Biomedical Engineering Reference
In-Depth Information
Fig. 7.16
Real part of impedance
R
6 evaluated at 6 Hz (
left
) and the tissue hysteresivity
η
r
in
1
: healthy and
2
: kyphoscoliosis. See corresponding
p
-values discussed in text
Ta b l e 7 . 9
Biometric
parameters of the healthy
children. Values are presented
as mean
±
standard deviation
values
Healthy
(16)
Female/male
13/3
Age (yrs)
9
.
66
±
0
.
47
Height (m)
1
.
39
±
0
.
07
Weight (kg)
32
.
3
±
6
.
34
factor
QF
6. The latter suggested an over-damped dynamical system. The reduced
lung and chest wall compliances increase the elastic load on the respiratory muscles
and therefore increase the inspiratory pressure needed to inhale a given air volume.
Consequently, the work of breathing is increased, reflected in the lower values for
the power factor
PF
6.
Tissue elastance was not significantly different between the groups, but the tissue
hysteresivity
η
r
provided a significantly increased heterogeneity in the lungs of the
kyphoscoliosis group. Indeed, this result reflects the modified structure of the lungs
as originated by the spinal deformity. For example, airway obstruction can occur
in some cases as a consequence of changes in the geometry of the airways, or as a
result of the aorta impinging on the tracheal wall.
7.3.4 FOT Measurements on Children
The measurements on children included also a
healthy children group
. This study
was approved by the local Ethics Committee of the University Hospital in Antwerp
(UZA) and informed consent was obtained from all volunteers before inclusion in
the study. The study involved 16 healthy children and their corresponding biometric
values are given in Table
7.9
. The measurements were performed in May 2009, at
the St. Vincentius Basis School in Zwijnaarde, Belgium.
