The return circuit is referenced to earth ground via a capacitive circuit, which reduces some of the hazards of electrosurgery by acting as an electrical filter, permitting only currents of specific frequencies to flow through the return plate attached to the patient.
Each grounding scheme has inherent advantages and disadvantages. In response to the need of many surgical disciplines for a very effective spray coagulation current, many manufacturers of ESUs have increased the performance of their solid state generators to deliver 10,000 or more volts. Since high voltages have the ability to seek and find earth ground effectively, it is difficult to contain these higher voltages with an isolated circuit. Because direct grounding would only compound this problem, when high voltages are used, capacitive grounding becomes the method of choice. Most generators producing lesser voltages use isolated circuitry because this grounding scheme reduces alternate pathway possibilities and is generally considered to be the safest.
Jinhua Huacheng Medical Appliance Co.,Ltd.
Manufactuer of disposable medical products: Electrosurgical pencil,grounding plate,skin stapler and ECG electrode
