Page 313 - Control Theory in Biomedical Engineering

CHAPTER 11

Continuum NasoXplorer

manipulator with shape memory

actuators for transnasal

exploration

Phoebe Lim, Leoni Goh Yi Ting, Ong Kwok Chin Douglas, Honglin An,
Chwee Ming Lim, Hongliang Ren
Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore,
Singapore

1 Clinical needs and intended engineering
design objectives

According to the Singapore Cancer Registry Annual Registry Report in
2015, nasopharyngeal cancer (NPC) was found to be the seventh most fre-
quent cancer in males in the period 2011–15 (National Registry of Diseases
Office, 2017; Albery, 1995). NPC cancer is proved to be one of the most
lethal cancers in Singapore. Hence it is crucial for patients to seek treatment
as early as possible. However, NPC does not display pronounced symptoms
in the early stages. As a result, patients often only get diagnosed with NPC in
the later stages of the disease. At the same time, it is also crucial to note that
the later the patient gets diagnosed with NPC, the lower the chance of
survival (Taylor et al., 2019). In addition, the rate of recurrence after primary
treatment of NPC ranges from 15% to 58% (Kalairaj et al., 2019). The inter-
val between the initial treatment and recurrence ranges between 1 month
and 10 years (Kalairaj et al., 2019). As a result, there is a need for the
monitoring of the nasopharynx, especially for patients that have received
treatment for NPC, to enable early detection of recurrence, thus allowing
for immediate medical attention. Patients with a family medical history of
NPC can also benefit from a monitoring device for the nasopharynx,
enabling them to assess the region and the surrounding areas.
There are two methods for diagnosing NPC: direct nasopharyngoscopy
and indirect nasopharyngoscopy by a skilled physician. For indirect naso-
pharyngoscopy, the physician employs the use of small unique mirrors

Control Theory in Biomedical Engineering © 2020 Elsevier Inc.
https://doi.org/10.1016/B978-0-12-821350-6.00011-1 All rights reserved. 287