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

Author(s):  
Ramesh Kumar ◽  
Rajesh Mahadeva

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.

2019 ◽  
Vol 31 (02) ◽  
pp. 1950010 ◽  
Author(s):  
Ramesh Kumar ◽  
Sharvan Kumar ◽  
A. Sengupta

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.


Author(s):  
Sylvia Lehmann ◽  
Klaus Tenbrock ◽  
Simone Schrading ◽  
Robert Pikkemaat ◽  
Christoph Hoog Antink ◽  
...  

AbstractElectrical impedance tomography (EIT) is a radiation-free technique generating cross-sectional images of the lung. EIT visualizes global and regional ventilation by illustrating the distribution of electrical bioimpedance. With an electrode belt around the patient’s thorax, rotating injection-couples of a harmless alternating current allow voltage measurement of the remaining electrodes. This enables the reconstruction of a tomogram with highly dynamic changes within ventilation. We report on a female six-year-old patient with cystic fibrosis and complete destruction of the upper and middle lobe of the right lung. Lobectomy, a rare therapeutic option in patients with cystic fibrosis that needs to be considered in cases of severe localized destruction, was performed. We show a pre- and postoperative documentation of static (radiology) and dynamic investigation tools (spirometry) in correlation with EIT as a new non-invasive and radiation-free diagnostic tool for this patient group.


2003 ◽  
Vol 24 (2) ◽  
pp. 509-516 ◽  
Author(s):  
Alexander S Ross ◽  
G J Saulnier ◽  
J C Newell ◽  
D Isaacson

Author(s):  
Georgios Lymperopoulos ◽  
Panagiotis Lymperopoulos ◽  
Victoria Alikari ◽  
Chrisoula Dafogianni ◽  
Sofia Zyga ◽  
...  

2019 ◽  
Vol 17 (9) ◽  
pp. 688-695
Author(s):  
Ramesh Kumar ◽  
Sharvan Kumar ◽  
A. Sengupta

This paper proposed an advanced digital voltage-controlled multi-frequency based constant current source, which is a wide range of loads and high SNR ratio for Electrical Impedance Tomography (EIT) application. In EIT a constant current source is required for injecting a sinusoidal current pulse to the phantom boundary. The boundary potentials are measured by inserting content current from the phantom boundary according to the variation in frequency and current levels. For studying the wide range of tissue conductivity among different type of subjects (the multi-frequency scanning) is desired in medical Electrical impedance tomography. The proposed Current source, which shows that the simulation has good performance at multi-frequency range with accuracy and stability. In proteus simulation software, the results show that the proposed circuit presents a more stable impedance output and the obtained boundary data at multi-frequency for the validation of the obtained data has been shown using suitable image reconstruction algorithm and is found suitable for image reconstruction much easier.


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