CQM - the Unknown Risk in Electrosurgery

摘要

The principle of a CQM system in electrosurgicalunits (ESU) is shown and various such systems are discussed.Theoretical calculations of the current distribution inside thepatient's skin showed the influence of the size and shape of aneutral electrode (NE).Measurements of the temperature increase under a NE on asuitable test device showed the relation between the change ofthe CQM impedance for a detached NE, the skin properties,and the temperature increase with a reduced contact area ofthe NE.It could be shown that CQM systems that activate an alarmsimply when the CQM impedance exceeds a fixed upper limitare not safe in all circumstances.Systems taking into account the skin properties of the patientby measuring an initial CQM impedance and reacting to arelative impedance increase proved to be safe under all testedcircumstances.