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Cable-driven flexible endoscope utilizing diamond-shaped perforations: FlexDiamond 49

Figure 3.2
Axis corresponding to the direction of the endoscope and the bending segment (back segment).
to view different regions of the nasopharynx. Nylon strings of 0.35 mm diameter are used for the
cable-driven mechanism, for both the mechanical zooming and bending segment.

3.3.3.3 Materials selection
The material used for the fabrication of all the prototypes is made up of a composite of
95% VeroClear and 5% TangoBlack. This is due to the restriction on the material that the
current 3D printing machine can provide. The current prototype can function without
damaging the endoscope, but the mechanical properties of the prototype should be further
improved in order to develop a prototype that is durable enough for regular endoscopy for
up to 2 years. Additionally, the biocompatibility of the material used should also be
considered. TangoBlack-VeroClear composite is nonbiocompatible with the human body.
However, the design process of the prototype has not reached the stage for clinical trials.
Hence, the TangoBlack-VeroClear composite was used as a substitute to test the
functionality and feasibility of the prototype (Table 3.3).

The material that would be used for the actual prototype would be polyurethane. Altering
the composition of the material will enable us to obtain the desired mechanical strength that
is suitable for the safety, proper functionality, and durability of the prototype. Additionally,
polyurethane is a biocompatible material and is FDA approved.
Verifications tests were done to determine the mechanical properties of both TangoBlack-
VeroClear composite and polyurethane, to determine if the use of TangoBlack-VeroClear
composite is appropriate as a substituting material for polyurethane.
FlexDiamond has two different types of material composition. For the bodies of the
shooting and bending tubes, 5% of TangoBlackPlus was added to provide for the flexibility
needed to achieve bending. For the covers, they were purely made of VeroClear for their
mechanical strength to ensure the performance of FlexDiamond.
FlexDiamond got the name by combining the terms “flexible” and “diamond-shaped”
together, as they are the points of focus and the basis of our whole design, which is a
flexible manipulator with diamond-shaped cuts.