Systems and methods for ablation with catheter assemblies

Abstract

The present disclosure provides systems and methods for ablation. An ablation catheter assembly includes a shaft, and at least one balloon coupled to the shaft, the at least one balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure, and a) a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon and / or b) an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

Description

15740WOO1(32736-2128)SYSTEMS AND METHODS FOR ABLATION WITH CATHETER ASSEMBLIESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 690,411, filed September 4, 2024, the entire contents of which are hereby incorporated by reference herein.FIELD OF THE DISCLOSURE

[0002] The present disclosure relates generally to tissue ablation systems. In particular, the disclosure relates to catheter assemblies for pulsed field and / or radiofrequency energy delivery'.BACKGROUND

[0003] It is generally know n that ablation therapy may be used to treat various conditions afflicting the human anatomy. For example, ablation therapy may be used in the treatment of atrial arrhythmias or other arrhythmias (e.g., ventricular arrhythmias). Further, ablation therapy may be used for ablating soft tissue, cancerous tissue, benign tumors, etc. When tissue is ablated, or at least subjected to ablative energy' generated by an ablation generator and delivered by an ablation catheter, lesions form in the tissue. Electrodes mounted on or in ablation catheters are used to cause tissue destruction in cardiac tissue to correct conditions such as ventricular and atrial arrhythmias (including, but not limited to, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter).

[0004] Arrhythmia (i.e., irregular heart rhythm) can create a variety of dangerous conditions including loss of synchronous atrioventricular contractions and stasis of blood flow which can lead to a variety of ailments and even death. It is believed that the primary cause of atrial arrhythmia is stray electrical signals within the left or right atrium of the heart. The ablation catheter imparts ablative energy (e.g., radiofrequency energy, cryoablation, lasers, chemicals, high-intensity focused ultrasound, etc.) to cardiac tissue to15740WOO1(32736-2128) create a lesion in the cardiac tissue. This lesion disrupts undesirable electrical pathways and thereby limits or prevents stray electrical signals that lead to arrhythmias.

[0005] Radiofrequency (RF)-based ablation systems are known in the field of cardiac electrophysiology. During RF ablation procedures, a catheter (e.g., an ablation catheter) which is capable of administering RF energy is typically positioned directly into region of interest within a patient's heart. RF energy may be delivered as alternating electrical current typically in the frequency range of 350-750 kilohertz (kHz) in order to accelerate the electrons in the cardiac cells — generating heat which destroys the cells within a certain range of the catheter tip.

[0006] Pulsed field ablation (PF A) is a non-thermal ablation technique that involves applying strong electric fields that induce pore formation in the cellular membrane (also referred to as electroporation). Electric energy may be delivered as a pulsed electric field in the form of short-duration pulses (e.g., having a 10 nanosecond (ns) to 100 millisecond (ms) duration) between closely spaced electrodes capable of delivering an electric field strength of about 0.05 to 100.0 kilovolts / centimeter (kV / cm). Such a pulse may be repeated to form a pulse train. The electric fields may be applied between pairs of catheter electrodes (e.g., bipolar therapy) or between one or more catheter electrodes and a return patch (e.g., monopolar therapy). When such an electric field is applied to tissue in an in vivo setting, the cells in the tissue are subjected to a trans-membrane potential, which induces the formation of the pores in the cell membrane. Electroporation may be reversible (i.e., the temporarily-opened pores will reseal) or irreversible (IRE, i.e., the pores will remain open, resulting in cell destruction).

[0007] EP4346667A1 and US10172673B2 describe known ablation catheters for mapping and PF ablation. Catheter configurations that place electrodes near or in contact with the vessel wall are described in WO2022 / 251163A1, which is herein incorporated by reference in its entirety.

[0008] Catheter assemblies which realize benefits of pulsed field (PF) and / or radiofrequency (RF) energy with high fidelity mapping capabilities are desirable.15740WOO1(32736-2128)BRIEF SUMMARY OF THE DISCLOSURE

[0009] In one aspect, an ablation catheter assembly is provided. The ablation catheter assembly includes a shaft, and at least one balloon coupled to the shaft, the at least one balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure, and a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon.

[0010] In another aspect, an ablation system is provided. The ablation system includes an ablation generator, and an ablation catheter assembly coupled to the ablation generator. The ablation catheter assembly includes a shaft, and at least one balloon coupled to the shaft, the at least one balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure, and a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon.

[0011] In yet another aspect, a method of assembling an ablation system is provided. The method includes forming an ablation catheter assembly by coupling at least one balloon to a shaft, the at least one balloon including i) a conductive material configured to dissipate electrical energy into tissue during an ablation procedure and ii) a non- conductive masking material covering a portion of the conductive material and defining a plurality of w indows of exposed conductive material on a surface of the balloon. The method further includes coupling the ablation catheter assembly to an ablation generator.

[0012] In yet another aspect, an ablation catheter assembly is provided. The ablation catheter assembly includes a shaft, and a balloon coupled to the shaft, the balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure, and an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

[0013] In yet another aspect, an ablation system is provided. The ablation system includes an ablation generator, and an ablation catheter assembly coupled to the ablation generator. The ablation catheter assembly includes a shaft, and a balloon coupled to the(32736-2128) shaft, the balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure, and an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

[0014] In yet another aspect, a method of assembling an ablation system is provided. The method includes forming an ablation catheter assembly by coupling a balloon to a shaft, the balloon including i) a conductive material configured to dissipate electrical energy7into tissue during an ablation procedure and ii) an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator. The method further includes coupling the ablation catheter assembly to the ablation generator.

[0015] In yet another aspect, an ablation catheter assembly is provided. The ablation catheter assembly includes a shaft, and a plurality of balloons coupled to the shaft, each balloon comprising a conductive material configured to dissipate electrical energy7into tissue during an ablation procedure.

[0016] In yet another aspect, an ablation system is provided. The ablation system includes an ablation generator, and an ablation catheter assembly coupled to the ablation generator. The ablation catheter assembly includes a shaft, and a plurality7of balloons coupled to the shaft, each balloon comprising a conductive material configured to dissipate electrical energy into tissue during an ablation procedure.

[0017] In yet another aspect, a method of assembling an ablation system is provided. The method includes forming an ablation catheter assembly by coupling a plurality of balloons to a shaft, each balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure. The method further includes coupling the ablation catheter assembly to an ablation generator.

[0018] In one or more of these aspects, the balloon(s) may be relatively compliant (i.e., stretchable) and may have a relatively low hardness (as measured using a durometer). Alternatively, the balloon(s) may be relatively non-compliant (e.g., rigid).15740WOO1(32736-2128)

[0019] In one or more of these aspects, conductive material of the balloon(s) may be made of polyurethane, polyolefin, and / or a polyamide-polyether block copolymer, such as Pebax® (e.g., Pebax MH1657, MV1074, MV2080, and / or MH2030) (Pebax is a registered trademark of Arkema France, Colombes, France). The conductive material may have a conductivity in a range from 1 x 10'2Siemens per meter (S / m) to 1 x 10'7S / m. In some implementations, the conductive material may be doped biaxially-oriented polyethylene terephthalate (PET), and / or may include PET with a conductive additive such as a conductive coating, conductive particles, or conductive polymers.

[0020] In one or more of these aspects, materials for the conductive material and / or other components of balloon(s) may be selected to facilitate reducing impedance, generating larger lesions at lower applied voltages, and / or mitigating temperature increase of the tissue. For example, materials may be selected to limit an electric field gradient to a predetermined value (e.g., 400 Volts per centimeter (V / cm). 600 V / cm. etc.) and / or to keep tissue temperature below 50° C during PFA therapy for a relatively long amount of time.

[0021] In one or more of these aspects, balloon(s) may be selectively inflatable and deflatable. In an inflated state, balloon(s) may have a diameter, for example, in a range from 8 millimeters (mm) to 40 mm.

[0022] In one or more of these aspects, windows of conductive material may be generally rectangular in shape, arranged in a brick -like pattern, and / or generally aligned with a widest part of balloon(s). Alternatively, windows may have any suitable shape and / or be arranged in any suitable pattem / location on balloon(s).

[0023] In one or more of these aspects, the inverted tip may be used for bipolar PFA applications, monopolar PFA applications, and / or RF applications. For bipolar applications, electrical pulses may be applied between the inverted tip and conductive material. In bipolar applications, conductive material may not be directly electrically connected to an ablation generator (e.g., via a wire), but may be energized via a conductive fluid (e.g., saline) inside balloon(s). For monopolar applications, electrical pulses may be applied between the inverted tip and one or more external body patches.15740WOO1(32736-2128)

[0024] In one or more of these aspects, one or more sensing components (e.g., temperature sensing components, tissue contact sensing components, mapping components, etc.) may be coupled to balloon(s). These may include balloon size sensors that facilitate determining a current size of balloon(s). Balloon size sensors may include, for example, a first magnetic sensor that maintains the same orientation as a balloon inflates / deflates, and a second magnetic sensor (e.g., located on a surface of the balloon) that changes its orientation as the balloon inflates / deflates.

[0025] In one or more of these aspects, the balloon(s) may be irrigated to facilitate cooling. For example, an irrigant (e.g., saline) may be pumped through the shaft (e.g., through a fluid conduit) into an interior of balloon (s), and be dispersed through holes defined through balloon(s). The holes may be laser cut into the balloon(s). The irrigant may be directed to a particular portion of the balloon(s). For example, irrigant may be directed towards the inverted tip.

[0026] In one or more of these aspects, the conductive material may comprise a non-conductive polymer with a conductive dopant.

[0027] In one or more of these aspects, the inverted tip may comprise a ring electrode and / or a flex circuit electrode.

[0028] In one or more of these aspects, an angle between a longitudinal axis of the ablation catheter assembly and a normal vector defined by at least one window of the plurality7of windows may be in a range from 50 to 70 degrees.

[0029] In one or more of these aspects, at least one conductive component may be coupled to a surface of the at least one balloon.

[0030] In one or more of these aspects, the conductive material may comprise a first conductive layer and a second conductive layer.

[0031] In one or more of these aspects, the plurality of balloons may comprise four balloons that each form a respective quadrant of a balloon structure.15740WOO1(32736-2128)

[0032] In one or more of these aspects, at least one of the plurality- of windows may have a serpentine or scalloped edge.

[0033] In one or more of these aspects, at least one of the plurality of windows may have edges coated with a conductive polymer.

[0034] Pulsed field energy may be delivered using any suitable waveform. A waveform may be delivered using an ablation generator. A waveform may include a positive pulse followed by a negative pulse. Further, there may be an intrapulse delay (which may also be referred to as an interphase delay) between the positive and negative pulses. The waveform may include a series of consecutive pairs of positive and negative pulses. That is, the waveform may include i) a first positive pulse followed by (i.e., after an intrapulse delay) a first negative pulse and ii) a second positive pulse followed by a second negative pulse. The time period between the beginning of the first positive pulse and the beginning of the second positive pulse (i.e., the time it takes for the pairs of positive and negative pulses to repeat) may be referred to as the pulse period. The intrapulse delay and / or the pulse period may be on the order of nanoseconds, microseconds, or milliseconds, and the intrapulse delay may be relatively short compared to the pulse period. However, any suitable time periods may be used.

[0035] Each pulse may have a pulse width and a pulse amplitude (which may also be referred to as a peak magnitude). For example, the positive pulse may have a first pulse width and a first pulse amplitude. Similarly, the negative pulse may have a second pulse width and a second pulse amplitude. When first pulse amplitude and second pulse amplitude are both non-zero, the waveform is biphasic. For a monophasic waveform, one of first pulse amplitude and second pulse amplitude is zero. For example, if the first pulse amplitude is zero, the waveform is monophasic with single negative pulse. If the second pulse amplitude is zero, the waveform is monophasic with single positive pulse. Pulse widths may be, for example, in a range from 0 nanoseconds (ns) to 5 microseconds (ps), e.g., 3ps. Pulse amplitudes may be, for example, in a range from 10 Volts (V) to about 20.000V. e.g., on the order of 1800V. These values are examples, and any suitable pulse width and amplitude may be used.15740WOO1(32736-2128)

[0036] The waveform may be symmetric (i.e.. with the first pulse width and first pulse amplitude substantially equal to the second pulse width and second pulse amplitude) or asymmetric (i.e., with at least one of the first pulse width and first pulse amplitude different from the second pulse width and second pulse amplitude).BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a diagrammatic view of a medical device localization system.

[0038] Figure 2 is a schematic diagram of a catheter assembly that may be used with the system shown in Figure 1.

[0039] Figure 3 is a schematic diagram of another catheter assembly that may be used with the system shown in Figure 1.

[0040] Figures 4A and 4B are schematic diagrams of alternative catheter assemblies that may be used with the system shown in Figure 1.

[0041] Figure 5 is a schematic diagram of another catheter assembly that may be used with the system shown in Figure 1.

[0042] Figure 6A is a cross-sectional schematic diagram of an example balloon structure.

[0043] Figure 6B is a schematic diagram of an example catheter assembly generated from the balloon structure shown in Figure 6A.

[0044] Figures 7A and 7B are cross-sectional schematic diagrams of an example balloon structure.

[0045] Figure 8 is a cross-sectional schematic view of an example balloon structure.

[0046] Figure 9 is a cross-sectional schematic view of an example balloon structure.15740WOO1(32736-2128)

[0047] Figure 10 is a cross-sectional schematic view of an example balloon structure.

[0048] Figure 11 is a cross-sectional schematic view of an example balloon structure.DETAILED DESCRIPTION OF THE DISCLOSURE

[0049] The present disclosure provides systems and methods for ablation. An ablation catheter assembly includes a shaft, and at least one balloon coupled to the shaft, the at least one balloon including a conductive material configured to dissipate electrical energy' into tissue during an ablation procedure, and a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon.

[0050] A localization and navigation system may be provided for visualization, mapping and navigation of internal body structures. Figure 1 illustrates a diagrammatic view of a medical device localization system 108 that can be used in conjunction with a catheter 10. System 108 includes a main electronic control unit 1 12 (e.g., a processor) having various input / output mechanisms 114, a display 116, an electrocardiogram (ECG) monitor 118, a localization system, such as a localization and navigation system 122, an ablation generator 124 and catheter 10. Catheter 10 includes an expandable assembly 30 having electrodes 50 distributed at the distal end of catheter shaft 110. Catheter shaft 110 and expandable assembly 30 may be referred to collectively as a catheter assembly (e.g., catheter assembly 200, 400, 450, 500, and / or 620, discussed below).

[0051] As shown in Figure 1, electrodes 50 of catheter 10 are configured to be conformable to a tissue (e.g., cardiac tissue) to interface electrodes 50 with the tissue. The configuration of expandable assembly 30 and electrodes 50 discussed herein facilitates insertion of expandable assembly 30 using a handle 100 of catheter 10, deployment of expandable assembly 30 and electrodes 50 within a heart 16, and withdrawal of expandable assembly 30 from a patient 17. Electrodes 50 can be used to interface with the tissue as the expandable assembly 30 is advanced, or retracted to receive signals. The signals can be(32736-2128) transmitted via a connector 56 to system 108 for analyzing the signal e.g., to determine localization.

[0052] Input / output mechanisms 114 may include conventional apparatus for interfacing with a computer-based control unit including, for example, one or more of a keyboard, a mouse, a tablet, a foot pedal, a switch and / or the like. Display 116 may also comprise conventional apparatus, such as a computer monitor. ECG monitor 118 is configured to continuously detect an electrical timing signal of the heart organ through the use of a plurality of ECG electrodes (not shown), which may be externally affixed to the outside of a patient’s body. The timing signal generally corresponds to a particular phase of the cardiac cycle, among other things. Generally, the ECG signal(s) may be used by control unit 112 for ECG synchronized play-back of a previously captured sequence of images (cine loop). ECG monitor 120 and ECG-electrodes may both include conventional components.

[0053] Localization and navigation system 122 may be provided for visualization, mapping and navigation of internal body structures and may be configured to serve to determine position (localization) data with respect to the one or more location sensors and / or electrodes 50 and output a respective location reading. A plurality of return electrodes designated 18, 19, 20 are diagrammatic of the body connections that may be used by the various sub-systems included in the overall system 108. The return electrodes may be one or more patch electrodes 18 (body electrodes) or any other type of electrode suitable for use as a return electrode including, for example, one or more catheter shaft electrodes 19, 20 or spline electrodes 50. Return electrodes may be part of the catheter 10 or part of a separate catheter or device (not shown).

[0054] Electrodes 50 can be individually electrically coupled to an ablation generator 124 (e.g., via suitable electrical wire or other suitable electrical conductors extending through catheter shaft 110). Ablation generator 124 generates ablative energy7which is delivered by catheter 10 to the tissue, to form lesions in the tissue, for example. All electrodes 50 of catheter 10 may deliver an electric current simultaneously. Alternatively, stimulation is delivered between pairs of electrodes 50 on catheter 10. Delivering electric current simultaneously using a plurality7of electrodes may facilitate15740WOO1(32736-2128) creating a sufficiently deep lesion. To facilitate activating electrodes simultaneously, the electrodes may be switchable between being connected to a 3D mapping system and being connected to EP amplifiers.

[0055] Localization and navigation system 122 may include conventional apparatus known generally in the art. For example, localization and navigation system 122 may be substantially similar to the EnSite Precision™ System, commercially available from Abbott Laboratories, and as generally shown in commonly assigned U.S. Pat. No. 7.263,397 titled "Method and Apparatus for Catheter Navigation and Location and Mapping in the Heart”, the entire disclosure of which is incorporated herein by reference. In another example, localization and navigation system 122 may be substantially similar to the EnSite X™ System, as generally shown in U.S. Pat. App. Pub. No. 2020 / 0138334 titled “Method for Medical Device Localization Based on Magnetic and Impedance Sensors”, the entire disclosure of which is incorporated herein by reference. It should be understood, however, that localization and navigation system 122 is an example only, and is not limiting in nature. Other technologies for locating / navigating a catheter in space (and for visualization) are known, including for example, the CARTO navigation and location system of Biosense Webster. Inc., the Rhythmia® system of Boston Scientific Scimed. Inc., the K.ODEX® system of Koninklijke Philips N.V., the AURORA® system of Northern Digital Inc., commonly available fluoroscopy systems, or a magnetic location system such as the gMPS system from Mediguide Ltd.

[0056] In this regard, some of the localization, navigation, and / or visualization systems may include a sensor for producing signals indicative of catheter location information, and may include, for example, one or more electrodes in the case of an impedance-based localization system, or alternatively, one or more coils (i.e., wire windings) configured to detect one or more characteristics of a magnetic field, for example in the case of a magnetic-field based localization system. As yet another example, system 108 may utilize a combination electric field-based and magnetic field-based system as generally shown with reference to U.S. Pat. No. 7,536,218 entitled “Hybrid Magnetic- Based and Impedance Based Position Sensing,” the disclosure of which is incorporated herein by reference in its entirety.15740WOO1(32736-2128)

[0057] Pulsed field ablation (PFA), which is a methodology for achieving irreversible electroporation and cell death, may be implemented using the systems and methods described herein. In some cases, PFA may be used at specific cardiac tissue sites such as the pulmonary veins to perform a pulmonary vein isolation (PVI), or to perform focal ablation. In PFA, electric fields may be applied between catheter electrodes (in a bipolar approach) or between one or more catheter electrodes and a return patch (in a monopolar approach) or a combination of catheter electrodes and a return patch (in a multipolar approach). There are advantages and disadvantages to each of these approaches.

[0058] Both approaches, using an appropriate electrode geometry, are able to provide contiguous lesions. For lesion size and proximity, the monopolar approach can potentially create deeper lesions with the same applied voltage. Further, the monopolar approach may be able to create lesions from a distance (e.g., generally proximate, but not necessarily contacting tissue). The bipolar approach may create smaller lesions, requiring closer proximity or contact with tissue to create transmural lesions (depending on, for example, tissue thickness). To monitor operation of localization and visualization system 122, one or more impedances between spline electrodes 50 and / or return electrodes 18, 19, and 20 may be measured. For example, for system 122, impedances may be measured as described in U.S. Patent Application Publication No. 2019 / 0117113, filed on October 23, 2018, U.S. Patent Application Publication No. 2019 / 0183378, filed on December 19, 2018, and U.S. Patent Application No. 63 / 027,660, filed on May 20, 2020, all of which are incorporated by reference herein in their entirety’.

[0059] Figure 2 is a schematic diagram of a catheter assembly 200 that may be used with catheter 10 in system 108. Catheter assembly 200 may be referred to as a catheter. As described herein, catheter assembly 200 provides a relatively low-cost PFA energy delivery tool.

[0060] As shown in Figure 2, catheter assembly 200 includes a balloon 202 coupled to a distal end 204 of a shaft 206 (e.g., shaft 44 as shown in Figure 1). Balloon 202 extends from a balloon proximal end 208 to a balloon distal end 210. To deliver PFA therapy, catheter assembly 200 can be maneuvered into a patient’s anatomy, and energy can15740WOO1(32736-2128) be delivered while balloon 202 is in contact with patient tissue to generate one or more lesions.

[0061] Balloon 202 may be relatively compliant (i.e., stretchable) and may have a relatively low hardness (e.g.. as measured using a durometer). Alternatively, balloon 202 may have any suitable characteristics. For example, balloon 202 may be relatively non- compliant (e.g., rigid).

[0062] Balloon 202 includes a conductive material 212. For example, conductive material 212 may be made of polyurethane, polyolefin, and / or a poly amide-poly ether block copolymer, such as Pebax® (e.g., Pebax MH1 57, MV1074, MV2080, and / or MH2030) (Pebax is a registered trademark of Arkema France, Colombes, France). Alternatively, conductive material 212 may be made of any suitable material. Conductive material 212 may have a conductivity in a range from 1 x 10'2Siemens per meter (S / m) to 1 x 10'7S / m. In some implementations, the conductive material 212 may be doped biaxially-oriented polyethylene terephthalate (PET), and / or may include PET with a conductive additive such as a conductive coating, conductive particles, or conductive polymers.

[0063] Further, the conductive material 212 may include a non-conductive polymer with a conductive dopant. For example, conductive material 212 may include a non-conductive polymer doped with up to 20% carbon black, or up to 40% carbon black.

[0064] Materials for conductive material 212 and / or other components of balloon 202 may be selected to facilitate reducing impedance, generating larger lesions at lower applied voltages, and / or mitigating temperature increase of the tissue. For example, materials may be selected to limit an electric field gradient to a predetermined value (e.g., 400 Volts per centimeter (V / cm), 600 V / cm, etc.) and to keep tissue temperature below 50° C during PFA therapy for a relatively long amount of time.

[0065] As discussed herein, depending on, for example, a size of balloon 202 and an intended lesion size / pattem, at least some portions of balloon 202 may be covered or masked with a non-conductive masking material (e.g., non-conductive masking material 302, 512, shown in Figures 3 and 5, respectively). In Figure 2, substantially all of conductive material 212 is exposed (i.e., no non-conductive masking material is used).15740WOO1(32736-2128)

[0066] Balloon 202 may be selectively inflatable and deflatable (e.g., using an actuator on handle 42 (shown in Figure 1)). In an inflated state, balloon 202 may have a diameter, for example, in a range from 8 millimeters (mm) to 40 mm. Alternatively, balloon 202 may have any suitable dimensions. Further, although only a single balloon 202 is shown in Figure 2, multiple selectively inflatable balloons 202 (e.g., two or three balloons 202) may be coupled to shaft 206.

[0067] For smaller balloons 202 (e.g., 8-12 mm in diameter), substantially all of conductive material 212 may be exposed. For example, non-conductive masking material may be omitted or only included at proximal and distal ends of balloon 202. Accordingly, during ablation therapy (e.g., PFA therapy), energy is delivered through substantially the entire surface of balloon 202.

[0068] For larger balloons (e.g., 12-40 mm in diameter), non-conductive masking material may be used to direct energy delivery to specific locations on balloon 202 during ablation (e.g., PFA therapy). For example, Figure 3 shows balloon 202 including non- conductive masking material 302.

[0069] As shown in Figure 3, non-conductive masking material 302 covers a majority' of balloon 202 such that a plurality of windows 304 of exposed conductive material 212 are defined. Windows 304 are generally rectangular in shape, arranged in a brick-like pattern, and are generally aligned with a widest part of balloon 202. Alternatively, windows 304 may have any suitable shape and / or be arranged in any suitable pattem / location on balloon 202. For example, windows 304 may include a ring-shaped window' that extends around a circumference of balloon 202, etc.

[0070] As shown in Figures 2 and 3, balloon 202 includes an inverted tip 320 (alternatively, inverted tip 320 may be omitted). More specifically, inverted tip 320 extends proximally from balloon distal end 210 into an interior of balloon 202. Inverted tip 320 may include a highly conductive dispersive electrode electrically coupled to a generator (e.g., ablation generator 124 (shown in Figure 1)). During, for example, PFA therapy, the generator selectively energizes inverted tip 320, and the electrical energy emitted from inverted tip 320 is dissipated through a fluid (e.g., saline) inside the balloon to15740WOO1(32736-2128) conductive material 212. Conductive material 212 disperses the electrical energy into tissue in contact with balloon 202.

[0071] Inverted tip 320 may be used for bipolar PFA applications, monopolar PFA applications, and / or RF ablation applications. For bipolar applications, electrical pulses may be applied between inverted tip 320 and conductive material 212. In bipolar applications, conductive material 212 may not be directly electrically connected to the ablation generator (e.g., via a wire), but may be energized via a conductive fluid (e.g., saline) inside balloon 202. Inverted tip 320 may include a ring electrode or flex circuit electrode in some implementations.

[0072] For monopolar applications, electrical pulses may be applied between inverted tip 320 and one or more external body patches (e.g., return electrodes 18, 20, and / or 21 (shown in Figure 1)).

[0073] Although balloon 202 is shown as generally spherical in Figures 2 and 3, the balloon may take other shapes. That is, balloon 202 may have a particular shape to facilitate targeting specific anatomy of a patient and / or generating desired electnc field geometries. For example, balloon 202 may have a tubular shape (i.e., a generally cylindrical shape) with conductive / non-conductive portions to achieve desired lesion patterns.

[0074] Catheter assembly 200 may include one or more sensing components (e.g., temperature sensing components, tissue contact sensing components, mapping components, etc.) coupled to balloon 202. Balloon 202 may include balloon size sensors (not shown) that facilitate determining a current size of balloon 202. Balloon size sensors may include, for example, a first magnetic sensor that maintains the same orientation as balloon 202 inflates / deflates, and a second magnetic sensor (e.g., located on a surface of balloon 202) that changes its orientation as balloon 202 inflates / deflates. By tracking the orientation of the second magnetic sensor relative to the first magnetic sensor, a size of balloon 202 may be monitored. Those of skill in the art will appreciate that the one or more sensing components may be communicatively coupled to a mapping system (e.g., localization and navigation system 30 (shown in Figure 1)). Magnetic sensors may be, for example, coil sensors deposited on a surface of balloon 202.15740WOO1(32736-2128)

[0075] Balloon 202 may be selectively inflated and deflated to adjust energy delivery. For example, as balloon 202 is inflated, a wall thickness of balloon 202 generally decreases, reducing a resistance of balloon 202. In contrast, as balloon 202 is deflated, the wall thickness of balloon 202 generally increases, increasing a resistance of balloon 202.

[0076] Further, balloon 202 may be irrigated to facilitate cooling catheter assembly 200. For example, an irrigant (e.g., saline) may be pumped through shaft 206 (e.g., through a fluid conduit) into an interior of balloon 202, and be dispersed through holes defined through balloon 202. The holes may be laser cut into balloon 202.

[0077] The irrigant may be directed to a particular portion of balloon 202. For example, irrigant may be directed towards inverted tip 320, as inverted tip 320 will generally be the primary source of thermal energy generation during operation of catheter assembly 200.

[0078] Figure 4A is a schematic diagram of an alternative catheter assembly 400. The features and functionality described in association with catheter assembly 200 (shown in Figures 2 and 3) may be implemented within catheter assembly 400 as well.

[0079] Catheter assembly 400 includes a first balloon 402 and a second balloon 404 coupled to a shaft 406. Second balloon 404 is located at a distal end 410 of catheter assembly 400, and is located distal of first balloon 402. Further, as shown in Figure 4, second balloon 404 is smaller than first balloon 402. Alternatively, first and second balloons 402 and 404 may have any suitable relative sizes (e.g., first balloon 402 may be smaller than or the same size as second balloon 404).

[0080] First and second balloons 402 and 404 may be selectively inflatable independent of one another. For bipolar applications, first and second balloons 402 and 404 may be electrically activated independent of one another (i.e., to deliver electrical energy between first and second balloons 402 and 404). For monopolar applications, first and second balloons 402 and 404 may be electrically activated together (i.e., to function as a single, larger electrode) to deliver electrical energy between both of first and second balloons 402 and 404 and an external patch electrode (e.g., return electrodes 18, 20, and / or 21 (shown in Figure 1)). Alternatively, for monopolar applications, only one of first and15740WOO1(32736-2128) second balloons 402 and 404 may be electrically activated to deliver electrical energy between the electrically activated balloon and an external patch electrode (e.g., return electrodes 18, 20, and / or 21 (shown in Figure 1)).

[0081] Figure 4B is a schematic diagram of an alternative catheter assembly 450. The features and functionality described in association with catheter assembly 200 (shown in Figures 2 and 3) may be implemented within catheter assembly 450 as well.

[0082] Catheter assembly 450 includes balloon 452 coupled to a shaft 454. As compared to catheter assembly 200, balloon 452 does not include an inverted tip. Rather, a distal end 460 of balloon 452 is convex (e.g., spherical), such that balloon 452 has a more spherical shape than balloon 202 (shown in Figures 2 and 3). Distal end 460 may include an electrode (not shown) for use in monopolar and / or bipolar applications. For example, for bipolar applications, the electrode on distal end 460 may be electrically activated independent of other conductive material on balloon 452 (i.e., to deliver electrical energy between the electrode on distal end 460 and other conductive material on balloon 452). For monopolar application, the electrode on distal end 460 may be electrically activated (e.g., possibly together with other conductive material on balloon 452) to deliver electrical energy between balloon 452 and an external patch electrode (e.g., return electrodes 18, 20, and / or 21 (shown in Figure 1)).

[0083] Figure 5 is a schematic view of another alternative catheter assembly 500. The features and functionality described in association with catheter assembly 200 (shown in Figures 2 and 3) may be implemented within catheter assembly 500 as well.

[0084] Catheter assembly 500 includes a balloon 502 coupled to a shaft 504. Notably, balloon 502 is not located at a distal end 506 of shaft 504. Rather, a distal portion 508 of shaft 504 extends distally from balloon 502. This arrangement of balloon 502 and shaft 504 may facilitate positioning balloon 502 at a particular location within a patient anatomy.

[0085] In Figure 5, balloon 502 includes a conductive material 510 partially covered by a non-conductive masking material 512. This results in a plurality' of window s 514 of exposed conductive material 510. Windows 514 are generally elliptical in shape,15740WOO1(32736-2128) are arranged in a brick-like patern, and are concentrated towards a distal end 520 of balloon 502. Alternatively, windows 514 may have any suitable shape and / or be arranged in any suitable patem / location on balloon 502.

[0086] With windows 514 concentrated towards a distal end 520 of a balloon 502, at least some windows 514 face at least partially distally. For example, an angle between a normal vector for a window 514 (i.e., a vector extending orthogonally from a surface of or a plane defined by the window 514) and a longitudinal axis of the catheter assembly 500 may be in a range from 50 to 70 degrees, more particularly in a range from 55 to 65 degrees, or more particularly approximately 60 degrees. This orientation facilitates improving contact (and lesion generation) between windows 514 and tissue. Those of skill in the art will appreciate that window s 304 in catheter assembly 200 (and in other catheter assemblies within the spirit and scope of this disclosure) may be similarly oriented.

[0087] Those of skill in the art wall appreciate that non-conductive and conductive patterns on a catheter (such as the window and masking paterns discussed herein) may be made using any suitable manufacturing process. In one example, conductive patterns are formed by selectively removing non-conductive material overlaying a conductive material. In another example, conductive patterns are formed by plating (or otherwise depositing) conductive material onto a non-conductive material.

[0088] For example, Figure 6A is a cross-sectional schematic diagram of an example balloon structure 600. Figure 6B is a schematic diagram of an example catheter assembly 620 generated from balloon structure 600. Balloon structure 600 includes a conductive layer 602 and anon-conductive layer 604 surrounding conductive layer 602. Conductive layer 602 and non-conductive layer 604 may be composed of stretchable, flexible materials such that conductive layer 602 and non-conductive layer 604 inflate and expand when a fluid is provided to a cavity 606 surrounded by conductive layer 602.

[0089] To create conductive patterns on a surface of balloon structure 600, portions of non-conductive layer 604 may be selectively removed (e.g., using laser ablation and / or laser cuting) to expose underlying portions of conductive layer 602. For example, as shown in FIG. 6B, portions of non-conductive layer 604 may be removed to expose corresponding portions of conductive layer 602, thereby forming first conductive elements15740WOO1(32736-2128)622 of catheter assembly 620. The removed portions of non-conductive layer 604 and / or the exposed portions of conductive layer 602 may extend over any area of balloon structure 600, including along a centerline of balloon structure 600, aligned with a widest part of balloon structure 600, within a distal region of balloon structure 600, and / or within a proximal portion of balloon structure 600. Where conductive layer 602 and non-conductive layer 604 extend beyond balloon structure 600 (e.g., along at least a portion of a catheter shaft, such as shaft 206, 406, 454, and / or 504), the removed portions of non-conductive layer 604 and / or the exposed portions of conductive layer 602 may likewise extend bey ond balloon structure 600.

[0090] Additionally or alternatively, conductive components 610 may be plated on top of (or otherwise applied to) non-conductive layer 604. For example, as shown in FIG. 6B, second conductive elements 624 may be generated by plating conductive components 610 on top of non-conductive layer 604. Conductive components 610 may include, for example, a single layer of metallic or polymeric material plated onto non- conductive layer, or multiple layers of material, such as a flex circuit structure (i.e., a flexible substrate and one or more electrodes positioned on the flexible substrate), plated onto non-conductive layer 604. The flex circuit structure may be fabricated from materials that have a similar stiffness to the materials of the balloon structure 600 (e.g., to promote flexibility' and reduce the risk of delamination during expansion and contraction).

[0091] Figure 7A is a cross-sectional schematic diagram of another example balloon structure 700. Balloon structure 700 includes a first conductive layer 702, a first non-conductive layer 704 surrounding first conductive layer 702, a second conductive layer 706 surrounding first non-conductive layer 704, and a second non-conductive layer 708 surrounding second conductive layer 706. Layers 702, 704, 706, and 708 may be composed of stretchable, flexible materials such that layers 702, 704. 706, and 708 inflate and expand when a fluid is provided to a cavity 710 surrounded by first conductive layer 702.(32736-2128)

[0092] To create conductive patterns on a surface of balloon structure 700, portions of layers 704, 706, and 708 may be selectively removed (e.g., using laser ablation) to expose underlying portions of first conductive layer 702 and / or second conductive layer 706.

[0093] For example, as shown in Figure 7B, to generate a first conductive element 720, portions of second non-conductive layer 708, second conductive layer 706, and first non-conductive layer 704 have been removed to expose a portion of first conductive layer 702. Further, to generate a second conductive element 730, portions of second non- conductive layer 708 have been removed to expose a portion of second conductive layer 706.

[0094] The removed portions of second non-conductive layer 708, second conductive layer 706, and / or first non-conductive layer 704, and / or the exposed portions of first conductive layer 702 may extend over any area of balloon structure 700, including along a centerline of balloon structure 700, aligned with a widest part of balloon structure 700, within a distal region of balloon structure 700, and / or within a proximal portion of balloon structure 700. Likewise, the removed portions of second non-conductive layer 708 and / or the exposed portions of second conductive layer 706 may extend over any area of balloon structure 700. Where first conductive layer 702, first non-conductive layer 704, second conductive layer 706. and / or second non-conductive layer 708 extend beyond balloon structure 700 (e.g.. along at least a portion of a catheter shaft, such as shaft 206, 406, 454, and / or 504), the removed portions of layers 704, 706, and / or 708 and / or the exposed portions of layers 702 and / or 706 may likewise extend beyond balloon structure 700.

[0095] First conductive layer 702 and second conductive layer 706 may be selectively energized independent of one another (e.g., with only one layer energized at a time, or with a different voltage and / or waveform applied to each layer). Although not shown in Figure 7B, conductive components (similar to conductive components 610, shown in Figure 6A) may also be plated on top of (or otherwise applied to) second non- conductive layer 708.15740WOO1(32736-2128)

[0096] Figure 10 is a cross-sectional schematic diagram of another example balloon structure 1000. Balloon structure 1000 includes a conductive layer 1002 and a non- conductive layer 1004. In some embodiments, non-conductive layer 1004 may concentrically surround conductive layer 1002. Non-conductive layer 1004 may also extend through conductive layer 1002 diametrically and / or radially, to further isolate conductive layer 1002 into isolated conductive portions 1006A-1006D, shown as wedge-shaped portions of conductive layer 1002, which may also be referred to as circuit paths. In various embodiments, any of isolated conductive portions 1006A-1006D may be energized independent of one another (e.g.. with only one conductive portion energized at a time, or with a different voltage and / or waveform applied to each conductive portion).

[0097] To create conductive patterns on a surface of balloon structure 1000, portions of non-conductive layer 1004 may be selectively removed (e g., using laser ablation) to expose underlying portions of conductive layer 1002. Additionally or alternatively, conductive components 1008 (similar to conductive components 610, shown in Figures 6A and 6B) may be plated on top of (or otherwise applied to) non-conductive layer 1004. Conductive layer 1002 and non-conductive layer 1004 may be composed of stretchable, flexible materials such that conductive layer 1002 and non-conductive layer 1004 inflate and expand when a fluid is provided to a cavity 1010 surrounded by conductive layer 1002 and / or non-conductive layer 1004.

[0098] Figure 11 is a cross-sectional diagram of another example balloon structure 1100. Balloon structure 1 100 includes a first conductive layer 1102, a second conductive layer 1104, and anon-conductive layer 1106. In some embodiments, non- conductive layer 1106 may concentrically surround first conductive layer 1102 and / or second conductive layer 1104 and may separate and isolate first conductive layer 1102 from second conductive layer 1104 in the radial direction. Non-conductive layer 1106 may also extend through first conductive layer 1102 and / or second conductive layer 1104 diametrically and / or radially, to further isolate first conductive layer 1102 into isolated first conductive portions 1108A-1108D, shown as wedge-shaped portions of first conductive layer 1102, and to isolate the second conductive layer 1104 into isolated second conductive portions 1 1 10A-11 10D, shown as wedge-shaped portions of second conductive layer 1 104. In various embodiments, any of isolated first conductive portions 1108A-1108D may be15740WOO1(32736-2128) energized independent of one another (e.g., with only one first conductive portion energized at a time, or with a different voltage and / or waveform applied to each first conductive portion). Likewise, any of isolated second conductive portions 1110A-1 HOD may be energized independent of one another (e.g., with only one second conductive portion energized at a time, or with a different voltage and / or waveform applied to each second conductive portion).

[0099] To create conductive patterns on a surface of balloon structure 1100, portions of non-conductive layer 1106 may be selectively removed (e.g., using laser ablation) to expose underlying portions of first conductive layer 1102 and / or portions of second conductive layer 1104. Additionally or alternatively, conductive components 1112 (similar to conductive components 610, shown in Figures 6A and 6B) may be plated on top of (or otherwise applied to) non-conductive layer 1106. First conductive layer 1102, second conductive layer 1104, and non-conductive layer 1106 may be composed of stretchable, flexible materials such that first conductive layer 1102, second conductive layer 1104, and non-conductive layer 1106 inflate and expand when a fluid is provided to a cavity 1114 surrounded by first conductive layer 1102, second conductive layer 1104, and / or non-conductive layer 1106.

[0100] At least one surface preparation process may be applied to the balloons described herein (e.g., to improve shielding and / or to improve the ability to adhere an electrode to the balloon surface (such as a flex circuit plated onto the balloon surface)). For example, surface roughing, electron beam applications, cross-linking applications, and / or plasma treatments may be applied to a balloon to improve surface characteristics of the balloon.

[0101] Figure 8 is a cross-sectional schematic view of an example balloon structure 800 that may be implemented with the catheter assemblies disclosed herein. Here, balloon structure 800 includes alternating conductive portions 802 and non-conductive portions 804 on the same layer. Conductive portions 802 may be energized together or may be selectively energized independent of one another during ablation therapy.15740WOO1(32736-2128)

[0102] Figure 9 is a cross-sectional schematic view of another example balloon structure 900 that may be implemented with the catheter assemblies disclosed herein. Here, balloon structure 900 includes a plurality of individual balloons 902 that collectively form a multi-lobed structure. Balloon structure 900 may include, for example, four balloons 902 that each form a respective quadrant of balloon structure 900. Each balloon 902 may include conductive portions 904 and non-conductive portions 906. For example, conductive portions 904 may face radially outward on balloon structure 900. Each balloon 902 may be selectively inflatable independent of other balloons 902 to generate catheter shapes as desired. Further, conductive portions 904 on each balloon 902 may be energized together or may be selectively energized independent of one another dunng ablation therapy. Each balloon 902 may include a single layer, or multiple nested layers, of conductive and / or non-conductive material(s) (e.g., nested conductive and non-conductive layers similar to what is shown in Figures 6A-7B, 10, and / or 11).

[0103] Those of skill in the art will appreciate that the specific window shapes disclosed herein (e.g., elliptical, rectangular, etc.) are merely examples, and that exposed conductive portions may have any suitable shape. For example, instead of having generally smooth or straight edges, windows may have serpentine or scalloped edges (e.g., undulating edges). This facilitates reducing current density when energy is applied by increasing a perimeter of a window while maintaining generally the same surface area. Further, edges of a window may be coated with a conductive material (e.g., a conductive polymer) that has less conductivity than the window itself to reduce edge effects when energy is applied.

[0104] The catheters disclosed herein may also include one or more mapping electrodes. For example, an array of mapping electrodes (e.g., spot electrodes, flex circuit electrodes, etc.) may be coupled to a surface of the balloon. The mapping electrodes may be used to facilitate, for example, omnipolar mapping applications.

[0105] Other balloon shapes beyond those specifically shown are within the spirit and scope of the disclosure as well. For example, instead of being generally spherical, balloons may include a multi-lobed structure and / or folds that result in balloons having15740WOO1(32736-2128) irregular shapes. In one example, balloons have an extended, oblong shape to better complement certain tissue structures.

[0106] The systems and methods described herein are directed to systems and methods for ablation. An ablation catheter assembly includes a shaft, and at least one balloon coupled to the shaft, the at least one balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure, and a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon.

[0107] Although certain ablation catheters, systems, and methods of this disclosure have been described above with a certain degree of particularity7, those skilled in the art could make numerous alterations to the disclosed ablation catheters, systems, and methods without departing from the spirit or scope of this disclosure. All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader’s understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the disclosure. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the disclosure as defined in the appended claims.

[0108] When introducing elements of the present disclosure, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there mav be additional elements other than the listed elements.15740WOO1(32736-2128)

[0109] As various changes could be made in the above constructions without departing from the scope of the disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0110] In summary, the present disclosure provides systems and methods for ablation. An ablation catheter assembly includes a shaft, and at least one balloon coupled to the shaft, the at least one balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure, and a) a non-conductive masking material covering a portion of the conductive material and defining a plurality of w indow s of exposed conductive material on a surface of the balloon and / or b) an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

[0111] The following are numbered aspects of the invention:

[0112] Aspect 1. An ablation catheter assembly comprising: a shaft; and at least one balloon coupled to the shaft, the at least one balloon comprising: a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon.

[0113] Aspect 2. The ablation catheter assembly of aspect 1, wherein the at least one balloon comprises an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

[0114] Aspect 3. The ablation catheter assembly of aspect 2, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application betw een the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.15740WOO1(32736-2128)

[0115] Aspect 4. The ablation catheter assembly of any one of aspects 1 to 3. wherein the at least one balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

[0116] Aspect 5. The ablation catheter assembly of any one of aspects 1 to 4. wherein the at least one balloon comprises a plurality of balloons.

[0117] Aspect 6. The ablation catheter assembly of any one of aspects 1 to 5, wherein the shaft comprises a distal portion that extends distally from the at least one balloon.

[0118] Aspect 7. The ablation catheter assembly of any one of aspects 1 to 6, wherein the conductive material comprises a non-conductive polymer with a conductive dopant.

[0119] Aspect 8. The ablation catheter assembly of any one of aspects 1 to 7, wherein an angle between a longitudinal axis of the ablation catheter assembly and a normal vector defined by at least one window of the plurality of windows is in a range from 50 to 70 degrees.

[0120] Aspect 9. The ablation catheter assembly of any one of aspects 1 to 8, further comprising at least one conductive component coupled to a surface of the at least one balloon.

[0121] Aspect 10. The ablation catheter assembly of any one of aspects 1 to 9, wherein the conductive material comprises a first conductive layer and a second conductive layer.

[0122] Aspect 11. The ablation catheter assembly of any one of aspects 1 to 10, wherein at least one of the plurality of windows has a serpentine or scalloped edge.

[0123] Aspect 12. The ablation catheter assembly of any one of aspects 1 to 11, wherein at least one of the plurality of windows has edges coated with a conductive polymer.15740WOO1(32736-2128)

[0124] Aspect 13. An ablation system comprising: an ablation generator; and an ablation catheter assembly according to any one of aspects 1 to 12. wherein the ablation catheter assembly is coupled to the ablation generator.

[0125] Aspect 14. The ablation system of aspect 13, wherein the at least one balloon comprises an inverted tip positioned at a distal end of the balloon, the inverted tip electrically coupled to the ablation generator.

[0126] Aspect 15. The ablation system of aspect 13 or 14, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

[0127] Aspect 16. A method of assembling an ablation system, the method comprising: forming an ablation catheter assembly by coupling at least one balloon to a shaft, the at least one balloon including i) a conductive material configured to dissipate electrical energy into tissue during an ablation procedure and ii) a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon; and coupling the ablation catheter assembly to an ablation generator.

[0128] Aspect 17. The method of aspect 1 , wherein the at least one balloon includes an inverted tip positioned at a distal end of the balloon, the inverted tip electrically coupled to the ablation generator.

[0129] Aspect 18. The method of aspect 16 or 17, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

[0130] Aspect 19. The method of aspect 16, wherein the at least one balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.15740WOO1(32736-2128)

[0131] Aspect 20. An ablation catheter assembly comprising: a shaft; and a balloon coupled to the shaft, the balloon comprising: a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

[0132] Aspect 21. The ablation catheter assembly of aspect 20, wherein the balloon further comprises a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

[0133] Aspect 22. The ablation catheter assembly of aspect 20 or 21, wherein the balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

[0134] Aspect 23. The ablation catheter assembly of aspect 20, wherein the balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

[0135] Aspect 24. The ablation catheter assembly of any one of aspects 20 to 23, wherein the inverted tip comprises a ring electrode and / or a flex circuit electrode.

[0136] Aspect 25. An ablation system comprising: an ablation generator; and an ablation catheter assembly according to any one of aspects 20 to 34, wherein the catheter assembly is coupled to the ablation generator.

[0137] Aspect 26. The ablation system of aspect 25, wherein the balloon further comprises a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.15740WOO1(32736-2128)

[0138] Aspect 27. The ablation system of aspect 25 or 26, wherein the balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

[0139] Aspect 28. A method of assembling an ablation system, the method comprising: forming an ablation catheter assembly by coupling a balloon to a shaft, the balloon including i) a conductive material configured to dissipate electrical energy into tissue during an ablation procedure and ii) an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator; and coupling the ablation catheter assembly to the ablation generator.

[0140] Aspect 29. The method of aspect 28, wherein the balloon further includes a non-conductive masking material covenng a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

[0141] Aspect 30. The method of aspect 28 or 29, wherein the balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

[0142] Aspect 31. The method of any of aspect 28 or 29, wherein the balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

[0143] Aspect 32. An ablation catheter assembly comprising: a shaft; and a plurality7of balloons coupled to the shaft, each balloon comprising a conductive material configured to dissipate electrical energy- into tissue during an ablation procedure.

[0144] Aspect 33. The ablation catheter assembly of aspect 32, yvherein each of the plurality of balloons are selectively inflatable independent of one another, and electrically activatable independent of one another.15740WOO1(32736-2128)

[0145] Aspect 34. The ablation catheter assembly of aspect 32 or 33, wherein at least one of the plurality of balloons further comprises a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

[0146] Aspect 35. The ablation catheter assembly of any one of aspects 32-34, wherein at least one of the plurality of balloons comprises an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

[0147] Aspect 36. The ablation catheter assembly of aspect 32, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

[0148] Aspect 37. The ablation catheter assembly of any one of aspects 32 to 36, wherein the plurality of balloons comprises four balloons that each form a respective quadrant of a balloon structure.

[0149] Aspect 38. An ablation system comprising: an ablation generator; and an ablation catheter assembly according to any one of aspects 32 to 37, wherein the ablation catheter assembly is coupled to the ablation generator.

[0150] Aspect 39. The ablation system of aspect 38, wherein each of the plurality' of balloons are selectively inflatable independent of one another, and electrically activatable independent of one another.

[0151] Aspect 40. The ablation system of aspect 38 or 39. wherein at least one of the plurality of balloons further comprises a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.15740WOO1(32736-2128)

[0152] Aspect 41. The ablation system of any one of aspects 38-40. wherein at least one of the plurality of balloons comprises an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

[0153] Aspect 42. A method of assembling an ablation system, the method comprising: forming an ablation catheter assembly by coupling a plurality of balloons to a shaft, each balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and coupling the ablation catheter assembly to an ablation generator.

[0154] Aspect 43. The method of aspect 42, wherein at least one balloon of the plurality' of balloons further includes a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

[0155] Aspect 44. The method of aspect 42 or 43, wherein at least one balloon of the plurality’ of balloons includes an inverted tip positioned at a distal end of the balloon, the inverted tip electrically coupled to the ablation generator.

[0156] Aspect 45. The method of aspect 44, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application betyveen the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

[0157] Aspect 46. The method of any of aspect 42, wherein the at least one balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

Claims

1. 15740WOO1(32736-2128)WHAT IS CLAIMED IS:

1. An ablation catheter assembly comprising: a shaft; and at least one balloon coupled to the shaft, the at least one balloon comprising: a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon.

2. The ablation catheter assembly of claim 1, wherein the at least one balloon comprises an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

3. The ablation catheter assembly of claim 2, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

4. The ablation catheter assembly of claim 1, wherein the at least one balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

5. The ablation catheter assembly of any of the preceding claims, wherein the at least one balloon comprises a plurality of balloons.

6. The ablation catheter assembly of any of the preceding claims, wherein the shaft comprises a distal portion that extends distally from the at least one balloon.

7. The ablation catheter assembly of any of the preceding claims, wherein the conductive material comprises anon-conductive polymer with a conductive dopant.15740WOO1(32736-2128)8. The ablation catheter assembly of any of the preceding claims, wherein an angle between a longitudinal axis of the ablation catheter assembly and a normal vector defined by at least one w indow of the plurality of windows is in a range from 50 to 70 degrees.

9. The ablation catheter assembly of any of the preceding claims, further comprising at least one conductive component coupled to a surface of the at least one balloon.

10. The ablation catheter assembly of any of the preceding claims, wherein the conductive material comprises a first conductive layer and a second conductive layer.

11. The ablation catheter assembly of any of the preceding claims, wherein at least one of the plurality of windows has a serpentine or scalloped edge.

12. The ablation catheter assembly of any of the preceding claims, wherein at least one of the plurality of window s has edges coated with a conductive polymer.

13. An ablation system comprising: an ablation generator; and an ablation catheter assembly coupled to the ablation generator, the catheter assembly comprising: a shaft; and at least one balloon coupled to the shaft, the at least one balloon comprising: a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon.

14. The ablation system of claim 13, wherein the at least one balloon comprises an inverted tip positioned at a distal end of the balloon, the inverted tip electrically coupled to the ablation generator.15740WOO1(32736-2128)15. The ablation system of claim 13 or 14, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

16. A method of assembling an ablation system, the method comprising: forming an ablation catheter assembly by coupling at least one balloon to a shaft, the at least one balloon including i) a conductive material configured to dissipate electrical energy into tissue during an ablation procedure and ii) a non-conductive masking material covering a portion of the conductive material and defining a plurality of windows of exposed conductive material on a surface of the balloon; and coupling the ablation catheter assembly to an ablation generator.

17. The method of claim 16, wherein the at least one balloon includes an inverted tip positioned at a distal end of the balloon, the inverted tip electrically coupled to the ablation generator.

18. The method of claim 16 or 17, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

19. The method of claim 16, wherein the at least one balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

20. An ablation catheter assembly comprising: a shaft; and a balloon coupled to the shaft, the balloon comprising: a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and15740WOO1(32736-2128) an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

21. The ablation catheter assembly of claim 20, wherein the balloon further comprises a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

22. The ablation catheter assembly of claim 20 or 21, wherein the balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

23. The ablation catheter assembly of claim 20, wherein the balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

24. The ablation catheter assembly of any of claims 20 to 23, wherein the inverted tip comprises a ring electrode and / or a flex circuit electrode.

25. An ablation system comprising: an ablation generator; and an ablation catheter assembly coupled to the ablation generator, the ablation catheter assembly comprising: a shaft; and a balloon coupled to the shaft, the balloon comprising: a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.15740WOO1(32736-2128)26. The ablation system of claim 25, wherein the balloon further comprises a non- conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

27. The ablation system of claim 25 or 26, wherein the balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

28. A method of assembling an ablation system, the method comprising: forming an ablation catheter assembly by coupling a balloon to a shaft, the balloon including i) a conductive material configured to dissipate electrical energy into tissue during an ablation procedure and ii) an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator; and coupling the ablation catheter assembly to the ablation generator.

29. The method of claim 28, wherein the balloon further includes a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

30. The method of claim 28 or 29, wherein the balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

31. The method of claim 28 or 29, wherein the balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

32. An ablation catheter assembly comprising: a shaft; and15740WOO1(32736-2128) a plurality of balloons coupled to the shaft, each balloon comprising a conductive material configured to dissipate electrical energy into tissue during an ablation procedure.

33. The ablation catheter assembly of claim 32. wherein each of the plurality of balloons are selectively inflatable independent of one another, and electrically activatable independent of one another.

34. The ablation catheter assembly of claim 32 or 33, wherein at least one of the plurality of balloons further comprises a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

35. The ablation catheter assembly of any of claims 32-34, wherein at least one of the plurality of balloons comprises an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

36. The ablation catheter assembly of claim 32, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductive material, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

37. The ablation catheter assembly of any of claims 32 to 36, wherein the plurality of balloons comprises four balloons that each form a respective quadrant of a balloon structure.

38. An ablation system comprising: an ablation generator; and an ablation catheter assembly coupled to the ablation generator, the catheter assembly comprising: a shaft; and15740WOO1(32736-2128) a plurality of balloons coupled to the shaft, each balloon comprising a conductive material configured to dissipate electrical energy into tissue during an ablation procedure.

39. The ablation system of claim 38, wherein each of the plurality of balloons are selectively inflatable independent of one another, and electrically activatable independent of one another.

40. The ablation system of claim 38 or 39. wherein at least one of the plurality of balloons further comprises a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

41. The ablation system of any of claims 38-40, wherein at least one of the plurality of balloons comprises an inverted tip positioned at a distal end of the balloon, the inverted tip configured to be electrically coupled to an ablation generator.

42. A method of assembling an ablation system, the method comprising: forming an ablation catheter assembly by coupling a plurality of balloons to a shaft, each balloon including a conductive material configured to dissipate electrical energy into tissue during an ablation procedure; and coupling the ablation catheter assembly to an ablation generator.

43. The method of claim 42, wherein at least one balloon of the plurality of balloons further includes a non-conductive masking material covering a portion of the conductive material and defining at least one window of exposed conductive material on a surface of the balloon.

44. The method of claim 42 or 43, wherein at least one balloon of the plurality of balloons includes an inverted tip positioned at a distal end of the balloon, the inverted tip electrically coupled to the ablation generator.

45. The method of claim 44, wherein the at least one balloon is configured to deliver electrical pulses i) in a bipolar application between the inverted tip and the conductivematerial, and / or ii) in a monopolar application between the inverted tip and at least one body patch.

46. The method of claim 42, wherein the at least one balloon is configured to deliver electrical pulses in a monopolar application between the conductive material and at least one body patch.

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