Biomedical Engineering Reference
In-Depth Information
Fig. 1
Proposed colon leak detection system for open surgeries
3
Materials and Methods
For the experimental a box with dimensions of 115
57 mm was used to
simulate the interior part of the abdomen. The colon was represented by a sealed
rigid pipe placed inside the box. A flexible tube from the box goes to the inlet of the
N
2
O infra-red sensor and gas is pulled through the sensor by a pump with a flow rate
of 1 L/min. An injection pipe goes through the box into the rigid tube to allow gas
to be injected into the rigid pipe. The nature of the experimental procedure meant
that the methods for releasing the trace gas such as dissolving the gelatine capsule
or crushing it through a bowel compression, were not possible. Instead a capsule
was placed within a syringe and by compressing the syringe the capsule would be
fractured and the released gas would then be injected, via the flexible tube into the
rigid pipe (Fig.
2
).
To simulate a diversity of anastomotic leak conditions, a series of rigid tubes
were produced with holes varying from 1 to 3 mm drilled in them to simulate
115
