An integrated microfluidics-waveguide sensor developed at Stanford University School of Medicine has the potential to simplify the diagnosis of diseases ranging from life-threatening immune deficiencies to the common cold. The device sorts and counts cells in small samples of blood and other body fluids. The developers say the sensor, which is about the size of an adult's thumbnail, provides an easy way to measure different white blood cells, and could be deployed in doctors' offices, newborn nurseries, patients' homes, disaster sites, and battlefields.
The sensor was originally developed as a better way to screen newborns for severe combined immunodeficiency, a congenital illness commonly known as “bubble boy disease,” in which infants are born with much of their immune system missing. California's current method of screening newborns for this disease takes three to six weeks to return results, by which time infants could contract life-threatening infections. This new sensor has the potential to detect low T-cell counts, a hallmark of the disease, in a 15-minute test in the newborn nursery. However, the sensor could also present benefits for patients to monitor their immune systems at home.
The prototype sensor cost about $60 to build using off-the-shelf electronics components, but the per-unit cost would be lower if the sensors were manufactured in bulk. Patients — including those who have received organ transplants, suffer chronic kidney failure, or are taking immune-suppressing drugs to treat rheumatoid arthritis — could use the sensors to monitor their immune systems much in the way diabetics use glucometers to track their blood sugar at home.
A new class of heart monitoring devices is based on a sensor that measures intracardiac pressure in people who suffer from congestive heart failure.
