Surgical cutting apparatus having a treatment channel and a measurementchannel for conveying microwaveenergy from a source to an antenna at a cutting edge. The measurement channeloperates at lower power than the treatment channel fordetermining when higher energy can be safely applied. The apparatus maydeliver microwave radiation at differing frequencies toone or more antennas at the cutting edge, e.g. to provide different treatmenteffects. The source may generate an output for anantenna whose frequency can be selected e.g. for most efficient operation.Selection may be automatic based on detected magnitudeand phase of reflected signals during a frequency sweep of a forward signal.Power delivered to tissue via the cutting element maybe manually boosted to deal with large blood vessels. The apparatus mayinclude a reflected power monitor for recognisingbehaviour in reflected signals received from the antenna to trigger automaticpre-emptive action.
