Forward electrical transmission line model of the human arterial system

Abstract

A forward mathematical model of the human arterial system, based on an electrical transmission line analogy, has been developed, using a new method for the calculation of peripheral impedance. Simulations of the human arterial system under normal and stenotic arterial conditions were compared with other published simulations, as well as measured clinical data and known clinical quantitative and qualitative characteristics: the harmonic arterial input impedance spectrum demonstrated a mean error of 0.07-0.1 mmHg.s.cm(-1), compared with equivalent simulation and physiological data, respectively; qualitative and quantitative variation of blood pressure and flow waveforms along the arterial tree followed clinical trends; arterial pulse wave velocities compared favourably with physiological data close to the aortic root (-50-20 cm s(-1) difference), but there were larger differences in the periphery (149-1192 cm s(-1) difference); qualitative as well as quantitative variation of blood flow waveforms with progressive stenotic arterial disease, as measured by the pulsatility index, demonstrated an error between 2 and 16% in comparison with mean clinical data for critical stenosis. Under the given test conditions, the forward model was found closely to represent clinically observed haemodynamic characteristics of the human arterial system.

Numerical analysis of pulsatile blood flow and vessel wall mechanics in different degrees of stenoses

“…The wall thickness was h ¼ 0:55 mm, Young's Modulus E ¼ 0:4 MPa and Poisson's ratio n ¼ 0:499. The dimensions and wall properties are the same as the external iliac artery in John (2004).…”

“…3) from a 1D transmission line model of the arterial tree (John, 2004) as boundary conditions for the flow field. For the increasing degrees of stenosis, it shows a larger reduction in the peak flowrate but only a slightly reduction in the mean flowrate.…”

Frequency-Domain Modeling of Transients in Pipe Networks with Compound Nodes Using a Laplace-Domain Admittance Matrix

“…Many authors have utilised different methods to achieve a frequency-domain representation of complex networks (e.g. Ogawa [1980]; Margolis and Yang [1985]; Boucher and Kitsios [1986]; John [2004]; Kim [2007Kim [ , 2008a). However, these methods were designed simply for networks with junctions and reservoir node types only, with the exception of Kim [2007Kim [ , 2008a who included an emitter elements and some surge protection devices in his formulation.…”

Transient Modeling of Arbitrary Pipe Networks by a Laplace-Domain Admittance Matrix

“…Recently John [2004], applied an impedance based method to a tree network model of the human arterial system.…”

“…arterial blood flow) [John, 2004], and pipeline distribution systems (e.g. gas, petroleum, and water) [Fox , 1977;Chaudhry, 1987;Wylie and Streeter , 1993].…”