Modular architecture of a multi-frequency electrical impedance tomography system: design and implementation.

Electrical impedance tomography (EIT) provides means of imaging the electrical properties distribution of biological tissues and fluids while impedance spectroscopy (IS) allows measuring their frequency response in a more global way. Both require precise and well-integrated instrumentation. In this work, we propose a modular architecture of a multi-frequency EIT (MfEIT) system which has capabilities in implementing both IS and MfEIT. First, IS performance is assessed in vivo using a cuff electrode implanted around the rodent cervical vagus nerve. Second, MfEIT performance is evaluated in vitro based on saline phantom experiments. Overall system allows addressing a wide range of applications and proves effective both in vitro and in vivo.