Studies of Electromagnetic Interference from Electrosurgical Units

The problems of electromagnetic interference in hospitals have become more and more frequent since the number of electronic equipments installed in this environment has increased continuously. In surgery rooms, these problems are much more common, because in these places are located some devices wich are the most susceptible to EMI, like patient-connected devices, and others wich are the most harmful sources of EMI, like electrosurgical units and perfusion machines. These problems had or could have had life-threatening consequences for patients and medical staff thus justifying the need for studying this subject. The main goals of this work are: to quantify with special equipments (spectrum analyser, antenna and a Line Impedance Stabilization Network - LISN) the electromagnetic emissions (conducted and radiated) of an Electrosurgical Unit -ESU-, to verify if these emissions are in accordance with the Electromagnetic Compatibility -EMC-standards for medical devices and, based on this analysis, to propose a set of alternatives do reduce the EMI generated by Electrosurgical Units. The results of the measurements of the electromagnetic emissions from an ESU prove that its emissions are greater than the emissions thresholds imposed by the EMC standards for medical devices.