Blar i NTNU Open på forfatter "Urheim, Stig"
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Biomechanics of degenerative mitral valve leaflets: Mechanical behavior, collagen structure, and numerical simulations
Sadeghinia, Mohammad Javad (Doctoral theses at NTNU;2023:395, Doctoral thesis, 2023)Degenerative mitral valve disease impacts around 2% of the population and leads to mitral regurgitation because of valvular incompetence. Two distinct phenotypes of degenerative mitral valve disease are fibroelastic ... -
Comparison of ultrasound vector flow imaging and CFD simulations with PIV measurements of flow in a left ventricular outflow trackt phantom - Implications for clinical use and in silico studies
Leinan, Paul Roger; Grønli, Thomas; Skjetne, Paal; Wigen, Morten Smedsrud; Urheim, Stig; Løvstakken, Lasse; Dahl, Sigrid Kaarstad (Peer reviewed; Journal article, 2022)In this study we have compared two modalities for flow quantification from measurement data; ultrasound (US) and shadow particle image velocimetry (PIV), and a flow simulation model using computational fluid dynamics (CFD). ... -
Finite element analysis of mitral valve annuloplasty in Barlow's disease
Aguilera, Hans Martin; Urheim, Stig; Persson, Robert; Haaverstad, Rune; Skallerud, Bjørn Helge; Prot, Victorien Emile (Peer reviewed; Journal article, 2022)Barlow’s Disease affects the entire mitral valve apparatus causing mitral regurgitation. Standard annuloplasty procedures lead to an average of 55% annular area reduction of the end diastolic pre-operative annular area in ... -
In silico analysis provides insights for patient-specific annuloplasty in Barlow's disease
Aguilera, Hans Martin Dahl; Persson, Robert; Haaverstad, Rune; Skallerud, Bjørn Helge; Prot, Victorien Emile; Urheim, Stig (Peer reviewed; Journal article, 2023)Objective To predict the required mitral annular area reduction in patients with Barlow's disease to obtain a predefined leaflet area index by a novel in silico modeling method. Methods Three-dimensional echocardiography ... -
Influence of Annular Dynamics and Material Behavior in Finite Element Analysis of Barlow’s Mitral Valve Disease
Aguilera, Hans Martin; Urheim, Stig; Skallerud, Bjørn Helge; Prot, Victorien Emile (Peer reviewed; Journal article, 2021)Barlow’s disease affects the entire mitral valve apparatus, by altering several of the fundamental mechanisms in the mitral valve which ensures unidirectional blood flow between the left atrium and the left ventricle. In ... -
Mechanical behavior and collagen structure of degenerative mitral valve leaflets and a finite element model of primary mitral regurgitation
Sadeghinia, Mohammadjavad; Aguilera, Hans Martin Dahl; Urheim, Stig; Persson, Robert; Ellensen, Vegard Skalstad; Haaverstad, Rune; Holzapfel, Gerhard; Skallerud, Bjørn Helge; Prot, Victorien Emile (Peer reviewed; Journal article, 2023)Degenerative mitral valve disease is the main cause of primary mitral regurgitation with two phenotypes: fibroelastic deficiency (FED) often with localized myxomatous degeneration and diffuse myxomatous degeneration or ... -
Mitral annular dynamics are influenced by left ventricular load and contractility in an acute animal model
Persson, Robert Matongo; Aguilera, Hans Martin Dahl; Kvitting, Jon Peder Escobar; Grong, Ketil; Prot, Victorien Emile; Salminen, Pirjo-Riitta; Svenheim, Bård; Leiknes, Anita; Stangeland, Lodve; Haaverstad, Rune; Urheim, Stig (Peer reviewed; Journal article, 2023)The purpose of this study was to investigate the effects of loading conditions and left ventricular (LV) contractility on mitral annular dynamics. In 10 anesthetized pigs, eight piezoelectric transducers were implanted ... -
Numerical modeling of diseased mitral valves
Aguilera, Hans Martin Dahl (Doctoral theses at NTNU;2023:273, Doctoral thesis, 2023)In this thesis, we have developed methods to create digital replicas of patients’ mitral valves from echocardiographic images and perform structural simulations in a finite element framework. The methods allow us to study ... -
Quantified planar collagen distribution in healthy and degenerative mitral valve: biomechanical and clinical implications
Sadeghinia, Mohammad Javad; Persson, Robert; Ellensen, Vegard Skalstad; Haaverstad, Rune; Holzapfel, Gerhard; Skallerud, Bjørn Helge; Prot, Victorien Emile; Urheim, Stig (Journal article; Peer reviewed, 2024)Degenerative mitral valve disease is a common valvular disease with two arguably distinct phenotypes: fibroelastic deficiency and Barlow’s disease. These phenotypes significantly alter the microstructures of the leaflets, ... -
Velocity profiles in a 2D model of the left ventricular outflow tract, pathological case study using PIV and CFD modeling
Leinan, Paul Roger; Skjetne, Paal; Morud, John; Urheim, Stig; Dahl, Sigrid Kaarstad (Chapter, 2017)In the current study, we present an experimental (in vitro) 2D flow model for studying blood flow in the human left ventricular outflow tract (LVOT) and the first part of the aorta using particle image velocimetry (PIV) ...