Sensitivity Analysis of the Circuit Model of a Medical Equipment for the Evaluation of Leakage Currents

In an operating theatre the most hazardous events related to the circulation of low leakage currents (currents of the order of decades of microamperes that are not functional) through the human body during a surgical procedure (micro-shock), should be identified. The electrical circuit model of a surgical layout could be an important tool for the micro-shock risk analysis. The international standards on safety of Electrical Medical Equipment (EME) require the measurement of leakage currents in order to evaluate their compliance with limit values. Modeling of leakage current measurements set-up of each EME involved in a surgical procedure is a fundamental step to obtain the circuit model of a surgical layout. The case of a commercial defibrillator is taken as example to show how the circuit model is built. The model parameters assigned and the currents simulated are characteristic input and output data of the single test performed. In the present work, an evaluation of the model output of a commercial defibrillator due to the uncertainty in the estimation of model input is presented in order to verify the robustness of the circuit model. This evaluation has been performed by the adaptive Monte Carlo method. The results are encouraging for the application of the circuit in a modeling of a surgical intervention.