Implementation of a data acquisition system for contactless conductivity imaging

Ulker, B
Gençer, Nevzat Güneri
A data acquisition system is realized for conductivity imaging via contactless measurements. It is observed that field profiles are good representatives of the conductive objects scanned by the measurement system. Three different data sets are taken with different scanning resolutions. Note that although the scanning resolution is decreased 25 times, it is still possible to observe the conductive object. The data acquisition time is due to the data acquisition time limit of the lock-in amplifier. As might be expected, the secondary voltage profiles spreads. It is possible to employ an image reconstruction algorithm and obtain conductivity images with better resolution. In conclusion, the first results of a promising new medical imaging modality were presented. This system can provide necessary conductivity information for electromagnetic source imaging of the human brain. Moreover, this system can be applicable to brain, breast and lung imaging. Other application areas should further be explored.


Implementation of a data acquisition system for contactless conductivity imaging
ULKER, B; Gençer, Nevzat Güneri (2001-10-28)
A data acquisition system is realized to image electrical conductivity of biological tissues via contactless measurements. This system uses magnetic excitation to induce currents inside the body and measures the magnetic fields of the induced currents. A magnetically coupled differential coil system is scanned on the conductive object by a computer controlled scanning system. A data acquisition system is constructed using a PC controlled lock-in amplifier. 1.64V secondary voltage difference can be measured ...
Experimental results for 2D magnetic resonance electrical impedance tomography (MR-EIT) using magnetic flux density in one direction
Birgul, O; Eyüboğlu, Behçet Murat; Ider, YZ (IOP Publishing, 2003-11-07)
Magnetic resonance electrical impedance tomography (MR-EIT) is an emerging imaging technique that reconstructs conductivity images using magnetic flux density measurements acquired employing MRI together with conventional EIT measurements. In this study, experimental MR-EIT images from phantoms with conducting and insulator objects are presented. The technique is implemented using the 0.15 T Middle East Technical University MRI system. The dc current method used in magnetic resonance current density imaging...
Design of a dual polarized low profile antenna for microwave brain imaging
Üçel, Kaan; Alatan, Lale; Department of Electrical and Electronics Engineering (2022-5-9)
In this thesis, a low profile, low cost, wide band (0.9-2GHz) dual linearly polarized printed dipole antenna is designed to be used in microwave brain imaging systems. Dual polarization feature offers superior data acquisition through polarization diversity for better image quality. Starting from a simple printed dipole, antenna structure is modified step by step to meet these design requirements. Since a conductive surface in close vicinity of the antenna affects antenna performance, in order to obtain uni...
Implementation and comparison of reconstruction algorithms for magnetic resonance-electric impedance tomography (mr-eit)
Martin Lorca, Dario; Eyüboğlu, Behçet Murat; Department of Biomedical Engineering (2007)
In magnetic resonance electrical impedance tomography (MR-EIT), crosssectional images of a conductivity distribution are reconstructed. When current is injected to a conductor, it generates a magnetic field, which can be measured by a magnetic resonance imaging (MRI) scanner. MR-EIT reconstruction algorithms can be grouped into two: current density based reconstruction algorithms (Type-I) and magnetic flux density based reconstruction algorithms (Type-II). The aim of this study is to implement a series of r...
Realization of magnetic resonance current density imaging at 3 Tesla,
Göksu, Cihan; SADIGHI, MEHDI; Eyüboğlu, Behçet Murat (2014-08-26)
Magnetic Resonance Current Density Imaging (MRCDI) is an imaging modality, which reconstructs electrical current density distribution inside a material by using Magnetic Resonance Imaging (MRI) techniques. In this study, a current source with maximum current injection capability of 224.7mA, under 1k Omega resistive load is used. Experiments are performed with a 2D uniform phantom, in which a current steering insulator is inserted. Magnetic flux density distributions are measured, and current density images ...
Citation Formats
B. Ulker and N. G. Gençer, “Implementation of a data acquisition system for contactless conductivity imaging,” IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE, pp. 152–155, 2002, Accessed: 00, 2020. [Online]. Available: