@article {25498,
	title = {Effects of arterial wall models and measurement uncertainties on cardiovascular model predictions},
	journal = {Journal of Biomechanics},
	volume = {50},
	year = {2017},
	pages = {188--194},
	publisher = {Elsevier},
	abstract = {We developed a methodology to assess and compare the prediction quality of cardiovascular models for patient-specific simulations calibrated with uncertainty-hampered measurements. The methodology was applied in a one-dimensional blood flow model to estimate the impact of measurement uncertainty in wall model parameters on the predictions of pressure and flow in an arterial network. We assessed the prediction quality of three wall models that have been widely used in one-dimensional blood flow simulations. A 37-artery network, previously used in one experimental and several simulation studies, was adapted to patient-specific conditions with a set of three clinically measurable inputs: carotid{\textendash}femoral wave speed, mean arterial pressure and area in the brachial artery. We quantified the uncertainty of the predicted pressure and flow waves in eight locations in the network and assessed the sensitivity of the model prediction with respect to the measurements of wave speed, pressure and cross-sectional area. Furthermore, we developed novel time-averaged sensitivity indices to assess the contribution of model parameters to the uncertainty of time-varying quantities (e.g., pressure and flow). The results from our patient-specific network model demonstrated that our novel indices allowed for a more accurate sensitivity analysis of time-varying quantities compared to conventional Sobol sensitivity indices.},
	doi = {http://dx.doi.org/10.1016/j.jbiomech.2016.11.042},
	author = {Vinzenz Gregor {Eck} and Sturdy, Jacob and Leif Rune {Hellevik}}
}
@article {23949,
	title = {A guide to uncertainty quantification and sensitivity analysis for cardiovascular applications},
	journal = {International Journal for Numerical Methods in Biomedical Engineering},
	volume = {32},
	year = {2016},
	publisher = {John Wiley \& Sons},
	abstract = {As we shift from population-based medicine towards a more precise patient-specific regime guided by predictions of verified and well-established cardiovascular models, an urgent question arises: how sensitive are the model predictions to errors and uncertainties in the model inputs? To make our models suitable for clinical decision-making, precise knowledge of prediction reliability is of paramount importance. Efficient and practical methods for uncertainty quantification (UQ) and sensitivity analysis (SA) are therefore essential. In this work we explain the concepts of global UQ and global, variance-based SA along with two often-used methods that are applicable to any model without requiring model implementation changes: Monte Carlo (MC) and Polynomial Chaos (PC). Furthermore, we propose a guide for UQ and SA according to a six-step procedure and demonstrated it for two clinically relevant cardiovascular models: model-based estimation of the fractional flow reserve (FFR) and model-based estimation of the total arterial compliance (CT ). Both MC and PC produce identical results and may be used interchangeably to identify most significant model inputs with respect to uncertainty in model predictions of FFR and CT . However, PC is more cost efficient as it requires an order of magnitude fewer model evaluations than MC. Additionally, we demonstrate that targeted reduction of uncertainty in the most significant model inputs reduces the uncertainty in the model predictions efficiently. In conclusion, this article offers a practical guide to UQ and SA to help move the clinical application of mathematical models forward.},
	doi = {10.1002/cnm.2755},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/cnm.2755/full},
	author = {Vinzenz Gregor {Eck} and W. P. {Donders} and Sturdy, Jacob and Feinberg, Jonathan and Delhaas, T. and Leif Rune {Hellevik}}
}
@article {25500,
	title = {Roadmap for cardiovascular circulation model},
	journal = {American Journal of Physiology},
	volume = {594},
	number = {23},
	year = {2016},
	pages = {6909-6928},
	publisher = {The Physiological Society},
	abstract = {Computational models of many aspects of the mammalian cardiovascular circulation have been developed. Indeed, along with orthopaedics, this area of physiology is one that has attracted much interest from engineers, presumably because the equations governing blood flow in the vascular system are well understood and can be solved with well-established numerical techniques. Unfortunately, there have been only a few attempts to create a comprehensive public domain resource for cardiovascular researchers. In this paper we propose a roadmap for developing an open source cardiovascular circulation model. The model should be registered to the musculo-skeletal system. The computational infrastructure for the cardiovascular model should provide for near real-time computation of blood flow and pressure in all parts of the body. The model should deal with vascular beds in all tissues, and the computational infrastructure for the model should provide links into CellML models of cell function and tissue function. In this work we review the literature associated with 1D blood flow modelling in the cardiovascular system, discuss model encoding standards, software and a model repository. We then describe the coordinate systems used to define the vascular geometry, derive the equations and discuss the implementation of these coupled equations in the open source computational software OpenCMISS. Finally, some preliminary results are presented and plans outlined for the next steps in the development of the model, the computational software and the graphical user interface for accessing the model.},
	doi = {10.1113/JP272660},
	author = {Safei, S and C P {Bradley} and Suresh, V and Mithraratne, K and Muller, A and Ho, H and Ladd, D and Leif Rune {Hellevik} and Stig W. {Omholt} and J G {Chase} and L O {M{\"u}ller} and S M {Watanabe} and P J {Blanco} and de Bono, B and Peter J. {Hunter}}
}
@article {24018,
	title = {A benchmark study of numerical schemes for one-dimensional arterial blood flow modelling},
	journal = {International Journal for Numerical Methods in Biomedical Engineering},
	volume = {31},
	year = {2015},
	month = {10/2015},
	pages = {1-33},
	publisher = {John Wiley \& Sons},
	abstract = {Haemodynamical simulations using one-dimensional (1D) computational models exhibit many of the features of the systemic circulation under normal and diseased conditions. Recent interest in verifying 1D numerical schemes has led to the development of alternative experimental setups and the use of three-dimensional numerical models to acquire data not easily measured in vivo. In most studies to date, only one particular 1D scheme is tested. In this paper, we present a systematic comparison of six commonly used numerical schemes for 1D blood flow modelling: discontinuous Galerkin, locally conservative Galerkin, Galerkin least-squares finite element method, finite volume method, finite difference MacCormack method and a simplified trapezium rule method. Comparisons are made in a series of six benchmark test cases with an increasing degree of complexity. The accuracy of the numerical schemes is assessed by comparison with theoretical results, three-dimensional numerical data in compatible domains with distensible walls or experimental data in a network of silicone tubes. Results show a good agreement among all numerical schemes and their ability to capture the main features of pressure, flow and area waveforms in large arteries. All the information used in this study, including the input data for all benchmark cases, experimental data where available and numerical solutions for each scheme, is made publicly available online, providing a comprehensive reference data set to support the development of 1D models and numerical schemes.},
	doi = {10.1002/cnm.2732},
	url = {http://onlinelibrary.wiley.com/journal/10.1002/\%28ISSN\%292040-7947},
	author = {Boileau, Etienne and Nithiarasu, Perumal and Pablo J {Blanco} and Lucas O {Muller} and Fredrik Eikeland {Fossan} and Leif Rune {Hellevik} and Wouter P {Donders} and Huberts, Wouter and Willemet, Marie and Alastruey, Jordi}
}
@article {24020,
	title = {Cardiovascular hemodynamics: Advancement of numerical and experimental diagnostic tools},
	journal = {Advances in Mechanical Engineering},
	volume = {7},
	year = {2015},
	month = {04/2015},
	pages = {1-3},
	publisher = {SAGE Publishing},
	doi = {10.1177/1687814015581243},
	url = {http://ade.sagepub.com/content/7/4/1687814015581243.full.pdf+html},
	author = {Morsi, Yosry and Leif Rune {Hellevik} and Qiao, Aike and Muraleedharan C {Vayalappil} and Tu, Jiyuan and Yang, William}
}
@misc {24023,
	title = {Plenary Lecture: Computational models for the cardiovascular system and uncertainty quantification},
	howpublished = {28th Nordic Seminar  on Computational Mechanics (NSCM28), Tallinn, Estonia, 2015, October 22-23},
	year = {2015},
	note = {Plenary lecture},
	publisher = {TUT, Tallinn},
	address = {TUT, Tallinn},
	url = {www.ioc.ee/nscm28/files/Proceedings_of_NSCM28.pdf},
	author = {Leif Rune {Hellevik}}
}
@inproceedings {23912,
	title = {Sensitivity Analysis and Uncertainty Quantification in a Wave Propagation Model: A Study of Uncertain Arterial Stiffness},
	journal = {4th International Conference on Computational and Mathematical Biomedical Engineering (CMBE), Paris, June 29-July 3},
	year = {2015},
	author = {Vinzenz Gregor {Eck} and Feinberg, Jonathan and Sturdy, Jacob and Hans Petter {Langtangen} and Leif Rune {Hellevik}},
	editor = {Nithiarasu and E. {Budyn}}
}
@misc {23913,
	title = {Sensitivity Analysis and Uncertainty Quantification in a Wave Propagation Model: A Study of Uncertain Arterial Stiffness},
	howpublished = {4th International Conference on Computational and Mathematical Biomedical Engineering, France},
	year = {2015},
	author = {Vinzenz Gregor {Eck} and Feinberg, Jonathan and Sturdy, Jacob and Hans Petter {Langtangen} and Leif Rune {Hellevik}}
}
@article {23939,
	title = {Stochastic sensitivity analysis for timing and amplitude of pressure waves in the arterial system},
	journal = {International Journal for Numerical Methods in Biomedical Engineering},
	volume = {31},
	year = {2015},
	month = {04/2015},
	publisher = {John Wiley \& Sons},
	abstract = {In the field of computational hemodynamics, sensitivity quantification of pressure and flow wave dynamics has received little attention. This work presents a novel study of the sensitivity of pressure-wave timing and amplitude in the arterial system with respect to arterial stiffness. Arterial pressure and flow waves were simulated with a one-dimensional distributed wave propagation model for compliant arterial networks. Sensitivity analysis of this model was based on a generalized polynomial chaos expansion evaluated by a stochastic collocation method. First-order statistical sensitivity indices were formulated to assess the effect of arterial stiffening on timing and amplitude of the pressure wave and backward-propagating pressure wave in the ascending aorta, at the maximum pressure and inflection point in the systolic phase. Only the stiffness of aortic arteries was found to significantly influence timing and amplitude of the backward-propagating pressure wave, whereas other large arteries in the systemic tree showed marginal impact. Furthermore, the ascending aorta, aortic arch, thoracic aorta, and infrarenal abdominal aorta had the largest influence on amplitude, whereas only the thoracic aorta influenced timing. Our results showed that the non-intrusive polynomial chaos expansion is an efficient method to compute statistical sensitivity measures for wave propagation models. These sensitivities provide new knowledge in the relative importance of arterial stiffness at various locations in the arterial network. Moreover, they will significantly influence clinical data collection and effective composition of the arterial tree for in-silico clinical studies.},
	doi = {10.1002/cnm.2711},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/cnm.2711/full},
	author = {Vinzenz Gregor {Eck} and Feinberg, Jonathan and Hans Petter {Langtangen} and Leif Rune {Hellevik}}
}
@inproceedings {sturdy_towards_2015,
	title = {Towards robust clinical assessment of arterial compliance},
	journal = {28th Nordic Seminar on Computational Mechanics},
	year = {2015},
	month = {10/2015},
	pages = {171-174},
	publisher = {TUT, Tallinn},
	address = {Tallinn},
	url = {www.ioc.ee/nscm28/files/Proceedings_of_NSCM28.pdf},
	author = {Sturdy, Jacob and Vinzenz Gregor {Eck} and Feinberg, Jonathan and Hans Petter {Langtangen} and Leif Rune {Hellevik}}
}
@misc {24001,
	title = {Towards robust clinical assessment of arterial compliance},
	howpublished = {28th Nordic Seminar on Computational Mechanics},
	year = {2015},
	publisher = {TUT, Tallinn},
	address = {TUT, Tallinn},
	author = {Sturdy, Jacob and Vinzenz Gregor {Eck} and Feinberg, Jonathan and Hans Petter {Langtangen} and Leif Rune {Hellevik}}
}
@inproceedings {eck_uncertainty_2015,
	title = {Uncertainty quantification and sensitivity analysis for wave propagation models of the arterial systemic circulation},
	journal = {ICCB 2015, VI International Conference on Computational Bioengineering, Barcelona, 2015},
	year = {2015},
	author = {Vinzenz Gregor {Eck} and Feinberg, Jonathan and Sturdy, Jacob and Hans Petter {Langtangen} and Leif Rune {Hellevik}}
}
@inproceedings {sturdy_uncertainty_2015,
	title = {Uncertainty quantification of short term baroreflex regulation of blood pressure},
	journal = {CMBE15, 4th International Conference on Computational \& Mathematical Biomedical Engineering},
	year = {2015},
	month = {06/2015},
	publisher = {CMBE},
	address = {Ecol{\'e} Normale Sup{\'e}ieure de Cachan},
	author = {Sturdy, Jacob and Vinzenz Gregor {Eck} and Leif Rune {Hellevik}}
}
@inproceedings {sturdy_validation_2015,
	title = {A Validation of Coupling Carotid and Aortic Baroreflex Models to a 1D Blood Flow Model of the Systemic Arterial Tree},
	journal = {ICCB 2015, VI International Conference on Computational Bioengineering},
	year = {2015},
	month = {09/2015},
	publisher = {ICCB},
	address = {Barcelona},
	author = {Sturdy, Jacob and Vinzenz Gregor {Eck} and Leif Rune {Hellevik}}
}
@inproceedings {24073,
	title = {Effects of parametric uncertainty in blood flow simulations},
	journal = {Virtual Physiological Human Conference 2014, Trondheim},
	year = {2014},
	month = {2014},
	author = {Vinzenz Gregor {Eck} and Feinberg, Jonathan and Hans Petter {Langtangen} and Leif Rune {Hellevik}}
}
@inproceedings {eck_stochastic_2014,
	title = {Stochastic arterial flow simulations},
	journal = {Proceedings of the 27th Nordic Seminar on Computational Mechanics},
	year = {2014},
	pages = {74-76},
	author = {Vinzenz Gregor {Eck} and Feinberg, Jonathan and Hans Petter {Langtangen} and Leif Rune {Hellevik}}
}
@article {Simula.simula.1828,
	title = {A Fast Strong Coupling Algorithm for the Partitioned Fluid-Structure Interaction Simulation of BMHVs},
	journal = {Computer Methods in Biomechanics and Biomedical Engineering},
	volume = {15},
	number = {12},
	year = {2013},
	pages = {1281-1312},
	publisher = {Elsevier},
	author = {Annerel, Sebastiaan and Degroote, Joris and Claessens, T. and Sigrid Kaarstad {Dahl} and Bj{\o}rn H. {Skallerud} and Leif Rune {Hellevik} and Van Ransbeeck, Peter and Seegers, P. and Verdonck, P. and Vierendeels, Jan}
}
@article {Simula.simula.2396,
	title = {Human Ductus Venosus Velocity Profiles in the First Trimester},
	journal = {Cardiovascular Engineering and Technology},
	volume = {4},
	number = {3},
	year = {2013},
	pages = {257-266},
	doi = {10.1007/s13239-013-0133-y},
	author = {Paul Roger {Leinan} and Kiserud, Torvid and Leif Rune {Hellevik}}
}
@article {Simula.simula.2394,
	title = {Velocity Profiles in the Human Ductus Venosus: a Numerical Fluid Structure Interaction Study},
	journal = {Biomechanics and Modeling in Mechanobiology},
	volume = {12},
	number = {5},
	year = {2013},
	pages = {1019-1035},
	author = {Paul Roger {Leinan} and Degroote, Joris and Kiserud, Torvid and Bj{\o}rn H. {Skallerud} and Vierendeels, Jan and Leif Rune {Hellevik}}
}
@article {Simula.simula.1824,
	title = {Application of a Strong FSI Coupling Scheme for the Numerical Simulation of Bileaflet Mechanical Heart Valve Dynamics: Study of Wall Shear Stress on the Leaflets},
	journal = {Progress in Computational Fluid Dynamics},
	volume = {12},
	number = {2-3},
	year = {2012},
	pages = {68-80},
	author = {Annerel, Sebastiaan and Degroote, Joris and Vierendeels, Jan and Claessens, T. and Van Ransbeeck, Peter and Sigrid Kaarstad {Dahl} and Bj{\o}rn H. {Skallerud} and Leif Rune {Hellevik} and Segers, P. and Verdonck, P.}
}
@article {Simula.simula.1822,
	title = {FSI-Simulation of Asymmetric Mitral Valve Dynamics During Diastolic Filling},
	journal = {Computer Methods in Biomechanics and Biomedical Engineering},
	volume = {15},
	number = {2},
	year = {2012},
	pages = {121-130},
	publisher = {Taylor \& Francis Online},
	author = {Sigrid Kaarstad {Dahl} and Vierendeels, Jan and Degroote, Joris and Annerel, Sebastiaan and Leif Rune {Hellevik} and Bj{\o}rn H. {Skallerud}}
}
@article {Simula.simula.1820,
	title = {Impact of Pulmonary Venous Locations on the Intra-Atrial Flow and Mitral Plane Velocity Profile},
	journal = {Cardiovascular Engineering and Technology},
	volume = {3},
	number = {3},
	year = {2012},
	pages = {2069-281},
	author = {Sigrid Kaarstad {Dahl} and Thomassen, E. and Leif Rune {Hellevik} and Bj{\o}rn H. {Skallerud}}
}
@inproceedings {Simula.simula.1214,
	title = {A Biomechanical Model for Human Umbilical Veins and Wharton{\textquoteright}s Jelly},
	journal = {8th International Conference on Computational Fluid Dynamics in the Oil \& Gas, Metallurgical and Process Industries},
	year = {2011},
	type = {Conference},
	author = {Paul Roger {Leinan} and Victorien Emile {Prot} and C. N. {van den Broek} and Kiserud, T. and Bj{\o}rn H. {Skallerud} and Leif Rune {Hellevik} and F. N. {van de Vosse}}
}
@inproceedings {Simula.simula.1216,
	title = {A Strong Coupling FSI Scheme for Simulating BMHV Dynamics},
	journal = {8th International Conference on CFD in Oil \& Gas, Metallurgical and Process Industries},
	year = {2011},
	type = {Conference},
	author = {Annerel, Sebastiaan and Degroote, Joris and Claessens, T. and Sigrid Kaarstad {Dahl} and Bj{\o}rn H. {Skallerud} and Leif Rune {Hellevik} and Van Ransbeeck, Peter and Segers, P. and Verdonck, P. and Vierendeels, Jan}
}
@inproceedings {Simula.simula.80,
	title = {FSI Simulation of the Mitral Valve With Contact and Active Anisotropic Material Models},
	journal = {6th World Congress of Biomechanics},
	year = {2010},
	pages = {266},
	type = {Conference},
	author = {Leif Rune {Hellevik} and Astorino, M. and Moireau, P. and Victorien Emile {Prot} and Bj{\o}rn H. {Skallerud} and Gerbeau, Jean-Fr{\`e}d{\`e}ric}
}
@inproceedings {Simula.simula.82,
	title = {Initial Study on Material Modeling of Umbilical Veins in Fetal Sheep},
	journal = {6th World Congress of Biomechanics},
	year = {2010},
	pages = {361},
	type = {Conference},
	author = {Paul Roger {Leinan} and Leif Rune {Hellevik} and Victorien Emile {Prot} and Kiserud, T. and Bj{\o}rn H. {Skallerud}}
}
@article {Simula.sc.968,
	title = {An Assessment of Ductus Venosus Tapering and Wave Transmission From the Fetal Heart},
	journal = {Biomechanics and Modeling in Mechanobiology},
	volume = {8},
	number = {6},
	year = {2009},
	pages = {509-517},
	abstract = {Pressure and flow pulsations in the fetal heart propagate through the precordial vein and the ductus venosus (DV) but are normally not transmitted into the umbilical vein (UV). Pulsations in the umbilical vein do occur, however, in early pregnancy and in pathological conditions. Such transmission into the umbilical vein is not well understood. In particular, the effect of the impedance changes in the DV due to its tapered geometry is not known. This paper presents a mathematical model that we developed to study the transmission of pulsations, originating in the fetal heart, through the DV to the umbilical vein. In our model, the tapered geometry of the DV was found to be of minor importance and the only effective reflection site in the DV appears to be at the DV inlet. Differences between the DV inlet and outlet flow were also found to be minor for medium to large umbilical vein-DV diameter ratios. Finally, the results of a previously proposed lumped model were found to agree well with the present model of the DV-umbilical vein bifurcation.},
	doi = {10.1007/s10237-009-0155-4},
	author = {Leif Rune {Hellevik} and Vierendeels, Jan and Kiserud, T. and Stergiopulos, N. and Irgens, F. and Dick, E. and Riemslagh, K. and Verdonck, P.}
}
@misc {Simula.sc.708,
	title = {Implicit Interaction of Two Rigid Mitral Leaflets in a Partitioned Fluid-Structure Approach},
	howpublished = {Talk at MekIT{\textquoteright}09, Trondheim, May 27th},
	year = {2009},
	month = {May},
	abstract = {The aim of our study was twofold. First, to develop an implicit algorithm accounting for interaction of two rigid, asymmetric mitral leaflets in a partitioned, fluid-structure interaction simulation. Second, to study the impact of the imposed inlet conditions on the mitral valve movement during diastolic filling. Two-dimensional simulations with a transient patient-specific left ventricle geometry were carried out to test the algorithm, to introduce a higher degree of physiological realism in the simulations, and to reduce the computational cost. Two different inlet configurations were tested. The results indicate that the inlet configuration has significant impact on intramitral flow and the movement of the mitral leaflets during diastole.},
	author = {Sigrid Kaarstad {Dahl} and Vierendeels, Jan and Degroote, Joris and Annerel, Sebastiaan and Bj{\o}rn H. {Skallerud} and Leif Rune {Hellevik}}
}
@inproceedings {Simula.sc.692,
	title = {Implicit Interaction of Two Rigid Mitral Leaflets in a Partitioned Fluid-Structure Approach},
	journal = {MekIT{\textquoteright}09. Fifth~~national~~conference~~on~~Computational~~Mechanics},
	year = {2009},
	month = {May},
	pages = {135-149},
	publisher = {NTNU},
	type = {Conference},
	address = {Trondheim},
	abstract = {The aim of our study was twofold. First, to develop an implicit algorithm accounting for interaction of two rigid, asymmetric mitral leaflets in a partitioned, fluid-structure interaction simulation. Second, to study the impact of the imposed inlet conditions on the mitral valve movement during diastolic filling. Two-dimensional simulations with a transient patient-specific left ventricle geometry were carried out to test the algorithm, to introduce a higher degree of physiological realism in the simulations, and to reduce the computational cost. Two different inlet configurations were tested. The results indicate that the inlet configuration has significant impact on intramitral flow and the movement of the mitral leaflets during diastole.},
	isbn = {978-82-519-2421-4},
	author = {Sigrid Kaarstad {Dahl} and Vierendeels, Jan and Degroote, Joris and Annerel, Sebastiaan and Bj{\o}rn H. {Skallerud} and Leif Rune {Hellevik}},
	editor = {Bj{\o}rn H. {Skallerud} and H. I. {Andersson}}
}
@inproceedings {Simula.sc.834,
	title = {On Material Modelling of Umbilical Vein},
	journal = {Fifth National Conference on Computational Mechanics (MekIT{\textasciiacute}09)},
	year = {2009},
	pages = {281-295},
	publisher = {Tapir Akademisk Forlag},
	type = {Conference},
	isbn = {978-82-519-2421-4},
	author = {Paul Roger {Leinan} and Leif Rune {Hellevik} and Victorien Emile {Prot} and Kiserud, Torvid and Bj{\o}rn H. {Skallerud}},
	editor = {Bj{\o}rn H. {Skallerud} and Andersson, H.I.}
}
@inproceedings {Simula.sc.954,
	title = {A 2D Patient-Specific FSI Assessment of Mitral Valve Dynamics During Diastolic Filling},
	journal = {8th world Congress on Computational Mechanics/5th European Congress on Computational Methods in Applied sciences and Engineering, Venice, Italy},
	year = {2008},
	type = {Conference},
	author = {Sigrid Kaarstad {Dahl} and Leif Rune {Hellevik} and Bj{\o}rn H. {Skallerud}}
}
@misc {Simula.SC.242,
	title = {A 2D Patient-Specific FSI Assessment of Mitral Valve Dynamics During Diastolic Filling},
	howpublished = {Presented at 8th.World Congress on Computational Mechanics (WCCM8)/5th European Congress on Computational Methods in Applied Sciences and Engineeering (ECCOMAS 2008), Venice, Italy},
	year = {2008},
	month = {June},
	author = {Sigrid Kaarstad {Dahl} and Leif Rune {Hellevik} and Bj{\o}rn H. {Skallerud}}
}
@misc {Simula.sc.1100,
	title = {Wave Propagation in the Human Fetal Ductus Venosus-Umbilical Vein Bifurcation},
	howpublished = {Talk at Reproductive Bioengineering, Wenns im Piztal, Austria},
	year = {2008},
	author = {Leif Rune {Hellevik}}
}
@inproceedings {Simula.SC.77,
	title = {A First-Approach Towards Patient-Specific 2D FSI-Simulation of Mitral Valve Dynamics During Diastolic Filling},
	journal = {MekIT-07, Fourth national conference on Computational Mechanics},
	year = {2007},
	pages = {175-184},
	publisher = {Tapir Academic Press},
	type = {Conference},
	address = {Trondheim},
	abstract = {The mitral valve controls the flow of blood into the ventricle during diastole and prevents backflow into the atrium in systole. The two mitral valve leaflets have significantly different geometries. The dynamics of the leaflets and their influence on the transmitral and intraventricular flow is a controversial topic. In this paper we report results from work in progress on fluid structure interaction simulations of the mitral leaflets during left ventricular filling. The aim of the present study was to assess the impact of left ventricular initial pressures and vortices on the mitral leaflet dynamics. An explicitly coupled fluid structure interaction scheme was utilized for the numerical simulations. A 2D transient representation of the left ventricular wall movement was imposed as boundary conditions for the simulations. The left ventricular wall was rendered by ultrasound recordings, and speckle tracking was used for transient tracking of the wall movement during diastole. Thus, the structural calculations are simplified and involve only the mitral valves. The ultrasound measurements were used both for validation/comparison with the simulated mitral valve dynamics as well as for imposition of the left ventricular wall movement. Our simulations show that the initial pressure configuration in the left heart is significant for the mitral valve dynamics. The simulations also indicate that the mitral valve flutter has important bearings on the vortex formation in the vicinity of the mitral valves.},
	isbn = {978-82-519-2235-7},
	author = {Leif Rune {Hellevik} and Sigrid Kaarstad {Dahl} and Bj{\o}rn H. {Skallerud}},
	editor = {Bj{\o}rn H. {Skallerud} and H. I. {Andersson}}
}
