scholarly journals CoReHA 2.0: A Software Package forIn VivoMREIT Experiments

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kiwan Jeon ◽  
Chang-Ock Lee
Keyword(s):  
Electrical Impedance ◽  
Imaging Modality ◽  
Animal Experiments ◽  
Impedance Tomography ◽  
Cross Sectional ◽  
Computational Tools ◽  
Electrically Conducting ◽  
Simulation Validation ◽  
Conductivity Image

Magnetic resonance electrical impedance tomography (MREIT) is a new medical imaging modality visualizing static conductivity images of electrically conducting subjects. Recently, MREIT has rapidly progressed in its theory, algorithm, and experiment technique and now reached to the stage ofin vivoanimal experiments. In this paper, we present a software, named CoReHA 2.0 standing for the second version of conductivity reconstructor using harmonic algorithms, to facilitatein vivoMREIT reconstruction of conductivity image. This software offers various computational tools including preprocessing of MREIT data, identification of 2D geometry of the imaging domain and electrode positions, and reconstruction of cross-sectional scaled conductivity images from MREIT data. In particular, in the new version, we added several tools including ramp-preserving denoising, harmonic inpainting, and local harmonicBzalgorithm to deal with data fromin vivoexperiments. The presented software will be useful to researchers in the field of MREIT for simulation, validation, and further technical development.

AN EXPERIMENTAL ANALYSIS AND VALIDATION OF ELECTRICAL IMPEDANCE TOMOGRAPHY TECHNIQUE FOR MEDICAL OR INDUSTRIAL APPLICATION

2019 ◽  
Vol 31 (02) ◽  
pp. 1950010 ◽  
Author(s):  
Ramesh Kumar ◽  
Sharvan Kumar ◽  
A. Sengupta
Keyword(s):  
Current Pulse ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Imaging Modality ◽  
Current Source ◽  
Control Unit ◽  
Tikhonov Regularization Method ◽  
Impedance Tomography ◽  
Cross Sectional ◽  
On Chip

Electrical impedance tomography is a recently established technique by which impedance of an object (medical or nonmedical applications) is measured data from the surface of the object, and a numerically simulated reconstruction of the object internal shape of the image can be obtained. This imaging technique based on boundary or surface voltage is measured when the different current pattern is injected into it. For current pulse, we are creating a voltage controlled current source, which is based on the different RC circuits, according to current amplitude and frequency values. The current source used in inject the current pulse of the various phantoms. The current position and measuring voltage is controlled by the created control unit or programmable system on chip (PSOC) of the proposed EIT system. After that image reconstruction of the cross-sectional image of resistivity requires sufficient data collection from used phantoms, which is based on finite element method (FEM) method and Tikhonov regularization method with helps of graphical user interface (GUI) on MatLab. The objective of the GUI was to produce an image (2D/3D), impedance distribution graph, and the FEM mesh model according to used electrode combinations from the various phantoms. EIT system has a great potential for imaging modality, is non-invasive, radiation-free, and inexpensive for medical applications.

An Experimental Measurement and Control of Human Body Stomach Using Electrical Impedance Tomography

2020 ◽  
pp. 2150103
Author(s):  
Ramesh Kumar ◽  
Rajesh Mahadeva
Keyword(s):  
Electrical Impedance Tomography ◽  
Human Body ◽  
Electrical Impedance ◽  
Imaging Modality ◽  
Current Source ◽  
Voltage Measurement ◽  
Impedance Tomography ◽  
Cross Sectional ◽  
Non Invasive ◽  
The Cross

A newly proven technique is non-invasive bio-impedance, and also known as Electrical Impedance Tomography (EIT), which is used for medical or non-medical applications. EIT images are based on the internal distributions of the conductivity or resistivity from the boundary data, which depend on the voltage measurement of the stomach attached electrodes of the human body. An experimental study of the EIT system presented here has been used 8/16 surface electrodes configurations for the human body’s stomach. Then, according to the data acquisition methods of the EIT, the surface potentials of the stomach through the current injection were measured. For current pulses, a voltage-controlled current source has been created, and the created current source is a combination of voltage to current converter and current signal generator. Current positions and measuring voltages have been calculated using the designed control unit. However, the imaging algorithm requires sufficient data through the experimental work, which defines the cross-sectional image of resistivity. The cross-sectional image has been based on the Finite Element Method (FEM). It produces 2D/3D images, impedance distribution graphs and Mesh models. The proposed EIT system has been used for non-medical and industrial applications, which have non-invasive, inexpensive, radiation-free and a high potential for imaging modality.

scholarly journals Modern Trends in Imaging V: Optical Coherence Tomography for Rapid Tissue Screening and Directed Histological Sectioning

2012 ◽  
Vol 35 (3) ◽  
pp. 129-143 ◽  
Author(s):  
Woonggyu Jung ◽  
Stephen A. Boppart
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Image Guidance ◽  
Diagnostic Yield ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Optical Coherence ◽  
Sampling Errors ◽  
Cross Sectional

In pathology, histological examination of the “gold standard” to diagnose various diseases. It has contributed significantly toward identifying the abnormalities in tissues and cells, but has inherent drawbacks when used for fast and accurate diagnosis. These limitations include the lack ofin vivoobservation in real time and sampling errors due to limited number and area coverage of tissue sections. Its diagnostic yield also varies depending on the ability of the physician and the effectiveness of any image guidance technique that may be used for tissue screening during excisional biopsy. In order to overcome these current limitations of histology-based diagnostics, there are significant needs for either complementary or alternative imaging techniques which perform non-destructive, high resolution, and rapid tissue screening. Optical coherence tomography (OCT) is an emerging imaging modality which allows real-time cross-sectional imaging with high resolutions that approach those of histology. OCT could be a very promising technique which has the potential to be used as an adjunct to histological tissue observation when it is not practical to take specimens for histological processing, when large areas of tissue need investigating, or when rapid microscopic imaging is needed. This review will describe the use of OCT as an image guidance tool for fast tissue screening and directed histological tissue sectioning in pathology.

scholarly journals Role of Optical Coherence Tomography on Corneal Surface Laser Ablation

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Bruna V. Ventura ◽  
Haroldo V. Moraes ◽  
Newton Kara-Junior ◽  
Marcony R. Santhiago
Keyword(s):  
Optical Coherence Tomography ◽  
Laser Ablation ◽  
Imaging Modality ◽  
Corneal Thickness ◽  
Optical Coherence ◽  
Corneal Surface ◽  
Cross Sectional ◽  
Surface Laser ◽  
The Time Domain

This paper focuses on reviewing the roles of optical coherence tomography (OCT) on corneal surface laser ablation procedures. OCT is an optical imaging modality that uses low-coherence interferometry to provide noninvasive cross-sectional imaging of tissue microstructurein vivo.There are two types of OCTs, each with transverse and axial spatial resolutions of a few micrometers: the time-domain and the fourier-domain OCTs. Both have been increasingly used by refractive surgeons and have specific advantages. Which of the current imaging instruments is a better choice depends on the specific application. In laserin situkeratomileusis (LASIK) and in excimer laser phototherapeutic keratectomy (PTK), OCT can be used to assess corneal characteristics and guide treatment decisions. OCT accurately measures central corneal thickness, evaluates the regularity of LASIK flaps, and quantifies flap and residual stromal bed thickness. When evaluating the ablation depth accuracy by subtracting preoperative from postoperative measurements, OCT pachymetry correlates well with laser ablation settings. In addition, OCT can be used to provide precise information on the morphology and depth of corneal pathologic abnormalities, such as corneal degenerations, dystrophies, and opacities, correlating with histopathologic findings.

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