Abstract: An electrosurgical system includes a generator for generating radio frequency power, and an electrosurgical instrument including at least three electrodes. The generator includes a radio frequency output stage having at least a pair of RF output lines, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to limit the radio frequency output voltage developed across the output lines to at least a first predetermined threshold value to produce a cutting RF waveform, and a second threshold value to produce a coagulating RF waveform. In a combined mode, the controller delivers both cutting and coagulating waveforms by alternating discontinuously between the first and second threshold values to form a blended signal.

Abstract: An electrosurgical system includes a generator for generating radio frequency power, and an electrosurgical instrument including at least three electrodes and. The generator includes a radio frequency output stage having at least a pair of RF output lines, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to limit the radio frequency output voltage developed across the output lines to at least a first predetermined threshold value to produce a cutting RF waveform, and a second threshold value to produce a coagulating RF waveform. In a combined mode, the controller delivers both cutting and coagulating waveforms, either simultaneously or by alternating constantly between the first and second threshold values to form a blended signal.

Abstract: A device for morcellating tissue within a body cavity of a patient comprises a stationary tube having a distal end portion, and a bipolar electrosurgical electrode assembly located at the distal end of the tube. The electrosurgical electrode assembly comprises first and second electrodes separated by an insulation member, the bipolar electrosurgical electrode assembly extending around the circumference of the distal edge of the tube. When an electrosurgical cutting voltage is applied to the electrode assembly, and relative movement is initiated between the tube and the tissue, a core of severed tissue is formed within the tube such that it can be removed from the body cavity of the patient. A tissue-pulling device such as a jaw assembly can be employed to pull tissue against the distal end of the tube.

Abstract: An electrosurgical generator for supplying RF power to an electrosurgical instrument for cutting or vaporizing tissue has an RF output stage (42) with an RF power bridge (Q1, Q2, Q3, Q4), a pair of output lines (74) and a series-resonant output network (48). The output impedance of the output stage (42) at the output lines (74) is less than 200/?P ohms, where P is the maximum continuous RF output power of the generator. The generator offers improved cutting and vaporizing performance, especially in relation to the reliability with which an arc can be struck when presented with an initial low impedance load. Overloading of the output stage is prevented by rapidly operating protection circuitry responsive to a predetermined electrical condition such as a substantial short-circuit across the output lines. In the preferred embodiment, the output stage is capable of maintaining output pulses at least 1 kW peak by supplying the power bridge from a large reservoir capacitor (60).

Abstract: In an electrosurgical generator for generating radio frequency power, the generator comprises a radio frequency output stage having three or more output connections, one or more sources of output power coupled to the output stage, and a controller operable to cause the generator to supply a first cutting RF waveform to the output connections or a second coagulating RF waveform to the output connections. In a combined mode, the controller causes the generator to deliver both first and second RF waveforms, the controller including means for feeding the waveforms to the output connections such that the first RF waveform is delivered between a first pair of the output connections, and the second RF waveform is delivered between a second pair of the output connections. The combined mode is adjustable between various settings, each setting having a different proportion of the first and second RF waveforms.

Abstract: A method for skin treatment comprises the steps of delivering at least one pulse of radio frequency power to at least one electrode in order to create an electric field; passing gas through the electric field in order to form plasma from the gas; and applying the plasma to the surface of skin. The amount of radio frequency power may be relatively low such that the application of plasma causes denaturation of collagen within the collagen-containing tissue beneath the skin surface, which may promote the generation of new collagen within the collagen-containing tissue.

Abstract: An electrosurgical instrument includes a handpiece, an electrode assembly comprising one or more electrodes attached to the handpiece, and connection means for connecting the handpiece to an electrosurgical generator. The handpiece comprises a housing, fluid supply lines for directing a cooling fluid to and from the electrode assembly, and a pump for driving cooling fluid through the fluid supply lines. The handpiece may also include a fluid reservoir. The pump, the fluid supply lines, and the reservoir are all wholly contained within the housing.

Abstract: 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.

Abstract: An electrode assembly for an electrosurgical instrument, comprises a bipolar cutting blade, and fluid supply lines for directing a cooling fluid to the cutting blade, the cutting blade comprising first, second and third electrodes, and electrical insulators spacing apart the electrodes, the fluid supply lines being such that cooling fluid enters the cutting blade via the first electrode, passes through an aperture in the second electrode, and exits the cutting blade via the third electrode.

Abstract: An electrosurgical generator for supplying RF power to an electrosurgical instrument for cutting or vaporising tissue has an RF output stage (42) with an RF power bridge (Q1, Q2, Q3, Q4), a pair of output lines (74) and a series-resonant output network (48). The output impedance of the output stage (42) at the output lines (74) is less than 200/?P ohms, where P is the maximum continuous RF output power of the generator. The generator offers improved cutting and vaporising performance, especially in relation to the reliability with which an arc can be struck when presented with an initial low impedance load. Overloading of the output stage is prevented by rapidly operating protection circuitry responsive to a predetermined electrical condition such as a substantial short-circuit across the output lines. In the preferred embodiment, the output stage is capable of maintaining output pulses at least 1kW peak by supplying the power bridge from a large reservoir capacitor (60).

Abstract: An electrosurgical generator for supplying RF power to an electrosurgical instrument for cutting or vaporising tissue has an RF output stage with RF output devices, a series-resonant output network and an RF output. The generator offers improved cutting and vaporising performance, especially in relation to the reliability with which an arc can be struck when presented with an initial load impedance load. This is achieved by virtue of the output stage being capable of maintaining output pulses of at least 1 kW peak by supplying the RF output devices from a large reservoir capacitor. An appropriate combination of cutting performance and haemostasis is provided by allowing for pulsed or continuous wave operation once an arc has been established, according to whether or not a surplus energy condition exists, as indicated by the voltage across the reservoir capacitor.

Abstract: An electrosurgical system includes a generator for generating radio frequency (RF) power, and an electrosurgical instrument including at least three electrodes. The generator comprises an RF output stage having at least a pair of RF output lines, a power supply coupled to the output stage for supplying power to the output stage, and a controller capable of varying the RF power signal supplied to the output lines. The system also includes a selection circuit having at least three output connections each in electrical connection with a respective one of the at least three electrodes. This selection circuit operates to vary the coupling between the RF output stage and the three or more output connections.

Abstract: A surgical instrument comprises at least two elongate hollow tubes (14, 15), each having an aperture (18) at the distal end portion. The inner tube (14) is disposed within the other tube (15), and is mounted for rotation about its longitudinal axis. A cutting tool (4) is located at the distal end of the tube (14), and is positioned adjacent to the apertures (18). A motor (5) is provided for rotating the inner tube (14), and the inner tube (14) has a central lumen (21) through which tissue cut by the cutting tool (4) is removed under the action of a source of suction (12). Heat is supplied to the tissue, prior to, or simultaneously with, the cutting thereof, such that the tissue being cut by the cutting tool (4) is coagulated tissue. In one embodiment, there is a third tube (16), and saline is fed to the apertures (18) via a channel (19) between the tubes (15) and (16). The outer tube (16) constitutes an active electrode, and the inner tube (14) constitutes the return electrode of an electrosurgical device.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for skin treatment comprises the steps of delivering at least one pulse of radio frequency power to at least one electrode in order to create an electric field; passing gas through the electric field in order to form plasma from the gas; and applying the plasma to the surface of skin. The amount of radio frequency power may be relatively low such that the application of plasma causes denaturation of collagen within the collagen-containing tissue beneath the skin surface, which may promote the generation of new collagen within the collagen-containing tissue.

Abstract: In an electrosurgical system which is operable within the frequency range of from 100 kHz to 50 MHz and which has a handheld instrument with an elongate instrument shaft, the distal end of the shaft carries a bipolar electrode assembly for use in a conductive fluid field. The electrode assembly has an active electrode and, set back from the active electrode, a return electrode coated with an insulative dielectric layer. The insulative layer may be made of a plastics or a ceramic material and acts as the dielectric of a capacitor when the electrode assembly is immersed in the conductive fluid. One of the effects of the insulative layer is to provide a more uniformly distributed electric field over the return electrode than is obtained with an exposed return electrode, yielding improved tissue desiccation and vaporisation characteristics. The active electrode may have a similar dielectric covering.

Abstract: An electrosurgical generator for supplying RF power to an electrosurgical instrument for cutting or vaporising tissue has an RF output stage (42) with an RF power bridge (Q1, Q2, Q3, Q4), a pair of output lines (74) and a series-resonant output network (48). The output impedance of the output stage (42) at the output lines (74) is less than 200/{square root}P ohms, where P is the maximum continuous RF output power of the generator. The generator offers improved cutting and vaporising performance, especially in relation to the reliability with which an arc can be struck when presented with an initial low impedance load. Overloading of the output stage is prevented by rapidly operating protection circuitry responsive to a predetermined electrical condition such as a substantial short-circuit across the output lines. In the preferred embodiment, the output stage is capable of maintaining output pulses at least 1kW peak by supplying the power bridge from a large reservoir capacitor (60).

Abstract: An electrosurgical generator has output terminals for connection to active and return electrodes respectively of an electrosurgical instrument and, connected to the output terminals via at least one isolation capacitor, a radio frequency (r.f.) source which may be pulsed by a pulsing circuit. To permit tissue removal at a high rate, the source and the pulsing circuit are arranged so as to generate a pulsed r.f. output signal having a peek-to-peek voltage of at least 1250V, a mark-to-space ratio not more than 1:1, and a pulse length not more than 100 ?s.