Anomaly Detection Using Electric Impedance Tomography Based on Real and Imaginary Images

Abstract

This research offers a method for separating the components of tissue impedance, namely resistance and capacitive reactance. Two objects that have similar impedance or low contrast can be improved through separating the real and imaginary images. This method requires an Electrical Impedance Tomography (EIT) device. EIT can obtain potential data and the phase angle between the current and the potential measured. In the future, the device is very suitable for imaging organs in the thorax and abdomen that have the same impedance but different resistance and capacitive reactance. This device consists of programmable generators, Voltage Controlled Current Source (VCCS), mulptiplexer-demultiplexer potential meters, and phase meters. Data collecting was done by employing neighboring, while reconstruction was used the linear back-projection method from two different data frequencies, namely 10 kHz and 100 kHz. Phantom used in this experiment consists of distillated water and a carrot as an anomaly. Potential and phase data from the device is reconstructed to produce impedance, real, and imaginary images. Image analysis is performed by comparing the three images to the phantom. The experimental results show that the device is reliable.

Characterization and Monitoring of Titanium Bone Implants with Impedance Spectroscopy

“…An integrated circuit approach could be followed, making use of the different electrical models for the decoding of the measured impedance values. The medical sensor could also be improved with the design and implementation of microelectrode arrays (MEAs) that could characterize the 3D spatial distribution of the implant porosity with impedance spectroscopy, in a similar way as has been explored in other works for other applications [ 5 , 32 ], to perfectly verify the manufacturing process of the implant in 3D, and to address possible practical issues to measure the properties of the titanium materials after they have been implanted in patients. Furthermore, it would also be interesting to verify if impedance spectroscopy could also be used to characterize corrosion processes or fractures that could occur inside the implant, which have been studied by other methods [ 12 , 20 ], or to characterize the process of adhesion of osteoblasts and bacteria on implants [ 33 ].…”

“…Electrical impedance measurements have long been used in biomedical engineering [1], and they are also receiving recent interest for a wide variety of applications, such as cardiovascular diagnosis [2], prostheses osseointegration assessment [3], wearable medical devices [4], or 3D image analysis for the detection of medical anomalies, such as cancer [5].…”

“…We present in this work the use of electrical impedance as a method to characterize the porosity of the structure, in a non-invasive and affordable way, with the potential to create 3D maps of the implant (known as electrical impedance spectroscopy [5]). For this objective, it was first needed to study the sensitivity of electrical impedance spectroscopy to changes in the porosity of titanium samples.…”

Localización de emuladores de carcinomas en modelos experimentales de mama mediante tomografía de impedancia eléctrica basada en linear back projection

“…Por otra parte, el algoritmo LBP es genérico y no requiere adecuaciones para funcionar correctamente con cualquier sistema de medición. Existe la posibilidad de combinar estos dos métodos y obtener mejores resultados en la imagen reconstruida (Sapuan et al, 2020). Por otra parte, existen modificaciones realizadas al algoritmo LBP que permiten una mejoría en la resolución y sensibilidad de la imagen reconstruida, como es el caso del algoritmo Modified Weighted Back Projection (MWBP), capaz de calcular equipotenciales con mayor precisión al tomar en cuenta la naturaleza de las líneas de campo eléctrico establecidas al momento de inyectar corriente a través de un electrodo, sin embargo este método solo se ha probado en una matriz de 256 electrodos montados en una placa (Khalighi, y Mikaeili, 2019).…”

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

“…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.…”