434 results about "Radiofrequency generator" patented technology

An electrosurgical system comprises a radio frequency generator (1), an electrosurgical instrument (E1), and a fluid enclosure (42). The generator (1) has a radio frequency output for delivery of power to the electrosurgical instrument (E1) when immersed in an electrically-conductive fluid. The electrosurgical instrument (E1) has an electrode assembly (32) at the distal end thereof, the electrode assembly comprising a tissue treatment electrode (34), and a return electrode (38) axially spaced therefrom in such a manner as to define, in use, a conductive fluid path that completes an electrical circuit between the tissue treatment electrode and the return electrode. The fluid enclosure (42) is adapted to surround an operation site on the skin of a patient or an incision leading to a cavity surgically created within the patient's body. The fluid enclosure (42) includes sealing means (44) for sealing against the patient's tissue, and the fluid enclosure includes at least one port (50a, 52a) through which the electrosurgical (E1) is insertable, and through which the electrically-conductive fluid can enter and / or leave the enclosure. The fluid enclosure device of the present invention can also be used to treat tumours within the colon. The enclosure, which includes a proximal and a distal bung, is inserted into the colon in a deflated condition and then inflated with a conductive fluid or gas. The colon can be supported against the pressure of the fluid or gas with a pressure sleeve that has been inserted to surround the region of the colon being treated. An electrosurgical instrument is then inserted into the colon and manipulated to vaporize the tumor.

Systems, methods, and apparatus for providing power to an electrosurgical instrument. In particular, a power supply is disclosed in which non-sinusoidal (e.g., pulsed) constant frequency voltage having a variable amplitude is passed to an LC circuit to produce a quasi-sinusoidal current in the LC circuit. The constant driving frequency can be one half the resonant frequency of the LC circuit allowing the LC circuit to operate as an impedance, and thus limit current spikes and arcing. The frequency and phasing of the driving voltage also enables the LC circuit to discharge energy back into a power provider of the power supply so that energy does not build up in the LC circuit. These features result in less severe current spikes and arcing, as well as reduced cutoff times.

A catheter for the treatment of tumors and other affections using hyperthermia induced by radio frequency includes a tubular body with or without an anchoring balloon at its distal end. An active electrode is positioned around the body and connected to a radio frequency generator. At least one thermistor needle measures the temperature around the electrode. The active electrode is flexible and connectable to a supply source of a fluid for cooling the electrode. It includes a helical conduit, which can be metal, conductive ceramic or graphite.

A radiofrequency reactor for use in thermally recovering oil and related materials includes a radiofrequency antenna configured to be positioned within a well, where the well is provided within an area in which crude oil exists in the ground. The radiofrequency antenna includes a cylindrically-shaped radiating element for radiating radiofrequency energy into the area in which crude oil exists. The cylindrically-shaped radiating element is configured to allow passage of fluids there through. The radiofrequency reactor also includes a radiofrequency generator electrically coupled to the radiofrequency antenna. The radiofrequency reactor is operable to control the radiofrequency energy generated.

A magnetic resonance system obtaining magnetic resonance exposures of an examination subject, has an examination tunnel, a whole-body antenna with two connection terminals. The whole-body antenna cylindrically extends around the examination tunnel along a longitudinal axis. The system has a radio-frequency supply device in order to respectively supply the whole-body antenna with radio-frequency signals for emission of a radio-frequency field in the examination tunnel. The radio-frequency supply device has a radio-frequency generator for generation of a radio-frequency signal, a signal splitter that divides a radio-frequency signal coming from the radio-frequency generator into two partial signals that are phase-shifted by 90° relative to one another. Two radio-frequency feed lines are connected with the two connection terminals of the whole-body antenna. Via these radio-frequency feed lines, the two partial signals are fed into the whole-body antenna. The whole-body antenna has an intrinsic transmission characteristic such that a radio-frequency field is emitted that is elliptically polarized in a defined manner in a plane lying perpendicular to the longitudinal axis (at least in the unloaded state of the examination tunnel).

A method for treating tissue of a mammalian body in which the conductivity of the tissue is characterized. The amount of a conductive liquid to supply to the tissue is determined as a function of the conductivity of the tissue and injected into the tissue over an interval of time. Electromagnetic energy is supplied to the tissue to form a lesion in the tissue. A computer-readable memory and a radio frequency generator and controller utilizing such method are further provided.

Aspects of the present disclosure include methods for producing an output laser beam having two or more angularly deflected laser beams (e.g., for irradiating a sample in a flow stream) with a predetermined intensity profile. Systems for practicing the subject methods having a laser, an acousto-optic device, a radiofrequency generator and a controller for adjusting the amplitude of the radiofrequency drive signals to produce an output laser beam of angularly deflected laser beams with a predetermined intensity profile are also described.

This disclosure describes systems, methods, and apparatuses for impedance-matching radio frequency power transmitted from a radio frequency generator to a plasma load in a semiconductor processing chamber. Impedance-matching can be performed via a match network having a variable-reactance circuit. The variable-reactance circuit can comprise one or more reactive elements all connected to a first terminal and selectively shorted to a second terminal via a switch. The switch can comprise a bipolar junction transistor (BJT) or insulated gate bipolar transistor (IGBT) controlled via bias circuitry. In an on-state, the BJT base-emitter junction is forward biased, and AC is conducted between a collector terminal and a base terminal. Thus, AC passes through the BJT primarily from collector to base rather than from collector to emitter. Furthermore, the classic match network topology used with vacuum variable capacitors can be modified such that voltages do not overload the BJT's in the modified topology.