Electrical Impedance Tomography Hardware with Demodulation

Abstract

Electrical impedance tomography (EIT) is a promising imaging technology. It is portable, user-independent, and low cost (compared to other imaging technologies). There are two main approaches for EIT equipments: dynamic and absolute images. Absolute images are technologically more difficult and are limited by hardware. Phase information is required to create permittivity images. This is an ongoing research with the objective of evaluating the phase information. A new architecture with up to 64 electrodes is proposed. Each electrode has its own Howland current source and microcontroller. The proposed hardware consists of three main modules: the electrode hardware (with Howland current source and microcontroller); the demodulator algorithm; and, the electrode synchronizer. Some results are presented with the electrode hardware that demonstrate data acquisition with two electrodes. Tests with the demodulator algorithm were also presented. Simulated tests with the designed electrode synchronizer were performed, and the implementation remains, and it is considered a future work.