55
Human NIBP Nano
Owner’s Guide
0
50
100
150
200
25
26
27
28
29
30
Time (s)
Pressure (mmHg)
Finger pressure
Brachial pressure
Pre
ss
ure
(m
m
H
g)
Time (s)
Brachial pressure
Finger pressure
0
50
100
150
200
25
26
27
28
29
30
Time (s)
Pressure (mmHg)
Finger pressure
Brachial pressure
Pre
ss
ure
(m
m
H
g)
Time (s)
Finger pressure
Brachial pressure
Pressure gradient
Mean finger blood pressure is lower than mean intra-arterial brachial
pressure due to a pressure gradient over the arm arteries caused by flow.
This pressure decay was found to increase with age, whereas pulse wave
amplification is highest in the young. Due to the combined eff ects of pulse
wave amplification and pressure decay, systolic pressure is elevated in
the young but equal to or even lower than brachial pressure in elderly
subjects. The mean pressure gradient is clearly present in Figure A–10 and
Figure A–11.
Bias and precision
In a group of 53 subjects, described in previous studies [Bos 1992, Idema
1987, Rongen 1995] the following data were obtained for brachial and
finger pressure:
Figure A–10
Finger and brachial artery
pressure waveforms in
a woman aged 73. [Data
from a study in elderly
healthy volunteers by
Rongen et al., 1995.]
Figure A–11
Finger and brachial artery
pressure waveforms in a
man aged 27. [Data from
study of Harms et al,
1999.].
