Zurich, Switzerland – 17 Nov 2009: 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 causes of death, cardiovascular
disease*. The results are so quick and accurate that a small sample
of a patient’s serum or blood, could be tested immediately
following a heart attack, to enable the doctor to quickly take a
course of action to help the patient survive.
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Point of Care Diagnostics
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 force 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 force 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.
“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”.
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 in 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.
Collaboration
True to IBM’s strategy of open collaboration, scientists in
Zurich tested their ideas 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.
IBM’s track
record of improving heatlhcare through scientific
achievements and collaboration with healthcare companies dates back
to the 1950s. In the last decade, IBM has developed a national
digital mammography archive with the University of Pennsylvania;
developed a clinical trial participant system with the Mayo Clinic;
collaborated with Scripps to understand how influenza viruses
mutate and proactively develop treatments; collaborated with
European universities to develop better methods to decide on
antiretroviral therapies for HIV; launched the World Community
Grid, which has done projects on cancer, aids, dengue fever; and
much more.
*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)
