613 results about "Electric arc discharge" patented technology

Various safe switching mechanisms are provided for use with electrosurgical instruments which prevent arcing between the high-energy contacts as the high-energy source is activated. The switching mechanisms generally include a pair of high-energy contacts and a pair of activation contacts. An actuator is provided which initially engages the high-energy contacts in advance of engagement of the activation contacts to prevent arcing and subsequently disengages the activation contacts in advance of the high-energy contacts as the energy source is deactivated. A method of switching power to an electrosurgical instrument while avoiding damage to high-energy contacts is also disclosed.

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.

An electrosurgical instrument and method for treating varicose veins. In one embodiment, an elongate catheter has a distal working end that carries an electrosurgical energy delivery surface comprising at least one electrode with a positive temperature coefficient of resistance (PTCR) surface and / or an electrode with a pressure sensitive variable resistance to provide a smart surface for controlling Rf current flow at the interface of electrosurgical surface and the tissue. The electrode surface then can limit or modulate Rf energy delivery through the surface in response to the temperature of the surface or the engagement pressure of the surface against the engaged tissue. In operation, the smart electrosurgical surface prevents arcing at the electrode-tissue interface, and thus controls ohmic heating to prevent tissue desiccation, charring and emboli formation.

Controlling a level of electrosurgical energy provided to tissue based on detected arcing patterns or impedance changes. The drag force imposed on an electrode or blade of an electrosurgical instrument may be controlled by adjusting the level of electrosurgical energy based on the arcing patterns or impedance changes. The arcing patterns or impedance changes may be detected by sensing and analyzing voltage and / or current waveforms of the electrosurgical energy The current and / or voltage waveform analysis may involve calculating impedance based on the voltage and current waveforms and calculating changes in impedance over time. The waveform analysis may involve detecting harmonic distortion using FFTs, DFTs, Goertzel filters, polyphase demodulation techniques, and / or bandpass filters. The waveform analysis may involve determining a normalized difference or the average phase difference between the voltage and current waveforms.

A system and method for performing electrosurgical procedures are disclosed. The system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue in form of one or more electrosurgical waveforms having a crest factor and a duty cycle. The system also includes sensor circuitry adapted to measure impedance and to obtain one or more measured impedance signals. The sensor circuitry is further adapted to generate one or more arc detection signals upon detecting an arcing condition§. The system further includes a controller adapted to generate one or more target control signals as a function of the measured impedance signals and to adjust output of the electrosurgical generator based on the arc detection signal. An electrosurgical instrument is also included having one or more active electrodes adapted to apply electrosurgical energy to tissue.

An electrode structure and a mechanism for automated or user-selected operation or compensation of the electrodes, for example to determine tissue coverage and / or prevent arcing between bottom electrodes during electrocautery is disclosed.

A plasma jet device belongs to a plasma generator and settles the problem the unsafe electrode and the likely generation of arc discharging between the electrode and the grounding existing in the prior plasma jet device. The plasma jet device according to the invention comprises a power supply, a working gas source and an electrode. The working gas of the working gas source enters the electrode from the gas input port of the electrode. The electrode is in the shape of empty tube, is provided with a gas input port at one end and is provided with a gas output port at the other end. The electrode is connected with the power supply through a resistor and a capacitor. The plasma jet device according to the invention has the advantages of easy manufacture, easy maintenance, convenient use, low cost and easy carrying. The temperature of the generated plasma jet can be different when resistor with different resistance, capacitor with different capacitance, different driving power supply and different working gas are selected. The human body can touch with the plasma jet safely when the temperature of the plasma jet is approximate to the room temperature. At the same time the plasma jet can be provided with different shapes and can diffuse to different directions simultaneously. The specific application with large scale and large area in normal temperature and normal pressure can be realized.

A power charging assembly and methods are provided to provide a pre-charge low-current state, a steady-state, high-current charging state, and an unconnect state for an electrical load of an electrical propulsion system in a hybrid electrical vehicle (HEV). The power charging assembly includes a positive contactor device, a negative contactor device, and a non-contactor device means. The rate at which that electrical load is pre-charged may be effectively controlled by using a pulse-width modulated (PWM) signal received by the non-contactor device means. A current-only carrying positive or negative contactor may be configured with the non-contactor device means to further prevent electrical arcing of the contacts of the positive and the negative contactor during power charging assembly operation.