In this paper, the purpose is to discuss the relationships among different voltage patterns on the surface so as to compare the noise sensitivity in the voltage measurements for two current patterns frequently used in electriccurrent computed tomography (ECCT). The relationship between the voltageand current patterns on the boundary of homogeneity and concentrically symmetric inhomogeneity can be represented by a pseudo operatorR (a)for a32-electrode system. Thus, using the eigencurrents and their correspondingeigenvalues forR, which are called characteristic resistances, any arbitraryvoltage patterns can be synthesized. The two currents studied here are aset of spatial trigonometric patterns and a set of an4'adjacent-pair5' patterns. Comparing the synthesized and experimentally measured surface voltages for the two current patterns, the sensitivity to noise for systems using thesetwo types of current patterns may be obtained. Based upon the results, itis shown that the system with the trigonometric current patterns is better thanthe one with adjacent-pair current patterns for producing the impedance images.
|Number of pages||10|
|Journal||Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an|
|Publication status||Published - 1992 Jan|
All Science Journal Classification (ASJC) codes