Flush Electrophysiology Catheter with Resolvable Electrodes for Multi-Electrode Identification and Orientation

Abstract

The present invention is titled "Flush Electrophysiology Catheter with Resolvable Electrodes for Multi-Electrode Identification and Orientation under Two-Dimensional Visualization". An electrophysiology catheter having a balloon with a membrane is disclosed. Electrodes may be disposed on the membrane. Each electrode may include a radiopaque marker. The marker may have different forms, such as alphanumeric or polygonal, to facilitate visualization of the electrodes using a bistable image and to allow selection of the appropriate electrodes to be energized during tissue ablation. The subject matter of the present invention allows for proper orientation of the electrodes on the balloon under a two-dimensional imaging system. This allows an operator or physician to determine whether certain electrodes are adjacent or contiguous to the posterior surface of the left atrium and to ablate such posterior surface for a shorter duration or at a lower power to create an effective transmural lesion on the posterior wall of the left atrium while reducing the chance of damaging adjacent anatomical structures.

Description

Technical Field

[0001] The subject matter disclosed herein relates to electrophysiological catheters, specifically those capable of ablating cardiac tissue. Background Art

[0002] Ablating cardiac tissue has been used to treat arrhythmias. Ablation energy is typically provided to the cardiac tissue through a tip portion that can deliver the ablation energy adjacent to the tissue to be ablated. Some of these catheters deliver ablation energy from various electrode three-dimensional structures. Fluoroscopic examination can be used to observe ablation procedures incorporating such catheters. Summary of the Invention

[0003] Although fluoroscopic visualization of cardiac devices is an established visualization method that is easier to use than magnetic position and impedance systems for electrophysiology procedures (EP), it is currently only used to determine the overall device position relative to the cardiac silhouette. The limitations of fluoroscopic visualization become apparent when considering the use of multi-electrode devices for EP with fluoroscopic visualization. This is because fluoroscopic images are strictly 2D and lack any depth-related visual cues. In the world of human visual perception, this is known as a bistable image. To correctly resolve the relative orientation of the device in a bistable image, the human brain requires cues to orient the image. When designing an electrophysiological catheter having a plurality of electrodes arranged in an array about a longitudinal axis of a balloon for ablation of the PV, the applicant has found that for a bistable image, it is necessary to determine the orientation of the electrodes and which electrodes should be energized. That is, according to the electroanatomical mapping of the subject, it may not be necessary to energize all electrode arrays, which would typically form a circular ablation tissue under bistable visualization. Additionally, in determining that some electrodes may be in contact with tissue while some other electrodes may not be in contact with tissue, it may be desirable to only activate those electrodes that are in contact with the tissue. Therefore, the applicant has configured the catheter to allow the operator to determine which electrode in the electrode array of the balloon is energized under bistable visualization in order to minimize the excess energy applied to tissue that does not need to be ablated.

[0004] Accordingly, the applicant has designed an electrophysiology catheter having a balloon with a membrane. The balloon may have a distal end and a proximal end defining a longitudinal axis. A first electrode may be disposed on the membrane. The first electrode may include a first radiopaque marker of a first form disposed thereon. A second electrode may also be disposed on the membrane. The second electrode may include a second radiopaque marker of a second form disposed thereon. In some embodiments, the second form may be different from the first form. In some embodiments, the first form may be a first number, and the second form may be a second number. For example, the first number may be "1", and the second number may be a number greater than "1", such as "4". These different forms allow the operator to distinguish which electrode is spaced apart relative to another electrode arranged on the balloon and allow the technique to identify all other electrodes arranged on the balloon. In one embodiment, two markers of different forms on two corresponding electrodes are separated by at least one electrode without any different marker forms. Additionally, two markers of different forms on two corresponding electrodes are separated by one or more electrodes from markers of another form. In some embodiments, two markers of different forms on two corresponding electrodes are separated by two electrodes without any different forms. Additionally, two markers of different forms on two corresponding electrodes are separated by two electrodes from markers of another form for other electrodes. As described herein, the markers may be provided on a substrate as a component different from the electrode or formed as part of the electrode.

[0005] In some embodiments, the first form may be a first polygon, and the second form may be a second polygon. For example, the first polygon may be rectangular or it may be a rectangle, and the second polygon may be triangular or it may be a triangle. These polygons may be solid or filled, or they may be hollow or unfilled. Thus, the first polygon may be solid, and the second polygon may be hollow, or alternatively it may be solid. In certain embodiments, the second polygon may be asymmetric with respect to other features of the catheter. For example, the second polygon may be asymmetric about a centerline parallel to the longitudinal axis of the balloon. An example of an asymmetric polygon is an arrow not indicating along the centerline. Instead, the arrow may point to another electrode, such as a third electrode, which may be an electrode adjacent to the electrode including the marker. In those embodiments including markers in the form of asymmetric polygons, the forms of these asymmetric polygons may be the same or some may be different. For example, at least one may be solid, and at least one may be hollow.

[0006] In the foregoing embodiments, a third radiopaque marker may additionally be included on the third electrode. In those embodiments where the first and second electrodes include markers in the form of alphanumeric symbols, the third electrode may also include a marker in the form of an alphanumeric symbol. For example, the form of the third marker may be a number greater than the number of the second marker. Thus, the third marker may have the following form, for example, "7". In those embodiments where the first and second electrodes include markers in the form of polygons, the third electrode may also include a marker in the form of a polygon. Thus, the third marker may be in the form of a triangle, for example, it may be a triangle. Like the first and second polygon markers, the third polygon marker may be solid or hollow. In certain embodiments, the first marker is solid and the second and third markers are both hollow. In other embodiments, the first marker is hollow and the second and third markers are both solid. In other embodiments, the first and second markers are both solid and the third marker is hollow. In those embodiments including an asymmetrical polygon, the third marker may be another asymmetrical polygon, such as a triangle or an arrow, which may point to another electrode, such as the final electrode or the last electrode, which may be adjacent to the first electrode.

[0007] Each of the electrodes may be disposed on the membrane of the catheter balloon in a circumferential pattern. Thus, in certain embodiments, the first, second, third, and final electrodes are disposed circumferentially around the membrane such that the final electrode is disposed on the membrane between the third and first electrodes. A fourth electrode may be disposed on the membrane between the first and second electrodes, and a fifth electrode may be disposed on the membrane between the second and third electrodes. The fourth electrode may include a radiopaque marker in a fourth form, the fifth electrode may include a radiopaque marker in a fifth form, and the final electrode may include a radiopaque marker in a final form.

[0008] In certain embodiments, the first form may additionally include a first line, the second form may additionally include a second line, and the third form may additionally include a third line. The radiopaque marker does not need to be in the form of a number or a polygon. For example, the radiopaque marker may be only a ridge or a line. The line may be solid, dashed, or hashed. Thus, in certain embodiments, the fourth form may be a fourth line, the fifth form may be a fifth line, and the final form may be a final line.

[0009] In additional embodiments, a sixth electrode may be disposed on the membrane between the first and fourth electrodes, a seventh electrode may be disposed on the membrane between the second and fifth electrodes, an eighth electrode may be disposed on the membrane between the third and final electrodes, and a ninth electrode may be disposed on the membrane between the eighth and final electrodes.

[0010] In some of these embodiments, the first line may be solid, the second line may be solid, the third line may be solid, the fourth line may be dashed, the fifth line may be dashed, and the final line may be dashed. In some of these embodiments, the fourth line may be solid, the second line may be dashed, the fifth line may be dashed, the third line may be dotted, and the final line may be dotted.

[0011] In any of the embodiments including radiopaque markers in the form of lines, the lengths of the lines may be the same or may vary. For example, the fourth line may be longer than the first line, the second line may be longer than the fourth line, the fifth line may be longer than the second line, the third line may be longer than the fifth line, and the final line may be longer than the third line.

[0012] In some embodiments including polygonal markers, the first polygon may be disposed near the end of the first line, such as the proximal end of the first line. The second polygon may be disposed near the end of the second line, such as the proximal end of the second line. Additionally, the second polygon may be disposed near the midpoint of the second line.

[0013] In other embodiments including polygonal markers, the first polygon may be disposed near the midpoint of the first line, and the second polygon may be disposed near the end of the second line, such as the proximal end of the second line. Additionally, the second polygon may be disposed near the midpoint of the second line.

[0014] The catheter may be part of an electrophysiology system. In addition to the catheter, the electrophysiology system may further include an ablation module. The ablation module may include a radiofrequency signal generator, a first output terminal, and a second output terminal. The system may further include a first line in the circuit path between the first output terminal and a first electrode disposed on the balloon. The system may further include a second line in the circuit path between the second output terminal and a second electrode disposed on the balloon. In some embodiments, the first line may be at least partially disposed within the catheter, and the second line may be at least partially disposed within the catheter. Additionally, the first electrode may include a first radiopaque marker in a first form thereon, and the second electrode may include a second radiopaque marker in a second form different from the first form thereon. For example, the first form may be a rectangle, and the second form may be a triangle. In some embodiments, the rectangle is solid. In some embodiments, the triangle is also solid. However, in other embodiments, the triangle may be hollow.

[0015] A catheter can be used in its methods and variations to ablate tissue. In certain variations, a catheter can be provided. The balloon of the catheter can include a first electrode and a second electrode disposed thereon. The first electrode can be connected to a radiofrequency signal generator via a first switch. The second electrode can be connected to the same or a different radiofrequency generator via a second switch. The first electrode can include a first radiopaque marker disposed at least partially thereon. The second electrode can include a second radiopaque marker disposed at least partially thereon. The balloon can be positioned adjacent to tissue within a subject's anatomy, e.g., adjacent to or within a pulmonary vein ostium in a subject's heart. The balloon can be visualized therein using medical visualization techniques (e.g., MRI or fluoroscopy). From this visualization, a user can determine that the first marker contacts the tissue and then activate the first electrode by closing the switch. In some variations, the user can also determine that the second marker does not contact the tissue such that activation of the second electrode may be undesirable. However, in other variations, the user can determine that the second marker contacts the tissue and then activate the second electrode by closing the switch.

[0016] Because fluoroscopic images can be bistable, it may be difficult for a user to determine that the first switch can be used to activate the first electrode and that the second switch can be used to activate the second electrode. However, using radiopaque markers, the user can determine that the first switch activates the first electrode and that the second switch activates the second electrode. For example, the user can be aware that the first marker includes a first form that corresponds to the first switch such that the user can determine which switch to activate based on associating the first form with the first switch. In some variations, the user can also determine that the second switch activates the second electrode at least in part based on being aware of the association of the first form with the first switch by applying the right hand rule.

[0017] Furthermore, in those embodiments including a single radiofrequency generator, each electrode can receive radiofrequency energy having a similar frequency. However, in those embodiments including more than one radiofrequency generator, e.g., one generator per electrode, each electrode can receive radiofrequency energy having a different frequency.

[0018] In another aspect, we have designed a method of ablating tissue that can be achieved by the following steps: positioning an inflatable member adjacent to tissue within a subject's anatomy, the inflatable member having a longitudinal axis and including a plurality of electrodes disposed about the longitudinal axis, each electrode being capable of being independently energized, at least a first electrode being electrically connected to a first switch, the first electrode having a first radiopaque marker, and a second electrode being electrically connected to a second switch, the second electrode having a second radiopaque marker different from the first radiopaque marker; viewing a fluoroscopic image of the inflatable member; determining that the first marker contacts the tissue; and activating the first electrode using the first switch.

[0019] In addition, we have designed a method for applying energy to a subject's tissue, which can be achieved through the following steps: Position an inflatable member adjacent to the tissue within the subject's anatomical structure. The inflatable member has a longitudinal axis and includes a plurality of electrodes disposed around the longitudinal axis. Each electrode can be independently energized. At least a first electrode is electrically connected to a first switch, the first electrode has a first radiopaque marker, and a second electrode is electrically connected to a second switch, the second electrode having a second radiopaque marker different from the first radiopaque marker; View an image of the inflatable member; Determine that one or more electrodes adjacent to one of the first markers or the first markers contact the tissue; and Energize the one or more electrodes to ablate the tissue.

[0020] Finally, we have designed a method for applying energy to a target tissue area without damaging adjacent anatomical structures of the subject through the following steps: Position an inflatable member adjacent to the left atrium. The inflatable member has a longitudinal axis and includes a plurality of electrodes disposed around the longitudinal axis. Each electrode can be independently energized. The plurality of electrodes include a first electrode having a first radiopaque marker and a second electrode having a second radiopaque marker different from the first radiopaque marker; View an image of the inflatable member and the first and second radiopaque markers in the left atrium; Determine the orientation of the first and second radiopaque markers relative to the portion of the subject's left atrium closest to the esophagus, phrenic nerve, or lung; Move one of the first and second radiopaque markers to the portion of the left atrium closest to the esophagus, phrenic nerve, or lung; and Energize one or more electrodes indexed to one of the radiopaque markers with a lower energization setting compared to other electrodes to create a transmural lesion in the left atrium with little or no effect on adjacent anatomical structures such as the esophagus, phrenic nerve, or lung, the radiopaque marker being adjacent to the portion close to the esophagus, phrenic nerve, or lung. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Although the claims that particularly point out and clearly claim the subject matter described herein are set forth after the description, it is believed that the subject matter may be better understood from the following description of certain examples in conjunction with the accompanying drawings, in which like reference numerals represent the same elements, and in the drawings:

[0022] Figure 1 Is a schematic diagram of an invasive medical procedure;

[0023] Figure 2 Is a top view of a catheter with a balloon in an inflated state for use with a snare catheter;

[0024] Figure 3 IsFigure 2 Perspective view of balloon together with a snare catheter;

[0025] Figure 4 For deployment in the pulmonary veins and the area of the pulmonary vein ostia Figure 2 Side view of the distal end of the catheter;

[0026] Figure 5 Top plan view of a plurality of flexible circuit electrode assemblies before being assembled onto a Figure 3 balloon;

[0027] Figure 5A Top plan view of a plurality of flexible circuit electrode assemblies before being assembled onto a Figure 3 balloon, said plurality of flexible circuit electrode assemblies including radiopaque markers;

[0028] Figure 5B For Figure 3 fluoroscopic image illustration of a balloon, which includes Figure 5A a flexible circuit electrode assembly;

[0029] Figure 6 Perspective detail view of a flexible circuit electrode assembly after being assembled onto a Figure 3 balloon;

[0030] Figure 7A For Figure 5 magnified view of a part of one of the flexible circuit electrode assemblies, which includes a form of radiopaque marker;

[0031] Figure 7B For Figure 5 magnified view of a part of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0032] Figure 7C For Figure 5 magnified view of a part of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0033] Figure 7D For Figure 5 magnified view of a part of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0034] Figure 7E For Figure 5 magnified view of a part of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0035] Figure 7F For Figure 5An enlarged view of a portion of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0036] Figure 7G is Figure 5 An enlarged view of a portion of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0037] Figure 7H is Figure 5 An enlarged view of a portion of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0038] Figure 7I is Figure 5 An enlarged view of a portion of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0039] Figure 7J is Figure 5 An enlarged view of a portion of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0040] Figure 7K is Figure 5 An enlarged view of a portion of one of the flexible circuit electrode assemblies, which includes another form of radiopaque marker;

[0041] Figure 8A shows a balloon Figure 3 when including a radiopaque marker according to one embodiment;

[0042] Figure 8B is Figure 8A an alternative rotational view of the balloon;

[0043] Figure 9A shows a balloon Figure 3 when including a radiopaque marker according to another embodiment;

[0044] Figure 9B is Figure 9A an alternative rotational view of the balloon; and

[0045] Figure 10 shows a balloon Figure 3 when including a radiopaque marker according to a different embodiment;

[0046] Figure 11 、 Figure 12A 、 Figure 12B 、 Figure 13 and Figure 14 show more embodiments of radiopaque markers that can be used with the balloon;

[0047] Figure 15 shows a Figure 5B cross-sectional view of a balloon in the left atrium of a subject and other anatomical structures adjacent to the heart. DETAILED DESCRIPTION

[0048] The following detailed description should be read in conjunction with the accompanying drawings, in which like reference numerals refer to like elements in the different drawings. The drawings (not necessarily to scale) illustrate selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention in an illustrative, but not limiting, manner. This detailed description will clearly enable one of ordinary skill in the art to make and use the invention and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.

[0049] As used herein, the term "about" or "approximately" with respect to any numerical value or range indicates a suitable dimensional tolerance that allows the collection of components or elements to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values of plus or minus 10% of the recited value, e.g., "about 90%" can refer to a range of values from 81% to 99%. Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, although use of the subject invention in human patients represents a preferred embodiment.

[0050] Overview

[0051] Cardiac tissue ablation to correct a malfunctioning heart is a well-known procedure for achieving such correction. Typically, in order to effect successful ablation, it is necessary to measure cardiac electrode potentials at various locations in the myocardium. Additionally, temperature measurements during ablation provide data that enables the efficacy of the ablation to be measured. Typically, for an ablation procedure, electrode potentials and temperatures are measured before, during, and after the actual ablation.

[0052] Contrary to existing technology systems that use two or more separate instructions (e.g., one for electrode potential and temperature measurement and another for ablation), the embodiments disclosed herein facilitate both of these measurements and, in addition, are capable of using radiofrequency electromagnetic energy and using a single catheter for ablation. The catheter has a lumen, and a balloon is deployed through the catheter lumen (the balloon travels through the lumen in a collapsed, un-inflated configuration and is inflated when it exits the lumen). The balloon has an outer wall or membrane and has a distal end and a proximal end that define a longitudinal axis of an extending lumen.

[0053] A multi-layer flexible metal structure is attached to the outer wall or membrane of a balloon. The structure includes a plurality of electrode groups circumferentially arranged around a longitudinal axis, wherein each electrode group includes a plurality of ablation electrodes typically arranged longitudinally.

[0054] Each electrode group may further include at least one microelectrode that is physically and electrically insulated from the ablation electrodes in the group.

[0055] Each electrode group may further include at least one thermocouple.

[0056] In some embodiments, each electrode group has a microelectrode and a thermocouple formed at the same location.

[0057] In the case of having three functions of performing ablation, electrode potential measurement, and temperature measurement, using a single balloon catheter simplifies the cardiac ablation procedure.

[0058] System Description

[0059] Figure 1 FIG. is a schematic diagram of an invasive medical procedure using device 12 according to an embodiment of the present invention. The procedure is performed by a medical professional 14, and by way of example, it is assumed that the procedure in the following description includes ablating a portion of the myocardium 16 of the heart of a human patient 18. However, it should be understood that the embodiments disclosed herein are not limited to this particular procedure and may also include substantially any procedure for biological tissue or non-biological materials.

[0060] To perform ablation, the medical professional 14 inserts the probe 20 into a sheath 21 that has been pre-positioned in the patient's body cavity. The sheath 21 is positioned such that the distal end 22 of the probe 20 enters the patient's heart. A diagnostic / therapeutic catheter 24 (such as a balloon catheter) is deployed through the lumen 23 of the probe 20 and exits from the distal end of the probe 20. The diagnostic / therapeutic catheter is Figure 2 described in more detail below.

[0061] As Figure 1 shown, the device 12 is controlled by a system processor 46, which is located in the operation console 15 of the device. The console 15 includes controls 49 used by the professional 14 to communicate with the processor. During the procedure, the processor 46 typically uses any method known in the art to track the position and orientation of the distal end 22 of the probe 20. For example, the processor 46 may use a magnetic tracking method, wherein magnetic transmitters 25X, 25Y, and 25Z outside the patient 18 generate signals in coils located in the distal end of the probe 20. The system purchased from Biosense Webster, Inc., Irvine, California uses such a tracking method.

[0062] Software for the processor 46 can be downloaded electronically, for example, via a network, to the processor. Alternatively or in addition, the software can be provided on a non-transitory tangible medium such as an optical, magnetic, or electronic storage medium. On the screen 62, the tracking of the distal end 22 can be displayed on a three-dimensional representation 60 of the patient 18's heart. However, it can be displayed two-dimensionally, for example, by fluoroscopy or MRI.

[0063] To operate the device 12, the processor 46 communicates with a memory 50 that has a plurality of modules used by the processor to operate the device. Thus, the memory 50 includes a temperature module 52, an ablation module 54, and an electrocardiogram (ECG) module 56, the functions of which are described below. The memory 50 generally includes other modules, such as a force module for measuring the force on the distal end 22, a tracking module for operating the tracking method used by the processor 46, and a flush module that allows the processor to control the flush provided for the distal end 22. For simplicity, Figure 1 such other modules are not shown. The modules can include hardware elements as well as software elements. For example, the module 54 can include a radiofrequency generator with at least one output or output channel, for example, ten outputs or ten output channels. Each output can be individually and selectively activated or deactivated by a switch. That is, each switch can be disposed between the signal generator and the corresponding output. Thus, a generator with ten outputs will include ten switches. These outputs can each be individually coupled to electrodes (e.g., ten electrodes 33 on the balloon 80) on the ablation catheter, as described in further detail below. This electrical connection can be achieved by establishing a circuit path between each output and each electrode. For example, each output can be connected to the corresponding electrode by one or more wires or suitable electrical connectors. Thus, in some embodiments, the circuit path can include at least one wire. In some embodiments, the circuit path can also include an electrical connector and at least a second wire. Thus, the electrodes 33 can be selectively activated and deactivated with the switches to receive radiofrequency energy from each of the other electrodes, respectively.

[0064] Figure 3 is a schematic perspective view of a diagnostic / therapeutic catheter 24 in its expandable configuration in the form of a balloon in an expandable configuration according to one embodiment. In the disclosed embodiment, wherein the diagnostic / therapeutic catheter 24 is used to ablate a lumen, such as the lumen 11 of the pulmonary vein 13, as Figure 4As shown, the diagnostic / therapeutic catheter 24 is supported by a tubular shaft 70 having a proximal shaft portion 82 and a distal shaft end 88. The shaft 70 includes a hollow central tube 74 that permits the catheter to pass therethrough and past the distal shaft end 88. The catheter can be a linear lesion catheter or a lasso catheter 72, as shown. The lasso catheter 72 can be inserted into a pulmonary vein to properly position the diagnostic / therapeutic catheter 24 relative to the ostium prior to ostial ablation. The distal lasso portion of the catheter 72 is typically formed of a shape memory retention material such as nitinol. It should be understood that the diagnostic / therapeutic catheter 24 can also be used in the PV or other locations of the heart together with a linear or lesion catheter 99 (as shown by the dashed line in Figure 3 ). The lesion catheter 99 can include a force sensor located at its distal end. Suitable force transmitting distal ends are disclosed in U.S. Patent No. 8,357,152 to Govari et al. entitled "CATHETER WITH PRESSURE SENSING" issued on January 22, 2013 and U.S. Patent Application No. 2011 / 0130648 to Beeckler et al. entitled "CATHETER WITH PRESSURE MEASURING TIP" filed on November 30, 2009, the entire contents of which are incorporated herein by reference. Any catheter used in conjunction with the diagnostic / therapeutic catheter can have features and functions including, for example, pressure sensing, ablation, and diagnosis (e.g., navigation and pacing).

[0065] The balloon 80 of the diagnostic / therapeutic catheter 24 has an outer wall or membrane 26 of a biocompatible material (e.g., a material formed of a plastic such as polyethylene terephthalate (PET), polyurethane, or ). The shaft 70 and the distal shaft end 88 define a longitudinal axis 78 of the balloon 80. The balloon 80 is deployed in a collapsed configuration via the lumen 23 of the probe 20 and can be inflated after exiting the distal end 22. The membrane 26 of the balloon 80 is formed with flushing holes or apertures 27 ( Figure 6 shown), through which fluid (e.g., saline) can be discharged from the interior of the balloon 80 to the exterior of the balloon to cool the tissue ablation site at the ostium. Although Figure 2 and Figure 4 show the fluid exiting the balloon 80 as a jet, it should be understood that the fluid can exit the balloon at any desired flow rate or pressure, including the rate at which the fluid oozes from the balloon.

[0066] The membrane 26 supports and carries a combined electrode and temperature detection member constructed as a multi-layer flexible circuit electrode assembly 84. The "flexible circuit electrode assembly" 84 can have many different geometric configurations. In the illustrated embodiment, the flexible circuit electrode assembly 84 has a plurality of radiating substrates or strips 30, as Figure 5As shown. The bases 30 are evenly distributed around the distal end 88 and the balloon 80. Each base has a wider proximal portion that tapers to a narrower distal portion. Figure 5A An alternative embodiment of the base 30 of the flexible circuit electrode assembly 84 that includes radiopaque markers (e.g., 602, 604, 606) is shown, which will be described in more detail below. In Figure 5A , for clarity, the electrodes 33 and Figure 5A other details shown in

[0067] Reference Figure 3 , Figure 5 and Figure 5A , each base 30 has a proximal tail 31P and a distal tail 31D. The proximal tail 31P is tucked under and fastened to the catheter 24 by a proximal ring 28P mounted on the proximal shaft portion 82 of the shaft 70. The distal tail 31D is tucked under and fastened to the catheter 24 by a distal ring (not shown). Either or both of the tails 31D and 31P may be further covered by a corresponding hemispherical cap (such as the distal cap 28D). One or more electrodes 33 on each base begin electrical contact with the lumen 11 during the ablation procedure, during which current flows from the electrodes 33 to the orifice 11, as Figure 4 shown.

[0068] For simplicity, as Figure 6 shown, the flexible circuit electrode assembly 84 is described for one of the bases 30 of the flexible circuit electrode assembly 84, but it should be understood that the following description may apply to each base of the assembly. The flexible circuit electrode assembly 84 includes a flexible and elastic sheet-like base 34 constructed of a suitable biocompatible material (e.g., polyimide). In some embodiments, the sheet-like base 34 has a higher heat resistance (or higher melting temperature) than the balloon membrane 26. In some embodiments, the base 34 is constructed of a thermosetting material having a decomposition temperature that is about 100 °C or higher than the melting temperature of the balloon membrane 26.

[0069] The base 34 is formed with one or more flushing holes or apertures 35 that are aligned with the flushing holes 27 of the balloon member 26 such that fluid passing through the flushing holes 27 and 35 can pass through the ablation site on the orifice.

[0070] The substrate 34 has a first or outer surface 36 remote from the balloon membrane 26 and a second or inner surface 37 facing the balloon membrane 26. On its outer surface 36, the substrate 34 supports and bears a contact electrode 33 adapted to contact the ostial tissue. On its inner surface 37, the substrate 34 supports and bears a wiring electrode 38. The contact electrode 33 delivers radiofrequency energy to the ostium during ablation or is connected to a thermocouple junction for temperature sensing of the ostium. In the illustrated embodiment, the contact electrode 33 has a longitudinally elongated portion 40 and a plurality of thin transverse straight portions or fingers 41 that extend perpendicularly from each side of the elongated portion 40 generally between an enlarged proximal end 42P and a distal end 42D and are generally evenly spaced therebetween. The elongated portion 40 has a greater width, and each finger has a generally equal smaller width. Thus, the configuration or trace of the contact electrode 33 may resemble a "fishbone", but it should be noted that the present invention is not limited to such a configuration. Contrary to area or "patch" ablation electrodes, the fingers 41 of the contact electrode 33 advantageously increase the circumferential or equatorial contact surface of the contact electrode 33 with the ostium, and the void regions 43 between adjacent fingers 41 advantageously allow the balloon 80 to collapse inwardly or expand radially at positions along its equator as needed. In the illustrated embodiment, the fingers 41 have different lengths, some longer and some shorter. For example, the plurality of fingers includes distal fingers, proximal fingers, and fingers therebetween, with each finger therebetween having shorter adjacent fingers. For example, the length of each finger is different from its distal or proximal adjacent finger, such that the length of each finger generally follows the tapered configuration of each substrate 30. In the illustrated embodiment, there are 22 fingers extending across the elongated portion 40 (through each side), and the longest finger is the third finger from the enlarged proximal end 42P. In some embodiments, the contact electrode 33 includes gold 58B having a seed layer located between the gold 58B and the membrane 26. The seed layer may comprise titanium, tungsten, palladium, silver, or combinations thereof.

[0071] One or more discharge zones 47 are formed within the contact electrode 33, each discharge zone surrounding a flushing hole 35 formed in the substrate 34. The discharge zones 47 are intentionally formed voids in the contact electrode 33, as further detailed below, to avoid damage to the position and function of the contact electrode 33 during construction of the electrode assembly 84 to accommodate the flushing hole 35.

[0072] One or more conductive blind vias 48 are also formed in contact electrode 33, the blind vias being conductive formations or metal formations extending through through-holes in substrate 34 and configured as electrical conduits connecting contact electrode 33 on outer surface 36 and wiring electrode 38 on inner surface 37. It should be understood that in all relevant instances, "conductive" may be used interchangeably with "metal-containing" herein.

[0073] In the illustrated embodiment, contact electrode 33 measures approximately 0.1 inches to 1.0 inches longitudinally, preferably approximately 0.5 inches to 0.7 inches, more preferably approximately 0.57 inches, and has four discharge zones 47 and nine blind vias 48.

[0074] On inner surface 37 of substrate 34, wiring electrode 38 is generally configured as an elongate body generally similar in shape and size to elongate portion 40 of contact electrode 33. Wiring electrode 38 loosely resembles a "ridge" and also functions as a ridge in providing a predetermined degree of longitudinal stiffness to each substrate 30 of electrode assembly 84. Wiring electrode 38 is positioned such that each blind via 48 makes electrical contact with both contact electrode 33 and wiring electrode 38. In the illustrated embodiment, the two electrodes 33 and 38 are longitudinally aligned with other electrodes and all nine blind vias 48 make electrical contact with the two electrodes 33 and 38. In some embodiments, wiring electrode 38 has an inner portion of copper 57 and an outer portion of gold 58.

[0075] Wiring electrode 38 is also formed with a discharge zone 59 surrounding flush hole 35 in substrate 34. Wiring electrode 38 is also formed with pad portions 61, at least one active pad portion 61A, and one or more inactive pad portions 61B may be present. Pad portions 61A and 61B are extensions of the sides of the elongate body of wiring electrode 38. In the illustrated embodiment, active pad portion 61A is formed at approximately the mid-position along the elongate body and corresponding inactive pad portions 61B are provided at each of enlarged distal end 42D and enlarged proximal end 42P.

[0076] A pair of wires (e.g., constantan wire 51 and copper wire 53) is attached to active pad portion 61A, for example by welding 63. Copper wire 53 provides a lead to wiring electrode 33 and copper wire 53 and constantan wire 51 provide a thermocouple with the junction at welding 63. The pair of wires 51 / 53 passes through via 29 formed in membrane 26. It should be understood that in other embodiments, in the absence of via 29, the pair of wires 51 / 53 may extend between membrane 26 and substrate 34 and also extend proximally between membrane 26 and proximal tail 31P until the pair of wires 51 / 53 enters tubular shaft 70 via another via (not shown) formed in the sidewall of the tubular shaft closer to proximal ring 28.

[0077] A flexible circuit electrode assembly 84 including a base 30 and tails 31P and 31D is attached to the balloon membrane 26 such that the outer surface 36 of the base 34 is exposed and the inner surface 37 of the base 34 is attached to the balloon membrane 26, with the wiring electrode 38 and the wire pairs 51 / 53 sandwiched between the base 34 and the balloon membrane 26. The flushing holes 35 in the base 34 are aligned with the flushing holes 27 on the balloon membrane 26. The discharge regions 59 in the wiring electrode 38 and the discharge regions 47 in the contact electrode 33 are concentrically aligned with each other and are respectively concentrically aligned with the flushing holes 27 in the balloon 26 and the flushing holes 35 in the base 34.

[0078] A method of constructing a diagnostic / therapeutic catheter according to the foregoing disclosure can be seen in U.S. Patent Application 15 / 360,966, published as U.S. Patent Application Publication 2017 / 0312022, which is hereby incorporated by reference in its entirety.

[0079] Radiopaque Marker

[0080] A radiopaque marker made of a material opaque to x-rays can be incorporated into the diagnostic / therapeutic catheter 24 to assist in visualizing the position of the diagnostic / therapeutic catheter 24 and its electrodes 33 during a fluoroscopy procedure. Fluoroscopic images are two-dimensional, while the portions of the diagnostic / therapeutic catheter 24 and the cardiac anatomy that the diagnostic / therapeutic catheter 24 is intended to ablate with the electrodes 33 are three-dimensional objects. Thus, the fluoroscopic images reflecting the deployment of the diagnostic / therapeutic catheter 24 within the heart can be visually ambiguous, i.e., bistable, such that it may be difficult for a user (e.g., a surgeon) to distinguish between the electrodes 33 and how each individual electrode 33 contacts the cardiac tissue. Radiopaque markers (e.g., Figure 5A , Figure 8A and Figure 8B 602, 604, 606) can assist the user in distinguishing between the various contact electrodes 33 and how they contact the tissue. Figure 5B Schematic diagram of how the balloon 80 of the diagnostic / therapeutic catheter 24 equipped with Figure 5A the base 30 may appear in the captured fluoroscopic image when the balloon 80 has been deployed and expanded within the subject (which incorporates radiopaque markers, e.g., 602, 604, and 606).

[0081] In various embodiments, radiopaque markers can be incorporated onto at least some of the various electrodes 33 of the flexible circuit electrode assembly 84 disposed on the balloon 80 such that during a fluoroscopy procedure, the user can easily identify which electrode 33 is which. Although the electrodes 33 can be metallic, such as made of gold and thus radiopaque, additional radiopaque material can be provided thereon as a marker to darken its fluoroscopic representation. Suitable materials include, for example, tungsten, gold, bismuth, and barium sulfate. Alternatively or in addition, the shape of certain individual electrodes 33 can be somewhat different from that of other electrodes to assist the user in identifying the electrode.

[0082] In the exemplary embodiment associated with the above Figure 5A and 5B , ten electrodes 33 are provided, one each on a respective substrate 30, each including a radiopaque marker. The ten electrodes 33 can be arranged in any configuration about the longitudinal axis 78. In a preferred embodiment, the electrodes 33 are equally angularly spaced about the longitudinal axis 78 ( Figure 3 ). Additional examples of markers are included in Figures 7A to 7K , each of which shows a close-up view of a portion of one substrate 30 from Figure 5 . Figures 7A to 7K has been modified relative to Figure 5 to show radiopaque markers of different forms disposed on or incorporated into the substrate 30 or the electrode 33. Any of the substrate 30 or the electrode 33 shown in these figures can replace any of the unmarked forms shown in Figures 2 to 5 and Figure 6 to design the diagnostic / therapeutic catheter 24 such that at least one, but preferably at least two, individual substrates 30, electrodes 33, or flexible circuit assemblies 84 can be distinguished from other substrates, electrodes, or flexible circuit assemblies under fluoroscopy.

[0083] Figure 7AThe substrate 30 is shown having markers 502 in the form of alphanumeric symbols, for example, numbers or letters. As shown, the number is "1", but it should be understood that due to the number of substrates 30 or electrodes 33 on the balloon 80, this form can be any alphanumeric symbol that has meaning. For example, if 10 electrodes 33 are used, the first substrate can have a marker 502 in the form of "1", another substrate can have a marker in the form of "2", another substrate can have a marker in the form of "3", another substrate can have a marker in the form of "4", another substrate can have a marker in the form of "5", another substrate can have a marker in the form of "6", another substrate can have a marker in the form of "7", another substrate can have a marker in the form of "8", another substrate can have a marker in the form of "9", and another substrate or the final substrate can have a marker in the form of "10" or "X".

[0084] The substrate 30 can also have markers in the form of polygons. For example: as Figure 7B shown, the marker 504 is rectangular; as Figure 7C shown, the marker 506 is a triangle or arrow pointing along the substrate 30; and as Figure 7D shown, the marker 508 is a triangle or arrow pointing perpendicular to the substrate 30. As Figure 7D shown, the marker 508 is provided in such a form that it is asymmetric about the center line passing through the substrate 30, or when the flexible circuit assembly 84 is mounted on the balloon 80, it is asymmetric about the center line parallel to the longitudinal axis of the balloon. As Figures 7B to 7D shown, the polygon markers 504, 506, and 508 are shown as opaque. However, they can also be provided as hollow. For example, as Figure 7E shown, the marker 510 has the form of a hollow polygon in the form of a triangle or arrow pointing along the substrate 30.

[0085] The markers can also have the form of lines or ridges extending along the substrate 30, which are provided on or incorporated into it. For example, the marker 512 can have the form of a solid line ( Figure 7F ), the marker 514 can have the form of a dashed line ( Figure 7G ), or the marker 516 can have the form of a dotted line ( Figure 7H ). The markers can also have the form of lines or ridges combined with other forms (for example, alphanumeric symbols or polygons). For example, as Figure 7I shown, the marker 518 has the form of a solid line with a hollow triangle or arrow at the end connected to the substrate 30 or the electrode 33. As shown, the triangle of the marker 518 can be considered to be at the proximal end of the line because see Figure 2and how the base 30 is fixed to the balloon 80, the triangle will be at the end of the electrode 33 that is furthest from the distal shaft end 88. However, the marker may also include a line or a ridge, where the polygonal form is set at a position between the two ends of the line or the ridge. For example, as Figure 7J shown, the marker 520 includes a line with a triangle or an arrow, and the triangle or the arrow is set adjacent to the midpoint of the line and points perpendicular to the line. In Figure 7K the variant reflected, the marker 522 is similar to the marker 520, but the part of the line that overlaps with the base of the triangle is removed. Thus, as used herein, the term "form" refers to a suitable marker on the electrode to allow the user to distinguish the orientation of the catheter balloon through a suitable imaging device (such as fluoroscopy or MRI). To show the Figures 7F to 7K marker in, which is characterized by Figure 5 certain features (such as the electrode 33) visible in being hidden in Figures 7F to 7K .

[0086] The marker described above in connection with Figures 7A to 7K can be incorporated onto at least one of the single base 30 or the electrode 33, so that any base 30 or electrode 33 on which the marker is set can be easily distinguished from those without the marker, including when observing the diagnostic / therapeutic catheter 24 under fluoroscopy during an ablation procedure. In some embodiments, three bases 30 or electrodes 33 include markers. In some embodiments, all bases 30 or electrodes 33 include markers.

[0087] Figure 8A and Figure 8B show two views of the distal end of a diagnostic / therapeutic catheter that includes a balloon 680 having a membrane 626, as detailed above with respect to the balloon 80 and the membrane 26. In Figure 8B , the balloon 680 is relative to its position in Figure 8ARotate approximately 160 degrees in the manner shown. The balloon 680 may have a distal end and a proximal end that define a longitudinal axis. A flexible circuit assembly similar to the flexible circuit assembly 84 may be assembled to the balloon. Each assembly may include an electrode similar to the electrode 33. For example, in the case of including ten assemblies, the catheter 624 has 10 electrodes 633a - 633j disposed on the balloon 680. One or more of these electrodes 633a - 633j may be combined with radiopaque markers. For example, the first electrode 633a may include a first radiopaque marker 602 of a first form, and the second electrode 633d may include a second radiopaque marker 604 of a second form different from the first marker 602 of the first form. For example, the first radiopaque marker 602 may have a solid line form connected to a solid rectangle, and the second radiopaque marker 604 may have a solid line form connected to a solid triangle. The third electrode 633g may further include a radiopaque marker 606 having a form different from the first marker 602 of the first form and the second marker 604 of the second form. For example, the third radiopaque marker 606 may have a solid line form connected to a hollow triangle. Figure 8A and Figure 8B should be considered exemplary. The markers may have alternative forms, such as Figures 7A to 7K those provided in. Thus, in certain embodiments, the markers 602, 604, or 606 may have a polygonal form, such as a rectangle or a triangle, for example. Additionally, in certain embodiments, one or more may be hollow, and one or more may be solid. One or more of these markers include solid lines, dashed lines, or dotted lines. Additionally, as Figure 8A and Figure 8B shown, the other electrodes 633b, 633c, 633e, 633f, 633h, 633i, and 633j may respectively include markers 612, 614, 616, 618, 620, 622, and 624, each of which has the form of a solid line. In certain embodiments, one or more of these solid lines may be replaced with a dashed line or a dotted line.

[0088] Alternatively, as Figure 9A and Figure 9B shown, the markers may take the form of alphanumeric symbols. In Figure 9B the balloon 780 is relative to its position in Figure 9ARotate approximately 160 degrees in the manner shown. In some embodiments, the first radiopaque marker 702 may have the form of "1", and the second radiopaque marker 704 may have the form of a number greater than "1", the number corresponding to the counting designation or position of the electrode relative to the first electrode, such as "the fourth electrode". As shown, the second electrode 733d may be considered the "fourth electrode" because there are two electrodes between electrode 733a (i.e., the "first electrode") and electrode 733d. Thus, in this example, the second marker 704 has the form of "4". Along these lines, additional electrodes may also include markers in the form of numbers. For example, in an instance where the counting designation of the third electrode 733g relative to the first electrode is "the seventh electrode", the third electrode is electrode 733g. Thus, in this example, the third electrode 733g may include a third marker 706 in the form of "7". In an alternative embodiment, at least one of the remaining electrodes may also include a marker in alphanumeric form. For example, the final electrode (i.e., the electrode adjacent to the first electrode that is not the "second electrode", such as electrode 733j) may include a marker 708 in the form of "10" or "X".

[0089] Alternatively, markers may be provided on the electrodes, the markers including an asymmetry relative to each electrode or the balloon, the asymmetry being usable to provide a further indication of the three dimensions of the balloon and the positions of the electrodes thereon in a bi-stable fluoroscopic image. For example, see Figure 10 , where ten electrodes 833a - 833j are provided on the balloon 880. Each electrode 833a - 833j may include a radiopaque marker (e.g., 802, 804, 806, 808, 810, etc.) in the form of an arrow or a triangle that points to the adjacent electrode when the balloon is viewed clockwise or counterclockwise. As Figure 10 shown, the arrow points to the adjacent electrode according to the so-called "right-hand rule". That is, the user's right thumb is oriented along the axis of the catheter towards the distal end of the catheter axis such that the other fingers on the user's right hand curl around the balloon in the direction in which the arrow points. Alternatively, the "left-hand rule" may be applied. For example, see Figure 5B , which is a schematic diagram of a fluoroscopic image of the balloon 80. The user's left thumb may point to the distal end of the catheter such that her fingers curl around the balloon 80 from the marker 602, above the marker 604, and then above the marker 606. Those skilled in the art will know that there are other conventions for correlating the relative positions of the markers and the electrodes. The specific convention for correlating the relative position of each marker with the other markers is not critical per se. What is important is that the user knows the convention and is able to use it to correlate the relative positions of each marker and electrode with the other markers and electrodes.

[0090] To further distinguish electrode 833a from other electrodes, one or more of the markers may be modified or changed relative to other markers. For example, marker 802 on electrode 833a may be a hollow arrow, while the other markers may be solid arrows. Alternatively, marker 802 may include a double arrow, while the manufacturer may include only a single arrow.

[0091] Additional embodiments including a substrate 30 and a flexible circuit assembly attachable to a balloon (e.g., balloon 80 of diagnostic / therapeutic catheter 24) are shown in Figures 11 to 14 In Figure 11 at least one marker 902 includes a hollow triangle at the top of the ridge and at least one other marker 906 includes a solid triangle at the top of the ridge. In Figure 12A six adjacent markers (1002, 1024, 1022, 1020, 1006, and 1018) each include a solid arrow, and the remaining four adjacent markers (1016, 1004, 1014, and 1012) each include a hollow arrow. Each of the arrows (whether solid or hollow) is oriented to point to an adjacent marker (e.g., the arrow of marker 1018 points to marker 1016). Figure 12B reflects how a balloon 12A equipped with a Figure 12A flexible circuit assembly may appear when viewed fluoroscopically. Each of the arrows may provide an indication to the user viewing the image as to which marker is which, where each marker is on the surface of balloon 80 and where each marker is relative to the subject's anatomy. As will be described in more detail below, specifically, the user may determine which marker is closest to the subject's esophagus within the subject's left atrium.

[0092] In Figure 13 some markers may include hollow circles, such as marker 1102, or solid circles, such as marker 1124. Other markers may include solid rectangles, such as marker 1112. Figure 14 It is shown that the size and location of the markers may vary. For example, the circle included in marker 1212 is larger than the circle of, for example, marker 1202. Additionally, marker 1212 is disposed at one end of substrate 30, while marker 1202 is disposed at the other end.

[0093] In operation, any embodiment incorporating radio-opaque markers can facilitate the user's ability to determine the location of a balloon (e.g., Figure 8A and Figure 8Bthe position or orientation of the balloon 680), since the radiopaque markers are readily visible in a fluoroscopic image. This increased visibility can help the user to achieve the desired result (i.e., proper ablation) without causing unnecessary trauma (e.g., unwanted lesions) to the subject's anatomy (such as the subject's esophagus). Using radiofrequency energy from the electrodes (e.g., Figure 8A and Figure 8B 633a - 633j in) successful ablation of tissue generally requires substantial contact between the electrode and the tissue (usually a precise tissue mass). However, it is not desired to ablate non-lesioned portions of the heart, such as those far from the pulmonary vein ostia or a precise tissue mass. Additionally, if the incorrect electrode is activated or an incorrect energization is set, other anatomical structures, such as the portion of the esophagus near the left atrium, may be damaged. Thus, with the radiopaque markers, the user can visualize which electrodes are in proper contact before activating the electrodes. That is, the user can avoid activating the electrodes when they are not in the proper position for ablating tissue (e.g., when the electrodes are not in contact with the tissue). By providing the user with a visual indication of each marker and thus the electrode, the user can selectively activate and deactivate the individual electrodes on the balloon. Additionally, the user can customize the amount of energy or energization received based on the position of each electrode within the heart. Similarly, by way of example, the user can position the balloon against the pulmonary vein ostia. When viewing the fluoroscopic image, she can see, for example, that markers 606 and 618 are in contact with the tissue at the sinus ostium, but the remaining markers are not. Thus, she can determine that the corresponding electrodes (e.g., Figure 8B 633f and 633g in) are in contact with the tissue such that ablation of the tissue can be achieved by activating these two electrodes. At the same time, she can also determine that the remaining electrodes should not be activated. However, at this point, she still needs to know which switches, for example, within the ablation module 54 are associated with activating electrodes 633f and 633g such that only these electrodes and not the others will receive radiofrequency energy from the radiofrequency generator. To this end, the user can be trained to understand the correspondence between the electrodes and the markers. For example, she can understand that: 1) the first marker 602 (which includes a solid rectangle as shown, for example, in Figure 5A corresponds to the first electrode 633a; 2) the second marker 604 (which includes a solid rectangle as shown, for example, in Figure 5AThe one shown (including the solid triangle) corresponds to the second electrode 633d; and 3) the third marker 606 corresponds to the third electrode 633g. She can also understand that there are two electrodes (i.e., 633b and 633c) between the electrodes 633a and 633d. She can also understand that there are two electrodes (i.e., 633e and 633f) between the electrodes 633d and 633g. Thus, in standard spoken English, she can understand the electrode 633a as the "first electrode", the electrode 633d as the "fourth electrode", and the electrode 633g as the "seventh electrode". Finally, she can also understand that the markers are circumferentially arranged around the balloon in a clockwise or counterclockwise manner, or preferably, arranged according to the so-called "right-hand rule" or "left-hand rule" described above.

[0094] Thus, when observing that the hollow arrow of the marker 606 contacts the tissue, she can quickly infer that the electrode 633g (in her view, the "seventh electrode") is in proper contact with the tissue and can be activated by the first switch of the ablation module 54 (in her view, perhaps the "seventh switch"). Additionally, applying the right-hand rule, she can infer that the electrode 633f (in her view, the "sixth electrode") can be activated by the second switch of the ablation module 54 (in her view, perhaps the "sixth switch"). Thus, she can activate the electrodes 633f and 633g with more confidence so that she will achieve a successful ablation protocol and the result for her subject.

[0095] In addition, the user can observe that the balloon 80 is set close to a part of the left atrium that is close to another anatomical structure of the subject, such as a part of the subject's esophagus, as Figure 15As seen, where the balloon 80 is shown as a dashed circle. To avoid unnecessary trauma to the esophagus, such as lesions, the user can customize or adjust the energy received by the electrodes when they are close to the esophagus. That is, the user can energize one or more electrodes closest to the esophagus (indexed or referenced to the marker 902) at a first energization setting that is lower than a second energization setting used when those same or other electrodes (indexed or referenced to the marker 906) can be positioned at other locations away from the esophagus. As used herein, the term "energization setting" indicates information regarding the energy received by the electrodes from the ablation module 54. For example, a constant amount of power (in watts, for example) can be delivered over a constant time span. The constant amount of power can be pre-determined. The constant amount of time can be pre-determined. Alternatively, the power can be variable (e.g., by magnitude, frequency, as a function of time, or as a function of impedance, which itself can be a function of, for example, lesion size). Alternatively, the amount of time can be variable (e.g., as a function of impedance). The phase of the delivered power can be in-phase or out-of-phase with the power delivered to other electrodes. In an exemplary embodiment, the power provided for tissue ablation depends on the measured impedance and can be from about 10 watts to about 250 watts. The duration of energy application can be from about 4 seconds to about 90 seconds to form an effective lesion.

[0096] Viewed together, the diagnostic / therapeutic catheter 24, which includes a balloon (e.g., balloon 80), the operation console 15, the console 15 includes the ablation module 54, and the wires connecting the electrodes disposed on the base of the balloon to the output of the ablation module, can be considered components of an electrophysiological system for providing ablation therapy to a patient. The ablation module 54 can include at least one radio frequency generator. For example, when the balloon includes electrodes, the ablation module 54 can include the same number of radio frequency generators. In this way, the frequency of the energy delivered to each electrode can be customized relative to other electrodes, for example, based on changing impedance (which is an indication of tissue ablation). Each wire can be part of the circuit path between the corresponding electrode and the output of the ablation module or the radio frequency generator. At least a portion of each wire can be disposed within the diagnostic / therapeutic catheter. Alternatively, the electrical path can consist of a single wire connecting one electrode directly to the corresponding output of the ablation module. A switch can be used to selectively activate and deactivate each electrode, i.e., connect and disconnect each electrode from the generator. In some embodiments, each switch can be included in each circuit path. In some embodiments, each switch can be included within the ablation module 54, for example, between the signal generator and the output, or between the power supply and the generator. Each circuit path can also include additional wires or electrical connectors, such as pin connectors, which can be used to facilitate connection of the catheter to the operation module 15, and the operation module 15 can include a direct or indirect connection to the ablation module 54. Each switch can be, for example, through a user-interface mechanism (such asFigure 1 Manual control is performed by the controller 49). In some embodiments, a mechanical switch may be provided within a circuit path external to the operation module 15. As detailed above, the base or electrodes of the balloon of the system may include radiopaque markers that the user can use to determine the relative positions of the markers relative to each other from two-dimensional or bistable images (e.g., fluoroscopic images) to determine which electrode to activate and to determine the correct switch for activating that electrode or those electrodes.

[0097] By means of the embodiments shown and described herein, the applicant has designed a method for selectively ablating tissue along a tissue surface (e.g., a curved tissue surface in contact with the balloon of a diagnostic / therapeutic catheter). That is, the user can use the above-described diagnostic / therapeutic catheter or an electrophysiological system of which the above-described diagnostic / therapeutic catheter is a part according to various methods and variations to activate at least one electrode while keeping other electrodes inactive. For example, the user may provide a diagnostic / therapeutic catheter (e.g., catheter 24) that includes a balloon (e.g., balloon 80) having various bases (e.g., base 30) circumferentially disposed thereon. The bases may also include radiopaque markers (e.g., markers 602, 604, 606) disposed thereon. In some embodiments, each base includes an electrode (e.g., electrode 33) disposed thereon, with at least a portion of the marker disposed on the electrode.

[0098] In some embodiments, ten substrates are employed, each substrate including an electrode and a marker. The balloon can be positioned at a desired location within the anatomy of a subject. For example, the balloon can be positioned within the heart of a subject. Specifically, the balloon can be positioned adjacent to or within the ostium of a pulmonary vein of the heart. The user can use various visualization techniques known in the art, such as fluoroscopy, to assist in positioning the balloon at the desired location. Once positioned at the desired location, the user can use the visualization technique to evaluate the position and orientation of the balloon. Specifically, the user can use the visualization technique to determine the relative positions and orientations of the markers with respect to each other, such that the user can further determine the relative positions and orientations of each substrate and each electrode with respect to the other electrodes. In addition, the user can use the visualization technique to determine whether any of the markers is in contact with the tissue of the subject, such that the user can further determine whether the corresponding electrode is in contact with the tissue. For example, the user can identify a first marker and, thus, determine that the first electrode is in contact with the tissue at the desired location. After this determination, the user can activate the first electrode, for example, by closing a first switch using a controller 49. The user can also determine that a second marker is not in contact with the tissue, or not in contact with the tissue at the desired location. After this determination, the user can determine not to activate the electrode. Alternatively, the user can determine that the second marker is in contact with the tissue at the desired location. After this determination, the user can activate the second electrode, for example, by closing a second switch using a controller 49.

[0099] In certain variations of the method, the user can determine that the first switch activates the first electrode and that the second switch activates the second electrode. As described above, it may not be readily apparent to the user which electrode corresponds to which switch, for example, due to the blurry nature of the bistable images generated by fluoroscopy. Markers disposed on the substrates of the balloon can assist the user in determining which electrode corresponds to which switch. For example, the first electrode can include a first marker having a first form thereon, and the second electrode can include a second marker having a second form thereon. The user can associate the first form (e.g., a rectangle, such as a solid rectangle) with the first switch, and the user can associate the second form (e.g., a line or a triangle) with the second switch. In additional variations, including those in which the second marker is a line, the user can use a right-hand rule or a left-hand rule associated with the first marker to associate the second form with the second switch.

[0100] In a variant of the method, a user may perform the following steps to ablate a desired portion of cardiac tissue: position an inflatable member adjacent to tissue within a subject's anatomy; use a suitable imaging device (e.g., fluoroscopy or x-ray) to view an image of the inflatable member; determine that one or more electrodes adjacent to one of a first marker or a second marker contact the tissue; and energize the one or more electrodes to ablate the tissue.

[0101] Also disclosed herein are methods of ablating a portion of the heart without ablating adjacent anatomy or creating lesions on other anatomy (e.g., esophagus, phrenic nerve, or lung) not disposed adjacent to the left atrium of the heart. In some variants, the method is used to apply energy to tissue adjacent to the esophagus, phrenic nerve, or lung in the left atrium of a subject. An inflatable member (e.g., balloon 80) may be positioned adjacent to the left atrium of the subject's heart. The inflatable member may have a longitudinal axis and include a plurality of electrodes (e.g., 30) disposed about the longitudinal axis. For example, it may include three to fifteen, or ten electrodes. Each electrode can be energized independently. The method can be achieved by positioning the inflatable member adjacent to the left atrium; viewing an image of the inflatable member and first and second radiopaque markers in the left atrium; determining the orientation of the first and second radiopaque markers relative to the portion of the left atrium closest to the subject's esophagus, nerve, or lung; moving one of the first and second radiopaque markers to the portion of the left atrium closest to the esophagus, phrenic nerve, or lung

[0102] ; and energizing one or more electrodes indexed to one of the radiopaque markers adjacent to the portion of the left atrium close to the esophagus, phrenic nerve, or lung at a lower energization setting compared to the other electrodes. Thus, a transmural lesion can be formed in the left atrium with no or substantially no damage to adjacent anatomy (including, for example, the esophagus, phrenic nerve, or lung).

[0103] Any examples and / or embodiments described herein may include various other features in addition to or as an alternative to those described above. The teachings, expressions, embodiments, examples, etc. described herein should not be considered in isolation from one another. With respect to the teachings herein, various suitable ways in which the teachings herein can be combined will be apparent to those of ordinary skill in the art.

[0104] Exemplary embodiments of the subject matter contained herein have been shown and described, and further improvements to the methods and systems described herein can be achieved by making appropriate modifications without departing from the scope of the claims. In addition, where the above methods and steps represent specific events occurring in a specific order, it is intended herein that certain specific steps need not necessarily be performed in the order described, but can be performed in any order as long as the steps enable the embodiment to achieve its intended purpose. Accordingly, if there are variations of the present invention and such variations fall within the scope of the substance of the present disclosure or equivalents thereof found in the claims, this patent is intended to cover such variations as well. Many such modifications will be obvious to those skilled in the art. For example, the examples, embodiments, geometries, materials, dimensions, ratios, steps, etc. described above are illustrative. Therefore, the claims should not be limited to the specific details of the structures and operations shown in this written description and the drawings.

Claims

1. An electrophysiological catheter, comprising: a balloon having a membrane, the balloon having a distal end and a proximal end defining a longitudinal axis; a first substrate disposed on the membrane, the first substrate including a first radiopaque marker of a first form disposed thereon; and a second substrate disposed on the membrane, the second substrate including a second radiopaque marker of a second form disposed thereon, the second form being different from the first form, wherein the first form includes a first polygon, and the second form includes a second polygon, wherein the second polygon is asymmetric about a center line parallel to the longitudinal axis of the balloon, wherein the second polygon includes an arrow, and wherein the second polygon points to a third substrate, wherein the third substrate includes a third radiopaque marker of a third form disposed thereon, the third form being different from the first form and the second form, and wherein the third form includes a third polygon, wherein the third polygon is asymmetric about a center line parallel to the longitudinal axis of the balloon, wherein the third polygon includes an arrow and wherein the third polygon points to a final substrate, wherein the second polygon is hollow or solid.

2. The electrophysiological catheter according to claim 1, wherein the first polygon includes a rectangle, and the second polygon includes a triangle.

3. The electrophysiological catheter according to claim 1, wherein the third polygon includes a triangle.

4. The electrophysiological catheter according to claim 1, wherein the third polygon is solid.

5. The electrophysiological catheter according to claim 1, wherein the third polygon is hollow.

6. The electrophysiological catheter according to claim 1, wherein the first substrate, the second substrate, the third substrate, and the final substrate are circumferentially disposed around the membrane, and the final substrate is disposed on the membrane between the third substrate and the first substrate.

7. The electrophysiological catheter according to claim 6, wherein at least a fourth substrate is disposed between the first substrate and the second substrate, and at least a fifth substrate is disposed between the second substrate and the third substrate.

8. The electrophysiological catheter according to claim 7, wherein the fourth substrate does not contain a radiopaque marker, and the fifth substrate does not contain a radiopaque marker.

Images