Information Technology Reference
In-Depth Information
Complement: The complement of a set is an opposite of that set (Fig. 10). For a
fuzzy set A the complement is:
μ
(
x
)
=
1
μ
(
x
)
notA
A
μ
( x
)
A
1
Not A
0
Fig. 10. Example of fuzzy complement
3 Calibration Phase and the System Overview
The system consists of a thermistor, sensing the finger temperature [41]. The sensor is
attached to the finger of a subject and connected to an electronic circuit that is con-
nected to the USB-port on a computer. Music is played to assist the subject to relax
and instructions are given on how to control breathing.
Table 3. Measurement procedure used to create an individual stress profile
Test
step
Observation
time
Conditions
Finger
temp
Notes
1.
3 min
Base Line
2.
2 min
Deep Breath
3.
2+2 min
Verbal Stress
4.
2 min
Relax
5.
2 min
Math stress
6.
2 min
Relax
A calibration phase [42] helps to establish an individual stress profile and is used
as a standard protocol in the clinical environment. For calibration purposes the finger
temperature is measured during different conditions in 6 steps (baseline, deep breath,
verbal stress, relax, math stress, relax) as shown in Table 3. The baseline indicates the
representative level for the individual when he/she is neither under intense stress nor
in a relaxed state. The clinician asks the subject to read a neutral text during this step.
The clinician not only identifies an individual's base finger temperature, but also
notes fluctuations and other effects, e.g. disturbances in the environment or observes
the subject's behavior. In the step 'Deep-breath', the subject breaths deeply which
under guidance normally causes a relaxed state. How quickly changes in temperature
occur during this step is relevant and recorded together with observed fluctuations.
 
Search WWH ::




Custom Search