Abstract: The present invention relates to a method, device, and system for improved mapping and/or ablation of a tissue. The device may generally include an elongate body and a distal assembly affixed to the elongate body that includes a treatment electrode having a conductive mapping region and a selectively conductive ablation region that is conductive of high-frequency current and substantially non-conductive of low-frequency current. Alternatively, the device may generally include a treatment electrode having a conductive mapping or ablation region and a region that is coated with an electrically insulated but thermally conductive layer.

Abstract: Devices, systems and methods are disclosed for the ablation of tissue. A steerable ablation catheter can include one or more ablation elements at its distal end and one or more ablation elements fixedly attached to its shaft. The distal end of the ablation catheter can be deflected to assume a number of different deflection geometries in at least one direction along the shaft. One feature of the ablation catheter is that its shaft can comprise materials of differing durometers or stiffnesses attached together at a joint. Methods associated with use of the ablation catheter are also covered.

Abstract: A device and method for treating a variety of tissue locations within a patient's body using a single device that includes an elongate body having a distal portion, a shaft rotatably and slidably disposed within the elongate body, and a first arm and a second arm each coupled to the elongate body distal portion. Retraction and rotation of the shaft transitions the each arm from a linear configuration to a radially expanded configuration in which each arm has an arcuate shape and lies in a plane that is substantially orthogonal to the elongate body longitudinal axis. Electrodes coupled to the arms are equidistant from the longitudinal axis of the elongate body in different radial directions when the device is in the radially expanded configuration. The electrodes are radially symmetrical about the shaft when the radially expanded configuration has a first diameter or a second diameter.

Abstract: A catheter including a proximal end and a distal end. An expandable element coupled to the distal end is included, the expandable element including a proximal portion and a distal portion, the expandable element defining an exterior surface. A first plurality of electrodes coupled to the exterior surface of the distal portion of the expandable element are included, each of the first plurality of electrodes being selectively operable to transmit unipolar radiofrequency energy. A second plurality of electrodes coupled to the exterior surface of the proximal portion of the expandable element are included, each of the second plurality of electrodes being selectively operable to transmit bipolar radiofrequency energy.

Abstract: A method of assessing a tissue ablation treatment, including positioning a medical device adjacent a target tissue; measuring a first impedance magnitude a first frequency with the medical device; measuring a first impedance phase at a second frequency with the medical device; ablating at least a portion of the target tissue with the medical device; measuring at second impedance magnitude at a third frequency with the medical device; measuring a second impedance phase at a fourth frequency with the medical device; comparing at least one of (i) the first and second impedance magnitudes and (ii) the first and second impedance phases; and providing an indication of the efficacy of the ablation treatment based at least in part on the comparison.

Abstract: A medical system is provided, including a catheter body having a proximal portion and a distal portion; a shaft slidably disposed within a portion of the catheter body, the shaft defining a distal tip; a fluid injection tube coupled to the distal portion of the catheter body and the distal tip of the shaft, the fluid injection tube being transitionable from a first geometric configuration to a second geometric configuration; a membrane coupled to the shaft and enclosing at least a portion of the fluid injection tube therein; and a coolant source in fluid communication with the fluid injection tube. The first geometric configuration may be substantially linear, the second geometric configuration may be substantially helical, and the membrane may be tensioned across at least a portion of the fluid injection tube in the second geometric configuration.

Abstract: A method and system for detecting microbubble formation during a radiofrequency ablation procedure. The method includes measuring an impedance of a pair of electrodes, at least one electrode in the pair of electrodes being coupled to a treatment assembly of a medical device. Radiofrequency ablation energy is transmitted between the pair of electrodes. The transmission of radiofrequency ablation energy between the pair of electrodes is terminated when after a predetermined period of time the measured impedance in either of the electrodes in the pair of electrodes is a predetermined percentage above a measured minimum impedance and a measured power is above a predetermined power threshold. An alert is generated indicating at least one of the formation and release of microbubbles proximate the pair of electrodes.

Abstract: A system and method for identifying the location of a medical device within a patient's body may be used to localize the fossa ovalis for trans-septal procedures. The systems and methods measure light reflected by tissues encountered by an optical array. An optical array detects characteristic wavelengths of tissues that are different distances from the optical array. The reflectance of different wavelengths of light at different distances from an optical array may be used to identify the types of tissue encountered, including oxygenated blood in the left atrium as detected from the right atrium through the fossa ovalis.

Abstract: A method of producing a multi-lumen elongate body for a medical device. Unlike known methods requiring a solid core of material inserted into each lumen to maintain patency of the lumens during manufacture, the present method obviates the need for a solid core within one or more minor lumens, which saves cost and production complexity. One or more material overlay and mesh overlay steps may be used to produce the multi-lumen elongate body, but only the main lumen may include a solid core therein during all manufacturing steps. The one or more minor lumens may each be defined by a lumen tube having a sufficient stiffness to withstand external pressure during all manufacturing steps without the need for a solid core within.

Abstract: A method of dimensionally stabilizing a lumen of a multi-lumen device during manufacture wherein one or more minor lumens may contain a fluid that maintains patency of the one or more minor lumens without the need for a solid core within. The at least one second lumen tube may be in fluid communication with a fluid source during the manufacturing process, such as during extrusion and/or mesh overlay steps. Preventing collapse of the one or more minor lumens during manufacture using a fluid instead of a solid core allows the lumens to have any of a variety of shapes and configurations that would be difficult, cost prohibitive, or impossible for a solid core to be used. Also, obviating the need for a solid core within one or more lumens reduces cost and production complexity. The fluid may be a non-compressible liquid or a pressurized gas.

Abstract: A method and system for manufacturing a multi-lumen device that includes extruding a first layer of material to form an elongate body with a first lumen and a second lumen, the elongate body having a length of at least 100 feet, depositing a mesh layer over the first layer of material along the entire length of the elongate body, and extruding a second layer of material over the mesh layer along at least a portion of the length of the elongate body. The length of at least 100 feet may be considered a first length, the method further comprising cutting the elongate body into a plurality of shortened elongate bodies having a usable length, such as between approximately two feet and approximately six feet.

Abstract: A medical device is disclosed, including a catheter body; an electrode array coupled to the catheter body, the electrode array being transitionable from a substantially linear configuration to a substantially helical configuration; and a fluid conduit coupled to the catheter body spaced apart from the electrode array, wherein the fluid conduit is transitionable from a substantially linear configuration to a substantially helical configuration. The device may include a fluid source in communication with the fluid conduit and a radiofrequency signal generator coupled to the electrode array.

Abstract: A medical system is provided, including an ablation system having at least one ablation element and a sensor, a generator operable to deliver radiofrequency ablation energy to the ablation element. A power supply defines a duty cycle and provides a voltage to the generator, and the power supply has a duty cycle modulator and an amplitude modulator. A processor is connected to the power supply, the generator, and the sensor. The processor obtains a feedback signal from the sensor, and adjusts the duty cycle modulator and the amplitude modulator according to the feedback signal.

Abstract: A medical device including a catheter having a shaft with a distal portion; a first plurality of substantially hemispherical electrodes coupled to the distal portion; a second plurality of substantially hemispherical electrodes coupled to the shaft proximal of the first plurality, where the second plurality of electrodes are oriented substantially orthogonal to the first plurality of electrodes; and an additional electrode coupled to the shaft. A console may have a processor in electrical communication with the first and second plurality of electrodes and the reference electrode, the processor programmed to obtaining a monophasic action potential recording from at least one of the first and second plurality of electrodes.

Abstract: A system and method for preventing unintended tissue damage from the delivery of unintended bipolar radiofrequency energy. The system may include a multi-electrode ablation device and an RF delivery unit. The RF delivery unit may transmit unipolar energy to the plurality of electrodes, the energy being in phase, with all electrodes delivering the same voltage and being activated at the same time to deliver no bipolar energy. Additionally or alternatively, the RF delivery unit may transmit bipolar energy to the electrodes. Here, voltage differences between each pair of adjacent electrodes may be monitored and the level of bipolar energy being delivered may be calculated. The voltage of energy delivered to at least one electrode in each adjacent electrode pair may be adjusted if the amount of delivered bipolar energy exceeds a safety threshold.

Abstract: A method and system for producing deep lesions without the production of high heat. The method generally includes ablating target tissue cells with a device in communication with an energy generator programmable to ablate tissue using heat energy, electroporation, or a combination thereof. The system generally includes a medical device having a plurality of electrodes at a distal end, and an energy generator in communication with the plurality of electrodes, the generator programmable to deliver alternating current energy between approximately 100 volts RMS and approximately 2000 volts RMS or greater. The generator is further programmable to deliver energy in unipolar mode, bipolar mode, and a combination thereof.

Abstract: Systems and methods for assessing electrode position, including positioning a plurality of electrodes within a heart and proximate a pulmonary vein; obtaining an impedance measurement from each of the plurality of electrodes; determining whether any of the plurality of electrodes is located within the pulmonary vein based at least in part on the obtained impedance measurements; and generating an indication if at least one of the plurality of electrodes is determined to be located within the pulmonary vein.

Abstract: A system and method are described for sensing the orientation of a catheter relative to a tissue and regulating the application of power to maintain the tissue at a pre-determined temperature.

Abstract: A method and system for detecting a short circuit during a radiofrequency ablation procedure. The method includes measuring an impedance of a pair of electrodes coupled to a treatment assembly of a medical device. Radiofrequency ablation energy is transmitted between the pair of electrodes. The transmission of radiofrequency ablation energy between the pair of electrodes is terminated when after a predetermined period of time the measured impedance in either of the electrodes in the pair of electrodes is below a predetermined threshold impedance value. An alert is generated indicating a short circuit between the pair of electrodes.

Abstract: A system and method for anchoring a round catheter pull wire within the distal end of a catheter. A steering deflection mechanism includes a pull ring having a plurality of apertures and one or more receiving slots. The method includes affixing one or more round pull wires to the one or more receiving slots of the pull ring. The shape of the round wire and manner of affixing the wire to the pull ring provide a steering assembly that can withstand greater pull forces while maintaining design integrity.