Annals of Biomedical Engineering

, Volume 37, Issue 11, pp 2266–2287

The Use of Finite Element Methods and Genetic Algorithms in Search of an Optimal Fabric Reinforced Porous Graft System

  • M. S. Yeoman
  • B. D. Reddy
  • H. C. Bowles
  • P. Zilla
  • D. Bezuidenhout
  • T. Franz
Article

Abstract

The mechanics of arteries result from the properties of the soft tissue constituents and the interaction of the wall layers, predominantly media and adventitia. This concept was adopted in this study for the design of a tissue regenerative vascular graft. To achieve the desired structural properties of the graft, most importantly a diametric compliance of 6%/100 mmHg, finite element methods and genetic algorithms were used in an integrated approach to identify the mechanical properties of an adventitial fabric layer that were required to optimally complement an intimal/medial polyurethane layer with interconnected porosity of three different size classes. The models predicted a compliance of 16.0, 19.2, and 31.5%/100 mmHg for the non-reinforced grafts and 5.3, 5.5, and 6.0%/100 mmHg for the fabric-reinforced grafts. The latter, featuring fabrics manufactured according to the required non-linear mechanical characteristics numerically predicted, exhibited an in vitro compliance of 2.1 ± 0.8, 3.0 ± 2.4, and 4.0 ± 0.7% /100 mmHg. The combination of finite element methods and genetic algorithms was shown to be able to successfully optimize the mechanical design of the composite graft. The method offers potential for the application to alternative concepts of modular vascular grafts and the incorporation of tissue ingrowth and biodegradation.

Keywords

Adventitial reinforcement Constitutive model Diametric compliance Numerical modeling Optimization Vascular mechanics Vascular prosthesis 

Copyright information

© Biomedical Engineering Society 2009

Authors and Affiliations

  • M. S. Yeoman
    • 1
    • 3
  • B. D. Reddy
    • 1
  • H. C. Bowles
    • 2
  • P. Zilla
    • 3
  • D. Bezuidenhout
    • 3
  • T. Franz
    • 3
  1. 1.Centre for Research in Computational and Applied MechanicsUniversity of Cape TownRondeboschSouth Africa
  2. 2.Finite Element Analysis ServicesCape TownSouth Africa
  3. 3.Cardiovascular Research Unit, Chris Barnard Department of Cardiothoracic Surgery, Faculty of Health SciencesUniversity of Cape TownObservatorySouth Africa

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