Eletrocardiógrafo portátil de baixo custo

Abstract

This study aims to present the relative concepts of the project and development of low cost and portable electrocardiography, a device used for monitoring of heart electrical activity for sickness diagnose. The equipment can be divided into the steps of acquisition and strengthen biological signal, analog filtering, offset, analog-digital conversion, digital filtering, and signal reconstruction by software for result preview, as well as characterization and digital file recording of the signal. The acquisition and strength of signal are accomplished by use an instrumentation amplifier built with low coast operational amplifiers. The circuit is developed in order to present high gain and good common mode rejection noise. The filtering process is realized with second-order active filters, minimizing the interference of unwanted spectral components in the acquired signal. By treating of alternate signal it is necessary to uptown your reference for this take only positive values, process occurs by offset circuit. With the conditioned signal yet occur the discretization of this in Arduino platform. All the process is developed using IDE Arduino. The discretized points are sent in real time to the computer, is the set of points took by MATLAB software, where occur the digital filtering, reconstruction, and characterization process of the signal, and also, the result of exam recorded in the archive. The circuit is powered by 9V batteries due to portability and can be recharged by external charger.