Biomedical Engineering Reference
In-Depth Information
Fig. 8.7 a Pin connection of
TGS sensor b conditioning
circuit
The total time duration of the test is of 25 s. The initial 15 s are spent to get a
steady-state level of the TGS sensor. While the sensor accommodates with the
environment, the timer clearly displays the time elapsed. After the 15th second, the
message box displays ''Apply Breath'' and the test is made for another 10 s. After
completion of 25 s, the VI filters the signal using wavelet denoising and calibrates
the results using peak and valley detection of the sensor response. The ultimate
change is calculated and according to the change measured with sensor, the system
gives results of severity of asthma. Figures
8.9
and
8.10
display the patient data
entry window and level of asthma detection with prescribed medicines.
8.1.10.3 Result
The sensor used for detection of nitrogen oxide level and the sensor response for
different patients corresponding to nitrogen oxide (NO) level in their breath is
shown in Figs.
8.11
,
8.12
, and
8.13
: result window. Sensor indicates the presence
of NO in terms of corresponding amplitude signal. The amplitude of the sensor
output signal varies in accordance with the NO level.
The reference line is formed through the breath sample analysis of healthy
people. From the sensor responses of healthy breath samples, the threshold level of
Search WWH ::
Custom Search