On the impact of modelling assumptions in multi-scale, subject-specific models of aortic haemodynamics.
Simulation of haemodynamics has become increasingly popular within the research community. Irrespective of the modelling approach (zero-dimensional (0D), one-dimensional (1D) or three-dimensional (3D)), in vivo measurements are required to personalize the arterial geometry, material properties and boundary conditions of the computational model. Limitations in in vivo data acquisition often result in insufficient information to determine all model parameters and, hence, arbitrary modelling assumptions. Our goal was to minimize and understand the impact of modelling assumptions on the simulated blood pressure, flow and luminal area waveforms by studying a small region of the systemic vasculature-the upper aorta-and acquiring a rich array of non-invasive magnetic resonance imaging and tonometry data from a young healthy volunteer. We first investigated the effect of different modelling assumptions for boundary conditions and material parameters in a 1D/0D simulation framework. Strategies were implemented to mitigate the impact of inconsistencies in the in vivo data. Average relative errors smaller than 7% were achieved between simulated and in vivo waveforms. Similar results were obtained in a 3D/0D simulation framework using the same inflow and outflow boundary conditions and consistent geometrical and mechanical properties. We demonstrated that accurate subject-specific 1D/0D and 3D/0D models of aortic haemodynamics can be obtained using non-invasive clinical data while minimizing the number of arbitrary modelling decisions.
Department of Biomedical Engineering, King's College London, St Thomas' Hospital, London, UK jordi.alastruey-arimon@kcl.ac.uk.
Jordi
0000-0003-3742-5259
J
Alastruey
Department of Biomedical Engineering, King's College London, St Thomas' Hospital, London, UK.
Nan
N
Xiao
Department of Clinical Pharmacology, King's College London, St Thomas' Hospital, London, UK.
Henry
H
Fok
Department of Biomedical Engineering, King's College London, St Thomas' Hospital, London, UK.
Tobias
T
Schaeffter
Department of Biomedical Engineering, King's College London, St Thomas' Hospital, London, UK Department of Bioengineering and Surgery, University of Michigan, Ann Arbor, MI, USA.
C Alberto
CA
Figueroa
D001011:Aorta / Q000033:anatomy & histology / Q000502:physiology*; D003198:Computer Simulation; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular
applanation tonometry; haemodynamics; magnetic resonance imaging; pulse wave propagation; subject-specific modelling