B-K Medical Pro Focus 2202, User Manual

Page: 226 / 356

226 Chapter 15
Accuracy of Resistance Index/Pourcelot Ratio (RI)
Accuracy of Pulsatility Index (PI)
Accuracy of A/B Ratio (Stuart Index)
Accuracy of Heart Rate (HR)
A RI
( )
RI
max
RI
min
–
( )
RI
--------------------------------------------- where
RI
max
1.025 F
max
t
PS
( ) ×
0.975 F
max
t
ED
( ) ×
–
( )
1.025 F
max
t
PS
( ) ×
---------------------------------------------------------------------------------------------------------------- and
RI
min
0.975 F
max
t
PS
( ) ×
1.025 F
max
t
ED
( ) ×
–
( )
0.975 F
max
t
PS
( ) ×
----------------------------------------------------------------------------------------------------------------
Example: F
max
t
PS
( )
10 F
max
t
ED
( ) ×
A RI
( )
1% and
F
max
t
PS
( )
2 F
max
t
ED
( ) ×
A RI
( ) ⇒
=
=
⇒
=
=
=
10%
=
=
A PI
( )
A F
max
t
PS
( )
F
max
t
MD
( )
–
( )
A F
max
t
( )
t t
SS
=
t
ED
∑
⎝ ⎠
⎜ ⎟
⎜ ⎟
⎜ ⎟
⎛ ⎞
Assuming F
max
t
PS
( )
F
max
t
MD
( )
Provides A F
max
t
PS
( )
F
max
t
MD
( )
–
( )
A F
max
( )
5%
A PI
( )
A F
max
( )
A F
max
t
( )
t t
SS
=
t
ED
∑
⎝ ⎠
⎜ ⎟
⎜ ⎟
⎜ ⎟
⎛ ⎞
+ 10% = =
⇒
= =
»
+ =
A A/B
( )
A B/A
( )
2 A F
max
( ) ×
10% = = =
A HR
( )
A time
( )
=