invasive pressure data obtained from the aortic arch, with measurements taken
on the left arm. Validation was performed in subjects aged between 30 and 80
years.
Central blood pressure measurement results may not be accurate in subjects
who are not similar to those used in validation.
3.5 Pulse Wave Parameters Calculations
Referring to Figure 19, the equations for calculating pulse wave parameters
displayed on the main screen and Pulse Wave Analysis screen are:
Suprasystolic Augmentation index (%):
0
1
0
3
sAI
p
p
p
p
−
−
=
Suprasystolic Pulse rate variability (milliseconds):
(
)
∑
−
=
−
+
−
−
=
1
2
2
1
,
0
1
,
0
2
1
sPRV
N
n
n
n
t
t
N
Suprasystolic Pulse Rate (beats per minute):
(
)
∑
=
−
−
−
=
N
n
n
n
t
t
N
2
1
,
0
,
0
1
1
sPR
Signal to Noise Ratio (decibels):
(
)
(
)
−
−
=
∑
=
N
n
n
t
p
t
p
N
t
p
t
p
1
2
2
10
)
(
)
(
1
)
(
)
(
log
10
SNR
where
∫
=
=
T
t
dt
t
f
T
t
f
0
)
(
1
)
(
Systolic ejection period (milliseconds):
0
4
sSEP
t
t
−
=
Reflected wave transit time (peak-to-peak, milliseconds):
1
3
p
sRWTT
t
t
−
=
Reflected wave transit time (foot-to-foot, milliseconds):
0
2
f
sRWTT
t
t
−
=
Suprasystolic Pulse Pressure (mmHg):
)
,
max(
sPP
0
3
0
1
p
p
p
p
−
−
=
Suprasystolic Pulse Pressure Variation (%) of the rhythm strip with n pulses:
( )
( )
n
n
p
p
min
max
sPP
n
−
=
and then
(
)
(
)
(
)
(
)
)
min
max
(
2
1
min
max
sPPV
n
n
n
n
sPP
sPP
sPP
sPP
+
−
=
Maximum Suprasystolic pressure gradient (mmHg/s):
=
dt
t
dP
t
)
(
max
sdP/dt
Page 23 of 31
BP+ User Manual (R7)
