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The problem of determining a current density confined to a volume from measurements of the magnetic field it produces exterior to that volume is known to have non-unique solutions. To uniquely determine the current density, or the…

Medical Physics · Physics 2014-07-03 Daniel J. Sheltraw

We consider the problem of determining the shape and location of an unknown penetrable object in a perfectly conducting electromagnetic waveguide. The inverse problem is posed in the frequency domain and uses multistatic data in the near…

Numerical Analysis · Mathematics 2019-09-04 Peter Monk , Virginia Selgas , Fan Yang

In this paper we investigate the non-linear and ill-posed inverse problem of simultaneously identifying the conductivity and the reaction in diffuse optical tomography with noisy measurement data available on an accessible part of the…

Numerical Analysis · Mathematics 2020-07-10 Tran Nhan Tam Quyen

We present a procedure for recovering the conformal factor of an anisotropic conductivity matrix in a known conformal class in a domain in Euclidean space of dimension greater than or equal to 2. The method requires one internal…

Analysis of PDEs · Mathematics 2013-03-01 Nicholas Hoell , Amir Moradifam , Adrian Nachman

Electrical impedance tomography (EIT) is a non-invasive imaging method in which an unknown physical body is probed with electric currents applied on the boundary, and the internal conductivity distribution is recovered from the measured…

Numerical Analysis · Mathematics 2014-02-07 Sarah Jane Hamilton , Samuli Siltanen

In acousto-electric tomography the goal is to reconstruct the electric conductivity in a domain from electrostatic boundary measurements of corresponding currents and voltages, while the domain is penetrated by a time-dependent acoustic…

Medical Physics · Physics 2024-02-01 Bjørn Jensen , Adrian Kirkeby , Kim Knudsen

The inverse problem of electrical impedance tomography is severely ill-posed, meaning that, only limited information about the conductivity can in practice be recovered from boundary measurements of electric current and voltage. Recently it…

Analysis of PDEs · Mathematics 2018-09-20 Henrik Garde , Stratos Staboulis

A new non-linear optimization approach is proposed for the sparse reconstruction of log-conductivities in current density impedance imaging. This framework comprises of minimizing an objective functional involving a least squares fit of the…

Optimization and Control · Mathematics 2020-06-30 Madhu Gupta , Rohit Kumar Mishra , Souvik Roy

This work presents a new constructive uniqueness proof for Calder\'on's inverse problem of electrical impedance tomography, subject to local Cauchy data, for a large class of piecewise constant conductivities that we call "piecewise…

Analysis of PDEs · Mathematics 2020-08-18 Henrik Garde

Magnetic Induction Tomography (MIT) is a promising modality for noninvasive imaging due to its contactless and nonionizing technology. In this imaging method, a primary magnetic field is applied by excitation coils to induce eddy currents…

Quantitative Methods · Quantitative Biology 2024-12-19 Mohammad Reza Yousefi , Amin Dehghani , Ali Asghar Amini , S. M. Mehdi Mirtalaei

We consider the ultrasound imaging problem governed by a nonlinear wave equation of Westervelt type with variable wave speed. We show that the coefficient of nonlinearity can be recovered uniquely from knowledge of the Dirichlet-to-Neumann…

Analysis of PDEs · Mathematics 2022-02-04 Sebastian Acosta , Gunther Uhlmann , Jian Zhai

Lorentz transmission electron microscopy is a unique characterization technique that enables the simultaneous imaging of both the microstructure and functional properties of materials at high spatial resolution. The quantitative information…

Materials Science · Physics 2020-12-09 Tao Zhou , Mathew Cherukara , Charudatta Phatak

Convolutional Neural Networks (CNN) have shown promising results for displacement estimation in UltraSound Elastography (USE). Many modifications have been proposed to improve the displacement estimation of CNNs for USE in the axial…

Image and Video Processing · Electrical Eng. & Systems 2022-12-20 Ali K. Z. Tehrani , Md Ashikuzzaman , Hassan Rivaz

Ultrasound attenuation is caused by absorption and scattering in tissue and is thus a function of tissue composition, hence its imaging offers great potential for screening and differential diagnosis. In this paper we propose a novel method…

Signal Processing · Electrical Eng. & Systems 2019-10-15 Richard Rau , Ozan Unal , Dieter Schweizer , Valery Vishnevskiy , Orcun Goksel

We consider the imaging of anisotropic conductivity tensors $\gamma=(\gamma_{ij})_{1\leq i,j\leq 2}$ from knowledge of several internal current densities $\mathcal{J}=\gamma\nabla u$ where $u$ satisfies a second order elliptic equation…

Analysis of PDEs · Mathematics 2014-03-21 Guillaume Bal , Chenxi Guo , François Monard

Accurate modeling of ultrasound wave propagation is essential for high-fidelity simulation and imaging in ultrasonic testing. A primary challenge lies in characterizing the excitation source, particularly for transducers with large…

Medical Physics · Physics 2026-03-26 Tim Bürchner , Simon Schmid , Ernst Rank , Stefan Kollmannsberger , Andreas Fichtner

Accurate determination of microscopic transport and magnetization currents is of central importance for the study of the electric properties of low dimensional materials and interfaces, of superconducting thin films and of electronic…

Mesoscale and Nanoscale Physics · Physics 2019-07-24 Alexander Y. Meltzer , Eitan Levin , Eli Zeldov

Displacement estimation is a critical step of virtually all Ultrasound Elastography (USE) techniques. Two main features make this task unique compared to the general optical flow problem: the high-frequency nature of ultrasound…

Image and Video Processing · Electrical Eng. & Systems 2022-06-14 Ali K. Z. Tehrani , Hassan Rivaz

Electrically percolating nanowire networks are amongst the most promising candidates for next-generation transparent electrodes. Scientific interest in these materials stems from their intrinsic current distribution heterogeneity, leading…

Applied Physics · Physics 2024-04-11 J. Fekete , P. Joshi , T. J. Barrett , T. M. James , R. Shah , A. Gadge , S. Bhumbra , F. Oručević , P. Krüger

Ultrasound elasticity images which enable the visualization of quantitative maps of tissue stiffness can be reconstructed by solving an inverse problem. Classical model-based approaches for ultrasound elastography use deterministic finite…

Image and Video Processing · Electrical Eng. & Systems 2021-07-29 Narges Mohammadi , Marvin M. Doyley , Mujdat Cetin