ELECTROSURGICAL APPARATUS FOR DELIVERING RADIOFREQUENCY ENERGY AND MICROWAVE ENERGY AND A METHOD FOR ITS USE

An electrosurgical waveform having both radiofrequency (RF) energy and microwave energy components that is arranged to perform efficient haemostasis in biological tissue. The waveform comprises a first portion primarily of RF electromagnetic energy, and a second portion primarily of microwave electromagnetic energy that follows the first portion. The second portion further comprises a plurality of RF pulses, wherein the first portion transitions to the second portion when either a duration of the first portion meets or exceeds a predetermined duration threshold, or an impedance determined during the first portion meets or exceeds a predetermined threshold. The waveform is arranged to deliver energy rapidly so that haemostasis can occur in a short time frame in a situation where the maximum available power is limited, or to avoid undesirable thermal damage to the biological tissue.