Using electrical impedance tomography in following up skin conductivity change for different sonophoresis conditions

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Mamdouh M. Shawki
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Impedance Tomography ◽  
Conductivity Change ◽  
Skin Conductivity

scholarly journals Imaging Conductivity Changes in Monolayer Graphene Using Electrical Impedance Tomography

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1074
Author(s):  
Anil Kumar Khambampati ◽  
Sheik Abdur Rahman ◽  
Sunam Kumar Sharma ◽  
Woo Young Kim ◽  
Kyung Youn Kim
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Monolayer Graphene ◽  
Impedance Tomography ◽  
Graphene Surface ◽  
Conductivity Distribution ◽  
Conductivity Change ◽  
Modeling Errors ◽  
Imaging Approach ◽  
Difference Imaging

Recently, graphene has gained a lot of attention in the electronic industry due to its unique properties and has paved the way for realizing novel devices in the field of electronics. For the development of new device applications, it is necessary to grow large wafer-sized monolayer graphene samples. Among the methods to synthesize large graphene films, chemical vapor deposition (CVD) is one of the promising and common techniques. However, during the growth and transfer of the CVD graphene monolayer, defects such as wrinkles, cracks, and holes appear on the graphene surface. These defects can influence the electrical properties and it is of interest to know the quality of graphene samples non-destructively. Electrical impedance tomography (EIT) can be applied as an alternate method to determine conductivity distribution non-destructively. The EIT inverse problem of reconstructing conductivity is highly non-linear and is heavily dependent on measurement accuracy and modeling errors related to an accurate knowledge of electrode location, contact resistances, the exact outer boundary of the graphene wafer, etc. In practical situations, it is difficult to eliminate these modeling errors as complete knowledge of the electrode contact impedance and outer domain boundary is not fully available, and this leads to an undesirable solution. In this paper, a difference imaging approach is proposed to estimate the conductivity change of graphene with respect to the reference distribution from the data sets collected before and after the change. The estimated conductivity change can be used to locate the defects on the graphene surface caused due to the CVD transfer process or environment interaction. Numerical and experimental results with graphene sample of size 2.5 × 2.5 cm are performed to determine the change in conductivity distribution and the results show that the proposed difference imaging approach handles the modeling errors and estimates the conductivity distribution with good accuracy.

scholarly journals Reconstruction of conductivity change in lung lobes utilizing electrical impedance tomography

2017 ◽  
Vol 3 (2) ◽  
pp. 513-516 ◽  
Author(s):  
Benjamin Schullcke ◽  
Bo Gong ◽  
Sabine Krueger-Ziolek ◽  
Knut Moeller
Keyword(s):  
Image Reconstruction ◽  
Electrical Impedance Tomography ◽  
Lung Diseases ◽  
Electrical Impedance ◽  
Patient Specific ◽  
Impedance Tomography ◽  
Reconstruction Process ◽  
Obstructive Lung Diseases ◽  
Conductivity Change ◽  
Lung Lobes

AbstractElectrical Impedance Tomography (EIT) is a novel medical imaging technology which is expected to give valuable information for the treatment of mechanically ventilated patients as well as for patients with obstructive lung diseases. In lung-EIT electrodes are attached around the thorax to inject small alternating currents and to measure resulting voltages. These voltages depend on the internal conductivity distribution and thus on the amount of air in the lungs. Based on the measured voltages, image reconstruction algorithms are employed to generate tomographic images reflecting the regional ventilation of the lungs. However, the ill-posedness of the reconstruction problem leads to reconstructed images that are severely blurred compared to morphological imaging technologies, such as X-ray computed tomography or Magnetic Resonance Imaging. Thus, a correct identification of the particular ventilation in anatomically assignable units, e.g. lung-lobes, is often hindered. In this study a 3D-FEM model of a human thorax has been used to simulate electrode voltages at different lung conditions. Two electrode planes with 16 electrodes at each layer have been used and different amount of emphysema and mucus plugging was simulated with different severity in the lung lobes. Patient specific morphological information about the lung lobes is used in the image reconstruction process. It is shown that this kind of prior information leads to better reconstructions of the conductivity change in particular lung lobes than in classical image reconstruction approaches, where the anatomy of the patients’ lungs is not considered. Thus, the described approach has the potential to open new and promising applications for EIT. It might be used for diagnosis and disease monitoring for patients with obstructive lung diseases but also in other applications, e.g. during the placement of endobronchial valves in patients with severe emphysema.

Soft Areal Tactile Sensor Using Tomography Algorithm

2008 ◽  
Vol 20 (4) ◽  
pp. 628-633 ◽  
Author(s):  
Yo Kato ◽  
◽  
Tomonori Hayakawa ◽  
Toshiharu Mukai ◽  
Keyword(s):  
Inverse Problem ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Tactile Sensor ◽  
Problem Analysis ◽  
Impedance Tomography ◽  
Conductivity Change ◽  
Conductive Rubber ◽  
Pressure Sensitive

Using inverse problem analysis, we designed a soft areal tactile sensor with pressure-sensitive conductive rubber that does not need complex central wiring because we estimate conductivity change, i.e., pressure on the sensor, in the center based on electrical impedance tomography (EIT), i.e., a type of inverse problem analysis. We discuss results demonstrating the sensor's effectiveness.

CALIBRATION OF A LOW COST ELECTRICAL IMPEDANCE TOMOGRAPHY SYSTEM WITH A RING OF RESISTORS AND A KCL SOLUTION

2019 ◽  
Author(s):  
Bruno Furtado de Moura ◽  
francisco sepulveda ◽  
Jorge Luis Jorge Acevedo ◽  
Wellington Betencurte da Silva ◽  
Rogerio Ramos ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Low Cost ◽  
Impedance Tomography ◽  
Tomography System

Reconstruction of three-dimensional data for electrical impedance tomography

1992 ◽  
Vol 28 (11) ◽  
pp. 974-976 ◽  
Author(s):  
R. Gadd ◽  
F. Vinther ◽  
P.M. Record ◽  
P. Rolfe
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Three Dimensional ◽  
Impedance Tomography
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