Emulator of electrocardiographically biopotentials based on a sliding mode controlled buck power converter

Abstract

The primary objective of this research is to present the design of an artificial signal generation system of electrocardiography continuous signals based on the application of a buck power converter. A first-order sliding mode control application for a buck direct current–direct current power converter induces the generation of continuous variations of a direct current voltage as the response of a power converter. The output voltage reproduces the required electrocardiography signals corresponding to the regular or pathological variants. The equivalent control method permits introducing a novel design of a kind of cascade-like sliding mode controller that can regulate both current and voltage operative loops simultaneously, which force the controlled tracking of the reference bioinspired voltages at the output of the buck power converter. For the developed control design, the current regulation is enforced as the primary outcome of the sliding mode controller. Consequently, the required voltage from the buck converter is produced, regulating the switching operation in the electrical power system. The suggested control operates robustly concerning the internal uncertainties and perturbations for both input and voltage signals. Furthermore, the variation of the needed gain for the designed sliding mode controller is developed by studying the online amplitude of the electrocardiography electrophysiological signals used as references and their time derivatives over time. Two reference signals were developed to validate the controllers with the same quality at the numerical simulation and using some experimental validations. The proposed signals used as references were successfully generated in both evaluated cases.