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A Köksal

Publications and source records attributed to A Köksal.

4 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↗
PubMed1995

Determination of optimum injected current patterns in electrical impedance tomography.

The problem of finding the optimum current under different constraints in electrical impedance tomography is cast into a non-linear optimization problem. Optimum currents are investigated for a two-dimensional cylindrical body with a concentric or an eccentric inhomogeneity under the constraints of constant dissipated power and constant total injected current. For a concentric inhomogeneity, it is shown that the opposite drive results in a better distinguishability than the cosine current pattern under the constant-injected-current constraint. The results for the concentric case are extended to the eccentric case directly using the properties of the conformal transformation and of the constraints involved. Distinguishability and the minimum detectable object size achieved by the optimized currents are compared with the ones achieved by the cosine current pattern for conductivity distributions with the concentric and eccentric inhomogeneity.

Electric Impedance↗
PubMed1987

Spironolactone in the treatment of hirsutism.

Spironolactone was used in 90 hirsute women because of its antiandrogenic effect. The drug was administered twice daily from the 4th to the 22nd day of six cycles (total dosage was 200 mg per day). The results suggest that spironolactone is suitable for the treatment of hirsutism.

17-Ketosteroids↗