Biomedical Engineering Reference
In-Depth Information
et al.
2004; Rondonotti
et al.
2005; Meng
et al.
2004). In this chapter, we
introduce the state-of-the-art of wireless capsule endoscope. After a description of
the current status, we discuss the promising solutions for a wireless active capsule
endoscope.
13.2 MAJOR WORK IN WIRELESS CAPSULE ENDOSCOPE
The invention of the transistor made it possible to design swallowable electronic
radio telemetry capsules for the study of GI physiological parameters. These
capsules were first reported in the 1950
s
and were used to measure tempera-
ture, pressure and pH (Zworkin
et al.
1957; Mackay
et al.
1957). Although
the clinical applications were limited for these radio transmitting capsules, they
did give inspirations for the invention of the video capsule endoscope. In the
early 1990
s
, complementary metal oxide semiconductor (CMOS) technology for
imaging, along with progresses in application specific integrated circuit (ASIC) for
control system and light emitting diode (LED) for illumination, paved the way for
the advent of wireless capsule endoscope. In May 2000, the first video-telemetry
capsule endoscope was released by an Israeli company Given Imaging. The device,
which was named
M
2
A
TM
(Iddan
et al.
2000) and renamed to
PillCam
TM
later,
received marketing clearance from Food and Drug Administration (FDA) in 2001.
The wireless capsule endoscopy is a breakthrough in GI diagnosis. It releases
the patients from the discomfort caused by conventional GI endoscopy and allows
a direct visualization of the entire small intestine. Clinical practices have proved
capsule endoscopy an effective tool in diagnosis of the diseases of the small intes-
tine, such as obscure GI bleeding (Gossum
et al.
2002); Crohn's diseases (Chermesh
et al.
2008), Non-steroidal anti-inflammatory drugs (NSAIDs) induced damage,
and other indications (Rondonotti
et al.
2007). The device quickly attracted
widespread interest within endoscopists and researchers. Following the emer-
gence of
M
2
A
TM
, other companies and groups, such as Olympus, ChongQing
JinShan, and IntroMedic have developed their own capsule endoscopy systems,
which operate on the same principle as
M
2
A
TM
with more or less improvements.
13.2.1 Products of Given Imaging
13.2.1.1 M2A
TM
and PillCam
TM
SB
The first capsule endoscopy system,
Given
TM
Diagnostic System, was developed
by Given Imaging, which consisted of the first passive wireless capsule endoscope
M
2
A
TM
capsule endoscope is a disposable, swallowable capsule, which has
a dimension of 11 mm
it contains a miniature camera with a CMOS imager designed specifically for
direct imaging within the GI tract, LED lighting system for illumination, and two
silver oxide batteries. Different from the conventional endoscopes, the capsule also
contains an integrated circuit and an RF transmitter for transmitting the images.
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