Amplificador para registro de potenciais corticais

Abstract

Many organs in the human body manifest their functions through electric activities. Measurements of these and other biopotentials can provide vital clues that permits study as real functions of the organs. These measurements are not an easy task because envolves extremely low amplitudes data acquisition, between 1 μV and 10 mV, and also because these bioelectric recordings are often disturbed by an excessive level of interference presents, resulting in signal/noise degradation. Therefore, the biopotential amplifier project must be associated with precaution to final circuit can meet great characteristics in such signals measureming. This work shows a study about biopotentials origins, their characteristics, circuits used in signal amplifiering and filtering, interferences present in measurement systems and some circuits used to reduce such interferences. Thereafter, is developed a cortical biopotential amplifier with filtering and gain blocks. The tests with amplifier where realized by registering a visual evoked potential and the electroencephalogram. In the experimental results is possible to observe a satisfactory equipment performance.