Biomedical Engineering Reference
In-Depth Information
Fig. 10
The addition of a cushion on the colon analogue, in order to fix it in the testing ring
N
2
O
sensor A
Pump
Flow control
valve
N
2
O
sensor B
Colon analogue fitted with
sensing ring
Flow control
valve
N
2
O injection syringe
Fig. 11
The new arrangement showing the changes that were implemented and discussed in the
text
After these changes, further experiments were undertaken, Fig.
12
shows plots
with the results for the positions of 0
ı
,90
ı
, 180
ı
and 270
ı
, which previously were
difficult to separate from the collected data.
From these two plots, it can be seen that the values for the gas concentration
[ppm] increase over the time became lower compared to the previous tests. This
is because the volume of the groove and the total volume of the sensor ring has
increased. As can be seen from the graphs there is also a marked difference in the
two curves, which means that now it is possible to differentiate between the two
locations.
