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  • Journal article
    Matthys KS, Alastruey J, Peiro J, Khir AW, Segers P, Verdonck PR, Parker KH, Sherwin SJet al., 2007,

    Pulse wave propagation in a model human arterial network: Assessment of 1-D numerical simulations against in vitro measurements

    , J. Biomech., Vol: 40, Pages: 3476-3486

    A numerical model based on the nonlinear, one-dimensional (1-D) equations of pressure and flow wave propagation in conduit arteries is tested against a well-defined experimental 1:1 replica of the human arterial tree. The tree consists of 37 silicone branches representing the largest central systemic arteries in the human, including the aorta, carotid arteries and arteries that perfuse the upper and lower limbs and the main abdominal organs. The set-up is mounted horizontally and connected to a pulsatile pump delivering a periodic output similar to the aortic flow. Terminal branches end in simple resistance models, consisting of stiff capillary tubes leading to an overflow reservoir that reflects a constant venous pressure. The parameters required by the numerical algorithm are directly measured in the \emph{in-vitro} set-up and no data fitting is involved. Comparison of experimental and numerical pressure and flow waveforms shows the ability of the 1-D time-domain formulation to capture the main features of pulse wave propagation measured throughout the system test. As a consequence of the simple resistive boundary conditions used to reduce the uncertainty of the parameters involved in the simulation, the experimental set-up generates waveforms at terminal branches with additional non-physiological oscillations. The frequencies of these oscillations are well captured by the 1-D model, even though amplitudes are overestimated. Adding energy losses in bifurcations and including fluid inertia and compliance to the purely resistive terminal models does not reduce the underdamped effect, suggesting that wall visco-elasticity might play an important role in the experimental results. Nevertheless, average relative root-mean-square errors between simulations and experimental waveforms are smaller than 4% for pressure and 19% for the flow at all 70 locations studied.
  • Journal article
    Dongbin Xiu, Spencer Sherwin, 2007,

    Parametric uncertainty analysis of pulse wave propagation in a model of a human arterial network

    , J. Computational Physics, Vol: 226, Pages: 1385-1407
  • Journal article
    Alastruey J, Parker KH, Peiró J, Sherwin SJet al., 2006,

    Can the modified Allen's test always detect sufficient collateral flow in the hand? A computational study.

    , Comput Methods Biomech Biomed Engin, Vol: 9, Pages: 353-361, ISSN: 1025-5842

    Blood flow in the largest arteries of the arm up to the digital arteries is numerically modelled using the one-dimensional equations of pressure and flow wave propagation in compliant vessels. The model can be applied to different anatomies of arterial networks and can simulate compression of arteries, these allowing us to simulate the modified Allen's test (MAT) and to assess its suitability for the detection of sufficient collateral flow in the hand if radial blood supply is interrupted. The test measures blood flow in the superficial palmar arch before and during compression of the radial artery. The absence of reversal flow in the palmar arch with the compression indicates insufficient collateral flow and is referred to as a positive MAT. This study shows that small calibres of the superficial palmar arch and insufficient compression of the radial artery can lead to false-positive results. Measurement of the drop in digital systolic pressures with compression of the radial artery has proved to be a more sensitive test to predict the presence of sufficient ulnar collateral flow in networks with small calibres of the superficial palmar arch. However, this study also shows that digital pressure measurements can fail in detecting enough collateral flow if the radial artery is insufficiently compressed.
  • Conference paper
    Gambaruto AM, Radaelli A, Doorly DJ, Sherwin SJ, Peiro Jet al., 2005,

    Sensitivity study on by-pass graft reconstruction with emphasis on flow solutions

    , Pages: 832-833
  • Journal article
    Giordana S, Sherwin SJ, Peiró J, Doorly DJ, Crane JS, Lee KE, Cheshire NJW, Carco CGet al., 2005,

    Local and global geometric influence on steady flow in distal anastomoses of peripheral bypass grafts

    , JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, Vol: 127, Pages: 1087-1098, ISSN: 0148-0731
  • Journal article
    Sherwin SJ, Blackburn HM, 2005,

    Three-dimensional instabilities and transition of steady and pulsatile axisymmetric stenotic flows

    , JOURNAL OF FLUID MECHANICS, Vol: 533, Pages: 297-327, ISSN: 0022-1120
  • Conference paper
    Pitt RE, Sherwin SJ, Theofilis V, 2005,

    BiGlobal stability analysis of steady flow in constricted channel geometries

    , 8th ICFD Conference on Numerical Methods for Fluid Dynamics, Publisher: WILEY, Pages: 1229-1235, ISSN: 0271-2091
  • Journal article
    Giordana S, Sherwin SJ, Peiró J, Doorly DJ, Papaharilaou Y, Caro CG, Watkins N, Cheshire N, Jackson M, Bicknall C, Zervas Vet al., 2005,

    Automated classification of peripheral distal by-pass geometries reconstructed from medical data

    , JOURNAL OF BIOMECHANICS, Vol: 38, Pages: 47-62, ISSN: 0021-9290
  • Conference paper
    Alastruey J, Parker KH, Peiro J, Sherwin SJet al., 2005,

    A one-dimensional simulation of the human conduit arteries compared to experimental data

    , ASME Summer Biongineering Conference, abstract 0328683, Vail, CO, USA
  • Conference paper
    Alastruey J, Parker KH, Peiro J, Sherwin SJet al., 2004,

    Wave analysis of flow in the palmar arch

    , Journal of Physiology 561P PC18, Publisher: J. Physiol
  • Conference paper
    varghese S, Frankel S, Pitt R, Sherwin SJet al., 2004,

    Numerical simulation of pulsatile flow through stenotic vessels

    , Turbulence and shear flow phenomena, Sendai, Japan, 25 - 27 June 2003
  • Conference paper
    Giordana S, Radaelli A, Peiro J, Sherwin SJ, Doorly DJet al., 2004,

    Geometry reconstruction and CFD modeling of arterial flows

    , Proceedings ICFD conference on numerical methods for fluid dynamics, Oxford, England, 29 March - 1 April 2004
  • Journal article
    Sherwin SJ, Franke V, Peiró J, Parker Ket al., 2003,

    One-dimensional modelling of a vascular network in space-time variables

    , JOURNAL OF ENGINEERING MATHEMATICS, Vol: 47, Pages: 217-250, ISSN: 0022-0833
  • Journal article
    Sherwin SJ, Formaggia L, Peiró J, Franke Vet al., 2003,

    Computational modelling of 1D blood flow with variable mechanical properties and its application to the simulation of wave propagation in the human arterial system

    , INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Vol: 43, Pages: 673-700, ISSN: 0271-2091
  • Journal article
    Jackson MJ, Bicknell CD, Zervas V, Cheshire NJW, Sherwin SJ, Giordana S, Peiró J, Papaharilaou Y, Doorly DJ, Caro CGet al., 2003,

    Three-dimensional reconstruction of autologous vein bypass graft distal anastomoses imaged with magnetic resonance:: Clinical and research applications

    , JOURNAL OF VASCULAR SURGERY, Vol: 38, Pages: 621-625, ISSN: 0741-5214
  • Journal article
    Crane JS, Jackson MJ, Bicknell CD, Giordana S, Peiro J, Doorly DJ, Sherwin SJ, Cheshire NJW, Caro CGet al., 2003,

    In-vivo geometric features of distal vein graft anastomoses: magnetic resonance surface reconstruction in different graft techniques

    , British Journal of Surgery, Vol: 90, Pages: 16-16, ISSN: 0007-1323
  • Journal article
    Doorly DJ, Franke PT, Papaharilaou Y, Giordana S, Sherwin S, Peiró Jet al., 2003,

    Measuring and modelling the interaction between the arterial wall and blood flow transport

    , Internal Medicine Clinical and Laboratory, Vol: 11, Pages: 3-13, ISSN: 1590-9271

    This work describes computer simulation and experimental techniques applied in combination to investigate the geometry and haemodynamics of arteries, with particular reference to arterial graft design. The geometry of grafts is determined from in-vivo measurements and from resin casts by magnetic resonance imaging (MRI). Computational fluid dynamics (CFD) simulations are used to investigate the relation between arterial geometry, wall shear stress and particle transport. The use of stereo-lithographic (STL) techniques to supplement conventional MRI in-vivo, and to help to bridge the gap with computational modelling by providing realistic models for experimental investigations is reviewed. Methods to investigate the integrated fluid shear loading of particles, the transport of vasoactive species such as ADP, the residence time and the role of geometry in flow mixing are described. Finally the combined application of CFD, MRI and STL to study the flow in grafts and the effects of disease progression is discussed.
  • Book chapter
    Peiro J, Sherwin SJ, Parker KH, Franke V, Formaggia L, Lamponi D, Quarteroni Aet al., 2003,

    Numerical simulation of arterial pulse propagation using one-dimensional models

    , Wall-fluid interactions in physiological flows, Editors: Collins, Pontrelli, Atherton, Collins, Pontrelli, Atherton, Publisher: WIT Press, Pages: 1-36, ISBN: 9781853128998
  • Conference paper
    Pitt R, Sherwin SJ, Theofilis V, 2003,

    Biglobal stability analysis of stenotic flow

    , Turbulence and shear flow phenomena, Sendai, Japan, 25 - 27 June 2003
  • Conference paper
    Sherwin SJ, Blackburn HM, 2003,

    BiGlobal instabilities of steady and pulsatile flow in a 75% axisymmetric stenotic tube

    , International bio-fluid symposium and workshop, Caltech, USA, 12 - 14 December 2003
  • Journal article
    Franke V, Sherwin S, Parker K, Watkins N, Ling W, Fisk NMet al., 2003,

    Time domain computational modelling of 1D arterial networks in the placenta

    , ESAIM: M2AN, Vol: 37, Pages: 557-580
  • Journal article
    Papaharilaou Y, Doorly DJ, Sherwin SJ, 2002,

    The influence of out-of-plane geometry on pulsatile flow within a distal end-to-side anastomosis

    , JOURNAL OF BIOMECHANICS, Vol: 35, Pages: 1225-1239, ISSN: 0021-9290
  • Journal article
    Jackson MJ, Papaharilaou Y, Giordana S, Bicknell CD, Zervas V, Sherwin SJ, Doorly DJ, Peiro J, Cheshire NJW, Caro CGet al., 2002,

    <i>In vivo</i> geometric features of femoral bypass distal anastomoses

    , BRITISH JOURNAL OF SURGERY, Vol: 89, Pages: 56-56, ISSN: 0007-1323
  • Journal article
    Caro CG, Schroter RC, Watkins N, Sherwin SJ, Sauret Vet al., 2002,

    Steady inspiratory flow in planar and non-planar models of human bronchial airways

    , PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 458, Pages: 791-809, ISSN: 1364-5021
  • Journal article
    Caro C, Jeremy J, Watkins N, Bulbulia R, Angelini G, Smith F, Wan S, Yim A, Sherwin S, Peiró J, Papaharilaou Y, Falzon B, Giordana S, Griffiths Cet al., 2002,

    The geometry of unstented and stented pig common carotid artery bypass grafts

    , BIORHEOLOGY, Vol: 39, Pages: 507-512, ISSN: 0006-355X
  • Journal article
    Papaharilaou Y, Doorly DJ, Sherwin SJ, Peiro J, Griffith C, Cheshire N, Zervas V, Anderson J, Sanghera B, Watkins N, Caro CGet al., 2002,

    Combined MR imaging and numerical simulation of flow in realistic arterial bypass graft models

    , BIORHEOLOGY, Vol: 39, Pages: 525-531, ISSN: 0006-355X
  • Conference paper
    Frankel SH, Sherwin SJ, Varghese SS, 2002,

    Numerical simulation of pulsatile flow through stenotic vessels of different local morphologies

    , 24th Annual International Conference of the Engineering-in-Medicine-and-Biology-Society/Annual Fall Meeting of the Biomedical-Engineering-Society (EMBS 2002 BMES), Publisher: IEEE, Pages: 1307-1308, ISSN: 1094-687X
  • Book chapter
    Sherwin SJ, Doorly DJ, 2002,

    Flow dynamics within model distal arterial bypass grafts

    , Vascular Grafts: experiment and modelling (Advances in fluid mechanics series), Editors: Tura, Rahman, Satish, Tura, Rahman, Satish, Publisher: WIT Press, Pages: 327-374, ISBN: 9781853129001
  • Journal article
    Sherwin SJ, Doorly DJ, Franke P, Peiró Jet al., 2002,

    Unsteady near wall residence times and shear exposure in model distal arterial bypass grafts

    , BIORHEOLOGY, Vol: 39, Pages: 365-371, ISSN: 0006-355X
  • Journal article
    Doorly DJ, Sherwin SJ, Franke PT, Peiro Jet al., 2002,

    Vortical flow structure identification and flow transport in arteries

    , Computer Methods in Biomechanics and Biomedical Engineering, Vol: 5, Pages: 261-273, ISSN: 1025-5842

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