The plethysmographic signal allows quantification of blood volume changes under parameters of vasoconstriction and vasodilation in the venous diameter to detect possible abnormalities related to pulmonary and blood pathologies. Therefore, the research carried out has the objective of designing a non-invasive prototype that allows the measurement of pulse oximetry by means of the plethysmographic signal electronic conditioning. For this, was developed a circuit that processes the signal, digitizes it in time and then is parameterized to be sampled, determining its amplitude and establishing the quantification of the oximetry data. This in order to provide tools in the medium term as diagnostic support to the specialist.