Page 315 - Control Theory in Biomedical Engineering

Continuum NasoXplorer manipulator with shape memory actuators 289

hospitals or clinics. As the diameter of the nostril opening averages 10mm
(Schriever et al., 2013), our device aims to have a total diameter of less than
5mm. This not only allows the device to move smoothly within the region,
but also reduces the likelihood of the device touching any sensitive tissue.
The final prototype of NasoXplorer has a width of 3–3.84mm at the work-
ing end. The size of the nostrils’ opening also restricts the number of tubes
and wires we can use. The NasoXplorer consists of a single tube, with a sin-
gle working lane. Materials used in the NasoXplorer include an acrylic tube
and a shape memory alloy (SMA) spring.
Component Material
Body Acrylic tube
Body Aluminum tube
Spring Flexinol actuator spring CH 337
Loose wires Enamel coated copper wire
Bendy tube FLX-9070

The NasoXplorer has 2 degrees of freedom—one is characterized using
Arduino, and the other is by manually rotating the working device. NasoX-
plorer also aims to minimize patient discomfort. This was crucial in our
manufacturing process since the NasoXplorer is to be self-administered.
Conventional nasal endoscope treatments may use a topical anesthetic
(Atar, 2014). However, it is worth noting that the use of the anesthetic does
not guarantee any lack of discomfort and will only serve to alleviate patient
discomfort. In a study, patients rated the discomfort in sedated nasopharyn-
goscopy as about 2–3 on a scale of 1–10 with 10 being the most painful
(Gaviola et al., 2013; Huang et al., 2001; Morgan et al., 1995). Hence,
the NasoXplorer aims to minimize patient discomfort by minimizing the
diameter of its working end and creating a simple maneuvering system to
allow patients to navigate the nasopharynx easily.
Subsequent prototypes will aim at containing the control system as well
as reducing its size to reduce cost and allow the device to be more portable
for the convenience of patients.
As the design specification consultant, the requirements and guidelines
mention in this document will ensure that the information stated is met
and adhered to.
This section discusses the specifications and design features of the device
as well as restrictions imposed on its design. The NasoXplorer has no inten-
tion of curing NPC and will not be sufficient to provide treatment to