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Inertance

  • Nicolaas Westerhof
  • Nikolaos Stergiopulos
  • Mark I. M. Noble
  • Berend E. Westerhof
Chapter

Abstract

Inertance relates the pressure drop with the acceleration of flow. When blood flow is subjected to an increase in pressure difference the flow will change. Assuming no friction, the relation between the pressure drop, ΔP(t) and the rate of change of blood flow dQ/dt, depends on the density of the blood, ρ, the cross-sectional area, A = πri2, and the length, l, of the blood vessel. We call this combined effect the inertance, L = ρ l/A. Inertance pertains to oscillatory pressure and flow and plays a dominating role in large blood vessels, where the viscous resistance is small and pulsatility is considerable. Inertance and Poiseuille resistance together form the basis of the Oscillatory Flow Theory. The inertance and vessel compliance in combination determine the wave speed and the characteristic impedance of a blood vessel.

Keywords

Blood density Flow reversal Aortic valves Wave speed Characteristic impedance 

References

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Copyright information

© Springer International Publishing AG, part of Springer Nature 2019

Authors and Affiliations

  • Nicolaas Westerhof
    • 1
  • Nikolaos Stergiopulos
    • 2
  • Mark I. M. Noble
    • 3
  • Berend E. Westerhof
    • 1
  1. 1.Department of Pulmonary Diseases, Amsterdam Cardiovascular SciencesVU University Medical CenterAmsterdamThe Netherlands
  2. 2.Laboratory of Hemodynamics and Cardiovascular TechnologyEcole Polytechnique Fédérale de Lausanne (EPFL), Institute of BioengineeringLausanneSwitzerland
  3. 3.Cardiovascular Medicine, Department of Medicine and TherapeuticsUniversity of AberdeenAberdeenUnited Kingdom

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