Biomedical Engineering Reference
In-Depth Information
Ta b l e 8 . 3
Time delay in
samples; values are given as
mean
Mean
±
std
Confidence intervals
standard deviation;
values in brackets indicate the
corresponding 95 %
confidence intervals
±
545
±
185
Healthy adults
(487, 603)
±
COPD
798
208
(733, 863)
Kyphoscoliosis
352
±
50
(330, 373)
Healthy children
373
±
96
(339, 407)
Asthma
336
±
93
(308, 365)
Cystic fibrosis
377
±
96
(345, 408)
Fig. 8.19
ANOVA test for the calculated delay values: (
left
) the adult groups (
p
0
.
001); (
right
)
the children groups (
p<
0
.
0155)
Fig. 8.20
Dependence of
delay values with age in each
group
8.3.3 Fractal Dimension and Identification of Power-Law Trends
On each PV loop and PPP plot from each patient, the box-counting method was
applied to obtain the fractal dimension
F
d
and the constant
C
for each patient. The
models are identified for each set of measurements using the least-squares algo-
rithm [
136
]. Consequently, the box-counting values
N(ε)
and the box-sizes 1
/ε
