450 results about "Radiofrequency energy" patented technology

Methods for heating tissue completely, thoroughly, and uniformly comprise delivering radio frequency energy through a bipolar surgical instrument having first and second jaws with first and second electrode members within the treatment region. Tissue is grasped between the first and second jaws of the bipolar instrument. The electrode members are energized at a power level to deliver electrical energy to and heat tissue between the first and second electrode members. The power level is increased at a predetermined rate from an initial level. The initial level and predetermined rate are selected to avoid creating a vapor layer and to permit an impedance increase to occur as a result of complete tissue desiccation. A tissue impedance may also be measured and compared to a preset impedance limit for terminating the power delivery when the measured impedance exceeds the impedance limit.

An electrosurgical system has an electrosurgical generator and a bipolar electrosurgical instrument, the generator being arranged to perform a treatment cycle in which radio frequency energy is delivered to the instrument as an amplitude-modulated radio frequency power signal in the form of a succession of pulses characterized by successive pulses of progressively increasing pulse width and progressively decreasing pulse amplitude. There are periods of at least 100 milliseconds between successive pulses, and the treatment cycle begins with a predetermined pulse mark-to-space ratio. Energy delivery between pulses is substantially zero. Each burst is of sufficiently high power to form vapor bubbles within tissue being treated and the time between successive pulses is sufficiently long to permit condensation of the vapor.

An electrosurgical system has an electrosurgical generator and a bipolar electrosurgical instrument, the generator being arranged to perform a treatment cycle in which radio frequency energy is delivered to the instrument as an amplitude-modulated radio frequency power signal in the form of a succession of pulses characterized by periods of a least 100 milliseconds between successive pulses and by a predetermined pulse mark-to-space ratio. Energy delivery between pulses is substantially zero and the mark-to-space ratio is typically 1:4 or less. Each burst is of sufficiently high power to form vapor bubbles within tissue being treated and the time between successive pulses is sufficiently long to permit condensation of the vapor. The treatment cycles may each include an initial period and a subsequent period, the pulse duty cycle being increased or energy being delivered continuously in the subsequent period in order that tissue coagulation can be achieved quickly despite increasing tissue impedance.

An electrosurgical medical device and method for creating thermal welds in engaged tissue. In one embodiment, at least one jaw of the instrument defines a tissue engagement plane carrying a conductive-resistive matrix of a conductively-doped non-conductive elastomer. The engagement surface portions thus can be described as a positive temperature coefficient material that has a unique selected decreased electrical conductance at each selected increased temperature thereof over a targeted treatment range. The conductive-resistive matrix can be engineered to bracket a targeted thermal treatment range, for example about 60° C. to 80° C., at which tissue welding can be accomplished. In one mode of operation, the engagement plane will automatically modulate and spatially localize ohmic heating within the engaged tissue from Rf energy application—across micron-scale portions of the engagement surface. In another mode of operation, a conductive-resistive matrix can induce a “wave” of Rf energy density to sweep across the tissue to thereby weld tissue.

A surgical system and associated method for sealing the passageway of a fluid-carrying vessel with a diameter up to 5 millimeters comprises an electrosurgical generator capable of delivering electrosurgical power, a surgical instrument electrically connected to the electrosurgical generator and adapted to transfer electrosurgical power from the electrosurgical generator to a pair of end effectors disposed at a distal end of the surgical instrument. The system also includes a power control circuit for controlling the delivery of radio frequency energy to the vessel through the end effectors, wherein the delivery of the radio frequency energy to the vessel comprises, raising the output current to a range below 1.75 Amperes RMS and the output voltage to a range below 135 Volts RMS. Radio frequency energy is applied to the vessel for a period of time while the power is held approximately constant. The flow of radio frequency energy is terminated when the impedance of the vessel being sealed reaches a predetermined level.

A resection device includes an elongated probe shaft and a tissue resection member disposed at a distal end of the elongated probe shaft. The tissue resection member has a cutting surface configured for being placed in contact with tissue. In one aspect of the invention, at least one ejection port is located adjacent to the cutting surface of the tissue resection member, wherein the at least one ejection port is coupled to a source of a polymerizable hemostasis-promoting material that is delivered to the resection site of interest. In certain embodiments, polymerization of the hemostasis-promoting material may be accelerated by application of heat, radiofrequency energy, or ultra violet light.

Apparatus for forming a lesion in body tissue includes a probe having an active region with an electrode for contacting tissue to be treated, and an inactive region including an insulative sleeve around a portion of the electrode. The temperature of the inactive region is monitored using a temperature sensor. A controller supplies radio frequency energy to the electrode and samples signals from the temperature sensor. By performing a calculation using the sampled signals and a predetermined inactive region threshold temperature, and by adjusting the supplied radio frequency power, the inactive region of the probe can be maintained at or below an inactive region maximum temperature whilst the controller continues to supply radio frequency energy to the electrode. The probe has a second temperature sensor, mounted at a distal end of the electrode, the controller being configured to reduce the supplied radio frequency power when the electrode temperature reaches a predetermined maximum electrode temperature.

A method and system for the delivery of radiofrequency energy to the tissue, particularly, the prostate, to alleviate the symptoms of BPH is disclosed. The system incorporates a bipolar or multipolar electrode array to create an electric field where the heat created is confined solely to a specific volume of the prostate gland and therefore the heated tissue is defined only by the electrode geometry. The bipolar electrode array provides a variety of three dimensional, symmetric heating patterns within the prostatic tissue depending on the relative electrode lengths and angular separation. The system provides precision tissue temperature and impedance measurements thereby enabling the surgeon to accurately predict heating pattern performance and tissue response to RF heating.

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.

An instrument for ablation of tissue. The instrument including: a body having at least one surface for contacting a tissue surface, the at least one surface being substantially planar; an ultrasonic transducer disposed in the body for generating ultrasonic energy and directing at least a portion of the ultrasonic energy to the tissue surface, the ultrasonic transducer being operatively connected to an ultrasonic generator; at least one radio-frequency electrode disposed on the at least one surface for directing radio frequency energy to the tissue surface, the at least one radio-frequency electrode being operatively connected to a power source; and one or more switches for selectively coupling at least one of the ultrasonic transducer to the ultrasonic generator and the at least one radio-frequency electrode to the power source.

A medical probe assembly, system, and methods for the use thereof to treat tissue are described. The system optionally comprises an energy source, two internally-cooled 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, systems, and kits for treating breast tissue rely on transferring energy to or from cells lining an individual breast duct. Energy can be introduced into the breast duct, e.g., by filling the duct with an electrically conductive medium and applying radiofrequency energy to the medium. Other energy forms could also be used, such as light, ultrasound, radiation, microwave energy, heat, cold, direct current, and the like. By treating individual breast ducts, cancerous and pre-cancerous conditions originating in the duct can be effectively treated.

Systems and methods are disclosed to control the temperature of an RF hyperthermia system with minimum overshoot and to improve safety by, among other things, detecting a defective temperature sensor. Temperature overshoot may be minimized by compensating for the short-term temperature difference between the area being treated and the applicator delivering the RF energy. The RF energy may heat the tissue and then the tissue may transfer heat to the applicator sensor. The system may also adapt to various applicator sizes and shapes by modifying control loop coefficients based on initial probe response.

The invention provides a medical device that includes a housing, a tubular member extending from the distal end of the housing, a first arm extending from the distal end of the tubular member, the first arm including a first electrode, a second arm extending from the distal end of the tubular member, the second arm including a second electrode and being disposed coaxially with the first arm, at least one solution infusion opening on each electrode, and a solution delivery channel for delivery of a conductive solution to the solution infusion openings. According to the invention, at least one of the first arm or the second arm is translationally moveable, and at least one of the first arm or the second arm is adapted to be coupled to a source of radiofrequency energy. The invention also provides a corresponding method for treating blood vessels or other tissues of the body.

A method of lipolysis. The method comprises deforming a region of skin so that the region of skin protrudes from surrounding skin. One or more radio frequency (RF) electrodes are positioned on the protruding region of skin so as to generate an electrical current through adipose tissue in the protruding region of skin when a voltage is applied to the electrode or electrodes. A voltage is then applied to the electrode or electrodes so as to deliver sufficient RF energy to the protruding region of skin to damage subcutaneous adipose tissue. The method of the invention may be used, for example, to achieve a reduction in body weight, cellulite reduction, loose skin reduction, wrinkle treatment, body surface tightening, skin tightening, and collagen remodeling.

A device and method for repairing spinal discs in which the nucleus has been damaged. A central section of the nucleus is cored out using a device which ablates the tissue using RF energy. A nucleus implant comprising a shape memory material is placed in the central section of the disc through a cannula, which implant is activated by body heat to expand and fill the central section, such that the implant emulates the functions and strength of the disc's natural nucleus.

An apparatus and method for reducing wrinkles in the skin tissue of a patient. The method includes detecting a nerve. The nerve can be detected by inserting an electrode into the skin tissue, delivering a current and then observing any stimulation of muscle tissue. The process of inserting the electrode, delivering current and detecting muscle stimulation may be repeated at a plurality of different skin location to trace the nerve. Once the nerve is traced, the electrode can be inserted into the skin at various locations, either at or adjacent to the nerve, and deliver energy into the tissue at a level sufficient to disrupt interaction between the nerve and the adjacent muscle. Once the nerve / muscle interaction is disrupted the muscle will be relaxed and the wrinkle(s) will either be removed or reduced.

A method and systems for treating chronic total occlusions, particularly those that are difficult to treat, is disclosed. In this approach, recanalizing the CTO is achieved using a combined antegrade and retrograde approach. The proximal end of the occlusion is penetrated using an antegrade wire, using a traditional approach. Using collateral vessels, the distal end of the occlusion is crossed in a retrograde fashion. By appropriately maneuvering each member and applying radiofrequency energy between the proximal and distal ends of the occlusion, a continuous channel is created.

An electrosurgical generator is disclosed. The electrosurgical generator includes a power supply for generating a DC voltage. The electrosurgical generator also includes a first parallel inductor-capacitor circuit being driven by a first signal at a first predetermined frequency and a second parallel inductor-capacitor inductor-capacitor circuit driven by a second signal at the first predetermined frequency phase shifted 180°. The electrosurgical generator further includes a series inductor-capacitor resonant circuit operably connected in series with a primary winding of a transformer. The first and second parallel inductor-capacitor circuits are operably connected to the transformer, such that the first inductor-capacitor circuit generates a positive half sine wave and the second inductor-capacitor circuit generates a 180° phase-shifted positive half sine wave to generate a full sine wave in a secondary winding of the transformer.

A system for heat ablation of tissue in a patient comprises a plurality of electrodes operatively connected to a source of radiofrequency energy and configured to apply RF energy to tissue at a patient site, a plurality of RF current restricting circuits, each circuit coupled between one of the plurality of electrodes and the source of radiofrequency energy, and configured to restrict RF energy to the electrode when the current restricting circuit is enabled and not restrict RF energy to flow to the electrode when the current restricting circuit is disabled, at least one return electrode adapted to contact the patient and configured to return RF energy to the RF source; and a switching mechanism configured to selectively enable each of the plurality of RF current restricting circuits, in one of a sequential and non sequential fashion, wherein the switching mechanism is isolated from each of the current restricting circuits.

Systems and methods for providing radiofrequency (“RF”) energy to a target surgical site are provided. The systems include the use of at least one overlay which is super-imposed over an image of the target surgical site to assist the operator in evaluating parameters for performing the surgical procedure. The disclosure also include methods for creating at least one overlay and for using an overlay in surgical procedures using RF energy.

A device is described that may be positioned at a location in an intervertebral disc for diagnosis or treatment of the disc. Treatment may include, for example, applying energy or removing material, and may decrease intradiscal pressure. Radiofrequency energy may be applied. A percutaneous method of repairing a fissure in the annulus pulposus comprises placing an energy source adjacent to the fissure and providing sufficient energy to the fissure to raise the temperature to at least about 45-70° C. and for a sufficient time to cause the collagen to weld. An intervertebral fissure also can be treated by placing a catheter with a lumen adjacent to the fissure and injecting sealant into the fissure via the catheter, thereby sealing the fissure. An intervertebral fissure additionally can be treated by providing a catheter having a distal end, a proximal end, a longitudinal axis, and an intradiscal section at the catheter's distal end on which there is at least one functional element. The next step is applying a force longitudinally to the proximal of the catheter which is sufficient to advance the intradiscal section through the nucleus pulposus and around an inner wall of an annulus fibrosus, but which force is insufficient to puncture the annulus fibrosus. Next the functional element is positioned at a selected location of the disc by advancing or retracting the catheter and optionally twisting the proximal end of the catheter. Then the functional unit treats the annular fissure. Optionally, there is an additional step of adding a substance to seal the fissure. An externally guidable intervertebral disc apparatus also is disclosed.

A system for treating an abnormal vertebral body such as a compression fracture. In an exemplary embodiment, the system includes a biocompatible flow-through implant structure configured with a three-dimensional interior web that defines flow openings therein for cooperating with a two-part hardenable bone cement. The flow-through structure is capable of compacted and extended shapes and in one embodiment provides a gradient in flow openings for controlling flow parameters of a bone cement injected under high pressure into the interior thereof. The flow-through implant structure is configured for transducing cement injection forces into a selected direction for moving apart cortical endplates of a vertebra to reduce a fracture. In one embodiment, the flow-through implant structure is coupled to an Rf source for applying Rf energy to a two-part bone cement to accelerate curing of the cement to thereby allow on-demand alterations of cement viscosity. The Rf system allows for control of bone cement polymerization globally or regionally to prevent cement extravasion and to direct forces applied to a vertebra to reduce a fracture.

A method for the treatment of obesity or other disorders, by wireless electrical activation or inhibition of the sympathetic nervous system. This activation or inhibition can be accomplished by wirelessly stimulating the greater splanchnic nerve or other portion of the sympathetic nervous system using a wireless electrode inductively coupled with a radiofrequency field. The source of radiofrequency energy may be internal or external to the patient. This nerve activation can result in reduced food intake and increased energy expenditure.

Embodiments of the disclosed technology relate to a bipolar electrosurgical device for a laparoscopic environment, as well as methods for the use of such a device. Embodiments of the device may include a set of opposing jaws comprising at least one bipolar electrode pair disposed thereon, the set of jaws configured to deliver radiofrequency energy to a target tissue. Embodiments of the set of jaws, when closed, may have a diameter no greater than about 5 mm. The device may further include a shaft with a diameter that may be no greater than about 5 mm. Each of the jaws has a tissue-facing surface of each jaw that may include a complementary self-aligning configuration with respect to the longitudinal axis of the other jaw. Embodiments of the device may further include a pinless rotation assembly formed from rotatably cooperative features of the first jaw and the second jaw that connect the jaws together and enable the jaw set to pivot between an open position and a closed position.

A radiofrequency thermal balloon catheter uniformly heats tissues in contact with the balloon to achieve thermotherapy such as ablation or hyperthermia safely and properly for a diseased part. The radiofrequency thermal balloon catheter includes a catheter (4) having an outer shaft (2) and an inner shaft 3 extended through the outer shaft so as to be slidable relative to the outer shaft, an inflatable balloon (6) capable of being inflated so as to be in contact with a target lesion (18) and provided between respective front end parts of the outer and the inner shaft, and a radiofrequency electrode (8) extended in a wall of the balloon or inside the balloon to be used for radiofrequency energy supply in combination with a counter electrode (53). The counter electrode is disposed at a predetermined position, for example, inside the balloon, in the wall of the balloon, in a position neighboring the balloon or on the patient's body surface. A lead wire (10) electrically connects to the radiofrequency electrode. A temperature sensor (12) is capable of sensing temperature of a liquid contained in the balloon. A temperature distribution uniformizing device (14) uniformizes the temperature distribution in the liquid contained in the balloon.

Multipolar, multi-lumen, virtual-electrode catheters having at least one surface electrode, and methods for treatment (e.g., treatment of cardiac arrhythmias) with such catheters are disclosed. The catheters have at least two internal lumens, and at least one internal, flexible electrode rides in each internal lumen. The flexible electrodes carry treatment energy (e.g., radiofrequency energy). The energy exits the catheters via at least one exit feature (e.g., slots, portholes, or micro-pores). The methods for treatment include operating the catheters in different modes depending upon location and type of treatment to be performed. The treatment energy delivered by one of the internal, flexible electrodes may be directed to the other internal, flexible electrode; or the energy delivered by one or both of the internal, flexible electrodes may be directed to one or more surface electrodes. The delivered energy establishes at least one electric field, and possibly one or more lesions, in the tissue.