title: Reducing the number of parameters in 1D arterial blood flow modeling: less is more for patient-specific simulations.
abstract: Patient-specific one-dimensional (1D) blood flow modeling requires estimating model parameters from available clinical data, ideally acquired noninvasively. The larger the number of arterial segments in a distributed 1D model, the greater the number of input parameters that need to be estimated. We investigated the effect of a reduction in the number of arterial segments in a given distributed 1D model on the shape of the simulated pressure and flow waveforms. This is achieved by systematically lumping peripheral 1D model branches into windkessel models that preserve the net resistance and total compliance of the original model. We applied our methodology to a model of the 55 larger systemic arteries in the human and to an extended 67-artery model that contains the digital arteries that perfuse the fingers. Results show good agreement in the shape of the aortic and digital waveforms between the original 55-artery (67-artery) and reduced 21-artery (37-artery) models. Reducing the number of segments also enables us to investigate the effect of arterial network topology (and hence reflection sites) on the shape of waveforms. Results show that wave reflections in the thoracic aorta and renal arteries play an important role in shaping the aortic pressure and flow waves and in generating the second peak of the digital pressure and flow waves. Our novel methodology is important to simplify the computational domain while maintaining the precision of the numerical predictions and to assess the effect of wave reflections.
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, St. Thomas' Hospital, King's College London, London, United Kingdom; and.
authors.forename: Sally
authors.initials: S
authors.lastname: Epstein
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, St. Thomas' Hospital, King's College London, London, United Kingdom; and.
authors.forename: Marie
authors.initials: M
authors.lastname: Willemet
authors.affiliation: Department of Clinical Pharmacology, St. Thomas' Hospital, King's College London, London, United Kingdom.
authors.forename: Phil J
authors.initials: PJ
authors.lastname: Chowienczyk
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, St. Thomas' Hospital, King's College London, London, United Kingdom; and jordi.alastruey-arimon@kcl.ac.uk.
authors.forename: Jordi
authors.initials: J
authors.lastname: Alastruey
mesh_terms: D001011:Aorta / Q000502:physiology*; D001158:Arteries / Q000502:physiology; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology*; D003198:Computer Simulation; D006439:Hemodynamics; D006801:Humans; D008955:Models, Cardiovascular; D012077:Renal Artery / Q000502:physiology*
keywords: 1D modeling; aortic pulse wave; digital pulse wave; hypertension; windkessel model