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.
1691 Citations
25 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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23. 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 300 ms, the depth of amplitude modulation is at least 90%, the pulse mark-to-space ratio increases progressively from a value less than 2:
- 3 at the start of the treatment cycle, and the pulse repetition rate is less than 1 Hz, wherein a sensing circuit is arranged to detect an initial value of a load impedance associated with the start of the treatment cycle, and wherein the pulsing circuit is arranged such that the initial pulse mark-to-space ratio increases with increasing sensed initial load impedance.
- 24. 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.
Specification