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 periods of at least 100 ms between successive pulses and by a predetermined pulse mark-to-space ratio.
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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 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.
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Citations
58 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 periods of at least 100 ms between successive pulses and by a predetermined pulse mark-to-space ratio.
- 10. 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 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 is less than 2:
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38. 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 a succession of pulses with a predetermined initial pulse duty cycle 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.
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49. A method of electrosurgically coagulating tissue between the electrodes of a bipolar electrosurgical instrument, in which radio frequency (r.f.) energy is applied to the tissue via the electrodes in a succession of pulse bursts with a duty cycle of 40% or less, wherein the instantaneous r.f. current at the start of each successive burst is higher than the instantaneous r.f. current at the end of the previous burst.
- 50. An electrosurgical system comprising an electrosurgical generator and a bipolar electrosurgical instrument coupled to an output of the generator, the generator being such as to provide a succession of controlled bursts of electrosurgical energy to the instrument at a predetermined pulse mark-to-space ratio, wherein each burst has a sufficiently high power to form at least one vapour bubble within tissue being treated by the instrument, and the time duration between successive bursts is sufficiently long to permit recondensation of the or each vapour bubble, the peak delivered power being between the bursts being substantially zero.
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58. A method of electrosurgically coagulating tissue between the electrodes of a bipolar electrosurgical instrument, in which a succession of controlled bursts of r.f. energy are applied across the electrodes at a predetermined mark-to-space ratio, each burst being of sufficiently high power to form vapour bubbles within the tissue, and the time duration between successive bursts is sufficiently long to permit condensation of the bubbles.
Specification