The anesthesia covers a fundamental role in the success of surgical medical operation and not only. The evolution of medicine has led to the definition of specific and custom anesthetic therapy according to the body response of the patient, to minimize the risk and to avoid pains or unexpected reactions. We propose a portable, low power and low-cost solution to cope this challenge, obtaining a device able to continuously monitor the drugs concentration in the patient’s blood. The device is a custom Printed Circuit Board (PCB) designed to measure the RedOx current flow in an electrochemical sensor for anesthetics. A micro-controller, generates a Pulse Width Modulation (PWM) (similar digital) signal to drive the electrochemical cell.