an electrosurgical instrument that is capable of generating high - quality rf energy at a single frequency in the mhz range best suited for delicate , precise and quick - healing cutting procedures with low leakage currents using a monopolar handpiece , and also provides high - quality rf energy at the same frequency suited for use for carrying out similar procedures for use with a bipolar handpiece . in a preferred embodiment , the instrument is capable of generating sub - modes of electrosurgical currents with different waveforms optimized for cutting and hemostasis , and the various sub - modes are available for both the monopolar and bipolar handpieces . a preferred operating frequency is in the range of 4 mhz . the instrument includes means for maintaining a substantially constant power output irrespective of selection of one of the sub - modes .