A catheter has a multifunctional virtual tip electrode with a porous substrate and a multitude of surface microelectrodes. The surface microelectrodes are in close proximity to each other and in a variety of configurations so as to sense tissue for highly localized intracardiac signal detection, and high density local electrograms and mapping. The porous substrate allows for flow of conductive fluid for ablating tissue. The surface microelectrodes can be formed via a metallization process that allows for any shape or size and close proximity, and the fluid weeping from the porous substrate provides more uniform irrigation in the form of a thin layer of saline. The delivery of RF power to the catheter tip is based on the principle of virtual electrode, where the conductive saline flowing through the porous tip acts as the electrical connection between the tip electrode and the heart surface. The substrate and the surface electrodes are constructed of MRI compatible materials so that the physician can conduct lesion assessment in real time during an ablation procedure. The surface electrodes include noble metals, including, for example, platinum, gold and combinations thereof.

Various catheters are provided herein for recording, mapping, and/or ablating target tissue to reduce or eliminate unwanted electrical impulses. In one embodiment, a catheter can have a handle, an elongate body, and an end effector. The end effector has expanded and contracted configurations and can rotate about the elongate body. A plurality of electrodes can also be disposed on the end effector for recording, mapping, and/or ablating target tissue surrounding the catheter. The handle can guide the end effector through transitioning between the configurations and rotating about the elongate body.

A method and apparatus are disclosed for providing forward fluid delivery through an electrosurgical device, while avoiding coring when energy is delivered to the electrosurgical device. The device has a distal face defining an opening, with the distal face including at least one cutting portion and at least one non-cutting portion. An embodiment of the electrosurgical device for puncturing tissue includes an elongate member defining a lumen for fluid; a distal portion including an electrode and the distal face which defines at least one aperture. The portion of the at least one cutting portion defines a leading portion partially surrounding a circumference of the at least one aperture wherein the outer diameter of the at least one of the distal portion of the electrosurgical device or the electrode decreases towards a distal tip of the electrosurgical device.

A medical probe includes a shaft and an expandable flexible distal-end assembly. The shaft is configured for insertion into a cavity of organ of a patient. The expandable flexible distal-end assembly, which is fitted at a distal-end of the shaft, includes a flat flexible backing sheet, including irrigation channels, and two flexible substrates having respective arrays of electrodes disposed thereon, the substrates attached one on either side of the backing sheet.

Systems and methods for treating a patient's mucus hypersecretion condition are disclosed herein. Certain implementations may involve a method for reducing mucus secretion in an upper airway of a patient to treat at least one of post nasal drip or chronic cough. The method may include advancing a treatment delivery portion of an energy-based treatment device into a nostril of the patient. The treatment delivery portion may contact mucosal tissue of the upper airway without piercing the mucosal tissue. The treatment delivery portion may deliver treatment to at least one tissue selected from the group of the mucosal tissue and another tissue underlying the mucosal tissue to modify a property of the at least one tissue and thus treat at least one of post nasal drip or chronic cough in the patient.

Tissue is treated using a radiofrequency power supply connected to an applicator having a chamber filled with an electrically non-conductive gas surrounded by a thin dielectric wall. A radiofrequency voltage is applied at a level sufficient to ionize the gas into a plasma and to capacitively couple the ionized plasma with the tissue to deliver radiofrequency current to ablate or otherwise treat the tissue.

In some embodiments, the inventive subject matter is directed to a multimode electrosurgical system having an electrosurgical instrument with a first electrode configuration that operates in a bipolar mode and second electrode configuration that operates in a monopolar mode. In other embodiments, the inventive subject matter is directed to an instrument and system that provide multiple modes of surgical and/or therapeutic treatments, at least one being an electrosurgical mode of treatment, the instrument including at least one active electrode on a working portion, and the working portion including or supporting at least one non-electrosurgical functional element, the instrument including at least one operational return electrode configuration of selectively variable surface area.

An electrode assembly for use with an electrophysiological catheter has a plurality of independently controlled ablation electrodes distributed radially around the electrode assembly. Two ablation electrodes may be positioned in opposition to each other. The electrode assembly may also have microelectrodes for sensing tissue and/or temperature. Methods for using a catheter equipped with such an electrode assembly may include preferentially emitting energy in a radial direction.

A probe having a cutting electrode at its distal end, which is formed on an end piece of probe. From the end piece a wire extends over the entire length of probe therethrough. The wire can serve for current supply to the end piece. The cutting electrode can include a junction site from which electrode surfaces extend away in at least three directions.

Cardiac ablation is carried out by placing two ablation electrodes on opposite sides of a wall of the heart to generally oppose one another. The effective current transmission area of one of the electrodes is then varied according to the distance between the two electrodes or the thickness of the wall. Sufficient electrical current is transmitted between the two electrodes to achieve transmural ablation.