November 17th, 2009
IBM researchers speed up medical diagnostic testing via chip
IBM researchers have cooked up a quick medical diagnostic testing system based on a silicon chip that can get by on small sample and test for multiple diseases.
The breakthrough to be announced Tuesday means that physicians can test a patient immediately following a heart attack to improve survival rates. The test checks for disease markers, proteins that can be detected in blood using “capillary action force.” In a nutshell, capillary forces refer to the tendency of a liquid to rise in narrow tubes or be drawn into a small opening. The IBM Research-Zurich findings will be detailed in the December issue of the Royal Society of Chemistry (see reprint PDF).
Big Blue’s chip measures 1 x 5 centimeters and contains sets of micrometer wide channels where a test sample would flow for 15 seconds. The filling speed of the fluid being tested can be adjusted if the chip needs extra time to read a disease marker. Here’s how the chip works in stages:
- First, a one microliter sample, 50 times smaller than a tear drop, is pipetted onto the chip, where the capillary forces begin to take effect…
- Then these forces push the sample through an intricate series of mesh structures…
- 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 are attached within the sample…
- In the reaction chamber, which is about the diameter of a human hair, captures the previously tagged marker. Under a red beam of light, the disease markers can be viewed using a portable sensor device that contains a chip similar to those used by digital cameras. Medical professionals can visually confirm the strength of the disease marker.
The linchpin to this process is the capillary pump, a series of microstructures about 180 micrometers deep. The pump pushes through enough of the sample to create a regular flow rate and make the test accurate.
IBM added that the chip is designed for multiple form factors.
Larry Dignan is Editor in Chief of ZDNet and Editorial Director of ZDNet sister site TechRepublic. See his full profile and disclosure of his industry affiliations.
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