Electrical Impedance Tomography

. This paper surveys some of the work our group has done in electrical impedance tomography. Key words. electrical impedance tomography, pulmonary embolus, inverse boundary value problem AMS subject classifications. 35R30, 35J25, 92C55, 78A30 PII. S0036144598333613 1. Introduction. There are a variety of medical problems for which it would be useful to know the time-varying distribution of electrical properties inside the body. By electrical properties, we mean specifically the electric conductivity and permittivity. The electric conductivity is a measure of the ease with which a material conducts electricity; the electric permittivity is a measure of how readily the charges within a material separate under an imposed electric field. High-conductivity materials allow the passage of both direct and alternating currents; high-permittivity materials allow the passage of only alternating currents. Both of these properties are of interest in medical applications, because di#erent tiss...