opening 110 in which the supported balloon 140 is located.

[0039] In some embodiments, as Figure 1 and Figure 2As shown, the shape memory support member 16 of the distal assembly 15 has an elongated form having a length sufficient to extend through the entirety of the distal assembly 15 and the combined shaft 12. As such, the elongated support member 16 includes the following parts:

[0040] (i) a longer, generally linear proximal portion 16P having a first diameter D1 and spanning the length of the proximal portion 12P of the shaft 12;

[0041] (ii) a shorter, generally linear distal portion 16D having a second diameter D2 and spanning the length of the distal portion 12D of the shaft 12;

[0042] (iii) a distal curved portion 16C having a third diameter D3 and spanning the curved distal portion 15C of the distal assembly 15; and

[0043] (iv) a relatively short elbow portion 16E having a transition diameter DT in the range of D2 to D3 and extending across the elbow section 15E between the generally linear distal portion 16D and the distal curved portion 16C of the support member 16;

[0044] Wherein diameter D1>diameter D2>diameter D3, so that the proximal portion 16P has the least flexibility, the distal portion 16D has greater flexibility, and the distal curved portion 16C has the greatest flexibility. In some embodiments, diameter D1 is approximately 0.030 inches, diameter D2 is approximately 0.014 inches to 0.018 inches, and diameter D3 is approximately 0.011 inches. Between the proximal portion 16P and the distal portion 16D, the diameter of the wire 16 can be stepped or gradually transitioned between diameters D1 and D2, as needed or appropriate. Between the distal portion 16D and the curved portion 16C, the elbow portion 16E is configured to gradually transition between diameters D2 and D3. In some embodiments, the gradual transition between diameters D2 and D3 occurs in a span of approximately 2 mm in the elbow portion 16E. The length of the proximal portion 16P of the support member 16 is not critical. However, in some embodiments, the length of distal portion 16D is at least the longitudinal length of balloon 140 so that it can accommodate the balloon when supporting the balloon. In some embodiments, the length of shaft 12 is about 2 meters, with the length of distal portion 12D (which has greater flexibility than proximal portion 12P) being between about 6 cm and 8 cm.

[0045] refer to Figure 2 and Figure 4The distal curved portion 16C of the shape memory support member 16 carries one or more SASs. It should be understood that each SAS 13 has a corresponding wire coil sensor 50 and a cable 20, wherein the wire coil sensor 50 is wrapped around a selected location on the distal curved portion 16C, and the cable 20 includes a pair of dedicated wires 21, 21', which are enclosed in an insulating sheath 22 that is substantially coextensive with the wires 21, 21' along with a shielding fiber 23. To simplify the description provided herein, the wires 21, 21' of all SASs 13 carried on the distal assembly 15 are shown herein as passing through a common insulating sheath 22 with a common shielding fiber 23, thereby forming a single cable 20 for all SASs 13.

[0046] exist Figure 2 In the illustrated embodiment, the distal assembly 15 carries three SASs, namely a proximal SAS 13A, a middle SAS 13B, and a distal SAS 13C, including three wire coils 50A, 50B, and 50C, respectively referred to herein as the proximal coil, the middle coil, and the distal coil, arranged in equiangular positions around the curved portion 16C at, for example, approximately 0 degrees, 120 degrees, and 240 degrees. The wire coil 50 of each SAS is connected to a pair of dedicated wires 21 and 21', wherein the wire 21 is connected to the distal end of the wire coil 50 and the wire 21' is connected to the proximal end of the wire coil 50. Thus, in the illustrated embodiment, the distal coil 50C ( Figure 6 1C and 21C′, intermediate coil 50B is connected to wire pair 21C and 21C′, and proximal coil 50A is connected to wire pair 21A and 21A′. To assemble SAS 13A, SAS 13B, and SAS 13C on curved portion 16C of preformed support member 16, in some embodiments, a method of manufacturing or assembling a preformed support member having a SAS includes: (i) winding wire coil 50C around preformed support member 16 at position 240 degrees to form SAS 13C, (ii) connecting wire pairs 21C and 21C′ to the distal end and proximal end of wire coil 50C, respectively, and (iii) winding wire pairs 21C and 21C′ around curved portion 16C in a proximal direction. Different winding methods can be used to relieve strain during use of the catheter to prevent wire breakage.

[0047] The assembly method also includes: (iv) winding the wire pairs 21C and 21C′ at a position of 120 degrees, (v) winding the wire coil 50B over the wound wire pairs 21C and 21C′ to form the SAS 13B, (vi) connecting the wire pairs 21B and 21B′ to the distal end and the proximal end of the coil 50B, respectively, and (vi) winding the wire pairs 21C and 21C′ and 21B and 21B′ around the curved portion 16D in the proximal direction.

[0048] The assembly method further includes: (vii) wrapping wire pairs 21C and 21C′ and 21B and 21B′ at position 0 degrees, (viii) wrapping wire coil 50A over the wrapped wire pairs 21C and 21C′ and 21B and 21B′ to form SAS 13A, (ix) connecting wire pairs 21A and 21A′ to the distal and proximal ends of coil 50A, respectively, and (x) wrapping wire pairs 21C and 21C′, 21B and 21B′, and 21A and 21A′ in a proximal direction around bend 16C. It should be understood that one or more heat shrink sleeves may be positioned over the wrapped wire pairs between the formed SAS and an adjacent SAS.

[0049] It should also be understood that the order of the above-described actions or the direction of winding (e.g., from distal to proximal or from proximal to distal) can be changed as needed or appropriate, and heat shrink tubing can be placed over each SAS, wire coil, or the wound wire pair below the wire coil as needed or appropriate. In any case, the distal SAS 13C includes a wire coil 50C having a distal end connected to wire 21C and a proximal end connected to wire 21C′, the intermediate SAS 13B includes a wire coil 50B having a distal end connected to wire 21B and a proximal end connected to wire 21B′, wherein wire coil 50B is wound over wires 21C and 21C′, and the proximal SAS 13A includes a wire coil 50A having a distal end connected to wire 21A and a proximal end connected to wire 21A′, wherein wire coil 50A is wound over wires 21C and 21C′ and 21B and 21B′.

[0050] At the elbow portion 16E, the cable 20 housing the wire pairs 21 (e.g., 21A, 21A′, 21B, 21B′, 21C, and 21C′) is advantageously positioned on the inner surface 52 (inwardly facing the curvature) of the elbow portion 16E to minimize the outer diameter of the distal assembly 15 in this area, as shown. Figure 4 、 Figure 5A and Figure 5BIn this regard, the distal end of the insulating jacket 22 of the cable 20 and the shielding fibers 23 therein are cut or otherwise terminated proximal to the elbow portion 16E, thereby exposing the plurality of conductor pairs 21. Furthermore, all of the conductors 21 are spread or fanned out, placed against the inner surface 52, and secured by the adhesive 37 ( Figure 5B ) to minimize the circumferential size and profile of the distal assembly 15 at its elbow portion 15E. The distal end portion of the shielding fiber 23 can be wrapped around the wire 21 and the preformed support member 16 ( Figure 4 ) to encircle them, thereby forming a tighter contour around the preformed support member 16. The heat shrink tubing 38 can extend over the cables 20 and shielding fibers 23 proximal to the elbow portion 16E, as well as over the exposed conductors 21 and security fibers 25 in the elbow portion 16E. The proximal and terminal ends of the heat shrink tubing can be located anywhere along the support member 16, as desired or appropriate.

[0051] Thus, a method of assembling a preformed support member 16 having a SAS includes: (i) preparing a cable 20 for attachment to an elbow portion 16E; and (ii) attaching the prepared cable to the elbow portion, wherein preparing the cable includes: (a) cutting or terminating a distal end of the outer insulating jacket 22 substantially proximal to the elbow portion; (b) exposing the wires 21 in the cable; and (c) spreading or fanning out the exposed wires 21, and wherein securing the prepared cable includes: (a) placing the fanned-out exposed wires on the inner surface 52 of the elbow portion; (b) applying an adhesive to the fanned-out exposed wires 21 on the inner surface of the elbow portion; and (c) covering the attached exposed wires and at least the distal portion of the insulating jacket 22 with heat shrink tubing. Preparing the cable may also include cutting or terminating a distal end of the shielding fiber 23 and wrapping the distal end around the exposed wires 21 and the preformed support member 16. Securing the prepared cable may also include covering a plurality of safety strands 25 (e.g., VECTRAN strands) with proximal ends anchored to the shaft 12 and having a length coextensive with the wires 21 beneath the heat shrink tubing 38 to tether the distal assembly 15 to the shaft 12 as a safety measure to prevent detachment of the distal assembly 15. The distal ends of the safety strands 25 may be anchored to the distal end of the preformed support member 16. A description of a suitable SAS is provided in U.S. Patent No. 8,792,962, the entire contents of which are hereby incorporated by reference.

[0052] As previously mentioned, the distal assembly 15 carries not only one or more SAS 13, but also one or more ring electrodes 11. Figure 6As shown, distal assembly 15 includes an outer braided tube 40 having ring electrodes 11 and conductive leads 41. Although tube 40 has an inner lumen 39, conductive leads 41 are embedded in sidewalls 42 as part of the extrusion manufacturing process of tube 40, as will be understood by one of ordinary skill in the art. In some embodiments, outer braided tube 40 covers the entire length of preformed support member 16, including proximal portion 16P, distal portion 16D, elbow portion 16E, and curved portion 16C. In the portion of braided tube 40 covering curved portion 16C, ring electrodes 11 carried thereon are formed by selectively removing (e.g., laser cutting) outer sidewall 42, thereby forming grooves 44 at predetermined locations to expose selected individual leads 41. Conductive epoxy 43, such as platinum or gold, is then applied to fill grooves 44 and also around the exterior of sidewall 42 along the circumference of the grooves to form a corresponding ring electrode 11 at each predetermined location. Extruding tube 40 with conductive leads 41 can be accomplished using a conventional wire extruder. The braided wires 41 embedded in the sidewall 42 of the tube 40 can extend distally of their respective ring electrodes without any adverse effect on the function of the ring electrodes. It should be understood that the ring electrodes 11 can also be formed using conductive tape that is mounted on the tube 40 to circumferentially surround the tube at each groove 44. Therefore, a method of constructing an outer tube 40 with ring electrodes 11 and embedded lead wires 41 includes: (i) extruding a tube 40 with the wires 41 embedded in the sidewall 42, wherein the tube has an outer surface and an inner surface defining an inner lumen; (ii) removing a portion of the sidewall from the outer surface to expose the wires 41 within the grooves; (iii) forming the ring electrodes around the outer surface, including applying a conductive epoxy to fill the grooves and a corresponding circumferential tape around the grooves to form the ring electrodes 11, or mounting the conductive tape on the tube at the locations of the grooves.

[0053] After the outer tube 40 with the ring electrodes 11 and embedded wires 41 has been constructed, the outer tube 40 can be slid onto the assembled distal assembly 15. In some embodiments, an assembly method includes: (i) the above-described method for manufacturing or constructing the outer tube 40 with the ring electrodes 11 and embedded wires 41; (ii) the above-described method for assembling the preformed support structure 16 with the SAS 13; and (iii) installing the constructed outer tube 40 onto the preformed support structure 16 with the SAS 13. Installation can be accomplished by inserting the assembled preformed support structure 16 into the lumen 39 of the constructed outer tube 40. This simplifies the construction of the catheter 10 by separating the outer tube 40, which provides the ring electrodes, from the underlying support structure 16, which carries the SAS. The distal ends of the outer tube 40 and support structure 16 can be collectively plugged and sealed with a sealant ball, such as polyurethane, to form the atraumatic, spherical distal end of the catheter 10.

[0054] At the proximal end of the outer tube 40, which terminates near or in the connector handle 27, the proximal portion of the wire 41 can be exposed from the tube 40 by selectively removing the side wall 42 for connection to appropriate electrical terminals in the connector handle 27 when transmitting the sensed electrical signals to an electrophysiology workstation for processing, as is known in the art. The cable 20 (including the wire pairs 21, 21' for each SAS carried on the distal assembly 15) extends through the lumen 39 of the outer tube 40, coextensive with the distal portion 16D and the proximal portion 16P of the support member 16, through the shaft 12 of the catheter and into the connector handle 27 to transmit the position signals to the electrophysiology workstation for processing, as is known in the art.

[0055] In use, catheter 10 is advanced into and through lumen 120 of balloon catheter 100, where lumen 120 extends through the balloon catheter's shaft 130 and balloon 140 itself. To advance distal assembly 15, it is straightened so that curved portion 15C enters lumen 120 first, followed by curved portion 15E, and so on. Distal assembly 15 is advanced relative to the balloon catheter until it passes through the distal end of the balloon catheter, at which point distal assembly 15 freely assumes a 3-D shape within the patient's left atrium, following the preformed shape memory support member 16 beneath it. Catheter 10 is then manipulated to insert distal assembly 15 into a pulmonary vein, with ring electrode 11 contacting tissue along the inner circumference of the tubular region of the pulmonary vein. Using shaft 12 (and particularly distal portion 12D) as a guidewire, balloon catheter 100 is then advanced toward the opening of the pulmonary vein until the distal surface of the balloon contacts the opening. The shaft 12 of the catheter 10 has a less flexible proximal portion 12P to serve as a guidewire for the balloon catheter 100, a more flexible distal portion 12D to allow flexure if the angle of approach of the distal assembly 15 is not aligned with the center of the opening, and sufficient rigidity to properly support the balloon thereon. One or more SAS 13 in the distal assembly 15 respond to an external magnetic field generator, typically located below the patient's bed, to provide position signals, and ring electrodes 11 carried on the distal assembly 15 sense electrical signals from the pulmonary vein tissue, including electrical signals to assess whether PV isolation has been achieved through the ablation opening or tissue adjacent to the opening.

[0056] The foregoing description has been presented with reference to the presently preferred embodiments of the invention. Those skilled in the art to which the invention pertains will appreciate that changes and modifications may be made to the structures described without intentionally departing from the principles, spirit and scope of the invention. Any feature or structure disclosed in one embodiment may be incorporated as needed or appropriate to replace or supplement other features of any other embodiment. It should be understood that the features of the invention may be applied to increase the linear motion of a pull wire, retraction wire, or any other object in a medical device that requires insertion, removal or tensioning, including the disclosed electrophysiology catheter. As will be understood by those of ordinary skill in the art, the accompanying drawings are not necessarily drawn to scale. Therefore, the specific embodiments described above should not be interpreted as being suitable only for the precise structures described and shown in the accompanying drawings, but should be interpreted as being consistent with and supporting the following claims, which have the full and fair scope of the invention.

Claims

1. An electrophysiological catheter, comprising: an elongated support member having shape memory and defining a longitudinal axis of the catheter, the support member including a distal portion configured with a generally circular portion generally transverse to the longitudinal axis and a curved portion proximal to the generally circular portion; a single-axis sensor positioned on the generally circular portion, the single-axis sensor comprising a wire coil sensor and a cable, wherein the wire coil sensor is wrapped around the generally circular portion, wherein the cable comprises a first wire and a second wire; an elongated outer tube generally coextensive with the support member, the elongated outer tube comprising a sidewall surrounding an inner lumen through which the support member extends, the elongated outer tube comprising a conductive wire embedded in the sidewall and a ring electrode on an outer surface of the sidewall; and An insulating sheath encapsulates the first and second wires, wherein a distal end of the insulating sheath is terminated proximal to the elbow portion such that the first and second wires fan out and are secured to an inner surface of the elbow portion.

2. The catheter of claim 1, wherein the elongated support member comprises a nitinol wire. 3 . The catheter of claim 1 , wherein the generally circular portion is configured for circumferential contact with tissue in the tubular region.

4. The catheter of claim 1, wherein the support member includes a linear portion located proximal to the generally circular portion and configured to support a balloon of a second catheter for contact with an opening of a pulmonary vein.

5. A catheter according to claim 1, wherein the support member includes a generally linear portion located proximal to the generally circular portion, and the generally linear portion is configured to support a balloon of a second catheter to contact the opening of a pulmonary vein while the generally circular portion is in circumferential contact with tissue in the pulmonary vein.

6. The catheter of claim 1, wherein the ring electrodes on the outer tube include electrically conductive contacts with embedded conductive wires.

7. The catheter of claim 1, wherein the outer tube includes a groove in which the ring electrode includes an electrically conductive contact with the conductive wire.

8. A method of constructing a catheter, comprising: providing an elongated support member having shape memory and a first length, the elongated support member defining a longitudinal axis of the catheter; forming a single-axis sensor as a wire coil sensor at a location on the generally circular portion of the elongated support member, wherein the single-axis sensor further comprises a cable including a first wire and a second wire; wrapping the first and second wires connected to the wire coil around the generally circular portion proximal to the location, wherein an insulating sheath encapsulates the first and second wires; terminating a distal end of the insulating sheath; before securing the first and second wires to the inner surface of the curved portion proximal to the generally circular portion of the elongated support member, expanding the first and second wires connected to the wire coil; providing an elongated outer tube having a second length coextensive with the first length, the elongated outer tube comprising a sidewall surrounding an inner lumen, the support member extending through the inner lumen, the elongated outer tube comprising a conductive wire embedded in the sidewall and a ring electrode on an outer surface of the sidewall; as well as The elongated support member is inserted through the lumen of the outer tube.

9. The method of claim 8, wherein providing the elongated outer tube comprises: The sidewall is extruded, wherein the conductive wire is woven into the sidewall.

10. The method of claim 8, wherein providing the elongated outer tube comprises: A portion of the sidewall is removed to expose the conductive wire and a ring electrode is formed on the outer tube in conductive contact with the exposed conductive wire.

11. The method of claim 10, wherein applying the conductive epoxy comprises: The conductive epoxy is applied to the tape area on the outer surface of the outer tube to form the ring electrode.

12. The method of claim 8, wherein the generally circular portion has a length spanning at least 360 degrees.

13. The method of claim 8, wherein the generally circular portion has a length spanning approximately 450 degrees.

14. The method of claim 8, wherein a center of the generally circular portion is offset from the longitudinal axis.

Images