Biomedical Engineering Reference
In-Depth Information
Time scale
Stream
Sensor
Start measurement sensor
Load selected stream
Loading calibration data
Loading data from stream
Read sensor data
0s - Start
Compare readings to calibration data
Measurement points (Data sets) 0 to i
(The amount of measurement points depends on the amount of
dataset inside the calibration file)
10s - Measurement point 0
i
s - Measurement point i
80s - Stop
Auto-Stop (end of file)
Display leak size and leak orientation under “Leak Detection”
Stop
Fig. 20
The SUSIE workflow diagram
7
Conclusions
The consequences of a failure in the Anastomosis of the colon are serious and any
steps that can be taken to reduce the likelihood of such failure must be welcomed.
The computer simulations were abandoned after demonstrating weaknesses in the
results, also because the simulations were taking close to 48 h for a simulation to
finish due to the complexity of the computational arrangement. The main reason for
running the simulations was to verify if there was any difference between different
sized holes regarding the increase of concentration of nitrous oxide over the time.
For the physical simulations the results presented are very positive because of the
stability that was achieved in the results. The curves for the different places where
the leakage was spotted around the colon analogue presented similar behaviour over
a time of 120 s. It is also possible to see a difference in the increase of nitrous oxide
for these different locations, which allows identifying the place of the leakage.
However, the objective of this project was to allow the surgeon to identify any
anastomosis dehiscence intraoperatively. Such an objective can be achieved with
the method proposed in this paper in a short time (60-120 s).
These tests have shown that it is possible to develop a system to detect the
presence and location of a small hole in a colon analogue. The use of small quantities
of a trace gas coupled to sensing technology should offer more dignified and safer
methods to intraoperatively test the integrity of anastomosis than are available at
present. The advantages of a gas sensing based approach are also currently being
explored by other groups for slightly different procedures though in this case dilute
H
2
is used and the work is primarily associated with a pass/fail type test rather than
one attempting to evaluate the nature of any leak.
Summarizing the whole process, a N
2
O infra-red sensor and gelatin capsules,
which would be introduced into the colon during surgery filled with N
2
Ogas,
would then dissolve and release the gas. A leakage containing nitrous oxide could
