IBM (NYSE: IBM)
scientists have created a one-step point-of-care-diagnostic test, based on an
innovative silicon chip that requires less sample volume, is significantly faster,
portable, easy to use and can test for many diseases, including one of world's
leading cause of death, cardiovascular disease*. The results are so quick and
accurate that a patient’s serum or blood sample, could be tested immediately
following a myocardial infarction, commonly known as a heart attack, to enable
the doctor to take a course of action and to predict the patients survival rate.
 | | IBM scientists in Zurich have created a one-step point-of-care-diagnostic test, based on an innovative silicon chip that requires less sample volume, is significantly faster, portable, easy to use and can test for many diseases, including one of world's leading cause of death, cardiovascular disease.
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As reported in Lab on a Chip, December 2009, Volume 9, Issue 23, IBM Research
- Zurich scientists Luc Gervais and Emmanuel Delamarche in collaboration with
the University Hospital of Basel in Switzerland have developed a new diagnostic
test that uses capillary forces to analyze tiny samples of serum or blood for
the presence of disease markers, which are typically proteins that can be detected
in people’s blood for diagnostic purposes. Capillary action is the tendency
of a liquid to rise in narrow tubes or to be drawn into small openings. An everyday
example of a capillary action can be viewed by dipping a paper towel in a cup
of water — the microstructures in the paper fiber enable the towel to
absorb the water.
All in the chip
IBM scientists have encoded the forces of capillary action on a microfluidic
chip made of a silicon compound, similar to those used in computer chips, thus
leveraging IBM's vast experience in developing and manufacturing silicon semiconductor
wafers. The chip, which measures 1 × 5 centimeters, contains sets of micrometer
wide channels where the test sample flows through in approximately 15 seconds,
several times faster then traditional tests. Uniquely, the filling speed can
be adjusted to several minutes when the chip requires additional time to read
a more complex disease marker.
The microfludic chip, which is based on nearly three years of research and
development, consists of a microscopic path for liquids with five innovative
stages:
Stage 1: A one microliter sample, 50 times smaller than a tear drop, is pipetted
onto the chip, where the capillary forces begin to take effect. Stage 2: These
forces push the sample through an intricate series of mesh structures, which
prevent clogging and air bubbles from forming. Stage 3: The sample then passes
into a region where microscopically small amounts of the detection antibody
have been deposited. These antibodies have a fluorescent tag and similar to
the antibodies within our body, they recognize the disease marker and attach
to it within the sample. Only seventy picoliters (a volume one million times
smaller than a tear) of these antibodies are used, making their dissolution
in the passing sample extremely fast and efficient. Stage 4: The most critical
stage is called the "reaction chamber" and it measures 30 micrometers
in width and 20 micrometers in depth, roughly the diameter of a strand of human
hair. Similar to a common pregnancy test, in this stage the disease marker that
was previously tagged is captured on the surface of the chamber. By shining
a focused beam of red light, the tagged disease markers can be viewed using
a portable sensor device that contains a chip similar to those used by digital
cameras, albeit this one being much more sensitive. Based on the amount of light
detected, medical professionals can visually confirm the strength of the disease
marker in the sample to determine the next course of treatment. Stage 5: Less
a stage and more a part of the entire process is the capillary pump. The capillary
pump, which has a depth of 180 micrometers, contains an intricate set of microstructures,
the job of which is to pump the sample through the device for as long as needed
and at a regular flow rate, just like the human heart. This pump makes the test
accurate, portable and simple to use. IBM scientists have developed a library
of capillary pumps so that tests needing a variety of sample volumes or test
times can still be done without having to re-engineer the entire chip. "This
point of care test has achieved the trifecta for medical staff in that it is
portable, fast and requires a very small volume of sample," comments Emmanuel
Delamarche, scientist, IBM Research - Zurich. "We are giving back precious
minutes to doctors so they can make informed and accurate decisions right at
the time they need them most to save lives".
Going to market
Proof positive of IBM's strategy of open collaboration, scientists in Zurich
followed a “bench to bedside” strategy where ideas from their lab
were tested with academic and healthcare partners. This research also would
not have been possible without the generous support of KTI/CTI, an organization
which fosters innovation in Switzerland.
"This microfluidic chip is the next step in the evolution of point of
care devices. We look forward to working with the scientists at IBM Research
- Zurich to develop this innovation even further," said Thierry Leclipteux,
Chief Executive Officer and Chief Science Officer, Coris BioConcept.
IBM scientists designed the chip with flexibility in mind in both its form
and uses. Due to its small size the chip can be embedded in several types of
form factors, depending on the application, including a credit card, a pen or
something similar to a pregnancy test. Besides diagnosing diseases, the test
is also flexible enough to test for chemical and bio hazards.
Why IBM?
From a technological perspective, IBM has been a pioneer in nanoscience ever
since the development of the Nobel Prizing winning Scanning Tunneling Microscope
in 1981. Ever since, IBM researchers have been pushing the frontiers of scientific
knowledge and manipulating at the nano scale and our work in one-step point-of-care
diagnostics is a direct result of this effort. IBM is currently embarking on
a grand vision called smarter planet helping industries, such as healthcare
become more instrumented, interconnected and intelligent.
*According to the World Health Organization Statistics 2009.
The scientific paper entitled “Toward one-step point-of-care immunodiagnostics
using capillary-driven microfluidics and PDMS substrates” by Luc Gervais
and Emmanuel Delamarche, appears in Lab on a Chip, Volume 9, Issue 23, pp. 3330
to 3337 (December 2009).
Posted November 16th, 2009
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