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Tiny probe gives wide-angle view of your insides.
13:47 06 November 2007
Enlarge image
A tiny probe could let doctors image the brain from inside out, using
ultrasound in several directions at once (Image: IEEE/Jingkuang Chen)
An
ultrasound probe about the size of a grain of rice that could offer
panoramic views from inside the human body is being tested by US
researchers. They say it could be threaded through blood vessels in the
brain or swallowed like a pill.
Ultrasound
scanners are normally used to peer into the body from the outside, in
order to examine unborn babies or look for tumours, for example.
Enabling
these devices to penetrate deep inside the body, and to provide
accurate images at this depth, is difficult because longer wavelengths
are required, which dramatically reduce resolution.
Putting
an ultrasound scanner inside the body, close to an area of interest, is
one solution, and tiny ultrasound probes have already been threaded
down veins and into other parts of the body.
But
this approach suffers from "tunnel vision" – doctors can only look out
in one direction, in front of the probe or to one side. At best, they
can rotate the probe to look around.
''Origami'' structure
The
new
device – about 1 millimetre across, 1 millimetre long and shaped
like a hexagonal cylinder – affords a panoramic picture, showing the
view from each side of the device, and to the front.
Jingkuang Chen
and colleagues from New Mexico University, Albuquerque, US, and
National Taiwan University, Taiwan, created the probe using a novel
"origami-style" manufacturing technique.
They
first patterned seven components, each capable of emitting ultrasound
and listening for the resulting echo, on top of a flat silicon wafer.
This silicon was then etched, allowing the wafer to be folded up to
form the hexagonal tube.
Stroke prevention
"All
the commercially available units can only look to one side or ahead,"
says Chen. "We can look out the front and all sides simultaneously."
The
team has completed tests of the device in tanks of water, and plans to
test it in animals, attached to the end of a wire-like endoscope.
If
these tests prove successful, the hope is that it could offer doctors a
much more complete picture of new locations inside the human body. "It
could be used to measure blood flow deep inside the brain," says Chen,
"to identify the early stages of strokes or other disease."
Journal reference: Journal of Microelectromechanical Systems (DOI: 10.1109/JMEMS.2007.902449)