Development for Electrical Impedance Tomography (EIT) System Base on an Arduino Microcontroller

Electrical Impedance Tomography (EIT) is a non-visual imaging-based measurement method that is widely used in both industrial and biomedical fields. In EIT, there are two critical components: the current source and the data acquisition system. The fundamental principle of EIT is to measure the impedance of an object. This measurement is performed by injecting current and measuring the resulting voltage, based on Ohm's Law, for each electrode. Therefore, the current source is a crucial element in EIT. In this study, a current source is developed based on the concept of a voltage-controlled current source (VCCS). The designed current source can deliver a 50 mA amplitude and operates optimally at a frequency of 50 Hz. The current source consists of a signal generator circuit, an offset voltage regulator, an amplifier, and a Howland current source circuit. The switching module uses a 16-channel multiplexer controlled by an Arduino.