Conditioning Electrical Impedance Mammography System

Abstract

A multi-frequency Electrical Impedance Mammography (EIM) system has been developed to evaluate the conductivity and permittivity spectrums of breast tissues, which aims to improve early detection of breast cancer as a non-invasive, relatively low cost and label-free screening (or pre-screening) method. Multi-frequency EIM systems typically employ current excitations and measure differential potentials from the subject under test. Both the output impedance and system performance (SNR and accuracy) depend on the total output resistance, stray and output capacitances, capacitance at the electrode level, crosstalk at the chip and PCB levels. This makes the system design highly complex due to the impact of the unwanted capacitive effects, which substantially reduce the output impedance of stable current sources and bandwidth of the data that can be acquired. To overcome these difficulties, we present new methods to design a high performance, wide bandwidth EIM system using novel second generation current conveyor operational amplifiers based on a gyrator (OCCII-GIC) combination with different current excitation systems to cancel unwanted capacitive effects from the whole system. We reconstructed tomography images using a planar E-phantom consisting of an RSC circuit model, which represents the resistance of extra-cellular (R), intra-cellular (S) and membrane capacitance (C) of the breast tissues to validate the performance of the system. The experimental results demonstrated that an EIM system with the new design achieved a high output impedance of at 1MHz to at least at 3MHz frequency, with an average SNR and modelling accuracy of over 80dB and 99%, respectively.

A survey of breast cancer screening techniques: thermography and electrical impedance tomography

“…Acc: 92% [80] Modeling of EIT distribution in a breast with a tumor, using ANN, PCA amd BEM ANN Abs. E: 0.23 [84] Review of the main advances in EIT for breast cancer diagnosis No MLT - [81] First test ever of EIT in breast cancerous tissue (1926) No MLT - [82] REIS system with 7 electrodes, 1 in the center, and 6 concentrically separated.REIS showed high false positive rate ANN Acc: 67% Sen: 54% Sp: 90% [85] Multi-Layer perceptron algorithm for the EIT data set from [22,80] ANN -MLP Acc: 96% MSE: 0.1 CC: 0.99 [86] CAD system for breast cancer classification in the EIT data set from [22,80] LR + NBN Acc-1: 97.5% Acc-2: 89.7% Acc-3: 77.35% [90] EIT system for early detection of breast cancer in 1103 women Multi LR - [87] 10 women clinical study, using 2 different setups with a EIT-Probe LDA, LSE - [88] OCCII-GIC system for make a map of the breast, using 85 electrodes and frequencies from 10kHz to 3MHz -- [89] The background of the electrical impedance tomography as an early breast cancer diagnosis system, is consider above, nonetheless the EIT devices were not studied, with this intention, the next section, will present the main EIT devices, mostly are not on the market yet.…”

“…The second setup, is EIS-Probe similar to the first one, but its electrodes and their location of installation are different, using least absolute deviation (LAD) and least square method (LSM) are implement for data's analysis [88]. Equally important Zarafshani, A., et al propose a 85 electrodes board to create an Electrical Impedance Mammogram similar to an EIM, likewise, the main device is describe as a wide bandwidth EIM system using novel second generation current conveyor operational amplifiers based on a gyrator (OCCII-GIC) and the input current range from 10kHz to 3MHz [89]. Table 4 describes references regarding electrical impedance technologies.…”

Low-Cost, Compact, and Rapid Bio-Impedance Spectrometer with Real-Time Bode and Nyquist Plots

“…Properties of electrical impedance have been reported to understand the nature and behavior of cell [4][5][6][7][8], bacteria detection and identification [9,10], identification of beverages and food ingredients [11][12][13][14][15][16], and so on. In the medical field, BIS is used to characterizations of serum and blood [17][18][19], identification of body composition and disease [20][21][22], and to assist the process of diagnosis and functional electrical stimulation of the body [23][24][25]. Research on BIS, as mentioned, mostly covers α and β dispersion, and is carried out using a frequency of 10 Hz to 1 MHz.…”

Electrical Impedance-Based Methodology for Locating Carcinoma Emulators on Breast Models

“…The experimental techniques based on bioimpedance measurement have been of great interest in the last decades, mainly because of minimally invasive characteristic and low cost in comparison to those mentioned above. Research in this area has generated techniques such as electrical impedance tomography [13], electrical impedance spectroscopy [14], and electrical impedance mammography [15]. The basic of these techniques is the bioimpedance tissue characterization, which has shown by in vitro tests of breast tissues that the conductivity of a carcinoma can be 20 to 40 times greater than that corresponding to a healthy breast tissue [16].…”

“…Biological tissues of interest in the study (normal, benign, and malignant) are emulated within such testing models. Different manufacturing materials and textures for such breast phantoms have been reported [15,21,22]. A recent example is the work of Zhou et al [22], where four silicone testing models are developed to evaluate the elastodigital image tomography technique for breast cancer detection.…”