Focal ablation catheter incorporating a guidewire inserted through an irrigation channel

Abstract

To provide an improved catheter for performing RF ablation in small and difficult-to-reach ablation sites.SOLUTION: A catheter 22 includes an ablation electrode and an irrigation channel. The ablation electrode is configured to ablate tissue of a patient organ and is fitted on an insertion tube for insertion into the patient organ. The irrigation channel includes: (i) a lumen which is formed along an axis of the insertion tube, and is configured to flow irrigation fluid to the ablation electrode, and (ii) one or more irrigation holes, which are formed in the ablation electrode, and are configured to apply the irrigation fluid to the organ. The irrigation channel is configured to simultaneously (i) receive a guidewire for guiding the catheter and (ii) flow the irrigation fluid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to medical catheters, and more particularly to methods and systems for steering focal ablation catheters using guidewires. [Background technology]

[0002] Focal catheters can be used in a variety of medical applications, including cardiology. Several techniques have been published for steering focal catheters using guidewires.

[0003] For example, U.S. Patent Application Publication No. 2013 / 0267901 describes a catheterization system including a catheter including a body having a proximal end and a distal end and defining first and second lumens extending therethrough, and a stylet. The stylet includes first and second stylet portions, each having a proximal end region and a distal end region, the distal end regions of the first and second stylet portions together defining a tapered piercing portion. The first and second stylet portions are configured and dimensioned to be slidably mounted within the first and second lumens of the catheter, respectively. The first and second stylet portions extend from the proximal end of the catheter beyond the distal end of the catheter and are independently movable relative to one another to facilitate selective removal of the first and / or second stylet portions from the catheter.

[0004] U.S. Patent Application Publication No. 2008 / 0108946 describes an intraluminal device for aspirating occluding or partially occluding material. The device includes a novel catheter extension that minimizes cavitation of the aspirated fluid and allows for better navigation through tortuous lumens or vascular systems. Summary of the Invention [Means for solving the problem]

[0005] One embodiment of the present invention described herein provides a catheter including an ablation electrode and an irrigation channel. The ablation electrode is configured to ablate tissue of a patient's organ and is mounted on an insertion tube for insertion into the patient's organ. The irrigation channel includes (i) a lumen formed along the axis of the insertion tube and configured to channel irrigation fluid to the ablation electrode, and (ii) one or more irrigation holes formed in the ablation electrode and configured to apply irrigation fluid to the organ, the irrigation channel being configured to (i) receive a guidewire for guiding the catheter while (ii) channeling the irrigation fluid.

[0006] In some embodiments, the ablation electrode has an opening for passing a guidewire through the ablation electrode. In other embodiments, the opening and the guidewire are matched in diameter to prevent leakage of irrigation fluid through the opening. In yet other embodiments, the catheter further comprises one or more sensing electrodes disposed on the insertion tube and configured to sense electrical signals from tissue when placed in contact with tissue of the organ.

[0007] According to one embodiment of the present invention, there is further provided a method including inserting a guidewire into a patient's organ and positioning the distal tip of the guidewire at an ablation site. The proximal tip of the guidewire is inserted into an irrigation channel of a catheter, the irrigation channel including (i) a lumen formed along the axis of the insertion tube for flowing irrigation fluid to an ablation electrode attached to the catheter's insertion tube and for passing the guidewire through the ablation electrode, and (ii) one or more irrigation holes formed in the ablation electrode for applying irrigation fluid to the organ. The catheter is slid over the guidewire and positioned at the ablation site. While the guidewire is in the irrigation channel, irrigation fluid is applied to the organ through the one or more irrigation holes.

[0008] According to one embodiment of the present invention, there is also provided a method for manufacturing a catheter for ablating tissue, the method comprising mounting an ablation electrode for ablating tissue on an insertion tube for insertion into a patient's organ, wherein an irrigation channel is formed in the ablation electrode by (i) forming a lumen along the axis of the ablation electrode for flowing irrigation fluid to the ablation electrode and for inserting a guide wire therethrough, and (ii) forming one or more irrigation holes in the ablation electrode for applying irrigation fluid to the organ.

[0009] Additionally, in accordance with one embodiment of the present invention, there is provided a catheter including an insertion tube for insertion into a patient's organ and an irrigation channel. The irrigation channel includes (i) a lumen formed along the axis of the insertion tube and configured to conduct irrigation fluid to a distal end of the insertion tube, and (ii) one or more irrigation holes formed in the distal end of the insertion tube and configured to apply irrigation fluid to the organ. The irrigation channel is configured to (i) receive a guidewire for guiding the catheter and (ii) conduct irrigation fluid.

[0010] In some embodiments, the catheter further comprises one or more (i) ablation electrodes or (ii) sensing electrodes disposed on the insertion tube and configured to, when placed in contact with tissue of the organ, at least one of: (i) apply one or more ablation pulses to the tissue; and (ii) sense one or more electrical signals from the tissue.

[0011] The present invention will be more fully understood from the following detailed description taken in conjunction with the drawings, in which: [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic, pictorial illustration of a catheter-based position tracking system and ablation system, in accordance with one embodiment of the present invention; [Figure 2]1 is a schematic cross-sectional view of a distal tip assembly of a focal ablation catheter, in accordance with one embodiment of the present invention. [Figure 3] 1 is a schematic, pictorial illustration of a distal tip assembly of a focal ablation catheter, in accordance with one embodiment of the present invention; [Figure 4] FIG. 1 is a flow diagram that schematically illustrates a method for performing microablation by steering a focal catheter using a guidewire, in accordance with an embodiment of the present invention. [Figure 5] 1 is a flow diagram that schematically illustrates a method for manufacturing a catheter for ablating tissue, in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Overview In ablation procedures, such as radiofrequency (RF) ablation, physicians typically use a catheter having an ablation electrode configured to ablate tissue at an ablation site to treat arrhythmias in a patient's organ, such as the patient's heart. In some cases, ablation must occur at an ablation site that is difficult to reach with a catheter, and the area to be ablated may be small, further complicating the manipulation of the catheter and the tissue ablation process.

[0014] The embodiments of the present invention described below provide improved techniques for performing RF ablation at small, hard-to-reach ablation sites, also referred to herein as microablation sites, and such procedures, also referred to herein as microablation procedures.

[0015] In some embodiments, a catheter for performing a microablation procedure includes an insertion tube for insertion into a patient organ, in this example the patient's heart, with an ablation electrode disposed on the insertion tube, the ablation electrode configured to ablate tissue at an ablation site when placed in contact with tissue to be ablated (also referred to herein as target tissue).

[0016] During tissue ablation, it is important to control the temperature profile of the tissue to be ablated and the temperature of the ablation electrodes, hi some embodiments, the catheter further comprises an irrigation channel configured to apply irrigation fluid to the tissue to be ablated and controlled by the processor to maintain said temperature.

[0017] In some embodiments, the irrigation channel includes a lumen formed along a longitudinal axis of the insertion tube and configured to channel irrigation fluid to a distal end of the insertion tube, and further includes a manifold formed in the distal end of the insertion tube and having a plurality of irrigation holes configured to apply irrigation fluid to tissue.

[0018] In some embodiments, the insertion tube has an opening sized and shaped to be sealed by a guidewire passing through the irrigation channel to prevent leakage of irrigation fluid from the opening, e.g., the guidewire and the opening typically have matching diameters to prevent leakage.

[0019] In such embodiments, the irrigation channel is configured to (i) receive a guidewire for guiding the catheter while (ii) flowing and applying irrigation fluid to the tissue being ablated.

[0020] In some embodiments, during an ablation procedure, a physician inserts and manipulates the distal tip of a guidewire into the ablation site. After inserting the guidewire into the irrigation channel, the physician slides the distal end of a catheter over the guidewire to position the distal end of the catheter at the ablation site and place one or more of the ablation electrodes in contact with the tissue to be ablated.

[0021] The disclosed techniques improve the maneuverability of ablation catheters without increasing the size of the catheter's distal tip. Thus, such catheters can be used to perform RF ablation procedures at small, hard-to-reach ablation sites. Furthermore, the disclosed techniques reduce the procedure time for such ablation procedures by allowing physicians to apply ablation pulses and irrigation fluid to the target tissue as soon as the ablation electrode is placed in contact with the target tissue, without requiring a time-consuming guidewire retraction process.

[0022] System Description 1 is a schematic, pictorial illustration of a catheter-based position tracking and ablation system 20, in accordance with an embodiment of the present invention. In some embodiments, system 20 comprises a catheter 22, in this example a cardiac catheter having a focal geometry, and a control console 24. In the embodiments described herein, catheter 22 may be used for any suitable therapeutic and / or diagnostic purposes, such as ablation of tissue within heart 26, and for mapping arrhythmias by sensing intracardiac electrical signals.

[0023] In some embodiments, console 24 includes processor 42, typically a general-purpose computer, with front-end and interface circuitry suitable for exchanging signals with catheter 22 (e.g., receiving intracardiac electrical signals and applying ablation pulses to tissue of heart 26) and for controlling other components of system 20 as described herein. Processor 42 may be programmed with software to perform functions used by the system, and processor 42 is configured to store data for the software in memory 50. This software may be downloaded to console 24 in electronic form, for example, over a network, or may be provided on a non-transitory, tangible medium, such as an optical, magnetic, or electronic storage medium. Alternatively, some or all of the functions of processor 42 may be performed using an application-specific integrated circuit (ASIC) or any suitable type of programmable digital hardware component.

[0024] Referring now to inset 25, in some embodiments, catheter 22 comprises a distal tip assembly 40 (shown in detail in FIGS. 2 and 3 below) having a focal shape and a shaft 23 for inserting distal tip assembly 40 to a target location for ablation of tissue within heart 26. During an ablation procedure, physician 30 inserts catheter 22 through the vascular system of patient 28 reclining on table 29. Physician 30 moves distal tip assembly 40 to the target location within heart 26 using a manipulator 32 near the proximal end of catheter 22, which is connected to interface circuitry of processor 42.

[0025] In some embodiments, catheter 22 includes a position sensor 39 of a position tracking system coupled to the distal end of catheter 22, e.g., in close proximity to distal tip assembly 40. In this example, position sensor 39 includes a magnetic position sensor, although in other embodiments, any other suitable type of position sensor (e.g., other than magnetic-based) may be used.

[0026] Referring again to the schematic diagram of Figure 1, in some embodiments, during guidance of the distal tip assembly 40 within the heart 26, the processor 42 receives signals from a magnetic position sensor 39 in response to a magnetic field from an external magnetic field generator 36, for example, to determine the position of the distal tip assembly 40 within the heart 26. In some embodiments, the console 24 includes a driver circuit 34 configured to drive the magnetic field generator 36. The magnetic field generator 36 is positioned at a known position external to the patient 28, such as, for example, beneath a table 29.

[0027] In some embodiments, the processor 42 is configured to display the tracked position of the distal tip assembly 40 overlaid on an image 44 of the heart 26, for example, on a display 46 of the console 24.

[0028] This method of position sensing using an external magnetic field has been implemented in various medical applications, for example, in the CARTO™ system manufactured by Biosense Webster Inc. (Irvine, Calif.), and is described in detail in U.S. Pat. Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612, and 6,332,089, WO 96 / 05768, and U.S. Patent Application Publication Nos. 2002 / 0065455(A1), 2003 / 0120150(A1), and 2004 / 0068178(A1), the disclosures of which are all incorporated herein by reference.

[0029] Catheter insertion over a guidewire inserted through the catheter irrigation channel FIG. 2 is a schematic cross-sectional view of a distal tip assembly 40, according to one embodiment of the present invention.

[0030] In some embodiments, distal tip assembly 40 is configured to ablate tissue in a patient's heart 26 and includes an ablation electrode 52 mounted on the distal end of an insertion tube (shown in FIG. 3 below) for inserting catheter 22 into heart 26 to perform the aforementioned cardiac ablation procedure. Distal tip assembly 40 further includes an irrigation channel 54 having a lumen 56 and one or more irrigation holes 60.

[0031] In some embodiments, a lumen 56 is formed along the axis 62 of the insertion tube (not shown) and the ablation electrode 52 and is configured to carry irrigation fluid 66 to the ablation electrode 52 .

[0032] In some embodiments, irrigation holes 60 are formed in the ablation electrode 52 and are typically, but not necessarily, configured to apply irrigation fluid 66 to the tissue of the heart 26 during tissue ablation.

[0033] In some ablation procedures, maneuvering the distal tip assembly 40 to the ablation site to apply the ablation pulses may be difficult due to the anatomy of the heart 26. In some embodiments, the physician 30 may use a guidewire 55 to improve maneuverability of the distal tip assembly 40 in the heart 26. The guidewire 55 is flexible yet sufficiently stiff, has a small diameter, such as about 0.89 mm or any other suitable diameter, and is configured to have better maneuverability than the catheter 22 and distal tip assembly 40.

[0034] In some embodiments, guidewire 55 may comprise any suitable type of guidewire, such as an Amplatz guidewire manufactured by Boston Scientific, Inc., of Middlesex County, Marlborough, Massachusetts.

[0035] In the context of this disclosure and in the claims, the term "about" or "approximately" used in connection with any numerical value or range of values ​​indicates an appropriate tolerance of dimensions that allows the portion of a component or collection of components to function in accordance with its intended purpose as described herein.

[0036] In some embodiments, ablation electrode 52 has an opening 70 that is sized and shaped to seal when guidewire 55 is inserted through irrigation channel 54 to prevent leakage of irrigation fluid 66 through opening 70. For example, opening 70 and guidewire 55 may have matching diameters, such as 0.89 mm, to prevent leakage of irrigation fluid through opening 70.

[0037] Additionally or alternatively, at least a sealing ring (not shown) may be mounted within opening 70. The sealing ring is configured to (i) fit snugly over guidewire 55 when distal tip assembly 40 is slid over guidewire 55, and (ii) prevent leakage of irrigation fluid 66 from opening 70 upon application of irrigation fluid 66 through irrigation channel 54.

[0038] It should be noted that in these embodiments, the distal end assembly 40 is configured to (i) receive a guidewire 55 for guiding the catheter 22 into the heart 26, while (ii) allowing the irrigation fluid 66 to flow through the lumen 56 and the irrigation holes 60 without leaking the irrigation fluid 66 from the openings 70.

[0039] FIG. 3 is a schematic, pictorial illustration of a distal tip assembly 40, according to one embodiment of the present invention.

[0040] In some embodiments, distal tip assembly 40 is coupled to insertion tube 51 and includes one or more sensing electrodes 64 that are inserted into openings formed at appropriate locations in ablation electrode 52. Sensing electrodes 64 are configured to sense electrical signals from tissue of heart 26, as described above.

[0041] In other embodiments, instead of the ablation electrode 52, the distal end assembly 40 may include the aforementioned insertion tube or any other suitable component, such that at least one of the plurality of electrodes 64 may include an ablation electrode or a sensing electrode.

[0042] In yet other embodiments, the distal end assembly 40 may include, instead of at least one of the plurality of sensing electrodes 64, one or more ablation electrodes configured to apply ablation pulses to tissue of the heart 26 as described above.

[0043] In this example, distal tip assembly 40 includes three sensing electrodes 64 arranged about shaft 62 and electrically isolated from ablation electrode 52. Each sensing electrode 64 is surrounded by irrigation holes 60 for controlling the temperature of ablation electrode 52, the temperature of sensing electrode 64, and the temperature profile within the tissue being ablated.

[0044] In one embodiment of the above-described technology, catheter 22 comprises a QDot Micro radiofrequency (RF) ablation catheter manufactured by Biosense Webster Inc. (Irvine, Calif.), where each sensing electrode 64 has a surface area of ​​approximately 0.167 mm and the distance between adjacent sensing electrodes 64 is approximately 1.349 mm.

[0045] In some embodiments, the distal tip 58 of the guidewire 55 is inserted along the shaft 62 through the lumen 56 and opening 70 and manipulated by the physician 30 or any other suitable user of the system 20 through the vascular system of the patient 28 to the ablation site. The physician 30 then slides the distal tip assembly 40 along the guidewire 55 into the heart 26. In an alternative embodiment, the physician 30 (i) inserts the distal tip 58 of the guidewire 55 into the patient 28 and manipulates the distal tip 58 through the vascular system of the patient 28 to the ablation site in the heart 26, and (ii) inserts the proximal tip 59 of the guidewire 55 into the lumen 56 of the distal tip assembly 40 and slides the distal tip assembly 40 along the guidewire 55 to the ablation site within the heart 26. It should be noted that in either embodiment, when applying irrigation fluid 66 to the tissue of heart 26, guidewire 55 typically remains inserted through irrigation channel 54 of distal end assembly 40, as shown and described above in FIG. 2.

[0046] It should be noted that the techniques of the present disclosure improve the maneuverability of the catheter 22 without increasing the size of the catheter 22 or the distal tip assembly 40, thereby enabling the physician 30 to perform RF ablation at small, hard-to-reach ablation sites, also referred to herein as microablation.

[0047] Microablation is performed by manipulating a catheter through a guidewire FIG. 4 is a flow diagram that schematically illustrates a method for performing microablation by manipulating catheter 22 over guidewire 55, in accordance with one embodiment of the present invention.

[0048] In a first guidewire insertion step 100 of the method, a guidewire 55 is inserted (e.g., by physician 30) into heart 26, and a distal tip 58 of guidewire 55 is positioned at an ablation site within heart 26. In a second guidewire insertion step 102, a proximal tip 59 of guidewire 55 is inserted through (i) lumen 56 of irrigation channel 54 and (ii) opening 70 of catheter 22.

[0049] In catheter positioning step 104, the distal end assembly 40 of the catheter 22 is moved by sliding it along the guidewire 55 toward the distal tip 58 and positioned at the ablation site, as described in detail above in Figures 2 and 3.

[0050] In the final ablation step 106 of the method, physician 30 controls catheter 22 (e.g., via processor 42) to (i) apply ablation pulses using ablation electrodes 64 and (ii) apply irrigation fluid 66 via irrigation channel 54 to the ablation site of heart 26. Note that during application of irrigation fluid 66, guidewire 55 resides within irrigation channel 54 to seal opening 70, thereby preventing leakage of irrigation fluid 66 through opening 70.

[0051] Forming a distal end assembly of a catheter for performing microablation FIG. 5 is a flow diagram that schematically illustrates a method of forming the distal end assembly 40 of the catheter 22, in accordance with one embodiment of the present invention.

[0052] The method begins with an ablation electrode attachment step 200, in which an ablation electrode 52 for ablating tissue is attached onto the distal end of an insertion tube 51 for insertion into the patient's heart 26. In an irrigation channel formation step 202, an irrigation channel 54 is formed in the ablation electrode 52 by (i) forming a lumen 56 along the axis 62 of the ablation electrode 52 for flowing irrigation fluid 66 to the ablation electrode 52 and for inserting a guidewire 55 therethrough, and (ii) forming irrigation holes 60 for applying irrigation fluid 66 through the ablation electrode 52 to the heart 26 during the ablation procedure.

[0053] In an opening formation step 204, an opening 70 is formed in the ablation electrode 52 for passing a guidewire 55 through the lumen 56 and the opening 70. In some embodiments, the opening 70 is sized and shaped to be sealed by the guidewire 55 to prevent leakage of irrigation fluid 66 through the opening 70 when irrigating tissue of the heart 26, as described in detail above in FIGS. 2 and 3 . For example, the opening 70 and the guidewire 55 may have matching diameters (e.g., about 0.89 mm each) to prevent leakage of irrigation fluid 66 through the opening 70. Additionally or alternatively, the distal tip assembly 40 may include a sealing ring mounted within the opening 70 to prevent leakage of irrigation fluid 66 through the opening 70.

[0054] In the final sensing electrode placement step 206 of the method, one or more sensing electrodes 64 for sensing electrical signals from the tissue of the heart 26 are coupled to or placed on the insertion tube 51 and inserted through the opening in the ablation electrode 52.

[0055] Although the embodiments described herein primarily address RF ablation procedures performed at small and hard-to-reach ablation sites, the methods and systems described herein can also be used for other applications, such as non-RF-based ablation techniques, electroporation and electrosurgical procedures, and any type of fluid delivery to small and / or hard-to-reach sites within a patient's body, such as precise delivery of drugs.

[0056] Accordingly, it will be understood that the above-described embodiments are cited by way of example, and that the present invention is not limited to what has been particularly shown and described above. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the foregoing specification, as well as variations and modifications thereof not disclosed in the prior art that would occur to one skilled in the art upon reading the foregoing description. Documents incorporated by reference into this patent application shall be deemed an integral part of this application, except that to the extent that any term is defined in these incorporated documents in a manner that is inconsistent with a definition expressly or impliedly made herein, only the definition in this specification shall be considered.

[0057] [Embodiment] (1) A catheter, an ablation electrode configured to ablate tissue of a patient organ, the ablation electrode attached to an insertion tube for insertion into the patient organ; an irrigation channel including: (i) a lumen formed along the axis of the insertion tube and configured to channel irrigation fluid to the ablation electrode; and (ii) one or more irrigation holes formed in the ablation electrode and configured to apply the irrigation fluid to the organ, the irrigation channel configured to (i) receive a guidewire for guiding the catheter while (ii) channeling the irrigation fluid; A catheter comprising: (2) A catheter as described in embodiment 1, wherein the ablation electrode has an opening for passing the guide wire through the ablation electrode. (3) A catheter as described in embodiment 2, wherein the opening and the guidewire have matching diameters to prevent leakage of the irrigation fluid from the opening. (4) The catheter of embodiment 1, further comprising one or more sensing electrodes disposed on the insertion tube and configured to detect electrical signals from tissue of the organ when placed in contact with the tissue. (5) A method comprising: inserting a guidewire into a patient's organ and positioning a distal tip of the guidewire at an ablation site; inserting the proximal tip of the guidewire through an irrigation channel of a catheter, the irrigation channel including: (i) a lumen formed along the axis of the insertion tube for flowing irrigation fluid to an ablation electrode attached to an insertion tube of the catheter and for passing the guidewire through the ablation electrode; and (ii) one or more irrigation holes formed in the ablation electrode for applying the irrigation fluid to the organ; sliding the catheter along the guidewire to position the catheter at the ablation site; applying the irrigation fluid to the organ through the one or more irrigation holes while the guidewire is within the irrigation channel; A method comprising:

[0058] (6) The method of embodiment 5, wherein inserting the proximal tip includes passing the guide wire through (i) the lumen and (ii) the opening of the ablation electrode. (7) The method of embodiment 6, wherein the opening and the guide wire have matching diameters to prevent leakage of the irrigation fluid from the opening. (8) The method of embodiment 5, further comprising detecting one or more electrical signals from tissue of the organ. (9) A method for manufacturing a catheter for ablation of tissue, comprising: mounting an ablation electrode on an insertion tube for insertion into a patient's organ for ablating said tissue; forming an irrigation channel within the ablation electrode by (i) forming a lumen along the axis of the ablation electrode for flowing irrigation fluid to the ablation electrode and for inserting a guide wire therethrough; and (ii) forming one or more irrigation holes in the ablation electrode for applying the irrigation fluid to the organ; A method comprising: (10) The method of embodiment 9, further comprising forming an opening in the ablation electrode, the opening being for passing the guide wire through the lumen and the opening.

[0059] (11) The method of embodiment 10, wherein forming the opening includes forming the opening of a size and shape that is sealed by the guidewire to prevent leakage of the irrigation fluid from the opening. (12) The method of embodiment 9, further comprising disposing one or more sensing electrodes on the ablation electrode for sensing electrical signals from the tissue. (13) A catheter, an insertion tube for insertion into a patient's organ; an irrigation channel including: (i) a lumen formed along an axis of the insertion tube and configured to channel irrigation fluid to a distal end of the insertion tube; and (ii) one or more irrigation holes formed in the distal end of the insertion tube and configured to apply the irrigation fluid to the organ, the irrigation channel configured to (i) receive a guidewire for guiding the catheter while (ii) channeling the irrigation fluid; A catheter comprising: (14) The catheter according to embodiment 13, wherein the insertion tube has an opening for passing the guide wire through the insertion tube. (15) The catheter of embodiment 14, wherein the opening and the guidewire are matched in diameter to prevent leakage of the irrigation fluid from the opening.

[0060] (16) The catheter of embodiment 1 further comprises one or more (i) ablation electrodes or (ii) sensing electrodes disposed on the insertion tube and configured to, when placed in contact with tissue of the organ, at least one of: (i) apply one or more ablation pulses to the tissue; and (ii) sense one or more electrical signals from the tissue.

Claims

1. A catheter, an ablation electrode having a longitudinal axis, the ablation electrode including: a cylindrical portion extending along the longitudinal axis; and a distal portion extending distally and radially inward from a distal circumferential portion of the cylindrical portion toward a distal end of the ablation electrode, the ablation electrode including a distal opening at the distal end for passing a guidewire therethrough, the ablation electrode configured to ablate tissue of a patient organ, the ablation electrode attached to an insertion tube for insertion into the patient organ; one or more sensing electrodes at least partially disposed on the distal portion of the ablation electrode so as to be in contact with the tissue of the patient organ, the one or more sensing electrodes being configured to sense electrical signals from the tissue when positioned in contact with the tissue of the patient organ; an irrigation channel including: (i) a lumen formed along an axis of the insertion tube and configured to channel irrigation fluid to the ablation electrode; and (ii) one or more irrigation holes formed in the ablation electrode and configured to apply the irrigation fluid to the patient organ, the ablation electrode, and the one or more sensing electrodes, the irrigation channel configured to (i) receive the guidewire for guiding the catheter while (ii) channeling the irrigation fluid; A catheter comprising:

2. The catheter of claim 1 , wherein the distal opening and the guidewire are matched in diameter to prevent leakage of the irrigation fluid from the distal opening.

3. A catheter as described in claim 1, wherein the one or more sensing electrodes are three sensing electrodes arranged around the longitudinal axis and electrically insulated from the ablation electrode.

4. A catheter as described in claim 1, wherein the patient organ is the heart.

5. 1. A method of manufacturing a catheter for ablation of tissue, comprising: mounting an ablation electrode on an insertion tube for insertion into a patient's organ for ablating said tissue; forming an irrigation channel within the ablation electrode by: (i) forming a lumen along the axis of the ablation electrode for flowing irrigation fluid to the ablation electrode and for inserting a guide wire therethrough; and (ii) forming one or more irrigation holes in the ablation electrode for applying the irrigation fluid to the patient organ, the ablation electrode, and one or more sensing electrodes; Including, the ablation electrode has a longitudinal axis, the ablation electrode includes a cylindrical portion extending along the longitudinal axis and a distal portion extending distally and radially inward from a distal end circumferential portion of the cylindrical portion toward a distal end of the ablation electrode, the ablation electrode including a distal opening at the distal end for passing the guidewire through the ablation electrode; the one or more sensing electrodes are at least partially positioned on the distal portion of the ablation electrode such that they can contact the tissue of the patient organ, and the one or more sensing electrodes are configured to sense electrical signals from the tissue when positioned in contact with the tissue of the patient organ.

6. 6. The method of claim 5, wherein forming the distal opening comprises forming the distal opening sized and shaped to be sealed by the guidewire to prevent leakage of the irrigation fluid from the distal opening.

7. The method described in claim 5, wherein the one or more sensing electrodes are three sensing electrodes arranged around the longitudinal axis and electrically insulated from the ablation electrode.

8. The method described in claim 5, wherein the patient organ is the heart.

9. A catheter, an insertion tube for insertion into a patient's organ; an ablation electrode having a longitudinal axis, the ablation electrode including: a cylindrical portion extending along the longitudinal axis; and a distal portion extending distally and radially inward from a distal circumferential portion of the cylindrical portion toward a distal end of the ablation electrode, the ablation electrode including a distal opening at the distal end for passing a guidewire through the ablation electrode; one or more sensing electrodes at least partially disposed on the distal portion of the ablation electrode so as to be in contact with tissue of the patient organ, the one or more sensing electrodes being configured to sense electrical signals from the tissue when positioned in contact with the tissue of the patient organ; an irrigation channel including: (i) a lumen formed along an axis of the insertion tube and configured to channel irrigation fluid to a distal end of the insertion tube; and (ii) one or more irrigation holes formed in the distal end of the insertion tube and configured to apply the irrigation fluid to the patient organ, the ablation electrode, and the one or more sensing electrodes, the irrigation channel configured to (i) receive the guidewire for guiding the catheter while (ii) channeling the irrigation fluid; A catheter comprising:

10. 10. The catheter of claim 9, wherein the distal opening and the guidewire are matched in diameter to prevent leakage of the irrigation fluid from the distal opening.

11. A catheter as described in claim 9, wherein the one or more sensing electrodes are three sensing electrodes arranged around the longitudinal axis and electrically insulated from the ablation electrode.

12. A catheter as described in claim 9, wherein the patient organ is the heart.

Images