Biomedical Engineering Reference
In-Depth Information
Fig. 8.17
The dendrogram tree clustering for the children data set using (
8.15
), in healthy (Hc),
asthma (A) and cystic fibrosis (CF)
Additionally, we also looked at the real part of impedance values at 6 Hz, i.e.
R
6,
which were also close to the reported and expected values from literature.
Before analyzing the MDS results, it is necessary to understand the nature of the
respiratory restrictions presented by these groups of patients. Normal quiet breath-
ing (such as during the forced oscillation technique lung function test) is accom-
plished by contraction of the diaphragm, the parasternal muscles and the scaleni.
During inspiration, the diaphragm pulls the lower surfaces of the lung downwards.
Expiration results from simple relaxation of these muscles. Changes in the elas-
tic recoil of the lungs (more, or less, stiffness) will affect their normal function, in
particular total lung volume and pressure-volume relationships.
