Source: https://patents.google.com/patent/CA2688973C/en
Timestamp: 2019-10-15 08:57:04
Document Index: 411731947

Matched Legal Cases: ['art 12', 'art 12', 'art 12', 'art 12', 'art 12', 'art 12']

CA2688973C - Dual-purpose lasso catheter with irrigation - Google Patents
CA2688973C
CA2688973C CA2688973A CA2688973A CA2688973C CA 2688973 C CA2688973 C CA 2688973C CA 2688973 A CA2688973 A CA 2688973A CA 2688973 A CA2688973 A CA 2688973A CA 2688973 C CA2688973 C CA 2688973C
CA2688973A
CA2688973A1 (en
2008-12-30 Priority to US12/345,720 priority
2010-06-30 Publication of CA2688973A1 publication Critical patent/CA2688973A1/en
2017-06-06 Publication of CA2688973C publication Critical patent/CA2688973C/en
Dual-Purpose Lasso Catheter with Irrigation FIELD OF THE INVENTION
This invention relates to cardiac mapping and abla-tion systems. More particularly, this invention relates to a lasso catheter for use in a cardiac mapping and ablation system.
Cardiac arrhythmia, such as atrial fibrillation, oc-curs when regions of cardiac tissue abnormally conduct electric signals to adjacent tissue, thereby disrupting the normal cardiac cycle and causing asynchronous rhythm.
Important sources of undesired signals are located in the tissue region along the pulmonary veins of the left atrium and in the superior pulmonary veins. In this condition, after unwanted signals are generated in the pulmonary veins or conducted through the pulmonary veins from other sources, they are conducted into the left atrium where they can initiate or continue arrhythmia.
Procedures for treating arrhythmia include surgically disrupting the origin of the signals causing the arrhyth-mia, as well as disrupting the conducting pathway for such signals. more recently, it has been found that by mapping the electrical properties of the endocardium and the heart volume, and selectively ablating cardiac tissue by appli-cation of energy, it is sometimes possible to cease or modify the propagation of unwanted electrical signals from one portion of the heart to another. The ablation process destroys the unwanted electrical pathways by formation of non-conducting lesions.
In this two-step procedure--mapping followed by abla-tion--electrical activity at points in the heart is typi-cally sensed and measured by advancing a catheter contain-ing one or more electrical sensors into the heart, and ac-quiring data at a multiplicity of points. These data are then utilized to select the target areas at which ablation is to be performed.
U.S. Pat. No. 6,063,022 to Ben-Haim, which is assigned to the assignee of the present patent application, de-scribes an invasive probe including two position sensors in a fixed, known relation to the distal end of the probe.
The position sensors generate signals responsive to their respective position coordinates and at least one contact sensor along a radial surface of the probe for generating a signal representing its contact with body tissue to be ablated by electrodes on the probe.
U.S. Pat. No. 6,272,371 to Ben-Haim, which is assigned to the assignee of the present patent application, de-scribes an invasive probe including a flexible portion that assumes a predetermined curve form when a force is applied thereto. Two position sensors, fixed to the distal portion of the probe in known positions, are used to de-termine position and orientation coordinates of at least one of the sensors, and to determine the locations of a plurality of points along the length of the distal portion of the probe.
PCT Patent Publication WO 96/05768 and corresponding U.S. Patent Application Publication 2002/0065455 to Ben-Haim et al., which are assigned to the assignee of the present patent application, describe a system that gener-ates six-dimensional position and orientation information regarding the tip of a catheter. This system uses a plu-rality of
2 , sensor coils adjacent to a locatable site in the catheter, for example near its distal end, and a plurality of radia-tor coils fixed in an external reference frame. These coils generate signals in response to magnetic fields gen-erated by the radiator coils, which signals allow for the computation of six position and orientation dimensions, so that the position and orientation of the catheter are known without the need for imaging the catheter.
A lasso catheter is disclosed in commonly assigned U.S. Patent No. 6,973,339. The lasso catheter is particu-larly adapted for pulmonary vein mapping and ablation.
This catheter comprises: a curved section having a first position sensor that is capable of generating fewer than six dimensions of position and orientation information, one or more electrodes, adapted to measure an electrical property of the pulmonary vein; and a base section at-tached to a proximal end of the curved section. Disposed on the base section within 3 mm of the distal end thereof is a second position sensor, capable of generating six di-mensions of position and orientation information.
Lasso catheters are generally used for ablating tissue along an arc surrounding an anatomical structure, such as the ostium of a pulmonary vein. Conventionally, the curved section or loop of the lasso catheter is generally thin and "floppy," for purposes of maneuverability, while ring electrodes disposed on the lasso are relatively large in order to minimize electrical resistance.
Embodiments of the present invention provide a lasso catheter that may be used for both ablation and sensing, and which has other advantageous features. Its distal curved portion, sometimes referred to herein as a "loop"
3 or "loop segment", is typically thicker and stiffer than that of conventional lasso catheters. Rather than ring electrodes, the lasso catheter has relatively small, raised protuberant electrodes. The small size of these electrodes is advantageous in permitting measurement of local electrical activity with good spatial resolution.
The bulges of the electrodes increase the surface area that is in contact with the heart tissue, and thus reduces the electrical resistance when the electrodes are used for ablation.
In order to provide local cooling and prevent adhesion during ablation, the electrodes may be fenestrated by mul-tiple perforations. The perforations are in fluid contact with a lumen, which carries irrigation fluid from within the catheter to the outer surfaces of the electrodes and thence to the adjacent tissues. Another lumen may contain wires connected to each of the electrodes.
An embodiment of the invention provides a catheter, including an insertion tube and a resilient distal section fixed to the distal end of the insertion tube. The distal section has an inner irrigating lumen and a plurality of electrodes that bulge above the outer surface. The elec-trodes have a plurality of perforations formed there-through, and the outer surface is in fluid communication with the irrigating lumen via the perforations.
According to an aspect of the catheter, the insertion tube is configured for insertion through a blood vessel into a heart of a subject, and wherein the resilient dis-tal section defines an open loop when deployed within the heart.
An embodiment of the invention provides a method for locating an arrhythmogenic area in a heart of a living subject, The method is further carried out by inserting a catheter into a chamber of the heart, the catheter includ-
4 , ing an insertion tube and a resilient distal section that has an inner irrigating lumen and is fixed to the distal end of the insertion tube. The distal section also in-cludes a plurality of electrodes that bulge above the out-er surface, the electrodes having a plurality of perfora-tions formed therethrough. The outer surface of the distal section is in fluid communication with the irrigating lu-men via the perforations, The method is further carried out by locating the catheter in proximity to a target in the chamber, analyzing electrical signals received from the target via the catheter to make a determination that the electrical signals are indicative of abnormal electri-cal conduction within the heart, and responsively to the determination, conducting energy into the heart to thereby affect the abnormal electrical conduction.
In accordance with another aspect, there is provided a catheter, comprising: an insertion tube having a distal end; and a resilient distal section fixed to the distal end of the insertion tube, the distal section having an outer surface with a circumference and an inner irrigating lumen and comprises a plurality of rounded cap-shaped electrodes that bulge above the outer surface, the elec-trodes each having a plurality of perforations formed therethrough, the outer surface being in fluid communica-tion with the irrigating lumen via the perforations, and wherein the electrodes extend over less than the circum-ference of the outer surface.
For a better understanding of the present invention, reference is made to the detailed description of the in-vention, by way of example, which is to be read in con-junction with the following drawings, wherein like ele-ments are given like reference numerals, and wherein:
Fig. 1 is a pictorial illustration of a system for de-tecting areas of abnormal electrical activity and perform-ing ablative procedures on a heart of a living subject in accordance with a disclosed embodiment of the invention;
5a Fig. 5 is a fragmentary elevational view of the shaft of a catheter that is constructed and operative in accordance with an alternate embodiment of the invention;
and Fig. 8 is a fragmentary elevational view of a shaft of a catheter having a plurality of linear electrode arrays that is constructed and operative in accordance with an alternate embodiment of the invention.
In the following description, numerous specific de-tails are set forth in order to provide a thorough under-standing of the various principles of the present inven-tion. It will be apparent to one skilled in the art, how-ever, that not all these details are necessarily always needed for practicing the present invention. In this in-stance, well-known circuits, control logic, and the de-tails of computer program instructions for conventional algorithms and processes have not been shown in detail in order not to obscure the general concepts unnecessarily.
Turning now to the drawings, reference is initially made to Fig. 1, which is a pictorial illustration of a system 10 for detecting areas of abnormal electrical ac-tivity and performing ablative procedures on a heart 12 of a living subject in accordance with a disclosed embodiment of the invention. The system comprises a lasso cathe-ter 14, which is percutaneously inserted by an opera-tor 16, who is typically a physician, through the pa-tient's vascular system into a chamber or vascular struc-
6 ture of the heart. The operator 16 brings the catheter's distal tip 18 into contact with the heart wall at a target site that is to be evaluated. Electrical activation maps are then prepared, according to the methods disclosed in the above-noted U.S. Patent Nos. 6,226,542, and 6,301,496, and in commonly assigned U.S. Patent No. 6,892,091.
Areas determined to be abnormal by evaluation of the electrical activation maps can be ablated by application of thermal energy, e.g., by passage of radiofrequency electrical current through wires in the catheter to one or more electrodes at the distal tip 18, which apply the ra-diofrequency energy to the myocardium. The energy is ab-sorbed in the tissue, heating it to a point (typically about 50 C) at which it permanently loses its electrical excitability. When successful, this procedure creates non-conducting lesions in the cardiac tissue, which disrupt the abnormal electrical pathway causing the arrhythmia.
Alternatively, other known methods of applying ablative energy can be used, e.g., ultrasound energy, as disclosed in U.S. Patent Application Publication No. 2004/0102769.
The principles of the invention can be applied to differ-ent heart chambers, and to mapping in sinus rhythm, and when many different cardiac arrhythmias are present.
The catheter 14 typically comprises a handle 20, hay-ing suitable controls on the handle to enable the opera-tor 16 to steer, position and orient the distal end of the catheter as desired for the ablation. To aid the opera-tor 16, the distal portion of the catheter 14 contains po-sition sensors (not shown) that provide signals to a posi-tioning processor 22, located in a console 24. The con-sole 24 typically contains an ablation power generator 25.
The catheter 14 may be adapted to conduct ablative energy
7 to the heart using any known ablation technique, e.g., ra-diofrequency energy, ultrasound energy, and laser energy.
Such methods are disclosed in commonly assigned U.S. Pa-tent Nos. 6,814,733, 6,997,924, and 7,156,816.
The positioning processor 22 is an element of a posi-tioning system 26 that measures location and orientation coordinates of the catheter 14. Throughout this patent ap-plication, the term "location" refers to the spatial coor-dinates of the catheter, and the term "orientation" refers to its angular coordinates. The term "position" refers to the full positional information of the catheter, compris-ing both location and orientation coordinates.
In one embodiment, the positioning system 26 comprises a magnetic position tracking system that determines the position and orientation of the catheter 14. The position-ing system 26 generates magnetic fields in a predefined working volume its vicinity and senses these fields at the catheter. The positioning system 26 typically comprises a set of external radiators, such as field generating coils 28, which are located in fixed, known positions ex-ternal to the patient. The coils 28 generate fields, typi-cally electromagnetic fields, in the vicinity of the heart 12.
Some position tracking systems that may be used for this purpose are described, for example, in the above-noted U.S. Patents 6,690,963, and in commonly assigned U.S. Patent Nos. 6,618,612 and 6,332,089, and U.S. Patent Application Publications 2004/0147920, and 2004/0068178.
Although the positioning system 26 shown in Fig. 1 uses magnetic fields, the methods described below may be imple-
8 mented using any other suitable positioning system, such as systems based on electromagnetic fields, acoustic or ultrasonic measurements. The positioning system 26 may be realized as the CARTO XP EP Navigation and Ablation 5ys-tem, available from Biosense Webster, Inc., 3333 Diamond Canyon Road, Diamond Bar, CA 91765.
As noted above, the catheter 14 is coupled to the con-sole 24, which enables the operator 16 to observe and reg-ulate the functions of the catheter 14. Console 24 in-cludes a processor, preferably a computer with appropriate signal processing circuits. The processor is coupled to drive a monitor 29. The signal processing circuits typi-cally receive, amplify, filter and digitize signals from the catheter 14, including signals generated by the sen-sors 31, 33 and a plurality of sensing electrodes 35. The digitized signals are received and used by the console 24 to compute the position and orientation of the catheter 14 and to analyze the electrical signals from the electrodes.
The information derived from this analysis is used to gen-erate an electrophysiological map of at least a portion of the heart 12 or structures such as the pulmonary venous ostia, for diagnostic purposes such as locating an ar-rhythmogenic area in the heart or to facilitate therapeu-tic ablation.
Typically, the system 10 includes other elements, which are not shown in the figures for the sake of sim-plicity. For example, the system 10 may include an elec-trocardiogram (ECG) monitor, coupled to receive signals from one or more body surface electrodes, so as to provide an ECG synchronization signal to the console 24. As men-tioned above, the system 10 typically also includes a ref-erence position sensor, either on an externally-applied
9 reference patch attached to the exterior of the subject's body, or on an internally-placed catheter, which is in-serted into the heart 12 maintained in a fixed position relative to the heart 12. By comparing the position of the catheter 14 to that of the reference catheter, the coordi-nates of catheter 14 are accurately determined relative to the heart 12, irrespective of heart motion. Alternatively, any other suitable method may be used to compensate for heart motion.
Reference is now made to Fig. 2, which is a side ele-vation of a lasso catheter 37 that is constructed and op-erative in accordance with a disclosed embodiment of the invention. The catheter 37 is a steerable device. Its han-dle, control and steering mechanisms (not shown) are con-ventional and are omitted from Fig. 2 for simplicity. The catheter 37 features a base segment 39, which is bendable responsively to forces applied by the steering mechanisms.
A distal curved section, referred to herein as loop seg-ment 41, completes the lasso configuration. The loop seg-ment 41 is joined to the base segment 39 by a range-restricted angle 0/ at a joint 43. The angle U between the loop segment 41 and the base segment 39 optimally is about 90 decrees. The joint 43 may define a point where two ini-tially-separate members (base segment 39; loop segment 41) are joined, or, alternatively, the joint 43 may define a point on the catheter 37 where a single member is bent, so as to form the base segment 39 and the loop segment 41.
The loop segment 41 is of a known fixed length, having a curvature dimensioned to a particular medical application.
The curvature may be adjustable using the steering and control mechanisms (not shown) of the catheter. A ra-dius 45 of adjustable between 7 - 15 mm is suitable for cardiac applications. However, the radius 45 may vary up to 25 mm in some applications. In any case, the loop seg-ment 41 may be dimensioned so as to conform to structures such as the ostia of pulmonary veins or the coronary si-nus.
The loop segment 41 is constructed of a material that preferably is twistable but not stretchable when subjected to typical forces encountered in medical practice. Pref-erably, the loop segment 41 is sufficiently resilient so as to assume a predetermined curved form, i.e., an open circular or semicircular form when no force is applied thereto, and to be deflected from the predetermined curved form when a force is applied thereto. Preferably, the loop segment 41 has an elasticity that is generally constant over at least a portion of its length, for example, be-cause of internal reinforcement of the curved section with a resilient longitudinal member, as is known in the art.
The loop segment 41 is generally thicker and stiffer than conventional lassos. For example, the loop segment 41 may be made from polyurethane and be at least one mm in diame-ter.
One or more electrodes 35, adapted for sensing elec-trical characteristics of cardiac tissue, are fixed to the loop segment 41. Reference is now made to Fig. 3, which is a cross section through the catheter 37 (Fig. 2) taken through line 3-3, illustrating one of the electrodes 35.
The electrodes 35 may bulge between about 0.1-0.5 mm above the outer surface 47 and have a generally rounded profile, forming a cap on the surface 47. In some embodiments the electrodes 35 may have a larger bulge, up to 1 mm above the surface. The electrodes 35 may extend over 25-270 per cent of the circumference of the surface 47, as contrasted with a conventional ring electrode, which covers 100% of the circumference. The electrodes 35 may have a circular border. Alternatively, they may be elliptical in contour, as further described below. These configurations provide substantial contact between the electrodes 35 and the car-diac tissue, lowering electrical resistance as compared with conventional electrodes. The electrodes 35 may be 2-5 mm in dimension. The electrodes 35 may also be used for ablation, in which case the reduced electrical resistance is particularly advantageous. In one embodiment, two of the electrodes 35 are selected for performing bi-polar ab-lation, e.g., radiofrequency ablation in which case a ca-ble 57 may include wires individually leading to the elec-trodes 35.
The exterior surface of the electrodes 35 is fenes-trated by multiple small perforations 49 formed there-through. Typically there are between 1 and 50 perforations having diameters of 0.05-0.4 mm. The perforations 49 are in fluid communication with an irrigating lumen 51 through a channel 53. A second lumen 55 carries cable 57 compris-ing one or more electrically conductive wires that link the electrodes 35 to the console 24 (Fig. 1), for example wire 59. The lumen 55 may also conduct additional wires as described below.
Reference is now made to Fig. 4, which is a fragmen-tary elevational view of a shaft 61 of a catheter that is constructed and operative in accordance with a disclosed embodiment of the invention. Electrodes 63 are circular in contour, and the surface distribution of perforations 49 is substantially uniform.
Reverting to Fig. 2, at least a first single-coil po-sition sensor 31 is fixed to loop segment 41. Preferably, the sensor 31 is fixed to the distal end of the loop seg-ment 41 (distal with respect to the base segment 39), and a second single-coil position sensor 33 is fixed to the approximate center of the loop segment 41. Optionally, one or more additional single-coil position sensors (not shown) are fixed to the loop segment 41. Additionally, a multi-coil position sensor 65 is preferably fixed near the distal end of the base segment 39, in the vicinity of the joint 43, typically within 10 mm of the distal end. The sensor 65 is preferably able to generate six position and orientation dimensions, using techniques described in the above-cited PCT Patent Publications to Ben-Haim et al., or other techniques known in the art. The sensor 65 prefera-bly comprises two or three coils, which are generally suf-ficient for generating six dimensions of position informa-tion. The sensors 31, 33 are preferably able to generate five position and orientation dimensions. A preferred electromagnetic mapping sensor is manufactured by Biosense Webster (Israel) Ltd., (Tirat Hacarmel, Israel) and mar-keted under the trade designation NOGA.TM. Alternatively, the sensors 31, 33, 65 comprise field sensors other than coils, such as Hall effect devices or other antennae, in which case the sensors 31, 33 are preferably smaller than the sensor 65.
The sensors 31, 33, 65 are fixed to the catheter 37 by any suitable method, for example, using polyurethane glue or the like. The sensors 31, 33, 65 are electrically con-nected to the cable 57 (Fig. 3), which extends through the catheter body and into a control handle (not shown) of the catheter 37. The cable 57 preferably comprises multiple wires encased within a plastic covered sheath. Within the catheter body, the cable 57 may be enclosed within a pro-tective sheath along with wire 59 (Fig. 3). Preferably, in the control handle, the wires of the sensor cable are con-nected to a circuit board (not shown), which amplifies the signals received from the position sensors and transmits them to a computer housed in the console 24 (Fig. 1), in a form understandable to the computer. Alternatively, ampli-fying circuitry is included at the distal end of cathe-ter 37, so as to reduce the effect of noise.
Reference is again made to Fig. 1. In order to use the position sensors 31, 33, 65, the subject is placed in a magnetic field that is generated, for example, by situat-ing under the subject a pad containing field generator coils 28 for generating a magnetic field. A reference electromagnetic sensor (not shown) is preferably fixed relative to the subject, e.g., taped to the subject's back, and the catheter 37 is advanced into the subject's heart and into a desired location in or near one of the cardiac chambers, for example one of the pulmonary veins.
Reverting now to Fig. 2, the coils in the sensors 31, 33, 65 generate weak electrical signals indicative of their position in the magnetic field. Signals generated by both the fixed reference sensor and the sensors 31, 33, 65 sen-sors in the heart are amplified and transmitted to coils 28 (Fig. 1), which analyzes the signals so as to fa-cilitate the determination and visual display of the pre-cise location of the sensors 31, 33, 65 relative to the reference sensor.
Each of the sensors 31, 33 preferably comprises one coil, and the sensor 65 preferably comprises three non-concentric, typically mutually orthogonal coils, such as those described in the above-cited PCT Patent Publication WO 96/05768. The coils sense magnetic fields generated by the coils 28, which are driven by driver circuits in the generator 25 (Fig. 1). Alternatively, the sensors may gen-erate fields, which are detected by fixed sensing coils (not shown), in which case the coils 28 can be omitted.
The system 10 thus achieves continuous generation of five dimensions of position and orientation information with respect to each of the sensors 31, 33, and six dimensions with respect to position the sensor 65.
Reference is now made to Fig. 5, which is a fragmen-tary elevational view of a shaft 67 of a catheter that is constructed and operative in accordance with an alternate embodiment of the invention. Electrodes 69 are elliptical in contour. The longitudinal axis 71 of the shaft 67 is aligned with the major axes of the elliptical electrodes.
As in the previous embodiment, the surface distribution of perforations 49 is substantially uniform.
Reference is now made to Fig. 6, which is a fragmen-tary elevational view of a shaft 73 of a catheter that is constructed and operative in accordance with an alternate embodiment of the invention. Electrodes 75 are elliptical in contour. The longitudinal axis 71 of the shaft 73 is aligned with the minor axes of the elliptical electrodes.
As in the previous embodiments, the surface distribution of perforations 49 is substantially uniform.
The irrigated bump electrodes shown in the figure may also be arrayed along the length of catheters or probes of other types than lasso catheters. Reference is now made to Fig. 7, which is a schematic view of a cardiac catheter 77 in accordance with an alternate embodiment of the inven-tion.
The catheter 77 includes a flexible body 79. An elec-trode 81 is at a distal portion 83 disposed for measuring the electrical properties of the heart tissue or for ab-lating defective cardiac tissue. The distal portion 83 further includes an array of non-contact electrodes 85 for measuring far field electrical signals in the heart cham-ber. The electrodes 85 may be constructed in accordance with any of the preceding embodiments. The details are not repeated in the interest of brevity.
An array is a linear array in that the non-contact electrodes 85 are linearly arranged along the longitudinal axis of the distal portion 83. The distal portion 83 fur-ther includes at least one position sensor 89 that gener-ates signals used to determine the position and orienta-tion of the distal tip 91 within the body. The position sensor 89 is preferably adjacent to the tip 91. There is a fixed positional and orientational relationship of the po-sition sensor 89, the tip 91 and the electrode 81.
A handle 93 of the catheter 14 includes controls 95 to steer or deflect the distal portion 83, or to orient it as desired. A cable 97 comprises a receptacle 99, which con-nects to the handle 93. The cable 97 may one or more iso-lation transformers (not shown), which electrically iso-late the catheter 77 from the console 24 (Fig. 1). Alter-natively, the isolation transformers may be contained in the receptacle 99 or in the system electronics of the con-sole 24.
In embodiments in which there are three or more elec-trodes 85, they may be aligned as a single linear array along the shaft of the distal portion 83 as shown in Fig. 7.
Reference is now made to Fig. 8, which is a fragmen-tary elevational view of a shaft 103 of a catheter that is constructed and operative in accordance with an alternate embodiment of the invention. Alternatively, the elec-trodes 85 may be disposed as one or more arrays that spi-ral about the having circumferentially aligned or stag-gered electrodes that are distributed about the circumfer-ence of the shaft 103, and may forming a plurality of lin-ear arrays. For example, as shown in Fig. 8, elec-trodes 105, 107 form a portion of a first linear array along broken line 109. Electrodes 111, 113 form a portion of a second linear array along broken line 115.
an insertion tube having a distal end; and a resilient distal section fixed to the distal end of the insertion tube, the distal section having an outer surface with a circumference and an inner irrigating lumen and comprises a plurality of rounded cap-shaped electrodes that bulge above the outer surface, the electrodes each having a plurality of perforations formed therethrough, the outer surface being in fluid communication with the irrigating lumen via the perforations, and wherein the electrodes extend over less than the circumference of the outer surface.
5. The catheter according to any one of claims 1-4, wherein the electrodes comprise at least three electrodes that are aligned as a linear array with a longitudinal axis of the distal section.
6. The catheter according to any one of claims 1-5, wherein the electrodes comprise at least 2 perforations.
7. The catheter according to any one of claims 1-5, wherein the electrodes comprise between 2 and 100 perforations.
8. The catheter according to any one of claims 1-7, wherein the perforations of the electrodes measure between 0.05 mm and 0.4 mm in diameter.
9. The catheter according to any one of claims 1-8, further comprising at least one electrically conductive wire that links the electrodes to a processor.
10. The catheter according to any one of claims 1-9, wherein the electrodes bulge up to 1 mm above the outer surface.
11. The catheter according to any one of claims 1-9, wherein the electrodes bulge between 0.05 mm and 0.5 mm above the outer surface.
12. The catheter according to any one of claims 1-11, wherein the electrodes are circular in contour.
13. The catheter according to any one of claims 1-11, wherein the distal section has a longitudinal axis and wherein the electrodes are elliptical in contour.
14. The catheter according to claim 13, wherein the electrodes have respective major axes that are aligned with the longitudinal axis.
15. The catheter according to claim 13, wherein the electrodes have respective minor axes that are aligned with the longitudinal axis.
16. The catheter according to any one of claims 1-15, further comprising a base section having a proximal end and a distal end and a multi-coil position sensor for generating position and orientation dimensions.
17. The catheter according to claim 16, wherein the multi-coil position sensor is within 10 mm of the distal end of the base section.
CA2688973A 2008-12-30 2009-12-22 Dual-purpose lasso catheter with irrigation Active CA2688973C (en)
US12/345,720 2008-12-30
CA2964662A CA2964662A1 (en) 2008-12-30 2009-12-22 Dual-purpose lasso catheter with irrigation
CA2688973A1 CA2688973A1 (en) 2010-06-30
CA2688973C true CA2688973C (en) 2017-06-06
CA2964662A Pending CA2964662A1 (en) 2008-12-30 2009-12-22 Dual-purpose lasso catheter with irrigation
CA2688973A Active CA2688973C (en) 2008-12-30 2009-12-22 Dual-purpose lasso catheter with irrigation
CA (2) CA2964662A1 (en)
CN103025226B (en) 2010-08-31 2017-02-22 库克医学技术有限责任公司 Ablation casing
CN101766502B (en) 2015-03-11