41 citations · 146 across the 38 of their papers we have counts for
27 papers · 1 filter
Direct reconstruction for acoustic inverse Born scattering
Nuutti Hyvönen, Lisa Schätzle
We consider the inverse medium scattering problem for the Helmholtz equation in two dimensions, i.e., the task to recover a compactly supported penetrable two-dimensional scatterer…
Möbius-transformed trapezoidal rule for polynomial weights
Nuutti Hyvönen, Yuya Suzuki
This work studies numerical integration by the Möbius-transformed trapezoidal rule, which combines the classical trapezoidal rule with a change of variables induced by a Möbius tra…
A bilinear inverse problem with forward operator inaccuracy applied to neonatal atlas-based diffuse optical tomography
Aada Hakula, Pauliina Hirvi, Nuutti Hyvönen
In this work, we assume to have a set of candidate forward operator matrices and suggest principal component analysis for modeling their variation from the mean. We use this princi…
Total variation regularization with reduced basis in electrical impedance tomography
A. Hannukainen, N. Hyvönen, V. Toresen
This work considers using reduced basis techniques in connection to (smoothened) total variation regularization in electrical impedance tomography, but analogous ideas can also be…
Projection-based preprocessing for electrical impedance tomography to reduce the effect of electrode contacts
Altti Jääskeläinen, Jussi Toivanen, Asko Hänninen +2
This work introduces a method for preprocessing measurements of electrical impedance tomography to considerably reduce the effect uncertainties in the electrode contacts have on th…
Möbius-Transformed Trapezoidal Rule
Yuya Suzuki, Nuutti Hyvönen, Toni Karvonen
We study numerical integration by combining the trapezoidal rule with a Möbius transformation that maps the unit circle onto the real line. We prove that the resulting transformed…
Linearization-based direct reconstruction for EIT using triangular Zernike decompositions
Antti Autio, Henrik Garde, Markus Hirvensalo +1
This work implements and numerically tests the direct reconstruction algorithm introduced in [Garde & Hyvönen, SIAM J. Math. Anal., 2024] for two-dimensional linearized electrical…
Bayesian experimental design for head imaging by electrical impedance tomography
N. Hyvönen, A. Jääskeläinen, R. Maity +1
This work considers the optimization of electrode positions in head imaging by electrical impedance tomography. The study is motivated by maximizing the sensitivity of electrode me…
Bayesian experimental design for linear elasticity
Sarah Eberle-Blick, Nuutti Hyvönen
This work considers Bayesian experimental design for the inverse boundary value problem of linear elasticity in a two-dimensional setting. The aim is to optimize the positions of c…
Bayesian design of measurements for magnetorelaxometry imaging
Tapio Helin, Nuutti Hyvönen, Jarno Maaninen +1
The aim of magnetorelaxometry imaging is to determine the distribution of magnetic nanoparticles inside a subject by measuring the relaxation of the superposition magnetic field ge…
Approximation error method for imaging the human head by electrical impedance tomography
Valentina Candiani, Nuutti Hyvönen, Jari P. Kaipio +1
This work considers electrical impedance tomography imaging of the human head, with the ultimate goal of locating and classifying a stroke in emergency care. One of the main diffic…
Electrodeless electrode model for electrical impedance tomography
J. Dardé, N. Hyvönen, T. Kuutela +1
Electrical impedance tomography is an imaging modality for extracting information on the interior structure of a physical body from boundary measurements of current and voltage. Th…
Sequentially optimized projections in X-ray imaging
Martin Burger, Andreas Hauptmann, Tapio Helin +2
This work applies Bayesian experimental design to selecting optimal projection geometries in (discretized) parallel beam X-ray tomography assuming the prior and the additive noise…
Inverse heat source problem and experimental design for determining iron loss distribution
Antti Hannukainen, Nuutti Hyvönen, Lauri Perkkiö
Iron loss determination in the magnetic core of an electrical machine, such as a motor or a transformer, is formulated as an inverse heat source problem. The sensor positions insid…
Mimicking relative continuum measurements by electrode data in two-dimensional electrical impedance tomography
Henrik Garde, Nuutti Hyvönen
This paper introduces a constructive method for approximating relative continuum measurements in two-dimensional electrical impedance tomography based on data originating from eith…
Computational framework for applying electrical impedance tomography to head imaging
Valentina Candiani, Antti Hannukainen, Nuutti Hyvönen
This work introduces a computational framework for applying absolute electrical impedance tomography to head imaging without accurate information on the head shape or the electrode…
An inverse boundary value problem for the -Laplacian
Antti Hannukainen, Nuutti Hyvönen, Lauri Mustonen
This work tackles an inverse boundary value problem for a -Laplace type partial differential equation parametrized by a smoothening parameter . The aim is to numericall…
Generalized linearization techniques in electrical impedance tomography
Nuutti Hyvönen, Lauri Mustonen
Electrical impedance tomography aims at reconstructing the interior electrical conductivity from surface measurements of currents and voltages. As the current-voltage pairs depend…
Smoothened complete electrode model
Nuutti Hyvönen, Lauri Mustonen
This work reformulates the complete electrode model of electrical impedance tomography in order to enable more efficient numerical solution. The model traditionally assumes constan…
Enhancing D-bar reconstructions for electrical impedance tomography with conformal maps
Nuutti Hyvönen, Lassi Päivärinta, Janne P. Tamminen
We present a few ways of using conformal maps in the reconstruction of two-dimensional conductivities in electrical impedance tomography. First, by utilizing the Riemann mapping th…
Thermal tomography with unknown boundary
Nuutti Hyvönen, Lauri Mustonen
Thermal tomography is an imaging technique for deducing information about the internal structure of a physical body from temperature measurements on its boundary. This work conside…
Compensation for geometric modeling errors by electrode movement in electrical impedance tomography
Nuutti Hyvönen, Helle Majander, Stratos Staboulis
Electrical impedance tomography aims at reconstructing the conductivity inside a physical body from boundary measurements of current and voltage at a finite number of contact elect…
Polynomial collocation for handling an inaccurately known measurement configuration in electrical impedance tomography
Nuutti Hyvönen, Vesa Kaarnioja, Lauri Mustonen +1
The objective of electrical impedance tomography is to reconstruct the internal conductivity of a physical body based on measurements of current and potential at a finite number of…
Efficient inclusion of total variation type priors in quantitative photoacoustic tomography
Antti Hannukainen, Nuutti Hyvönen, Helle Majander +1
Quantitative photoacoustic tomography is an emerging imaging technique aimed at estimating the distribution of optical parameters inside tissues from photoacoustic images, which ar…