Study of Voltage Control Current Source in Electrical Impedance Tomography System

A steady and efficient Voltage Control Current Source (VCCS ) with broad bandwidth plays a very important role in the quality of final images for Electrical Impedance Tomography (EIT) system. Therefore, two models of current source are proposed in the paper: Advanced Howland VCCS and Double Operational Amplifiers VCCS. Both of the two models are simulated through a software named Multisim, and the results of simulation show that both models can keep an output impedance higher than 1M Ω when the frequency changes from 10 kHz to 1 MHz and the load varies from 100 Ω to 1000 Ω .The results also show that both models meet the requirements of VCCS in EIT system, they are hoped to provide usefull approaches for the design of practical VCCS of EIT system.