Page 80 - Flexible Robotics in Medicine

64 Chapter 3

the advantages. The flaws of the large outer diameter and low bending angle can be
mitigated with the material selection with additional research and development.

Advantages: FlexDiamond prides itself on the optical zoom capability that is made possible
by the diamond cuts on the insertion tube. The optical zoom is made possible by the
movement of 5 mm in the z-axis direction. The optical zoom capability will allow smaller
abnormalities in the nasopharynx to be viewed without pushing the insertion tube into the
subject’s nasal cavity. This will ensure that minimal discomfort is experienced by the
subject. The specially designed gearbox system that houses the insertion tube allows the
subject to use this prototype in the comfort of his home. The self-administered nature of
FlexDiamond will enable the subject to perform nasopharyngoscopy without the presence of
a physician.

Disadvantages: The bending angle of 90 degrees for both up and down direction is lacking
when compared to the nasopharyngoscopes that are available. The average bending angle of
the existing nasopharyngoscopes is about 135 degrees. The viewing area, when combining the
bending angle and the camera’s field of vision, is at a value of 270 degrees (Table 3.12).

While current endoscopes may not be suitable for home use, it has been observed that
flexible endoscopes have conferring advantages over rigid endoscopes in terms of allowing
a more comfortable insertion and providing a wider viewing angle for users (Table 3.13).
As such, we incorporated this concept into our design and came up with a flexible
manipulator with diamond-shaped cutting for high steerability and bending angle.

Major prior arts of flexible nasopharyngoscope

1. Olympus Corporation: The Olympus ENF-V3’s key selling point will be its diameter
value of 2.6 mm for the distal end of the nasopharyngoscope. The diameter of the

Table 3.12: Comparison of prior arts.
Olympus Karl Storz 11101 Optim ENTity LED
Prototypes ENF-V3 VP/VN NasoView FlexDiamond
Outer diameter (mm) 2.9 3.7 3.6 7
Bending angle (degrees) 130 140 135 90
Effective vision range 360 360 360 270
(degrees)
Axes of movement 2 2 2 3

Optical zoom (mm) No No No 5
Self-administered No No No Yes
Home-based No No No Yes