COMPARISON OF LINEARIZED WAVE PROPAGATION MODELS FOR ARTERIAL BLOOD FLOW ANALYSIS

Linearized wave propagation models which can be used to predict both transmission characteristics and hydraulic fluid impedance values based upon system input parameters are reviewed. Most of these models considered herein are concerned with the propagation of small, axisymmetric, harmonic disturbances through an incompressible, Newtonian fluid contained within a distensible tube of long length. The equations of motion of the fluid are usually described by the linearized Navier-Stokes equations. The equations of motion of the wall used in the various models showed a great deal of variability. According to the tube equations of motion and the boundary conditions employed, these models can be divided into three categories: constrained, thin-walled tube models; freely moving, thin-walled models; and freely moving, thick-walled models. The differences in the results predicted by these three groups are generally a function of the values of the system parameters. A comparison of the phase velocity and transmission per wavelength predicted by the different models is made. The differences in the parameter variations of the fluid impedance, resistance and inertance among the different models are also discussed. The comparisons demonstrate the existence of significant differences in the values of propagation constant and fluid impedance predicted by the different models. © 1969.