In an electrosurgical generator for generating radio frequency power, the generator includes a radio frequency output stage having two or more output connections, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to cause the generator to supply a blended output signal alternating constantly between a first output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to at least a first predetermined threshold value for cutting or vaporisation of tissue, and a second output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to a second threshold value for coagulation. There is also provided adjustment means, operable by a user of the electrosurgical generator, for changing between various preset settings for the blended signal, the preset settings each having a predetermined duty cycle of the blended signal that is limited to the first threshold value for cutting or vaporisation, and a predetermined duty cycle of the blended signal that is limited to the second threshold value for coagulation.

Electrosurgical generator and system

Systems, devices and methods are provided for endoscopic procedures involving tissue manipulations beyond the capabilities of traditional endoscopic instruments. Embodiments of the systems include an elongated main body having a scope therethrough and at least one steerable tool arm which extends from the distal end of the main body. In preferred embodiments, the system includes two tool arms, each arm steerable to form a curve laterally outward which then bends laterally inward so that the arms form an angular shape. In addition, end effectors extend from the distal ends of each tool arm for use in manipulation of tissue. The angular shape brings the end effectors together in view of the scope for cooperative movements which are continuously visible by the surgeon. In addition, the tool arms may be steerable in any additional direction and may be rotateable to allow grasping, elevation and more complex manipulation of tissue.

Endoluminal tool deployment system

The present invention provides an apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current, such tissues including but not limited to liver, lung, cardiac, prostate, breast, and vascular tissues and neoplasms. An apparatus in accord with the present invention includes a supply of a conductive or electrolytic fluid to be provided to the patient, an alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode. A method in accord with the present invention includes delivering a conductive fluid to a predetermined tissue ablation site for a predetermined time period, applying a predetermined power level of radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and/or the fluid flow in response to the measured parameters.

Apparatus and method for creating, maintaining, and controlling a virtual electrode used for the ablation of tissue

An electrosurgical system including an electrode assembly having two electrodes for use immersed in an electrically conductive fluid has a generator with control circuitry for rapidly reducing the delivered radio frequency output power by at least 50% within at most a few cycles of the peak radio frequency output voltage reaching a predetermined threshold limit. In this way, tissue coagulation can be performed in, for example, saline without significant steam generation. The same peak voltage limitation technique is used in a tissue vaporization or cutting mode to limit the size of the steam pocket at the electrodes and to avoid electrode burning.

Electrosurgical generator method

A liquid embolic delivery system is provided for trapping an injected liquid embolic composition to prevent the liquid embolic from solidifying or otherwise passing outside of an embolization area. The delivery system includes a catheter for delivery of a liquid embolic composition and a containment member positioned at a distal end of the catheter which is shaped to trap the liquid embolic composition delivered through the lumen of the catheter. The containment member is formed as a brush, nest, sponge, swab, flexible sack, or other shape into and around which the liquid embolic composition is injected. The liquid embolic composition is trapped or meshes with the containment member during solidification containing the liquid embolic and preventing the embolic composition from passing into the blood stream.

Device and method for controlling injection of liquid embolic composition

An artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire. Electrothrombosis is facilitate by placing the ground electrode on the distal end of the microcatheter and flowing current between the microcatheter electrode and the tip.

Endovascular electrolytically detachable wire and tip for the formation of thrombus in arteries, veins, aneurysms, vascular malformations and arteriovenous fistulas

Apparatus for occluding a vascular cavity (64) containing blood, comprising: a thread (10) with a distal end; and an object (102, 104) including a proximal end and a distal end (106); and a separable electrolytic tip (14) disposed at said distal end of said wire (10) situated to release said object when the electrolysis is applied to said electrolytic severable tip (14), characterized in that said object (102, 104) is isolated from electric current flow by an insulating element.

Ivan Sepetka

Papers

Endovascular electrolytically detachable wire and tip for the formation of thrombus in arteries, veins, aneurysms, vascular malformations and arteriovenous fistulas

Apparatus for occluding a vascular cavity.