Multi-scale modelling of the blood chamber of a left ventricular assist device

  • 투고 : 2012.09.09
  • 심사 : 2013.05.03
  • 발행 : 2013.03.25


This paper examines the blood chamber of a left ventricular assist device (LVAD) under static loading conditions and standard operating temperatures. The LVAD's walls are made of a temperature-sensitive polymer (ChronoFlex C 55D) and are covered with a titanium nitride (TiN) nano-coating (deposited by laser ablation) to improve their haemocompatibility. A loss of cohesion may be observed near the coating-substrate boundary. Therefore, a micro-scale stress-strain analysis of the multilayered blood chamber was conducted with FE (finite element) code. The multi-scale model included a macro-model of the LVAD's blood chamber and a micro-model of the TiN coating. The theories of non-linear elasticity and elasto-plasticity were applied. The formulated problems were solved with a finite element method. The micro-scale problem was solved for a representative volume element (RVE). This micro-model accounted for the residual stress, a material model of the TiN coating, the stress results under loading pressures, the thickness of the TiN coating and the wave parameters of the TiN surface. The numerical results (displacements and strains) were experimentally validated using digital image correlation (DIC) during static blood pressure deformations. The maximum strain and stress were determined at static pressure steps in a macro-scale FE simulation. The strain and stress were also computed at the same loading conditions in a micro-scale FE simulation.



  1. Ebner, R., Lackner, J.M., Waldhauser, W., Major, R., Czarnowska, E., Kustosz, R., Lacki, P. and Major, B. (2006), "Biocompatibile TiN - based novel nanocrystalline films", Bull. Pol. Ac. Tech., 54, 167-173.
  2. Fraser, K.H., Taskin, M.E., Griffith, B.P. and Wu, Z.J. (2011), "The use of computational fluid dynamics in the development of ventricular assist devices", Med. Eng. Phys., 33, 263-280.
  3. Gregory, S.D., Timms, D., Gaddum, N., Mason, D.G. and Fraser, J.F. (2011), "Biventricular assist devices: a tchnical review", Ann. Biomed. Eng., 39, 2313-2328.
  4. Kopernik, M., Milenin, A., Major, R. and Lackner, J.M. (2011), "Identification of material model of TiN using numerical simulation of nanoindentation test", Mater. Sci. Tech., 27, 604-616.
  5. Milenin, A. (2010), Bases of finite element method, Akademia Gorniczo-Hutnicza, Krakow. (in Polish)
  6. Milenin, A. and Kopernik, M. (2011a), "Comparative analysis of ventricular assist devices POLVAD and POLVAD_EXT based on multiscale FEM model", Acta Bioeng. Biomech., 13(2), 13-23.
  7. Milenin, A. and Kopernik, M. (2011b), "Microscale analysis of strain-stress state for TiN nanocoating of POLVAD and POLVAD_EXT", Acta Bioeng. Biomech., 13(4), 11-19.
  8. Orteu, J.J. (2009), "3-D computer vision in experimental mechanics", Opt. Laser Eng., 47, 282-291.
  9. Pan, W., Fedosov, D.A., Caswell, B. and Karniadakis, G.E. (2011), "Predicting dynamics and rheology of blood flow: a comparative study of multiscale and low-dimensional models of red blood cells", Microvasc. Res., 82, 163-170.
  10. Sarna, J., Kustosz, R., Major, R., Lackner, J.M. and Major, B. (2010), "Polish artificial heart - new coatings, technology, diagnostics", Bull. Pol. Ac. Tech., 58, 329-335.
  11. Wiklund, U., Gunnars, J. and Hogmark, S. (1999), "Influence of residual stresses on fracture and delamination of thin hard coatings", Wear, 232, 262-269.
  12. Yamaguchi, T., Ishikawa, T., Imai, Y., Matsuki, N., Xenos, M., Deng, Y. and Bluestein, D. (2010), "Particle-based methods for multiscale modeling of blood flow in the circulation and in devices: challenges and future directions", Ann. Biomed. Eng., 38, 1225-1235.

피인용 문헌

  1. Development and Application of Multi-Scale Numerical Tool to Modeling Pneumatic Ventricular Assist Devices with Increased Athrombogenicity vol.17, pp.3, 2015,