Vascular Branching

159

(5.3.8)

In terms of the mother or source vessel characteristic impedance, Z,,,

and individual daughter or branch vessel characteristic impedance,

we obtain for the local wave reflection due to equi-vascular branching

only:

(5.3.9)

Fig.

5.3.1

Schematic representation

of

a branching vascular junction,

An

equi-bifurcation

is illustrated with characteristic impedance

of

the mother

(Zo,,,)

and daughter

(Z,,,)

vessels

respectively.

An alternative method that assumes frequency independence

of

characteristic impedance, is derived from the water-hammer formula (Li,

1985). In this formulation, the pressure and flow are expressed as:

P=p*v*c

(5.3.10)

Q=v.m2

(5.3.11)

The characteristic impedance is defined simply by the ratio

of

pressure to

flow, i.e.