Arbitrary Power Waveforms Measurement for Electrosurgical Unit Analyzers

The Standards and Calibration Laboratory (SCL) in Hong Kong has developed a measurement system for the testing of electrosurgical unit (ESU) analyzers. ESUs are medical device widely used by surgeons and medical practitioners in surgical operations and in outpatient procedures. ESUs generate high frequency signals usually in the range of 200 kHz to 500 kHz with power up to 300 W to heat up tissues by induced intracellular oscillation of ionized molecules. By precisely controlling the power and duty cycle of the output waveform, various electrosurgical procedures including cut, coagulate, desiccate, fulgurate or spray of tissues can be performed. Routine performance check of ESUs is commonly conducted by ESU analyzers, which is a high frequency electronic load designed to measure the output parameters of various ESU modes. In this paper a method developed for the testing of ESU analyzers at the SCL is presented. By utilizing high speed digital sampling system, high frequency arbitrary power waveforms measurement function of ESU analyzers can be tested by simultaneous measurement of voltage and current components.