High output-impedance current source for electrical impedance tomography

Abstract

This paper emphasized on analyzing the frequency-domain and the time-domain characteristic of the enhanced Howland circuit for electrical impedance tomography, and studied the influencing factor in depth. Firstly, the output current, impedance and their influencing factors were discussed in detail by numerical simulation. Secondly, it simulated the frequency characteristic of current source, and finally, designed the experiment to measure the output current and impedance. Simulation and experiment indicated that it could improve the performance by selecting the suitable amplifier, peripheral components to meet requirements of electrical impedance tomography.