868 results about "Radio frequency energy" patented technology

A system for efficient delivery of radio frequency (RF) energy to cardiac tissue with an ablation catheter used in catheter ablation, with new concepts regarding the interaction between RF energy and biological tissue. In addition, new insights into methods for coagulum reduction during RF ablation will be presented, and a quantitative model for ascertaining the propensity for coagulum formation during RF ablation will be introduced. Effective practical techniques a represented for multichannel simultaneous RF energy delivery with real-time calculation of the Coagulum Index, which estimates the probability of coagulum formation. This information is used in a feedback and control algorithm which effectively reduces the probability of coagulum formation during ablation. For each ablation channel, electrical coupling delivers an RF electrical current through an ablation electrode of the ablation catheter and a temperature sensor is positioned relative to the ablation electrode for measuring the temperature of cardiac tissue in contact with the ablation electrode. A current sensor is provided within each channel circuitry for measuring the current delivered through said electrical coupling and an information processor and RF output controller coupled to said temperature sensor and said current sensor for estimating the likelihood of coagulum formation. When this functionality is propagated simultaneously through multiple ablation channels, the resulting linear or curvilinear lesion is deeper with less gaps. Hence, the clinical result is improved due to improved lesion integrity.

A radio frequency tissue ablation system with a radio frequency generator, the generator comprising a radio frequency source, at least four independently controllable radio frequency outputs, a user interface and a controller configured to delivery radio frequency energy from the radio frequency source to the radio frequency outputs in one of at least two different output configurations in response to a configuration selection made through the user.

A process of activated cracking of high molecular organic waste material which includes confining the organic waste material in a reactor space as a mixture with a pulverized electrically conducting material (sensitizer) and / or catalysts and / or "upgrading agents" and treating this mixture by microwave or radio frequency electro-magnetic radiation. Organic waste materials include hydrocarbons or their derivatives, polymers or plastic materials and shredded rubber. The shredded rubber can be the source of the sensitizer and / or catalyst material as it is rich in carbon and other metallic species. This sensitizer can also consist of pulverized coke or pyrolytically carbonized organic feedstock and / or highly dispersed metals and / or other inorganic materials with high dielectric loss which absorb microwave or radio frequency energy.

Methods treat a tissue region. In one arrangement, the methods deploy an electrode on a support structure in a tissue region at or near the cardia of the stomach. In one embodiment, the support structure has a proximal region and a distal region. The proximal region is enlarged in comparison to the distal region, and the electrode is carried by the enlarged proximal surface. The methods advance the electrode in a path to penetrate the tissue region and couple the electrode to a source of radio frequency energy to ohmically heat tissue and create a lesion in the tissue region.

Skin treating devices and systems for delivering RF electromagnetic energy to the skin. The devices include one or more electromagnetic RF generating units, multiple RF electrode groups and a controller for controllably applying RF energy to the skin through any selected RF electrode group or any selected RF electrode group combination selected from the multiple groups. The electrodes may be stationary and / or movable electrodes. Different RF frequencies and / or frequency bands may be used. The alternation of energy application through different electrode groups at different times, and / or the changing of the inter-electrode distance and configuration by using movable RF electrodes may reduce or prevent electrode overheating, control RF energy distribution within the skin and enable use of the devices and / or for different skin treating applications.

A novel medical probe assembly, system, and methods for the use thereof to treat tissue are described. The system optionally comprises an energy source, two probe assemblies, and one or more cooling devices to provide cooling to at least one of the probe assemblies. The probe assemblies may be configured in a bipolar mode, whereby current flows preferentially between the probe assemblies. The probe assemblies and system described herein are particularly useful to deliver radio frequency energy to a patient's body. RF energy delivery may be used for various applications, including the treatment of pain, tumor ablation and cardiac ablation.

Methods and devices are provided for support of a body structure. The devices can be adjusted within the body of a patient in a minimally invasive or non-invasive manner such as by applying energy percutaneously or external to the patient's body. The energy may include, for example, acoustic energy, radio frequency energy, light energy and magnetic energy. Thus, as the body structure changes size and / or shape, the size and / or shape of the annuloplasty rings can be adjusted to provide continued reinforcement. In certain embodiments, the devices include a first body member including a first shape memory material configured to transform the annuloplasty ring from a first configuration having a first size of a dimension to a second configuration having a second size of the dimension. The second size is less than said first size in septal lateral distance. The devices also include a second body member including a second shape memory material configured to transform the annuloplasty ring from the second configuration to a third configuration having a third size of the dimension, wherein the second size is less than the third size in septal lateral distance.

An ablation catheter including an inner tube having a length, a distal end and a longitudinal axis, a plurality of needles extending from the distal end of the inner tube and biased away from the longitudinal axis, an outer sheath slideably moveable relative to the inner tube to surround at least a portion of the length of the inner tube and its extending needles, and a radio frequency energy source electrically connected to the plurality of needles.

An RFID reader for use in a security system based upon RFID techniques. The RFID reader can use power line carrier communications to communicate with the controllers in the security system. The RFID reader of the security system can be provided with multiple modulation techniques, multiple antennas, and the capability to vary its power level and carrier frequency. The controller of the security system determines which RFID readers may transmit, at what times, and the parameters with which to transmit. The RFID reader can detect interference or jamming, and respond. The RFID reader can transmit RF energy useful for detecting motion or for charging the batteries in RFID transponders. The RFID reader can receive wireless communications from active transmitters or from other RFID readers.

A system for controlling an electrosurgical generator using a full bridge topology is disclosed. The system includes a high voltage direct current power source which supplies power and a radio frequency output stage which receives power from the high voltage direct current power source and outputs radio frequency energy at a predetermined radio frequency set point. The system also includes one or more sensors which determine one or more parameters of radio frequency energy being applied to tissue and a microprocessor configured to receive one or more parameters and outputs the predetermined radio frequency set point to the radio frequency output stage as a function of one or more of the parameters of radio frequency energy.

Methods and devices are provided for support of a body structure. The devices can be adjusted within the body of a patient in a minimally invasive or non-invasive manner such as by applying energy percutaneously or external to the patient's body. The energy may include, for example, acoustic energy, radio frequency energy, light energy and magnetic energy. Thus, as the body structure changes size and / or shape, the size and / or shape of the annuloplasty rings can be adjusted to provide continued reinforcement. In certain embodiments, the devices include a tubular member configured to be attached to or near a cardiac valve annulus. The tubular member includes a receptacle end and an insert end configured to couple with the receptacle end of the tubular member such that the tubular member substantially forms a shape of a ring. The insert end is configured to move with respect to the receptacle end to change a circumference of the ring.

A micromanipulator comprising a tubular structure and a structural compliance mechanism that are formed from a tube made of an elastic and / or superelastic material. The micromanipulator is useful for intravascular interventional applications and particularly ultrasonic imaging when coupled with an ultrasound transducer. Also disclosed are medical devices for crossing vascular occlusions using radio-frequency energy or rotary cutting, preferably under the guidance of real-time imaging of the occlusion, as well as accompanying methods.

A method is provided for ablation in treatment of heart arrhythmias such as atrial fibrillation that includes positioning a catheter apparatus with multiple electrodes within a cardiac chamber, visualizing the catheter apparatus with an interventional system, navigating the catheter apparatus within the cardiac chamber, and delivering energy to selected electrodes of the catheter apparatus from an external source to ablate heart tissue at select locations. Preferably, the external source is an external patch placed on the patient for the delivery of radio-frequency energy. The electrodes of the catheter apparatus are connected to the patch through a patient interface unit where the interface unit selects the electrodes to which radio-frequency energy is to be delivered. In another aspect of the invention, a system for ablation of heart arrhythmias is provided that has a catheter apparatus with multiple electrodes, an interventional system for visualizing the catheter apparatus within a cardiac chamber, and an external source for delivering energy to selected electrodes of the catheter apparatus within the cardiac chamber to ablate heart tissue. Preferably, the system further includes a digital imaging system for obtaining cardiac image data, an image generation system for generating a 3D model of the cardiac chamber from the cardiac image data, and a workstation for registering the 3D model with the interventional system and for visualizing the catheter apparatus over this registered 3D model upon the interventional system.

Methods and devices are provided for support of a body structure. The devices can be adjusted within the body of a patient in a minimally invasive or non-invasive manner such as by applying energy percutaneously or external to the patient's body. The energy may include, for example, acoustic energy, radio frequency energy, light energy and magnetic energy. Thus, as the body structure changes size and / or shape, the size and / or shape of the annuloplasty rings can be adjusted to provide continued reinforcement. In certain embodiments, the devices include a body member including a ferromagnetic shape memory material. The body member has a first size of a dimension in a first configuration and a second size of the dimension in a second configuration. The body member is configured to be implanted into a heart so as to reinforce a cardiac valve annulus in the first configuration. The body member is configured to transform from the first configuration to the second configuration in vivo in response to a magnetic field. The body member in the second configuration is configured to reduce a size of the cardiac valve annulus.

The invention is a transvaginal ultrasound probe having an attached echogenic needle that is useful in the treatment of uterine fibroids. The echogenic needle has an echogenic surface near its tip that allows the physician to visualize its location using ultrasound imaging. In one embodiment, the needle has an active electrode at its distal end. The active electrode supplies radio frequency energy to a fibroids causing necrosis of the targeted fibroid or by destroying the fibroid's vascular supply. The radio frequency needle preferably has a safety device that shuts-off energy if the needle punctures the uterine wall. In a second embodiment, the needle has a cryogen supply tube and cryogen supply. This embodiment destroys fibroid tissue by freezing it or its vascular supply when the tissue comes in contact with the needle's frozen distal end. The invention further includes the method of using the ultrasound probe with the attached needle.

A control system for electrosurgical apparatus in which the energy delivery profile of both RF EM radiation and microwave EM radiation delivered to a probe is set based on sampled voltage and current information of RF energy conveyed to the probe and / or sampled forward and reflected power information for the microwave energy conveyed to and from the probe. The energy delivery profile for the RF EM radiation is for tissue cutting (without requiring a sharp blade) and the energy delivery profile for the microwave EM radiation is for haemostasis or sealing or coagulation or ablation of tissue. The RF EM radiation and microwave EM radiation may be applied separately or simultaneously.

A microwave antenna having a curved configuration is described herein. The antenna portion is formed into various shapes whereby the antenna substantially encloses, by a partial or complete loop or enclosure, at least a majority of the tissue to be irradiated. When microwave energy is delivered through the antenna, the curved configuration forms an ablation field or region defined by the curved antenna and any tissue enclosed within the ablation region becomes irradiated by the microwave energy. The microwave antenna is deployed through one of several methods, and multiple curved antennas can be used in conjunction with one another. Moreover, RF energy can also be used at the distal tip of the antenna to provide a cutting tip for the antenna during deployment in tissue.

A particular embodiment of the invention provides an electrosurgical working end for performing high strength welding of tissue comprising a body having a tissue contacting energy delivery surface. The body includes pixel portions and non-pixel portions distributed within the tissue contacting surface. The pixel portions comprise a positive temperature coefficient of resistance (PTCR) material with at least one pixel portion configured to switch Rf current on and off in the at least one pixel portion responsive to tissue temperature adjacent the at least one pixel portion. The pixel portions can be configured to be coupled to an Rf current source such as an Rf generator. The pixelated energy delivery surfaces are capable of highly localized modulation of Rf energy application to the engaged tissue to create high strength tissue welds.

A probe for resecting and coagulating tissue comprises an outer sleeve having a tissue cutting window and an inner sleeve having a tissue cutting distal end. And RF cutting region is formed at the distal end of the inner member and an RF coagulation region is formed on an exterior surface of the inner member immediately proximal to the cutting surface. A single power supply providing a single RF energy mode can be connected to both RF applicator regions to simultaneously cut and coagulate tissue.

A blood flow sensing system is disclosed, including a sensor coupled to an antenna, such that the sensor measures a flow of blood within a blood vessel when stimulated with a short range radio frequency energy field detectable by the antenna. Such a system additionally can include a transmitter and receiver unit (i.e., a transmitter / receiver), which can transmit the short range radio frequency energy field to the antenna of the sensor. The transmitter and receiver unit can also receive data transmitted from the sensor via the antenna. Such a system additionally includes a stent integrated with sensor, wherein the stent comprises a small diameter cylinder that props open a blood vessel and wherein the stent is moveable into the blood vessel to form a rigid support for holding the blood vessel open in order to measure the flow of blood within the blood vessel.

A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises at least one ionomer and a polar carrier. The ionomer and polar carrier are blended with one another and form a mixture, preferably a uniform mixture. The ionomer and polar carrier are present in an amount effective to allow the susceptor composition to be heated by RF energy. Also disclosed are RF induction heating systems.

An antenna system that is insensitive to the surface on which it is mounted for use with a RFID tag having a wireless communication device, including a plurality of conductive tabs coupled to the wireless communication device for receiving and radiating radio frequency energy. At least two of the tabs are substantially identical in shape and coupled to the wireless communication device at feedpoint differing in location on each of the two tabs wherein the width of said at least two of said plurality of tabs taken transverse to the longitudinal centerline axis of each tab varies with distance along the longitudinal centerline axis of each of said tabs from its feedpoint. Alternatively, the wireless communication device is coupled to the tab at a feedpoint selected at a location differing on each of the tabs where the conducting area per unit length of the longitudinal centerline axis of each tab varies with distance along the longitudinal centerline axis of each of said tabs from its feedpoint. A radio frequency reflecting structure is coupled to the conductive tabs for reflecting radio frequency energy radiated therefrom. A dielectric material is located intermediate the conductive tabs and the radio frequency reflecting means.

A method of producing liquid hydrocarbons from a hydrocarbon-bearing rock in situ in a geological formation begins with exploring the formation by drilling a plurality of boreholes into the formation and taking core samples of the hydrocarbon-bearing rock and at least one overburden layer. Electrical parameters of the hydrocarbon-bearing rock and the overburden layer are determined, as well as a roughness of a boundary between the hydrocarbon-bearing rock and the at least one overburden layer. These electrical parameters are used to construct a computer model of a portion of the hydrocarbon-bearing rock and at least one overburden layer, the computer model based upon modeling the formation as a rough-walled waveguide. This computer model is used to simulate propagation of radio frequency energy within the hydrocarbon-bearing rock, including simulation of radio frequency wave confinement within the hydrocarbon-bearing rock, at several frequencies and temperatures. A frequency for retorting is selected based upon simulation results. Radio frequency couplers are installed into at least one borehole in the hydrocarbon-bearing rock and driven with radio frequency energy to heat the hydrocarbon-bearing rock. As the rock heats, it releases carbon compounds and these are collected.