Page 480 - Flexible Robotics in Medicine

474 Chapter 21

forceps tool through the working channel of the flexible endoscopic manipulator. The
forceps are guided to the target site and a sample is collected and subsequently analyzed.
Though the process may sound simple, this procedure has its limitations.

Head and neck areas are compact and delicate areas in the body. Also, the nasopharynx is a
problematic area to examine, as it is located deep within the head. It is also not easily seen by
direct physical examination. Other than diagnosing tumors, a nasopharyngeal endoscopic
examination can diagnose sleep disorders such as snoring and sleep apnea [5].Hence, it isof
maximum importance that the distal end of the nasal endoscopic manipulator is flexible and
actively controllable to maneuver through the contours of the nasal cavity [6]. Therefore the
use of a nasal endoscope is to examine the interior surfaces of an organ or tissue to allow
clear visualization [7]. This procedure is a minimally invasive diagnostic medical procedure.
Hence, the scope should be small enough such that biopsies can be conducted in the clinic
and cause minimal discomfort to the patient even without the use of sedatives. However,
when structures are complicated and require the endoscopic manipulator to manipulate around
curved corners or places that are narrow and difficult to reach, it becomes a problem. The
procedure is seldom painful, but it can be very uncomfortable for some of the nasal cavity is
unusually narrow [8], or in the case of a condition called nasal polyps, which is the growth of
small cyst during infection of the nasal mucosa, the nasal lining becomes swollen [9].In
these situations, it can be challenging to move around the nasal cavity and to avoid collision
with the surrounding tissues.
It is still unclear what causes NPC in the first place [10]. A diet rich in salt-cured fish and
meat exposes a person to the risk of having NPC, and this diet is typical in Asia,
particularly in China, which is mainly the reason why NPC is more common in that region
[11]. The most commonly diagnosed symptom of NPC is the growth of a lump or tumor at
the nose or the neck [12]. Currently, the standard diagnostic option for NPC is by inserting
a nasopharyngoscope into the nasal passageway of the patient [13]. A physical examination
for a lump, such as swollen lymph nodes, is usually done first before undergoing
procedures such as nasopharyngoscopy inserted through the patient’s nasal passageway.
Other examination options of imaging tests include computed tomography scan, magnetic
resonance imaging for more precise noninvasive visualization.

21.1.2 Clinical significance

NPC is particularly common in southern China and Southeast Asia, which affects 10 50
per 100,000 people per year [14]. Currently, the approach to diagnose NPC is to have the
patient under local anesthesia to allow the nasal endoscope to be inserted through the nose
to view the nasopharynx. A small tissue sample (biopsy) is for subsequent tests for cancer.
However, the nasopharynx is a difficult area to examine and maneuver nonintuitively