Patent ID: 8398627

Claim:
An electrosurgical system comprising: an electrosurgical generator for generating radio frequency (RF) power at a generator operating frequency, an electrosurgical instrument, and a remote return pad, the electrosurgical instrument and the remote return pad both being coupled to the generator, the electrosurgical instrument including at least three tissue treatment electrodes, a first tissue treatment electrode being a cutting electrode and second and third tissue treatment electrodes being coagulation electrodes, the generator comprising a multiple-phase RF output stage having at least four outputs, three of the outputs being coupled to respective electrodes of the electrosurgical instrument for delivering RF power to the electrodes and the fourth output being coupled to the remote return pad, the multiple-phase RF output stage configured such that continuous RF output voltage waveforms are simultaneously delivered across the at least four outputs at the operating frequency, such that the waveforms delivered across a pair of the at least four outputs is phase-displaced with respect to the waveforms delivered across a different pair of the at least four outputs, the generator being configured so that an RF output voltage waveform delivered between the first tissue treatment electrode and at least one of the second and third tissue treatment electrodes has a magnitude that is sufficient to cause tissue vaporisation at the respective tissue treatment electrodes used for tissue vaporisation treatment when the electrosurgical system is used for such tissue treatment, and a circuit for varying a relative preponderance of monopolar and bipolar coagulation by, respectively, varying the RF output voltage delivered between either of the second and third outputs and the fourth output as compared with the RF output voltage delivered between the second and third outputs.