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Introduction: Despite of more than a hundred years of electrosurgery, only a few electrosurgical equipment manufacturers have developed methods to regulate the active power delivered to the patient, usually around an arbitrary setpoint. In fact, no manufacturer has a method to measure the active power actually delivered to the load. Measuring the delivered power and computing it fast enough so as to avoid injury to the organic tissue is challenging. If voltage and current signals can be sampled in time and discretized in the frequency domain, a simple and very fast multiplication process can be used to determine the active power. Methods: This paper presents an approach for measuring active power at the output power stage of electrosurgical units with mathematical shortcuts based on a simple multiplication procedure of discretized variables -frequency domain vectors -obtained through Discrete Fourier Transform (DFT) applied on time-sampled voltage and current vectors. Results: Comparative results between simulations and a practical experiment are presented -all being in accordance with the requirements of the applicable industry standards. Conclusion: An analysis is presented comparing the active power analytically obtained through well-known voltage and current signals against a computational methodology based on vector manipulation using DFT only for time-to-frequency domain transformation. The greatest advantage of this method is to determine the active power of noisy and phased out signals with neither complex DFT or ordinary transform methodologies nor sophisticated computing techniques such as convolution. All results presented errors substantially lower than the thresholds defined by the applicable standards.

The best way to understand the environment and its actors is monitoring them. Brazil has the two most biodiversified forests in the planet, the Amazon and the Atlantic forests, a vast field for biotelemetry. Biotelemetry is still made in the most part of the world with obsolete technologies, causing animal stress and demanding a lot of extra field human work. A good biotelemetric system must have quasi-real time, no animal stress, channels for biological, climate, meteorological, and positional data, low power, shorter antenna, and low cost as possible characteristics. It was designed a LORA® technology based animal tracking device, small enough to fit in a collar of a large mammal (e.g., Panthera onca), capable to provide real-time position information and other physiological parameters. Tests was made where a volunteer, with the device rode a bicycle through a large urban area and the real time data, collected by a fixed base, were successfully compared with reference GARMIN GPS® device data. Additionally, several Arduino based circuits for physiological, positional and meteorological data measurements can provide extra information for the biotelemetric system proposed. The system is ready to field biological tests and needs improvement and integration with other GPS, GPRS and UHF technologies.

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