Isaacson, David; Isaacson, Eli L. Comment on Calderón’s paper: “On an inverse boundary value problem”. (English) Zbl 0672.65107 Math. Comput. 52, No. 186, 553-559 (1989). Summary: A. P. Calderón [Semin. Numer. Anal. Appl. Continuum Physics, 65- 73 (1980; MR 81k:35160)] determined a method to approximate the conductivity \(\sigma\) of a conducting body in \(R^ n\) (for \(n\geq 2)\) based on measurements of boundary data. The approximation is good in the \(L_{\infty}\) norm provided that the conductivity is a small perturbation from a constant. We calculate the approximation exactly for the case of homogeneous concentric conducting disks in \(R^ 2\) with different conductivities. Here, the difference in the conductivities is the perturbation. We show that the approximation yields precise information about the spatial variation of \(\sigma\), even when the perturbation is large. This ability to distinguish spatial regions with different conductivities is important for clinical monitoring applications. Cited in 2 Documents MSC: 65Z05 Applications to the sciences 35R30 Inverse problems for PDEs 92C50 Medical applications (general) Keywords:conductivity; concentric conducting disks; perturbation; clinical monitoring PDFBibTeX XMLCite \textit{D. Isaacson} and \textit{E. L. Isaacson}, Math. Comput. 52, No. 186, 553--559 (1989; Zbl 0672.65107) Full Text: DOI