Author(s)

G. Gnudi

Abstract

The respiratory input impedance is often approximated by a ratio of two frequency-dependent polynomials. This ratio generally represents the input impedance (or admittance) of a lumped model characterised by a finite number of resistive, compliant, and inertial elements. In this paper, a new method for evaluating these parameters is presented. It is based on the minimisation of the weighted sum of squares of the apparent power errors, computed at various values of frequency. By adopting this particular criterion function the unknown polynomial coefficients can be evaluated analytically, following Levy's theory. Moreover, the included weighting function is proportional to the square modulus of pressure harmonics,

Keywords