Northwestern University

Chulin Wang

Matthew Grayson

Claire Cecelia Onsager

Can Cenap Aygen

Charles M Costakis

Andreas Tzavelis

Lauren E Lang

John A Rogers

Juncen Li

William H Reinhardt

Suzan Van Der Lee

The disclosed 2-D resistance tomographic imaging method optimizes computation speed for performing electrical impedance tomography using a model-space with a minimal number of orthonormal polynomial basis functions to describe discernable features in the 2-D resistance tomographic image, determining a minimal number of contacts to take fewer measurements than available information based on the number of basis functions, selecting a subset of rows of a matrix of calculated sensitivity coefficients to form a square Jacobian matrix for a linearized forward problem to be solved and inversion of the linear forward problem, and solving an inverse problem based on the square Jacobian matrix by performing at least one iteration of a Newton's method solve.

Optimized electrical impedance tomography

The disclosed 2-D and 3-D tomographic resistance imaging method improves tomographic resistance image resolution by adopting an orthogonal basis with the maximum number of elements N to describe the maximum resolution resistivity map ρ(r), where this number of elements N is set according to the number of electrodes Q; by defining the orthogonal basis according to any known constraints in the problem, thereby enhancing the resolution where it is needed; by positioning electrodes to be sensitive to these basis functions; and by choosing current I and voltage V contact electrode pairs that maximize signal-to-noise ratio.

High resolution two-dimensional resistance tomography

Systems and methods include an electrical switch that establishes a first electrical conducting path between terminals of an electrical measurement apparatus through one or more electrical leads and an electrically-conductive sample in a first state, and a second electrical conducting path between the terminals through the one or more electrical leads while bypassing the sample in a second state. A voltage Vis measured across all of the sample and the one or more electrical leads in the first state, while a voltage Vis measured across the one or more electrical leads while bypassing the sample in the second state. Calculations according to the equation V=V&#x2212;Vare performed to determine a precision DC voltage measurement of a voltage across the sample Vin the absence of Seebeck voltage offsets contributed by the one or more electrical leads.

Seebeck cancellation switch for precision DC voltage measurements

Growing community of inventors

Evanston, IL, United States of America

Chulin Wang