Chemistry Reference
In-Depth Information
at an ambient temperature of 303 °C (curve 3). Due to walking, the patient
started sweating and, at the same time, his sugar level dropped. Despite the
fact that after about 25 min the person was not feeling well (the need for
sugar became apparent), an increase in sweat formation could not be
detected because it was masked by the actual sweat formation due to
walking exercise. This experiment shows very clearly that the system is not
reliable as an early-warning system for diabetes unless special precautions
are taken to eliminate the possible sources of interference; for example, use
of the system in a hospital environment could be possible.
For the detection of cystic fibrosis, which is a quantitative analysis, the sit-
uation is different because such an analysis is performed only in the hospi-
tal environment. This requires that the conditions to execute such a test with
the sensor system can be chosen and controlled in such a way that possible
interference is avoided. In addition, for cystic fibrosis detection, the analyst
is interested in the electrolyte concentration of the sweat, regardless of how
this sweat formation was obtained (high temperature, exercise), with the
implication that the sources of interference are much less for cystic fibro-
sis detection than was the case for the detection of low sugar level in the
blood. The complication in this type of analysis is that it is not enough to
6.00E
+
05
R
(ohm)
5.00E
+
05
4.00E
+
05
3.00E
+
05
2.00E
+
05
1
1.00E
+
05
2
0.00E
+
00
-4
-3
-2
-1
0
1
2
3
4
Normalised
t
10.8
Resistance measured between two yarn electrodes implemented
in an electrochemical cell positioned at the leg of a human body
as a function of time. Sweat formation rate (1) for normal people
under strict conditions and (2) for cystic fibrosis patient.
