Reinventing Disease Detection and Diagnosis

Wednesday, January 27 2010

As devices for disease detection and diagnosis become more advanced, they also are becoming smaller. Next-generation technologies for faster detection of diseases such as cardiovascular disease, melanoma, and breast cancer are handheld devices that are easy to use, portable, and more accurate than many of the currently available diagnostic tools. As the following examples illustrate, immediate diagnosis and detection of life-threatening diseases may soon be held in the palm of your hand.

Microfluidic Test Chip

IBM scientists have created a one-step, point-of-care-diagnostic test, based on a silicon chip, that requires less sample volume, is significantly faster, portable, easy to use, and can test for many diseases, including one of the world’s leading causes of death, cardiovascular disease. 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 quickly take a course of action to help the patient survive.

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.

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. 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 than traditional tests. The filling speed can be adjusted to several minutes when the chip requires additional time to read a more complex disease marker.

The microfluidic chip consists of a microscopic path for liquids with five stages:
Stage 1: A one-microliter sample, 50 times smaller than a teardrop, 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.