An Electrosurgical System
First Claim
1. An electrosurgical generator comprising a source of radio frequency (r.f.) energy, at least a pair of output terminals for connection to a bipolar electrosurgical instrument and for delivering r.f. energy from the source to the instrument, and a pulsing circuit for the source, wherein the pulsing circuit and the source are so arranged as to deliver into a resistive load, when connected across the output terminals, an amplitude-modulated r.f. power signal in the form of a succession of pulses, which succession is characterised by successive pulses being of progressively decreasing power amplitude and of progressively increasing pulse width.
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Accused Products
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.
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Citations
40 Claims
- 1. An electrosurgical generator comprising a source of radio frequency (r.f.) energy, at least a pair of output terminals for connection to a bipolar electrosurgical instrument and for delivering r.f. energy from the source to the instrument, and a pulsing circuit for the source, wherein the pulsing circuit and the source are so arranged as to deliver into a resistive load, when connected across the output terminals, an amplitude-modulated r.f. power signal in the form of a succession of pulses, which succession is characterised by successive pulses being of progressively decreasing power amplitude and of progressively increasing pulse width.
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18. An electrosurgical generator comprising a source of radio frequency (r.f.) energy, at least a pair of output terminals for connection to a bipolar electrosurgical instrument and for delivering r.f. energy from the source to the instrument, and a pulsing circuit for the source, wherein the pulsing circuit and the source are arranged such that the r.f. energy is delivered over a period of time constituting a treatment cycle in which, when a resistive load is connected across the output terminals, is delivered as an amplitude-modulated r.f. power signal in the form of a succession of pulses in which the periods between successive pulses are at least 100 ms, the depth of amplitude modulation is at least 90% and the pulse mark-to-space ratio increases progressively from a value less than 2:
- 3 at the start of the treatment cycle.
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28. A method of electrosurgically coagulating tissue between the electrodes of a bipolar electrosurgical instrument, in which r.f. energy is applied to the tissue via the electrodes in a succession of pulse bursts of progressively increasing length and progressively decreasing amplitude.
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35. An electrosurgical generator comprising a source of radio frequency (r.f.) energy, at least a pair of output terminals for connection to a bipolar electrosurgical instrument and for delivering r.f. energy to the instrument, a pulsing circuit for the source, and control circuitry including means for monitoring at least one electrical parameter associated with the output terminals, wherein the arrangement of the control circuitry, the pulsing circuit and the source is such that, with the output terminals connected to a resistive load, the control circuitry causes the source to deliver into the load an amplitude-modulated r.f. power signal which, at least in an initial period, is at least one pulse with a predetermined ON-time, the or each such pulse being followed by a predetermined OFF-time in which substantially zero power is delivered and, in a subsequent period, has a different characteristic, the transition from the initial period to the subsequent period being controlled by the control circuitry in response to the at least one monitored parameter.
Specification