Catheter with deformable distal electrode

Abstract

A catheter probe configured to have the ability to present a larger tissue contact area or "footprint" for larger and deeper ablation lesions without increasing the french size of the catheter, particularly its distal segment, includes an elastically deformable electrode configured to adopt a neutral configuration and a tissue contact configuration. The deformable electrode includes a hollow porous tube having a distal portion with a closed distal end and a proximal portion defining an opening to the interior of the tube, wherein the distal tip end is housed in the tube through the opening and the distal segment is generally surrounded by the tube, wherein the proximal portion is attached to the outer surface of the distal segment. In some embodiments, the closed distal end is shaped to have a bulbous portion that is expandable and widened to provide a larger surface contact area.

Description

Technical Field

[0001] This invention relates to electrophysiological (EP) catheters, and more particularly to deformable EP catheters for RF ablation. Background Technology

[0002] Electrode catheters have been widely 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.

[0003] In use, an electrode catheter is inserted into a major vein or artery (e.g., the femoral vein) and then guided to the desired chamber of the heart. In some medical procedures, energy is applied locally to body tissue in a concentrated dose, and it is desirable to cool the treated area to reduce collateral tissue damage. For example, cardiac ablation therapy is used to treat arrhythmias by heating the tissue with radiofrequency (RF) electrical energy to create a non-conductive ablation focus within the myocardium. It has been found that cooling the ablation site reduces tissue charring and thrombosis. Catheters with a flushing distal end are known as part of integrated ablation systems. Typically, the metal catheter tip is energized with RF current to ablate tissue and has multiple flushing orifices distributed around the periphery of the treated site. A pump coupled to the catheter delivers a saline solution to the catheter tip, and the solution flows out through the orifices during this process, thereby cooling the catheter tip and the tissue.

[0004] In certain areas of the heart, such as in the thicker tissue of the ventricles, the formation of transmural ablation foci can be challenging. Deep ablation foci typically require higher RF energy, but higher RF energy can lead to undesirable vapor bursting. Therefore, it is desirable to form deeper ablation foci by increasing the electrode / tissue contact area without increasing the size of the catheter itself.

[0005] Catheters with flexible ends are known. U.S. Patent No. 5,720,719 describes a catheter having a probe end comprising an extensible tube and a flexible tube. U.S. Patent Publication No. 2014 / 0121657 (the disclosure of which is incorporated herein by reference) describes a medical probe having a deformable distal end comprising a flexible porous material. The flexible porous material may include a conductive material. An electrical conductor may be coupled to the flexible porous material to deliver RF energy to the deformable distal end, and RF energy may be delivered to tissue via the deformable distal end to deliver RF energy to tissue. The medical probe may include means for inflating the deformable end, which may include delivering fluid through orifices in the deformable distal end to flush tissue. The means for inflating the deformable distal end may include delivering fluid to generate a mechanical force sufficient to inflate the deformable distal end. When the deformable distal end is pressed against tissue, the contact area between the deformable distal end and the tissue may increase.

[0006] U.S. Patent No. 8,249,685 relates to a device for mapping and / or ablating tissue, the device including a braided conductive member that can be inverted to provide an annular surface. When the distal end of the braided conductive member is retracted into the braided conductive member, the absence of protrusions allows the annular surface to contact a tissue wall such as the heart wall. In an undeployed configuration, the braided conductive member extends longitudinally, and in a deployed configuration, the distal end of the braided conductive member is retracted to invert the braided conductive member.

[0007] The above description is presented as a general overview of the relevant technology in the art and should not be construed as an admission that any information contained therein constitutes prior art for this patent application. Summary of the Invention

[0008] This invention relates to a catheter probe configured to present a larger tissue contact area or "footprint" for larger and deeper ablation foci without increasing the french size of the catheter, particularly its distal segment. In some embodiments, the catheter probe includes a flexible elongating shaft and a distal segment having a distal end and a resiliently deformable electrode configured to employ a neutral and tissue contact configuration. The deformable electrode includes a hollow porous tube having a distal portion and a proximal portion, the distal portion having a closed distal end, and the proximal portion defining an opening to the interior of the tube, wherein the distal end is received within the tube through the opening and the distal segment is substantially surrounded by the tube, wherein the proximal portion is attached to the outer surface of the distal segment. Advantageously, the closed distal end of the tube is spaced apart from the distal end to allow the distal portion to deform and expand to provide a larger tissue contact area.

[0009] In some implementations, the distal portion has a pre-formed spherical configuration.

[0010] In some implementations, the preformed spherical configuration has continuous curvature.

[0011] In some embodiments, the distal portion of the tube has a greater width, which is at least about 1.5 to 3 times or more the width of the proximal portion.

[0012] In some implementations, the tube is porous.

[0013] In some implementations, the tube is constructed of woven material.

[0014] In some implementations, the tube is constructed from woven conductive fibers.

[0015] In some implementations, the tube is constructed from a biocompatible elastomer material.

[0016] In some implementations, the tube is constructed of a conductive material that is electrically connected to the RF terminal electrode.

[0017] In some embodiments, the catheter probe includes a connecting member between the distal segment and the elongation axis. In a more detailed embodiment, the connecting member includes a tubular member configured as a spring joint, wherein the spring joint is configured to respond to axial and angular forces acting on the distal segment.

[0018] In other embodiments, the catheter probe of the present invention includes a flexible elongation shaft and a distal segment having a distal end electrode and an elastically deformable woven fiber tube, wherein the deformable tube is configured to employ (i) a neutral configuration having a pre-formed spherical portion having a first width and (ii) a tissue contact configuration, wherein the spherical portion deforms into a second width greater than the first width.

[0019] In some embodiments, when the deformable tube is in a neutral configuration, the spherical portion does not contact the distal end electrode, and when the deformable tube is in a tissue contact configuration, the spherical portion contacts the distal end electrode.

[0020] In some embodiments, the deformable tube has a closed distal end including converging fibers and an open end defining an opening for receiving a distal end electrode.

[0021] In some implementations, the deformable tubular wire is electrically connected to the ablation energy source.

[0022] In some implementations, the spherical portion has continuous curvature when the deformable tube is in a neutral configuration and a tissue contact configuration.

[0023] In some embodiments, the catheter probe includes a connecting member between the distal segment and the elongation axis, wherein the connecting member is configured to respond to axial and angular forces acting on the distal segment. Attached Figure Description

[0024] These and other features and advantages of the invention will be better understood by referring to the following specific embodiments considered in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 This is a schematic diagram of a catheter probe ablation system according to an embodiment of the present invention.

[0026] Figure 2A The following is a side view of a catheter probe according to an embodiment of the present invention, the catheter probe including a distal segment with deformable electrodes.

[0027] Figure 2B A side view of the distal segment with tube and distal end electrode during assembly.

[0028] Figure 2C for Figure 2A A side view of the catheter probe, in which a deformable electrode is in contact with tissue.

[0029] Figure 3 This is a schematic diagram of a force sensing subsystem and a position sensing subsystem according to an embodiment of the present invention.

[0030] Figure 4 This is a side sectional view of the distal end electrode according to an embodiment of the present invention.

[0031] Figure 5A This is a side view of a tube for constructing a deformable electrode according to an embodiment of the present invention.

[0032] Figure 5B for Figure 5A A side view of the tube, which has been inverted and assembled with the distal end electrode.

[0033] Figure 5C for Figure 5B A side view of the assembled tube and distal end electrode, wherein the deformable electrode is in contact with the tissue.

[0034] Figure 6 A side view of a catheter probe according to another embodiment of the invention, the catheter probe including a distal segment with deformable electrodes.

[0035] Figure 7 This is a schematic diagram of a positive displacement distribution system as used in the present invention, according to one embodiment.

[0036] Figure 8A This is a side view of a catheter probe according to another embodiment of the present invention, the catheter probe including a balloon component.

[0037] Figure 8B for Figure 8A A view of the end of the catheter probe. Detailed Implementation

[0038] Now for reference Figure 1 and Figure 2A , Figure 1 This is a schematic diagram of a catheter probe ablation system 10 according to an embodiment of the present invention. Figure 2AThe distal segment 12 of a catheter probe 14 for use in the system according to an embodiment of the invention is shown. In system 10, probe 14 includes an elongation shaft 15 supporting the distal segment 12, and a portion of the distal segment 12 and shaft 15 is inserted into the vascular system of a subject 22, such as a chamber of heart 20. The probe is used by operator 24 of system 10 during a procedure, which typically involves performing ablation on body tissue 26. The distal segment 12 advantageously includes a deformable electrode 40.

[0039] In some implementations, for example for intracardiac procedures, the shaft 15 and distal segment 12 have very small outer diameters, typically about 2-3 mm. Therefore, all internal components of the catheter probe 14 are also made as small and thin as possible and are arranged to minimize damage due to small mechanical strains.

[0040] like Figure 1 As shown, the functions of system 10 are managed by system controller 30, which includes a processing unit 32 communicating with a memory 34 containing software for the operation of system 10. In some embodiments, controller 30 is a computer including the processing unit, and at least some of the controller's functions can be performed using custom-designed hardware and software such as application-specific integrated circuits (ASICs) or field-programmable gate arrays (FPGAs). Controller 30 is typically managed by operator 24 using pointing device 36 and graphical user interface (GUI) 38, enabling the operator to set parameters of system 10. The graphical user interface 38 also typically displays surgical results to the operator.

[0041] The software in memory 34 can be downloaded electronically to controller 30, for example, via a network. Alternatively or otherwise, the software can be provided via a non-transitory tangible medium such as an optical, magnetic, or electronic storage medium.

[0042] In some embodiments, the controller 30 includes a force module 48, an RF ablation module 50, a flushing module 52, and a positioning module 54. The processing unit 32 uses the force module to generate and measure signals supplied to and received from the force sensor 58 in the distal end 12 to measure the magnitude and direction of the force on the distal end. The operation and construction of the force sensor 58 will be described in more detail below.

[0043] Processing unit 32 uses RF ablation module 50 to monitor and control ablation parameters, such as the level of ablation power applied via electrodes on distal segment 12. The ablation module also monitors and controls the duration of the ablation provided.

[0044] Typically, heat is generated in and around the ablation electrode during ablation. To dissipate heat and improve the efficiency of the ablation process, system 10 supplies flushing fluid to the distal end 12. System 10 uses flushing module 52 to monitor and control flushing parameters, such as the flow rate and temperature of the flushing fluid, as will be described in more detail below.

[0045] Processing unit 32 uses positioning module 54 to monitor the position and orientation of the distal segment relative to patient 22. This monitoring can be achieved by any tracking method known in the art, such as the tracking methods provided in the Carto3.RTM. system (derived from Biosense Webster of Diamond Bar, Calif). Such systems use radio frequency (RF) magnetic transmitter and receiver elements on the exterior of patient 22 and within the distal end 12. Alternatively or otherwise, positioning and tracking can be achieved by measuring the impedance between one or more sensing electrodes 17 on catheter probe 14 and patch electrodes 18 attached to the skin of patient 22 (such as those also provided in the Carto3.RTM. system).

[0046] like Figure 2A As shown, the distal segment 12 is connected to the elongation shaft 15. The distal segment includes a force sensor 58. Various aspects of a force sensor similar to force sensor 58 are described in U.S. Patent No. 8,357,152, entitled “CATHETER WITH PRESSURE SENSING,” issued January 22, 2013, to Govari et al., and U.S. Patent Publication No. 2011 / 0130648, entitled “CATHETER WITH PRESSURE MEASURING TIP,” filed November 30, 2009, to Beeckler et al., the disclosures of which are incorporated herein by reference.

[0047] Figure 2A A side view of a force sensor 58 is shown. Sensor 58 includes a resilient connecting member 60 forming a spring joint 62. In some embodiments, the connecting member 60 has a hollow tubular form with a central lumen 68 passing through it. Although the connecting member 60 does not necessarily have to be formed of two parts or longitudinal halves, the specific implementation of two parts simplifies the assembly of the elements included in the force sensor, as well as other elements mounted in the distal segment 12, within the member 60. Typically, the connecting member 60 is formed of a superelastic alloy, such as nickel-titanium (NiTiNO3).

[0048] The connecting member 60 typically has one or more helical structures cut or otherwise formed within the member, causing the member to behave like a spring. In the embodiment described herein and shown in FIG. 2, the helical structures are formed as two intertwined helical structures, namely a first cut helical structure 72 and a second cut helical structure 74, which are also referred to herein as a double helix structure. However, the connecting member 60 may have any positive integer number of helical structures, and those skilled in the art will be able to modify the invention to cover other numbers of helical structures than two without excessive experimentation. Alternatively, the connecting member may comprise a coil spring or any other suitable type of elastic element having flexibility and strength characteristics similar to those produced by the one or more tubular helical cuts mentioned above.

[0049] The connecting member 60 is mounted within and covered by a sheath 46 (shown as transparent), which is typically formed of a flexible plastic material. The connecting member 60 typically has an outer diameter approximately equal to the inner diameter of the sheath 46. This configuration, which maximizes the outer diameter of the connecting member, increases the sensitivity of the force sensor 58. Furthermore, and as will be explained below, the relatively large diameter and relatively thin walls of the tubular connecting member provide a more spacious lumen 68 enclosed within the connecting member, which is used by other elements in the distal end (described below). The sheath 46 extends the length of the connecting member 60 to provide a fluid-impermeable seal around the hollow tubular form. The sheath 46 can be constructed from any suitable flexible and insulating biocompatible material, including CELCON, Teflon, or heat-resistant polyurethane.

[0050] When the catheter probe 14 is used to ablate endocardial tissue, for example by delivering RF electrical energy via electrodes on the distal segment 12, considerable heat is generated in the region of the distal end 12. For this purpose, it is desirable that the sheath 46 comprises a heat-resistant plastic material, such as polyurethane, whose shape and elasticity are substantially unaffected when exposed to heat.

[0051] like Figure 2A and Figure 3As shown, within a force sensor 58 typically located within the central lumen 68 of the connecting member 60, a connector sensing assembly including coils 76, 78, 80, and 82 provides accurate readings of any dimensional changes in the connector 62, including axial displacement and angular deflection of the connector, such as when the distal segment 12 is advanced into contact with tissue. These coils are one type of magnetic transducer that can be used in embodiments of the invention. In the context of this patent application and in the claims, "magnetic transducer" means a means of generating a magnetic field in response to an applied current and / or outputting an electrical signal in response to an applied magnetic field. Although the embodiments described herein use coils as magnetic transducers, other types of magnetic transducers may be used in alternative embodiments, as will be apparent to those skilled in the art.

[0052] The coil in the sensing assembly is separated between two sub-assemblies on opposite axial sides of connector 62. One sub-assembly includes coil 82, which is driven by current via cables (not shown) from controller 30 and force module 48 to generate a magnetic field. This magnetic field is received by a second sub-assembly including coils 76, 78, and 80, located in a segment of distal segment 12 axially spaced from coil 82 across spring connector 62. In the context of this patent application and in the claims, the term "axial" refers to the direction of the longitudinal axis of symmetry 84 of distal end 12. An axial plane is a plane perpendicular to this longitudinal axis, and an axial segment is the portion of the conduit contained between two axial planes. Coil 82 generally has an axis of symmetry that is substantially parallel to and coincides with axis 84.

[0053] Coils 76, 78, and 80 are fixed in the distal end 12 at different radial positions. (The term "radial" refers to the coordinates relative to axis 84.) Specifically, in this embodiment, coils 76, 78, and 80 are all located in the same axial plane at different azimuth angles around the conduit axis and each has an axis of symmetry generally parallel to axis 84. For example, the three coils may be 120° apart radially from the axis.

[0054] Coils 76, 78, and 80 generate electrical signals in response to the magnetic field emitted by coil 82. These signals are transmitted via cable 57, which extends from distal segment 12 and passes through shaft 15 and control handle 16. Figure 2A The signal is transmitted to controller 30, which uses force module 48 to process the signal in order to measure the displacement of joint 62 parallel to axis 84 and the angular deflection of joint 62 from that axis. Based on the measured displacement and deflection, controller 30 is able to typically evaluate the magnitude and direction of the force on joint 62 using a previously determined calibration table stored in force module 48.

[0055] The controller 30 uses the positioning module 54 to measure the position and orientation of the distal end 12. The measurement can be performed using any simple process known in the art. In one embodiment, a magnetic field generated outside the patient 22 forms an electrical signal in elements within the distal segment 12, and the controller 30 uses the level of said electrical signal to determine the position and orientation of the distal segment. Alternatively, a magnetic field can be generated in the distal segment 12, and the electrical signal formed by the field can be measured outside the patient 22. Elements in the distal segment 12 used for positioning the distal segment 12 include coils 85 and 86. Figure 3 And one of coils 76, 78 and 80 (in addition to their use as elements of force sensor 58) serves as an orthogonal (x,y,z) positioning element housed in distal segment 12.

[0056] like Figure 2A As shown, at or near the distal end of the sheath 46, the annular electrode 17 is mounted on the outer surface of the sheath 46. At or near the distal end of the sheath 46, the distal end member or electrode 21 has a shell wall 23 and a plug member 28, as shown. Figure 4 As shown. The shell wall 23 has an opening 25 and an internal cavity 27. The plug member 28 has an interference fit with the shell wall in the opening 25, thereby sealing the internal cavity 27. The plug member 28 has at least one axial through hole 29 that receives the distal end of the flushing tube 31 for use via the Luer interface 33 ( Figure 1 Fluid (e.g., saline) is delivered from a remote source, and the Luer interface communicates with the proximal end of the flushing tubing 31 located at or near the control handle 16. Fluid delivered to the internal cavity 27 of the distal end electrode 21 can cool the electrode 21 and then exit the internal cavity 27 via flushing holes 35 formed in the shell wall 23 to reach the outside of the electrode 21 to flush and / or cool surrounding tissue.

[0057] The distal end shell wall 23 and the plug member 28 are constructed of a conductive material such as platinum, gold, or stainless steel, and in some embodiments, are preferably made of a platinum-iridium alloy (90% platinum / 10% iridium). The plug member 28 may be configured on its proximal side to have one or more blind holes for receiving one or more components, such as the distal end of a lead 37 for energizing the plug member 28. The proximal side of the plug member 28 and the distal side of the spring connector 62, the coil 82 of the force sensing subassembly (… Figure 3 It can be accommodated in a sheath 46 within the lumen 68 of the connecting member 60. The lead wire 37 and the flushing tube 31 pass through the protective tube 65, which extends through the lumen 68 and further through the lumen of the conduit shaft 15.

[0058] Figure 5AA woven material suitable for constructing a deformable electrode 40 for the distal segment 12 is shown. For some applications, elastic woven fabrics or webs may be advantageous. To enhance mechanical strength and elasticity, the woven material can be at least partially woven from elastic metal fibers (such as nickel-titanium strands). The use of metal-based fabrics also facilitates the conduction of electrical energy to intracardiac tissues.

[0059] In some embodiments, the material includes interwoven fibers 41 formed as a hollow tube 42, such as Figure 5A As shown, the outer surface 51 and the inner surface 52 define a channel 43 between the proximal open end 44 and the distal closed end 45, wherein the distal free ends of the fibers 41 are aggregated, for example by other fibers, fasteners, and / or adhesives, to converge and bind together to form a knot 47, thereby closing the channel 43. When the knot 47 is located outside the channel 43 and points distally, as... Figure 5A As shown, tube 42 is turned inside out and inverted, so that nodule 47 enters channel 43 and points proximally, with inner surface 52 facing outward to present a smooth and untraumatized distal end surface, as... Figure 5B As shown. The tube 42 is then slid onto or otherwise mounted on the distal segment 12, wherein the distal end portion 13 is inserted through the proximal open end portion 44. The distal segment 12 is advanced to a position X proximal to the distal closed end portion 45 of the tube 42, such that when the tube 42 is in a neutral configuration without external deformation forces, there is a volumetric space gap S between the distal closed end portion 45 of the tube 42 and the distal end portion 13 of the distal segment 12. Thus, the tube 42 in its neutral configuration has a first or distal portion D that does not contact the distal end electrode 21, and a second or proximal portion P that is substantially in circumferential contact with the distal end electrode 21. The proximal open end portion 44 of the tube 42 extends around the proximal end of the shell wall 23 of the distal end electrode 21 and passes through one or more bands 49 (see...). Figure 2A The tube 42 is wrapped around and fixed to the shell wall 23. When attached in this way, the tube 42 is in direct conductive contact with the shell wall 23, so that the energization of the shell wall 23 also energizes the tube 42. Furthermore, since the tube 42 is elastic, when the catheter is inserted into the patient's vascular system, for example via a guide sheath (not shown), its distal portion D can be easily compressed to a size no larger than the width or french dimension of the distal terminal electrode 21 and the distal terminal segment 12, and can easily return to its neutral configuration when unfolded from the guide sheath.

[0060] In some embodiments, tube 42 may have a uniform cylindrical configuration, such as Figure 5A and Figure 5BAs shown. The tube 42, in its neutral configuration, has a generally uniform width W1 along its length, which is equal to or greater than the width of the distal end electrode 21, allowing the electrode 21 to be easily inserted into the tube 42 without significantly stretching the braided underlayer material. Furthermore, as... Figure 5C As shown, when the distal side F of tube 42 contacts the tissue after the distal segment 12 advances, and further when the distal terminal electrode 21 abuts or contacts the tissue surface T, the distal portion D of tube 42 radially expands from its neutral configuration and bulges to a width W2 > W1. This radial expansion allows the distal portion D of tube 42 to provide a larger contact surface area or footprint F compared to the distal terminal electrode 21 alone, enabling tissue ablation.

[0061] In other embodiments, tube 42 may have a neutral configuration, which has a mushroom shape, such as... Figure 2B As shown, it has a distal cap portion DC and a proximal rod portion PS. The proximal rod portion PS is generally straight and has a generally uniform width W3 along its length, wherein the width W3 may be generally equal to or less than the width of the distal end electrode 21. The distal cap portion DC of tube 42 has a generally flat or slightly curved distal side DF, and a spherical portion B with a continuous, larger curvature C2 and therefore without any corners or sharp transitions. The width W4 of the spherical portion B is at least about 1.5 times the width W3 of the rod portion PS. When mounted on the distal segment 12, the proximal rod portion PS is in general circumferential contact with the distal end electrode 21, and the distal cap portion DC is not in contact with the distal end electrode 21, as... Figure 2A As shown.

[0062] When the distal side DF of tube 42 contacts tissue T after the distal segment 12 advances toward the tissue, as Figure 2C As shown, the distal cap DC, including the spherical portion B, becomes flatter and unfolds, radially expanding to create a significantly enlarged contact surface area or footprint F compared to the distal end electrode 21. Utilizing the distal cap DC and its spherical portion B, which has a continuous curvature without sharp angles or corners, the distal cap DC and the spherical portion B can easily maintain their overall shape during expansion without any twisting or undesirable deformation.

[0063] For any embodiment of the invention, the tissue contact surface area F can be increased by pivoting the distal segment 12 about an axis perpendicular to the contact surface area (in the case of sweeping out a conical volume). In this way, the peripheral portion PY of the spherical portion B can also contact the additional tissue surface F'.

[0064] In operation, the distal portion D of tube 42 in this embodiment can be inflated and flushed with a fluid such as a saline solution or any other suitable flushing fluid. The flushing module 52 pumps saline solution through flushing tubing 31 to deliver it to the distal end electrode 21, where it exits through flushing orifice 35, thereby generating a mechanical force sufficient to inflate the distal portion D of tube 42. When the distal portion D of tube 42 is inflated and pressed against the endocardial tissue T, the distal portion conforms better to the endocardial tissue T, as shown in the figure.

[0065] When the deformable electrode 40 is conductive, for example, by comprising suitable metal strands or a conductive polymer, the ablation module 50 can deliver RF energy to the deformable electrode 40 via lead 37, and the deformable electrode 40 conducts the energy to the tissue. Alternatively or otherwise, lead 37 can apply RF energy to a conductive fluid (e.g., saline) delivered to the distal terminal electrode 21, in which case the conductive solution conducts the RF energy through the deformable electrode 40 to the endocardial tissue.

[0066] In other implementation schemes, such as Figure 6 As shown, the deformable electrode 40 may include a flushing balloon tube 90 comprising a biocompatible flexible and elastomeric substrate 91 having an outer surface 92, on which one or more conductive members or surface electrodes 93 are coated or otherwise applied, for example as printed circuitry, sputtered coatings, etc. It should be understood that the substrate 91 and the balloon member 90 may exhibit any one or more of the applicable features for the tube 42 described above and / or shown herein. Where the substrate 91 is not woven or otherwise porous, a flushing port 94 may be formed in the substrate 91 to allow fluid delivery into the internal cavity 27 of the balloon member 90 for exit from the balloon member 90.

[0067] In some embodiments, as understood by those skilled in the art, the conductive material forming the surface electrode 93 is applied via a micropen or a positive displacement dispensing system. The micropen can dispense a controllable volume of paste each time, thereby enabling thickness control by varying the print volume, paste concentration, and writing speed. Figure 7As shown, the positive displacement dispensing system 160 includes a pen tip 164 that remains substantially perpendicular to the surface of the substrate or underlying material. Such systems are disclosed in U.S. Patent 9,289,141, entitled "Apparatus and Methods for the Measurement of Cardiac Output". Positive displacement dispensing techniques and direct-write deposition tools (including aerosol nozzles and autoinjectors) are available under the trade name MICROPEN from MicroPen Technologies and Ohmcraft, Inc. (Honeoye Falls, NY).

[0068] like Figure 7 As shown, the balloon member 90 is at least partially inflated before the electrode 93 is printed onto its outer surface 92. A processing system, such as computer 162, generates a contour map showing the outline of the balloon member 90. The information from the contour map obtained above is provided to a positive displacement distribution system 160 that is responsive to the contour map by changing one or more printing dimensions. In some embodiments, the positive displacement distribution system 160 includes a writing head 164 (such as a pen tip) and a substrate 166 capable of moving the balloon member 93 in at least three independent dimensions. The writing head 164 is movable relative to the substrate 166. The writing head 164 applies any liquid or semi-solid material, as well as a conductive material used to form the electrode 93, onto the substrate.

[0069] The write head 164 is mounted on an axis that can only move in one dimension, such as... Figure 7 As shown, the y-axis is used. Conversely, the base stage 166 is capable of movement in at least three independent dimensions: the x-axis, (rotation clockwise or counterclockwise along the z-axis) and θ (rotation clockwise or counterclockwise along the x-axis). In some embodiments, the base stage 166 is capable of moving in a fourth independent direction, such as... Figure 7 As shown, the y-axis is used.

[0070] Surface electrode 93 can present any of the various patterns on balloon component 90. One or more solder pads 69 may be provided. Figure 6 The internal lead 37 and the surface electrode 93 are electrically connected. One or more leads 37 may transition from the inside of the sheath 46 to the outside via a hole 71 formed in the sheath 46 to connect with the pad 69. In other embodiments, the electrode 93 is connected to the end electrode 21 via leads to conduct RF energy. The leads may extend along the outer surface of the balloon member 90 to reach the end electrode 21, or they may extend through the interior of the balloon member to reach the end electrode 21.

[0071] In some embodiments, the balloon member 90 is constructed of a conductive polymer. In some embodiments, the balloon member 90 has a spherical or annular shape, defined as an annular configuration having a generally circular cross-section and a central opening through which the distal terminal electrode 21 extends, such as... Figure 8A and Figure 8B As shown. In some embodiments, the balloon component 90 has a width W ranging from approximately 4.0 mm to 5.1 mm. (As illustrated...) Figure 8B As shown, the balloon component 90, when inflated, presents a distal surface in the shape of a ring that contacts the tissue surface.

[0072] 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, and any feature or combination of features described in some embodiments may be incorporated into any other embodiment or combined with any other one or more features of another embodiment, as needed or required. 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 probe, comprising: Flexible elongation shaft; The distal segment has a distal terminal electrode and an elastically deformable tube made of woven fibers, wherein the elastically deformable tube is configured to adopt (i) a neutral configuration having a pre-formed spherical portion having a first width; and (ii) a tissue contact configuration, wherein the spherical portion is deformed into a second width greater than the first width; When the elastically deformable tube is in the neutral configuration, the spherical portion does not contact the distal end electrode; and when the elastically deformable tube is in the tissue contact configuration, the spherical portion contacts the distal end electrode. The resiliently deformable tube has a closed distal end and includes a plurality of interwoven fibers having free distal ends that converge into nodules located within an internal channel of the resiliently deformable tube and extending proximally from the closed distal end. The resiliently deformable tube also has an open end defining an opening for receiving the distal end electrode. The elastically deformable tube is electrically connected to the ablation energy source.

2. The catheter probe of claim 1, wherein the spherical portion has continuous curvature when the elastically deformable tube is in the neutral configuration and the tissue contact configuration.

3. The catheter probe according to claim 1, wherein the elastically deformable tube is porous.

4. The catheter probe according to claim 1, wherein the elastically deformable tube comprises woven conductive fibers.

5. The catheter probe according to claim 1, wherein the elastically deformable tube has an annular configuration.

6. The catheter probe according to claim 1, wherein the elastically deformable tube includes a surface electrode.

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