Electrosurgery works by concentrating the current (increasing its density) at the active electrode to produce the desired thermal tissue effect and dispersing it at the dispersive electrode to prevent unintended tissue burns. The thermal tissue effect is directly proportional to current density squared ([I/A]2), tissue impedance (R) and application time (T) – i.e. thermal effect = (I/A)2 × R × T, where A refers to the electrode surface area. To increase the thermal effect, it is important to avoid the temptation to step up the ESU wattage to increase the current, which would increase the risk of unintended tissue burns. Reducing the radius of the active electrode by half can result in a 16-fold increase in thermal change without changing the power setting. Modifying the surgical technique to increase tissue impedance by removing conductive fluid such as blood, compressing arteries or stretching tissue also increases the thermal effect without increasing the power setting.
Jinhua Huacheng Medical Appliance Co.,Ltd.
Manufactuer of disposable medical products: Electrosurgical pencil,grounding plate,skin stapler and ECG electrode
