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Fig. 20.6
LIC of a patient affected by AIDS. Two posible outcomes (read text).
with the less favourable LIC) and another one living in a modern country. The
difference in LICs is due to both a correct diagnostic and an appropriate treatment.
Figure 20.7 shows the LIC of a patient that has suffered a car accident in his
thirties, resulting in permanent spine damage. Two main regions can be seen for the
LIC: the one before the accident and the one after. Despite the sharp increase in the
μ
I
(
value resulting from the accident, the shape of each region resembles that of
a normal life, like in figure 2.
x
)
Fig. 20.7
LIC of a patient with permanent spine damage caused by an accident
We define a Life Quality Curve (LQC) as a graphical representation of the mem-
bership degree that a person has to the fuzzy set
L
of good quality of life over time.
This curve is defined by the expression:
t
As can be easily seen, such an expression generates a symmetrical curve from LICs
whose axis of symmetry is
y
y
=
μ
L
(
x
)=(
1
−
μ
I
(
x
))
,
=
0
.
5. Since the meaning of such type of curves is