Biomedical subjects

B M Eyüboglu

Publications and source records attributed to B M Eyüboglu.

3 recordsLinked to original sources

PubMed2000

Distinguishability analysis of an induced current EIT system using discrete coils.

The distinguishability of a discrete coil induced current electrical impedance tomography system is analysed. The solution methodology of the forward problem of this system is explained. An optimization procedure using this forward problem solution is developed to find optimum currents that maximize the distinguishability. For the concentric inhomogeneity problem, it is shown that the coil currents can be optimized to focus the current density in any desired location, in the field of view. Optimum coil currents under the constraints of limited peak coil currents and limited total power are determined. Examples that demonstrate the performance of the system are presented.

Electric Impedance↗

PubMed1988

Methods of cardiac gating applied potential tomography.

Electrical impedance imaging of the heart, pulmonary perfusion and the great blood vessels can only be achieved by synchronising the data collection with cardiac activity. Due to low signal-to-noise ratio, temporal averaging is needed to improve the image quality. In this study several methods of ECG gating are attempted to synchronise the applied potential tomography (APT) serial data collection with the cardiac cycle. They allow us to collect sequential images time-locked with the R-wave of the patient, and hence image the pulsatile movement of blood. Different methods are examined for their sampling speeds, noise levels and ability to image before systole. A method of image data rearrangement in order to provide an apparent increase in speed is also discussed.

Coronary Vessels↗

PubMed1988

Problems of cardiac output determination from electrical impedance tomography scans.

Impedance variations within the thorax related to cardiac activity have been localised using cardiac gated electrical impedance images. Since quantitative measurements of local variations can be made from those images, electrical impedance tomography gives more valuable information than impedance cardiography (ICG). However, because of the three-dimensional (3D) and non-uniform nature of the sensitivity function, localised measurements from electrical impedance tomography (EIT) scans are related to the position and geometry of the regions in which a resistivity change occurs. For accurate determination of volume changes from conductivity variations, the 3D sensitivity distribution needs to be known.

Cardiac Output↗