A flexible hardware implementation for multifrequency EIT measurements

Abstract

In electrical impedance tomography (E.!.T.), the boundary voltages obtained fromthe boundary of a cross sectional area of the object in response to injected currents are usedto reconstruct the internal impedance distribution for visualization. The overall performanceis determined by both the hardware and software.Considering that the electrical impedance of tissues is frequency dependent, fortissue characterization, measurements must be performed at several frequencies in the rangefrom 10kHz to 1 MHz. The hardware system that is constructed supply 8 different operatingfrequencies ranging from 10kHz to 500 kHz, and number of these frequencies can beupgraded up to 16 with the theoretical maximum operating frequency of IMHz withoutaffecting the system performance.Any of the existing EIT data collection strategies can be selected from the computerthrough the control software, making the hardware system very flexible.The data collection system is tested using a PSpice simulated resistive phantom bothfor homogeneous and non-homogeneous distributions.