The
Venous
System
191
compliance and frequency. Brower and Scholten (1 975) demonstrated
this latter in a collapsible Penrose, while Anliker et al. (1969) measured
this in dog veins. The former was analytically derived by Kresch and
Noordergraaf (1 969) for the case of uniform collapse tube:
A
=
/p(dAldp)
kv
where
and
(6.3.16)
(6.3.1
7)
(6.3.18)
Where
Jo
and
J1
are Bessel function of the zeroth and first order and
A
is
the cross-sectional area, dNdp is the distensibility of a circular tube with
the same cross-sectional area,
K
is the shape factor which equals 1
.O
for a
circular vessel and 2.0 for a collapsed vessel,
p
and
are the density and
viscosity of the fluid. Wave velocity is dependent on shape is observed
by Bailie (1972).
Thus, in this formulation the phase velocity is
frequency dependent and cross-sectional area dependent.
