Biomedical Engineering Reference
In-Depth Information
Fig. 5.21
Result of the identification for subject 7 (
left
) and subject 8 (
right
)
Fig. 5.22
Result of the identification for subject 9 (
left
) and subject 10 (
right
)
•
if symmetry exists, then the total input impedance can be calculated in a simpli-
fied, recurrent manner;
•
the impedance exhibits a fractional-order behavior leading to a fractional-order
value for the symmetric case, if the convergence conditions are fulfilled; other-
wise the constant-phase behavior is missing;
•
the ratios for inertance 1
/α
and for the conductance
o
elements do not play a role
in determining the value of the fractional order, the latter being determined solely
by the ratios of the resistance
λ
and of the capacitance
χ
elements.
For the asymmetric tree representation, the following remarks can be summa-
rized:
•
the impedance exhibits a fractional-order behavior in the nominal case, without
fulfilling the theoretical conditions for convergence; in this case it is difficult to
calculate analytically the value of the fractional order;
•
the fractional-order behavior is still present, although the fractal structure and
dimension is not uniquely characterized;
•
the fractional-order value is changing if the degree of asymmetry is changed (this
observation is significant for the case of diseased lungs).
