Power Calibration of Electrosurgical Units

This paper presents a performance test to validate the conformity of the cutting and coagulation power values delivered by 15 electrosurgical units (ESUs). In addition, the effect of the room temperature factor on the cutting and coagulation power values is investigated. This paper was based on a single factor design, where the room temperature was investigated on five levels. The planning matrix was applied to three points of the nominal range of the cutting and the coagulation powers. During the tests, an ESU was coupled to a power analyzer. In terms of the first test, the desired power was selected (input power), whereas the power delivered by the ESU (output power) was observed through means of the power analyzer. The error (difference), repeatability, expanded uncertainty, and maximum error were estimated. The measurement uncertainty was assessed according to the recommendations of the “Guide to the expression of uncertainty in measurement.” The proposed procedure for evaluating the metrological performance of ESUs based on the power values proved to be efficient of easy implementation and traceable; maximum errors values (all above those permitted by the manufacturer) were presented in 100% or 15 evaluated ESUs. This negative result can be justified mainly as the ESU manufacturers do not consider the fact that the maximum error increases as the cutting and coagulation power values increase. The increase in temperature factor, from 20 °C to 28 °C, affected statistically the values of the cutting and coagulation powers for all evaluated ESUs.