Page 60 - Flexible Robotics in Medicine

44 Chapter 3

Presently, the incision of slits is not seen to be widespread employment in commercial
endoscopes. In the surveillance of NPC using nasoscopes, primary employments are rigidly
segmented serpentine cable-driven endoscopes. These are typically 4 6 mm in diameter
with a bending angle of at least 70 degrees. Rigid endoscopes are more durable as the
bending segments can produce a longer flexural lifespan, and the deflection induced by
rigid bodies is more stable to in vivo musculoskeletal fluctuations than the flexible
counterparts. Rigid endoscopes can undergo high-temperature sterilization where flexible
endoscopes would experience material deformation under these elevated temperatures.

3.2 Specifications and instrumentation

3.2.1 User needs

The following needs of the patients were identified to develop a home-based nasal
endoscope, for the ease of operation.
• To develop a simple control system for the endoscope to facilitate the use of home-
based self-administered NPC surveillance system. This aims to reduce the burden on the
health care personnel and to provide convenience for the patients.
• A minimum bending angle of 90 degrees.
• The prototype should induce minimal discomfort when administered by the patient—such
as a small diameter of the endoscope, coupled with the use of soft and flexible materials.
• The prototype should be in minimal contact with the surrounding tissue throughout the
endoscopy process.
• The prototype should be portable for convenience and ease of use for the patient.
• The material used to construct the prototype should be mechanically robust, durable,
and medically approved to ensure the biocompatibility of the material with a human
body. The prototype should be durable enough for constant use to up to 2 years as
patients are recommended to monitor their condition for the first 2 years closely,
posttreatment [5].
• The prototype should be user-friendly and ergonomic for all patients above the age of 18,
especially those above the age of 35 and the elderly who are more prone to NPC disease.
• The prototype should be an economically viable option as a home-based NPC
surveillance system.

3.2.2 Design considerations for prototype specifications

Apart from the user needs and intended use of this prototype, other design considerations
that we have to take into account are the anatomical variations between different
individuals (Table 3.2).