High frequency interferences in video imaging systems during transurethral resections

During TUR, high frequency currents and voltages applied for cutting and coagulation may interfere with video imaging systems. To minimize this effect, all industrial video systems are shielded against electromagnetic radiation. In many cases, however, this shielding is insufficient. Unfortunately, it is not possible to shield all components of the high frequency circuit in order to avoid the remaining distortions. Sometimes, a careful arrangement of the video system, the high frequency unit, and the connection lines to the resectoscope and the patient plate may help. A very effective reduction of interference can be achieved by minimizing the high frequency power applied to the patient. Respective high frequency units have been developed primarily to reduce the well-known hazards for the patient. As a positive side effect, these units decrease the interference to video systems considerably.