Abstract: Systems and methods are provided for removal (ablation) or modification of soft tissue with high frequency voltage through a capacitive charge process. Specifically, one of the conductors of a capacitor device maybe positioned adjacent to, or in the region of, a body structure. The other conductor is spaced, and electrically insulated from, the first conductor. A high frequency voltage is applied across the conductors to create a potential difference that results in a charge on the conductors and creates an electric field therebetween. High frequency alternating current flows between the conductors to a degree dependent on the capacitance and the current frequency. The charge on the first conductor is sufficient to modify the adjacent tissue. In some variations the charge is sufficient to heat the tissue for tissue coagulation or tissue shrinkage (i.e., collagen contraction). In other variations, the charge is sufficient to ablate or volumetrically remove the tissue.

Abstract: An electrosurgical system and method for ablating, resecting, or cutting body structures, with minimal or no damage to tissue adjacent to the treatment site. The system includes an electrosurgical probe having a shaft with a shaft distal end bifurcated to provide first and second arms. First and second electrode supports are disposed on the first and second arms, respectively. At least one active electrode, in the form of a loop or partial loop, is arranged between the first and second electrode supports. A return electrode, also in the form of a loop or partial loop, is arranged between the first and second electrode supports distal to the active electrode. The active and return electrodes are configured to promote substantially high electric field intensities and associated high current densities between the active portion and the target site when a high frequency voltage is applied to the electrodes.

Abstract: The present invention comprises electrosurgical apparatus and methods for maintaining patency in body passages subject to occlusion by invasive tissue growth. The apparatus includes an electrode support disposed at a shaft distal end having at least one active electrode arranged thereon, and at least one return electrode proximal to the at least one active electrode. In one embodiment, a plurality of active electrodes each comprising a curved wire loop portion are sealed within a distal portion of the electrode support. The apparatus and methods of the present invention may be used to open and maintain patency in virtually any hollow body passage which may be subject to occlusion by invasive cellular growth or invasive solid tumor growth. Suitable hollow body passages include ducts, orifices, lumens, and the like, with exemplary body passages including the coronary arteries.

Abstract: In a breathing circuit such as a ventilator circuit, a heating element is used to provide improved temperature characteristics of the inspired air or breathing gas. An heating element retainer is disclosed which is operative to provide a central location of the heating element within the breathing circuit lumen.