Abstract: A medical system may include a shaft member and a structure physically coupled to the shaft member. A portion of the shaft member may be sized to be delivered through a bodily opening leading to a bodily cavity. The structure may include at least two flexible couplings, each flexible coupling extending transversely from an intermediate portion of a respective one of at least two elongate members of the structure. The flexible coupling extending transversely from the intermediate portion of a first one of the at least two elongate members forms at least a part of a first closed loop arranged to receive a portion of the flexible coupling of a second one of the at least two elongate members therethrough to limit a spacing between the intermediate portions of the first and the second ones of the at least two elongate members.

Abstract: Described here are devices, systems, and methods for forming a fistula between two blood vessels. The systems may comprise a first catheter including a housing and an electrode having a proximal end and a distal end. The proximal end is fixed relative to the housing and the distal end is longitudinally slidable within the housing.

Abstract: Systems, devices, and methods for electroporation ablation therapy are disclosed, with the device including a set of splines coupled to a catheter for medical ablation therapy. Each spline of the set of splines may include a set of electrodes formed on that spline. The set of splines may be configured for translation to transition between a first configuration and a second configuration. The devices described herein may be used to form a lesion via focal ablation.

Abstract: What is described is an apparatus for intravascular pressure measurement, comprising an elongate body, a first pressure sensor and a centering assembly disposed adjacent the sensor. In one aspect, the elongate body has a uniform diameter from the distal end to the proximal end. In another aspect, the uniform diameter is 0.035 inches or less. In still a further aspect, the elongated body is a catheter having a plurality of reinforcing filaments and the filaments are utilized to electrically connect the sensor to the proximal end.

Abstract: A system includes a display, an input device, and a processor. The processor is configured to present to a user, on the display, a GUI that illustrates multiple electrodes disposed on an expandable frame of a multi-electrode catheter, and indicates which of the electrodes is active and which of the electrodes is inactive. The processor is further configured to (a) receive, via the input device first user input that chooses between a single-electrode-selection mode and a fan-selection mode, (b) when in the single-electrode-selection mode, receive via the input device second user input that specifies for activation or deactivation individual ones of the electrodes, and (c) when in the fan-selection mode, receive via the input device third user input that specifies for activation or deactivation an angular sector including two or more of the electrodes, and activate and deactivate the electrodes responsively to the first, second and third user inputs.

Abstract: Catheter systems include direction-sensitive, multi-polar tip electrode assemblies for electroporation-mediated therapy, electroporation-induced primary necrosis therapy and electric field-induced apoptosis therapy, including configurations for producing narrow, linear lesions as well as distributed, wide area lesions. A monitoring system for electroporation therapy includes a mechanism for delivering electrochromic dyes to a tissue site as well as a fiber optic arrangement to optically monitor the progress of the therapy as well as to confirm success post-therapy. A fiber optic temperature sensing electrode catheter includes a tip electrode having a cavity whose inner surface is impregnated or coated with thermochromic/thermotropic material that changes color with changes in temperature. An optic fiber/detector arrangement monitors the thermochromic or thermotropic materials, acquiring a light signal and generating an output signal indicative of the spectrum of the light signal.

Abstract: Devices and systems for navigation and positioning a central venous catheter within a patient. In an exemplary embodiment of a system of the present disclosure, the system comprises a first pole and a second pole, the first pole and the second pole configured to generate an electric field within a mammalian body sufficient to obtain a plurality of field measurements therein, and an elongated body configured for at least partial insertion into a blood vessel of the mammalian body and advancement through a vasculature, said advancement dependent upon the plurality of field measurements indicative of one or more locations of a portion of the elongated body within the vasculature. In at least one embodiment, the elongated body is configured as a stylet.

Abstract: This disclosure is directed to a catheter having a basket-shaped electrode assembly formed from a plurality of spines, each with a plurality of electrodes. The spines are connected at their distal ends and extend through the catheter body to its proximal end. Each spine may be independently controlled, such as by adjusting its longitudinal position relative to the catheter body to causes it to bow outwards to a greater or lesser degree.

Abstract: A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an ? value at each of a plurality of time intervals, compute an initial estimate of ? from a cross product of E and the ? value for each of the plurality of time intervals, average the initial estimate of ? from each of the plurality of time for a best estimate of ?, determine a plurality of â(?) values and using the corresponding {circumflex over (n)}(?) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

Abstract: A method, including recording parameters indicative of a quality of ablation performed at one or more sites in a region of a human heart, and receiving a set of electrophysiological signals indicative of a wave of electrical activation flowing through the region. The method further includes identifying locations within the region at which the wave is blocked from flowing and estimating confidence levels with respect to a blockage of the wave at the locations in response to the signals and the parameters. The method also includes displaying a map of the human heart including an indication of the confidence levels.

Abstract: An ablation catheter equipped with ablation petals having electrodes that are continuous over an outer circumferential portion of the ablation petals. The ablation catheter can be moved from a rest position, where the petals are housed in an external tubular body, to an operating position, where the petals protrude from the external tubular body.

Abstract: A surgical instrument and method of tracking the surgical instrument includes a shaft, a cutting member, and navigation system. The shaft has a shaft lumen, a shaft window, and a shaft edge. The cutting member is disposed within the shaft lumen and is configured to cyclically move from a first position to a second position relative to the shaft. The cutting member includes a cutting window opening, a cutting edge, and a suction lumen to cut the tissue portion with the cutting member in the first position. The navigation system includes a navigation sensor positioned on at least one of the shaft or the cutting member that is configured to be tracked within a patient for identifying a positional movement of the shaft or the cutting member within the patient.

Abstract: A device and method for guided insertion of microelectrodes into tissue is provided. The device includes a flexible optical fiber for optical coherence tomography imaging, a metal layer coating the optical fiber for recording electrical signals and an outer insulation layer coating the metal layer along the optical fiber length. The method includes inserting an optical fiber coated with a metal layer and further coated with an insulation layer into a tissue, collecting intraoperative image data through the optical fiber by optical coherence tomography, receiving the image data on a computer and displaying the image on a monitor, using the image data to determine a location in the tissue, receiving an electrical nerve signal through the metal layer and measuring the electrical nerve signal on a electrophysiological recording system.

Abstract: An electrophysiology catheter with a distal electrode assembly having covered spine carrying a plurality of microelectrodes. The position of the microelectrodes on each spine is staggered relative to microelectrodes on adjacent spines so as to minimize the risk of electrodes on adjacent spines touching each other during use of the catheter. The staggered electrode configuration provides the distal electrode assembly with a greater effective contact surface because the effective concentric electrode arrays is increased or at least doubled.

Abstract: Disclosed are systems, devices and methods for providing proximity awareness to an anatomical feature while navigating inside a patient's chest, an exemplary method including receiving image data of the patient's chest, generating a three-dimensional (3D) model of the patient's chest based on the received image data, determining a location of the anatomical feature based on the received image data and the generated 3D model, tracking a position of an electromagnetic sensor included in a tool, iteratively determining a position of the tool inside the patient's chest based on the tracked position of the electromagnetic sensor, and indicating a proximity of the tool relative to the anatomical feature, based on the determined position of the tool inside the patient's chest.

Abstract: This disclosure is directed to a catheter having a multi-electrode assembly with a high electrode density. The multi-electrode assembly may be a basket-shaped electrode assembly or a brush-shaped electrode assembly each having a plurality of spines. Each spine includes a flexible wire core of a shape memory material. The flexible wires may have variable cross-section s to control the movement and stiffness of the spines.

Abstract: Systems and methods for forming a lesion on an endocardial tissue of a patients heart involve placing an ablation assembly inside of the heart and adjacent to the endocardial tissue, and placing a guiding assembly outside of the heart. An ablation assembly includes an ablation element and a first attraction element, and a guiding assembly includes a second attraction element. First and second attraction elements can be attracted via magnetism. Techniques involve forming an ablation on the cardiac tissue of a patient's heart with an ablation element of the ablation assembly. Optionally, techniques may include moving the second attraction element of the guiding assembly relative to the patient's heart, so as to effect a corresponding movement of the ablation element of the ablation assembly.

Abstract: Various embodiments provide a cardiac mapping method including: generating an activation map of a heart based on electrocardiogram (ECG) data of a heart and a three-dimensional (3D) heart model; performing an electrophysiology (EP) procedure to determine a first pacing location; pacing the heart at the first pacing location using an EP catheter; determining whether the pacing at the first pacing location generates a desired cardiac response; displaying guidance information related to a second pacing location on one or both of the activation map and the internal surface map, when the first pacing location is determined not to generate the desired cardiac response; moving the pacing catheter to the second pacing location, based on the guidance information; and pacing the heart at the second pacing location.

Abstract: Ablation systems and methods of the present disclosure control lesion depth and width such that, for example, wide and shallow lesions can be formed in target tissue in an anatomic structure of a patient during a medical procedure. Such wide and shallow lesions can be useful for treating, for example, thin tissue such as atrial tissue in atria of the heart of the patient.

Abstract: An electrophysiology catheter with a distal electrode assembly having covered spine carrying a plurality of microelectrodes. The spines have nonconductive covers that are reinforced with tensile members, e.g., wires or fibers, that extend (or have portions that extend) longitudinally so as to minimize any elongation of the covers and the microelectrodes carried thereon. The tensile members may also have a length greater than the length of the spines so the proximal portions extend proximally from the spines, through the catheter and at least into the control handle for actuation by an operator for deflecting and moving the spines, like “fingers.

Abstract: Methods, systems, and devices for providing treatment to a tissue in body lumens are described. The system may include a catheter, an expansion member coupled with a distal portion of the catheter, an ablation structure including one or more longitudinal electrode segments, and an ablation structure support coupled to the ablation structure configured to at least partially unfurl as the expansion member expands and furl as the expansion member contracts. The ablation structure may include multiple separately wired and/or separately controlled longitudinal electrodes, longitudinal electrode zones, or both, such that each longitudinal electrode or longitudinal electrode zone may be selectively enabled or selectively disabled. In some instances, one or more springs are coupled to the ablation structure configured to promote unfurl or furl around the expansion member. In some instances, one or more protection elements are be positioned along the catheter.

Abstract: Embodiments of the present disclosure provide for catheters for use in electrical neuromodulation. The catheter of the present disclosure includes an elongate body having a first end and a second end. The elongate body includes a longitudinal center axis that extends between the first end and the second end. The elongate body further includes three or more surfaces that define a convex polygonal cross-sectional shape taken perpendicularly to the longitudinal center axis. The catheter further includes one or more electrodes on one surface of the three or more surfaces of the elongate body, where conductive elements extend through the elongate body. The conductive elements can conduct electrical current to combinations of the one or more electrodes.

Abstract: Ablation systems and methods of the present disclosure are directed toward delivering pulsed radiofrequency (RF) energy to target tissue. The pulsations of the RF energy, combined with cooling at a surface of the target tissue, can advantageously promote local heat transfer in the target tissue to form lesions having dimensions larger than those that can be safely formed in tissue using non-pulsed RF energy under similar conditions.

Abstract: In the present invention, a system that has a navigation signal delivered by one of a signal or navigation catheter or treatment catheter as directed by a controller for detection by the other of the navigation catheter or the a treatment catheter to navigate the treatment catheter to a specific point or area of interest using the detected navigation signal is provided. The system is operable in a method to perform the above utilizing the mapping function of the electrophysiology mapping and/or recorder system to energize electrodes on either the navigation catheter or treatment catheter to direct the treatment catheter to the area, region or point of interest.

Abstract: A device for neural prosthetics is disclosed. The device comprises arrays of micro-wires and a control unit. The control unit connects to and communicates with the micro-wires. The ends of the micro-wires serve as microelectrodes. The microelectrodes are in contact with neural tissue. The micro-wires are covered in sheaths made of conformal material. The ends of the micro-wires protrude beyond the ends of the sheaths. This allows the electrodes to be individually positioned on the neural tissue.

Abstract: The present disclosure provides ablation catheter systems and electrode assemblies or baskets for use in the ablation catheter systems that include struts that are manufactured from a thermoplastic material. In many embodiments, the struts manufactured from a single piece of thermoplastic material. The struts are generally configured to operate in a double diamond formation, although an electrode basket including the struts described herein may include two, three, four or more diamonds, which may be of the same or different sizes. By manufacturing the struts from a thermoplastic material the diamond-shaped struts as described in the present disclosure may be manufactured with sufficient strength without the need for a nitinol frame or adhesives, thus reducing the overall cost of the strut, as well as overall manufacturing time.

Abstract: Ablation systems of the present disclosure facilitate the safe formation of wide and deep lesions. For example, ablation systems of the present disclosure can allow for the flow of irrigation fluid and blood through an expandable ablation electrode, resulting in efficient and effective cooling of the ablation electrode as the ablation electrode delivers energy at a treatment site of the patient. Additionally, or alternatively, ablation systems of the present disclosure can include a deformable ablation electrode and a plurality of sensors that, in cooperation, sense the deformation of the ablation electrode, to provide a robust indication of the extent and direction of contact between the ablation electrode and tissue at a treatment site.

Abstract: Flexible high-density mapping catheter tips and flexible ablation catheter tips with onboard high-density mapping electrodes are disclosed. These tips can be used for diagnosing and treating cardiac arrhythmias. The flexible, distal tips are adapted to conform to tissue and comprise a plurality of microelectrodes mounted to permit relative movement among at least some of the microelectrodes. The flexible tip portions may comprise a flexible framework forming a flexible array of microelectrodes (for example, a planar or cylindrical array) adapted to conform to tissue and constructed at least in part from nonconductive material in some embodiments. The flexible array of microelectrodes may be formed from a plurality of rows of longitudinally-aligned microelectrodes. The flexible array may further comprise, for example, a plurality of electrode-carrying arms or electrode-carrier bands. Multiple flexible frameworks may be present on a single device.

Abstract: Systems, devices, and methods for electroporation ablation therapy are disclosed, with the system including a pulse waveform signal generator for medical ablation therapy, and an endocardial ablation device includes at least one electrode for ablation pulse delivery to tissue. The signal generator may deliver voltage pulses to the ablation device in the form of a pulse waveform. The system may include a cardiac stimulator for generation of pacing signals and for sequenced delivery of pulse waveforms in synchrony with the pacing signal.

Abstract: An active cardiac electrical lead is disclosed, including a tip housing having a lumen, a soft tip plug and a marker band. The tip housing includes a body and an extension extending from a distal end of the body, and the body is of greater outer diameter than the extension. The soft tip plug fits over the extension and engaging the extension. The marker band is attached to an outer surface of the body or to an inner surface of the lumen.

Abstract: Flexible high-density mapping catheter tips and flexible ablation catheter tips with onboard high-density mapping electrodes are disclosed. These tips can be used for diagnosing and treating cardiac arrhythmias. The flexible, distal tips are adapted to conform to tissue and comprise a plurality of microelectrodes mounted to permit relative movement among at least some of the microelectrodes. The flexible tip portions may comprise a flexible framework forming a flexible array of microelectrodes (for example, a planar or cylindrical array) adapted to conform to tissue and constructed at least in part from nonconductive material in some embodiments. The flexible array of microelectrodes may be formed from a plurality of rows of longitudinally-aligned microelectrodes. The flexible array may further comprise, for example, a plurality of electrode-carrying arms or electrode-carrier bands. Multiple flexible frameworks may be present on a single device.

Abstract: Provided is a system including a surgical instrument comprising a handle assembly comprising a handle; a shaft assembly coupled to the handle assembly; and a flexible circuit. The handle assembly comprises a proximal portion of the flexible circuit and the shaft assembly comprises a distal portion of the flexible circuit; the shaft assembly further comprising: an exterior shaft positioned around the distal portion of the flexible circuit and configured to change position while a sub-portion of the distal portion of the flexible circuit remains stationary; and shaft control electronics comprising a stationary portion and a non-stationary portion, the stationary portion coupled to the distal portion of the flexible circuit and the non-stationary portion coupled to the exterior shaft; wherein the stationary portion of the shaft control electronics is configured to measure a distance to the non-stationary portion of the shaft control electronics as the exterior shaft changes position.

Abstract: The present disclosure relates to the field of tissue mapping and ablation. Specifically, the present disclosure relates to expandable medical devices for identifying and treating local anatomical abnormalities within a body lumen. More specifically, the present disclosure relates to systems and methods of focal treatment for overactive bladders.

Abstract: Cardiac ablation systems and methods of their use and manufacture involve an ablation mechanism, a stabilizer mechanism, and a cinching mechanism that urges the ablation mechanism toward a patient tissue. Embodiments encompass methods for administering epicardial and endocardial lesions, including box lesions and connecting lesions, to patient tissue.

Abstract: Systems and methods for impairing smooth muscle tissue function using energy and/or pressure are described herein. The systems and/or methods may be used in some embodiments to target smooth muscle tissue in the bronchial passages.

Abstract: An ablation device of a non-invasive radio-frequency ablation system includes a substrate having a first surface; a first electrode disposed on the first surface; a second electrode disposed on the first surface and adjacent to the first electrode; a moving unit electrically connected to the second electrode for moving the second electrode to regulate the distance between the second electrode and the first electrode; and a radio frequency generator connected to the ablation device for providing a radio frequency current to the first electrode and the second electrode. According to a method using the ablation device, the first and second electrodes are brought into contact with a third surface belonging to a subject in need of treatment, and the radio frequency current is applied to the electrodes to carry out a treatment procedure. The treatment depth and area are adjusted by changing the relative distance between the electrodes.

Abstract: This disclosure provides design, material, manufacturing method, and use alternatives for medical devices. An example medical device includes a scaffold including a central member and a plurality of extension members extending away from the central member. The central member includes a plurality of discrete attachment locations corresponding to each of the plurality of extension members and each of the plurality of extension members is pivotably coupled to the central member at a corresponding discrete attachment location. The medical device also includes a covering substantially surrounding the scaffold and an electrode located at a distal end of each of the plurality of extension members. Each electrode extends through at least a portion of the covering.

Abstract: Intravascular devices, systems, and methods are disclosed. In some instances, the intravascular device is a guide wire with electrical conductors printed on a solid core wire. In some instances, the electrical conductors are coupled to conductive bands adjacent a proximal portion of the guide wire. Methods of making, manufacturing, and/or assembling such intravascular devices and associated systems are also provided. In certain aspects, guidewires of the invention include a body having an inner core and an outer layer with one or more embedded conductors. The conductors are exposed at one or more locations along the body and a conductive material can be layered over the exposed locations. A sensor can also be coupled to the body via the conductive material at one of the exposed locations.

Abstract: In some embodiments, an electrosurgical device comprises an electrically conductive elongate member for traversing body vasculature defining a hollow lumen with one or more apertures at or near its distal end, wherein electrical energy can flow through the wall of the elongate member; and an energy delivery device in electrical communication with the elongate member located at or about the distal end of the elongate member. The energy delivery device includes an electrode for delivering energy, and a thermal shield positioned between the electrode and the elongate member.

Abstract: An antenna system is provided. The antenna system includes a coaxial cable, an antenna, and an impedance matching structure. The coaxial cable includes a center conductor extending a length of the coaxial cable, a dielectric material surrounding the center conductor along the length of the coaxial cable, and a conductive shield surrounding the dielectric material along the length of the coaxial cable. The antenna includes a conductor having an electrical length of half a wavelength at a selected operating frequency. The impedance matching structure includes a second center conductor mounted between an end of the center conductor of the coaxial cable and a feed end of the antenna. The impedance matching structure is configured to match an impedance of the coaxial cable to an impedance of the antenna.

Abstract: A surface of an object comprises a material having a low surface energy. A first cover comprising a material having a higher surface energy than the surface of the object may cover and be affixed to the surface. A second cover may be adhered to and/or secured by the first cover so that the second cover is fixedly coupled to the surface of the object.

Abstract: A balloon for renal nerve modulation is disclosed. The balloon may include a polymer material forming a balloon wall having an outer surface and flexible circuits comprising a base selectively adhered to the exterior surface of the balloon wall. Adhesive is selectively applied to the outer surface of the balloon, to the flexible circuit or to both such that the adhesive is selectively deposited on the at least a portion of the at least two pads or on the at least a portion of the at least two pads and to a portion of the distal spline. The portion of the at least two pads or the portion of the at least two pads and a portion of the distal spline are adhered to the outer surface of the balloon and a remainder of the flexible circuit moves freely with respect to the outer surface of the balloon.

Abstract: Methods and systems for combining ablation therapy with navigation of the ablation device. An ablation system may be configured for use with one of two methods to prevent loss of navigation signals during ablation energy delivery. In the first method, ablation energy signals are filtered from the navigation signal. In the second method, the delivery of ablation energy is sequenced with the delivery of navigation energy such that ablation energy and navigation energy are not delivered at the same time and navigation signals received by the system are time-division multiplexed to reconstruct the navigation signals and determine a location of the device within the patient.

Abstract: Various embodiments provide a cardiac mapping method including: recording premature ventricular contraction (PVC) electrocardiogram (ECG) data during PVC of a heart; generating a PVC activation map of the heart, based on the PVC ECG data and a three-dimensional (3D) heart model generated based on two-dimensional (2D) images of the heart, the PVC activation map including an area of earliest activation; generating a reference image by modifying on one of the 2D images to identify the area of earliest activation; displaying both the PVC activation map and the reference image; and pacing the heart at a first pacing location disposed in the area of earliest activation.

Abstract: An electrophysiology catheter constructed with assembly and wiring of ring electrodes using spacer rings of electrically-nonconductive material, whose length is predetermined/premeasured, includes a distal section with at least one spine having two electrodes, and a spacer member therebetween, wherein the spacer member configured to provide a separation gap between the two electrodes. The separation gap may span in an axial direction and/or in a circumferential direction. The spacer member may be configured generally as a ring with a center axial opening configured to receive the spine therethrough. The spacer member may include an axial extension providing a first separation gap between a first pair of electrodes in a circumferential direction, and a circumferential providing a second separation gap between a second pair of electrodes in an axial direction.

Abstract: Described herein are microelectrode array devices, and methods of fabrication, assembly and use of the same, to provide highly localized neural recording and/or neural stimulation to a neurological target. The device includes multiple microelectrode elements arranged protruding shafts. The protruding shafts are enclosed within an elongated probe shaft, and can be expanded from their enclosure. The microelectrode elements, and elongated probe shafts, are dimensioned in order to target small volumes of neurons located within the nervous system, such as in the deep brain region. Beneficially, the probe can be used to quickly identify the location of a neurological target, and remain implanted for long-term monitoring and/or stimulation.

Abstract: Medical devices and methods for making and using medical devices are disclosed. An example medical device may include a catheter shaft. An expandable balloon may be coupled to the catheter shaft. The balloon may be capable of shifting between a folded configuration and an expanded configuration. A support structure may be coupled to the balloon. The support structure may be capable of shifting the balloon toward the folded configuration. A plurality of elongate flexible electrode assemblies may be disposed on the balloon. The elongate flexible electrode assemblies may be oriented at an angle relative to a longitudinal axis of the balloon.

Abstract: Catheter systems include direction-sensitive, multi-polar tip electrode assemblies for electroporation-mediated therapy, electroporation-induced primary necrosis therapy and electric field-induced apoptosis therapy, including configurations for producing narrow, linear lesions as well as distributed, wide area lesions. A monitoring system for electroporation therapy includes a mechanism for delivering electrochromic dyes to a tissue site as well as a fiber optic arrangement to optically monitor the progress of the therapy as well as to confirm success post-therapy. A fiber optic temperature sensing electrode catheter includes a tip electrode having a cavity whose inner surface is impregnated or coated with thermochromic/thermotropic material that changes color with changes in temperature. An optic fiber/detector arrangement monitors the thermochromic or thermotropic materials, acquiring a light signal and generating an output signal indicative of the spectrum of the light signal.

Abstract: A catheter assembly for assessing contact between the catheter assembly and tissue is disclosed. The assembly includes a catheter shaft and a pressure sensitive conductive composite member whose electrical resistance varies with pressure applied to the catheter assembly. The assembly also includes at least one measurement terminal to permit the measurement of changes in the electrical characteristics of the pressure sensitive conductive composite member. The assembly may optionally include a measurement device to measure resistance, impedance and/or other electrical characteristics. The assembly may utilize a reference electrode secured to the patient's tissue, which permits the measurement device to measure changes between the reference electrode and the at least one measurement terminal. Optionally, the assembly may include a conductive outer layer.

Abstract: Systems, devices, and methods for electroporation ablation therapy are disclosed herein, including an inflatable member for positioning an ablation device within a pulmonary vein ostium. An apparatus can include first and second shafts moveable relative to one another, first and second electrodes configured to generate an electric field for ablating tissue, and an inflatable member disposed between the first and second electrodes. In some embodiments, the inflatable member is configured to transition from an undeployed configuration to a deployed configuration in response to movement of the first and second shafts. In some embodiments, the inflatable member in the deployed configuration can engage a wall of a pulmonary vein ostium and direct the electric field generated by the first and second electrodes toward the wall.