Biomedical Engineering Reference
In-Depth Information
13.2.4 Technical limitations
The technique of capsule endoscopy has revolutionized the study of the small
intestine; however, the same technical characteristics can represents, from a certain
point of view, limitations of capsule endoscopy. One technical problem reported
is a poor charge of the battery, resulting in short battery life and incompleteness
of examination. There is also concern of the potential toxicity brought by the
batteries. The problem of capsule retention is one of the main complications of
the capsule endoscopy, as mentioned in section 13.1.2.4, and the
Agile
TM
Patency
Capsule may be used to provide an early warning of the intestinal stricture
(ElMatary 2008, Rondonotti
et al.
2007).
At present capsule endoscopy is a diagnostic tool and one major limitation is
the absence of a remote control and the inability to take biopsies or perform any
therapeutic procedure. It is also impossible for the capsule to stay in specific areas
of the small intestine for repeated examinations. Sometimes double-balloon en-
teroscopy should be employed as a complimentary technique after initial imaging
using capsule endoscopy (Yamamoto 2001, Heine 2006).
To overcome the obstacles, the capsule needs an active locomotion mechanism
to vary its speed and reduce the transit time, and a braking mechanism to hold the
movement of capsule for a prolonged time, together with a orienting mechanism to
view around different directions. This would enable a more thorough analysis, at
wherever interesting. A more precise localization system is necessary for both the
actuation and the diagnosis (Wang
et al.
2005, Rondonotti
et al.
2007). Besides, the
integration of sensors for detection of blood, white blood cells, pH, temperature
and pressure measurement, and so forth are also needed to make other diagnostic
and therapeutic tasks feasible. As a successful attempt to fulfill this requirement,
a wireless ingestible capsule endowed with pH, temperature and pressure sensors
developed by SmartPill Corporation and named Bravo (Dickman
et al.
2006,
Gonzalez
et al.
2007), has been approved by FDA in 2006.
13.3 WIRELESS ACTIVE CAPSULE ENDOSCOPE
There has been continuous development and improvement of the wireless capsule
endoscope. Gong
et al.
(2000) introduced a conceptual interactive system, which
included a joystick to communicate with the wireless endoscope, controlling the
light, image capture and transmission of the capsule. Although methods of
propulsion have not been proposed in this paper, the authors did emphasize on
the need of some innovative and intriguing ideas about propulsion for the next
generation of wireless capsule endoscopy. The Intelligent Microsystem Center
(IMC), Seoul, Korea, has launched a project on designing of a multi-functional
capsule endoscope (Kim
et al.
2005). The conceptional capsule will be loaded
with moving mechanism, detecting sensors, medical information acquisition and
treatment system, telemetry and power source. With this device, not only video
based diagnosis but also physiological tests will be feasible in real time manner.
