Journal of Clinical Engineering, cilt.18, sa.3, ss.225-234, 1993 (Scopus)
Commonly used current injection methods in Electrical Impedance Imaging (Ell) — the adjacent electrode current patterns, the opposite electrode current patterns, and the cosine current patterns — were compared to maximize the current flow into the organs of interest in the human thorax. For the analysis, a two-dimensional boundary element model of the human thorax was used. Currents flowing into the different parts of the thorax were calculated as a fraction of the total current applied to the model. Previous authors have used constant sum squared current and constant power to compare different current patterns. The medical device safety regulations, however, limit the total current that can be injected into the human thorax. When the total input current flow into the body is kept constant, the opposite electrode current patterns give the highest current flow into almost all parts of the thorax. Higher current density in a particular region means higher sensitivity to the changes in that region's conductivity. With opposite electrode current patterns, the mean of the fractional current (MFC) flow into the heart, the lungs, and the aorta is increased, respectively, by about 3.5 times, 2.5 times, and 4.6 times the MFC flow obtained by using the adjacent electrode current patterns. With the opposite electrode current patterns, the MFC flow into the heart is over 25%, the MFCs into the lungs are about 18%, and the MFC flow into the aorta is about 30% more than the MFCs obtained by using the cosine current patterns. © 1993 Quest Publishing Co.