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ROBOTICS continued
tic laboratory has been shrunk down
to a size that enables insertion into
a small surgical opening in the eye.
Incredibly, the PillCam from Given
Imaging (Yoqneam, Israel) and other
robotic capsule endoscope (RCE) designs take microrobotics a step further
by adding vision to their repertoire:
these swallowable, clinically administered, and commercially available
capsules or pills (roughly 11 × 26 mm
in size) take pictures as they traverse
the human gastrointestinal (GI) tract.
Already proven in esophageal, colon,
and especially small-intestine disease
diagnosis, RCEs with advanced means
of locomotion, drug delivery, and even
biopsy capability are in the works.
Introduced back in 2000, the PillCam
has been used on more than 1. 7 million
patients and is the subject of 1900 clinical studies. Like all untethered RCEs,
PillCam is a battery-powered, wireless-data-transmission imaging device (
swallowed by the patient) that traverses the
GI tract through natural peristaltic motion in about nine hours.
PillCam SB, developed to visualize the entire small bowel, is now in
its third generation as PillCam SB 3,
which has 30% higher resolution than
the previous generation PillCam SB 2
and incorporates adaptive frame-rate
technology that automatically increases the frame rate from 2 frames/s up to
6 frames/s as transit speed increases (see
Fig. 1). A miniature white LED emitting from 450 to 700 nm consumes only
a few milliwatts to illuminate a 3000
mm2 section of GI tissue in a 150º field
of view using a six-part lens assembly
only 3 mm thick. With imaging resolution down to 0.07 mm, PillCam SB
is CE-marked, available in more than
75 countries, and is pending U.S. FDA
510(k) clearance.
Professor of pa-
thology Guillermo
J. Tearney and
colleagues at the
Wellman Center
for Photomedicine
at Massachusetts
General Hospital
(MGH; Boston,
MA) have devel-
oped an ingest-
ible multivita-
min-sized imaging
capsule on a fiber-
optic tether with
advantages over
the PillCam and
traditional endo-
scopes (see Fig. 2). 3 “We can screen
for pre-cancerous Barrett’s esopha-
gus or other respiratory/gastrointesti-
nal diseases using the imaging capsule
without requiring patient sedation, a
hospital setting, or even a trained phy-
sician,” says Tearney. “And we obtain
three-dimensional [3D] microscopic
images com-
pared to the
2D macroscopic images
acquired by
FIGURE 2. By manipulating a plastic ball (right side) attached to
a driveshaft sheath that encloses a flexible fiber-optic tether, a
physician can control the position of an imaging endomicroscopy
capsule (inset) in a patient’s esophagus. (Courtesy of Massachusetts
General Hospital)
