Factors modifying electrosurgical tissue effects
Waveform
Electrosurgical generators produce different electrical waveforms with distinct tissue effects. A continuous sinusoidal waveform with a high current and low voltage causes a rapid rise in tissue temperature to more than 100°C, which vaporises or cuts tissue with minimal coagulation. An interrupted waveform with a low current and high voltage causes a slow increase in temperature to less than 100°C, which desiccates and coagulates tissue. These two waveforms are inaccurately known as ‘cut’ (yellow-coded) and ‘coagulation’ (blue-coded) modes, respectively. Blend waveform is a modulated cut waveform with a variable duty cycle, current and voltage (Table 1). The blend mode can vary the duty cycle and the rate of temperature rise to produce variable degrees of cutting and coagulation (haemostasis). The rate of heat produced in the tissue is what makes a waveform cut or coagulate. Rapidly increasing temperature (>100°C) produces a cutting effect, whereas slowly increasing temperature (<100°C) produces coagulation and desiccation effects. Any of the above waveforms can produce both effects (cutting and coagulation) by modifying other factors that impact tissue effect; hence ‘cut’ and ‘coagulation’ modes are misnomers. They are better referred to as ‘continuous low-voltage’ and ‘interrupted high-voltage’, respectively, with the blend waveform referred to as ‘interrupted low-voltage’.
Jinhua Huacheng Medical Appliance Co.,Ltd.
Manufactuer of disposable medical products: Electrosurgical pencil,grounding plate,skin stapler and ECG electrode
