Simultaneous Imaging of Bio- and Non-Conductive Targets by Combining Frequency and Time Difference Imaging Methods in Electrical Impedance Tomography

Abstract

As a promising medical imaging modality, electrical impedance tomography (EIT) can image the electrical properties within a region of interest using electrical measurements applied at electrodes on the region boundary. This paper proposes to combine frequency and time difference imaging methods in EIT to simultaneously image bio- and non-conductive targets, where the image fusion is accomplished by applying a wavelet-based technique. To enable image fusion, both time and frequency difference imaging methods are investigated regarding the reconstruction of bio- or non-conductive inclusions in the target region at varied excitation frequencies, indicating that none of those two methods can tackle with the scenarios where both bio- and non-conductive inclusions exist. This dilemma can be resolved by fusing the time difference (td) and appropriate frequency difference (fd) EIT images since they are complementary to each other. Through simulation and in vitro experiment, it is demonstrated that the proposed fusion method can reasonably reconstruct both the bio- and non-conductive inclusions within the lung models established to simulate the ventilation process, which is expected to be beneficial for the diagnosis of lung-tissue related diseases by EIT.

A Rapid, Low-Cost, and High-Precision Multifrequency Electrical Impedance Tomography Data Acquisition System for Plant Phenotyping

“…A statistical analysis was performed with the obtained data using PrimaXL Data Analysis ToolPak [31,33]. A multiple linear regression analysis was performed for the obtained dataset considering the least square method [31,33] with the help of Equation (14).…”

“…𝑌 = 𝜔 + 𝜔 𝑍 + 𝜔 𝑍 + ⋯ + 𝜔 𝑍 (14) where Zf1, Zf2, …., Zfk are the average impedances for k number of features of f1 to fk. The intercept is 𝜔 , and 𝜔 , 𝜔 , … , 𝜔 are the coefficients.…”

“…The estimation performance can be potentially improved by considering a multispectral impedance imaging technique using an EIT system [7,9]. Due to its unique advantages, EIT has enormous applications in cell imaging [6], brain imaging [12], anomaly detection [13,14], and crop root imaging [15][16][17][18], respectively.…”

“…In addition, the changes on root characteristics during growth can be evaluated by employing the measurements considering frequency-difference and time-difference EIT [7,8,14,28]. Image reconstruction using difference data at two injecting frequencies at a particular time, or the data obtained for single frequency measurements over a time duration can be made successfully using a 3D imaging system.…”

Layered Fusion Reconstruction Based on Fuzzy Features for Multi-Conductivity Electrical Impedance Tomography

“…It has been verified that incorporating prior information can enhance the detection of local lung anomalies [ 17 , 32 ]. Effective reconstruction of multi-conductivity distributions can also be accomplished by employing multi-modal fusion techniques, e.g., the fusion of frequency-difference and time-difference reconstructions [ 33 ]. However, these methods rely on either sufficient prior information or additional measuring procedures.…”