• 02.05.13

A Mobile Device That Diagnoses STDs On The Spot With A Simple Finger Prick

To help curb HIV in the developing world, doctors need to be able to quickly find out who needs to be treated without waiting weeks for samples to be taken to the nearest hospital. The mChip does that, using just your blood and the cloud.

Samuel Sia, a biomedical engineering professor at Columbia University, has long been interested in making diagnostics more mobile. After launching and selling a company–Claros Diagnostics, now renamed OPKO Diagnostics–that’s working on a mobile solution to test for prostate cancer, Sia decided to apply his basic technology to problems in the developing world. In a study published this January in Clinical Chemistry, the engineer describes his latest innovation: a cheap mobile device that can diagnose HIV with lab-level accuracy in 15 minutes.


Sia’s device, dubbed the mobile microfluidic chip for immunoassay on protein markers (mChip), quickly analyzes blood and transmits data collected in the field to central medical records databases via satellite and cell phone network (it costs approximately 10 cents per result). It was engineered by OPKO, and clinical tests were done with ICAP and a number of Rwandan collaborators.

Sia and his colleagues tested 167 Rwandan patients with the mChip device; they found that it had diagnostic sensitivity and specificity of 100% and 99%. When tested on 40 whole-blood samples from patients at Muhima Hospital, sensitivity and specificity went up to 100% and 100%, respectively. All results from the hospital tests were successfully transmitted to an electronic patient health records database in the cloud.

There are other rapid HIV tests, but they aren’t as accurate in field conditions, says Sia. “We pick up weak positives missed by the rapid test,” he says. Plus, mChip results are transmitted automatically to the cloud. The mChip is slightly more expensive, however–Sia wants to get it down to $2 per test, compared to the current $1 cost for traditional rapid tests. But it can be used to diagnose a whole panel of STDs–HIV and two types of syphilis (HIV was the focus of the Clinical Chemistry paper).

Armed with a $2 million grant from organizations including the World Bank and the Bill and Melinda Gates Foundation, Sia and his colleagues are hoping to commercialize the technology in the next two to three years. “They’re funding us to try to be one of the pioneers in developing a high-tech but affordable product that will save lives in the developing world,” he says.

Eventually, Sia plans to use the mChip technology in the U.S., with some tweaks in the user interface, experience, and the kinds of diseases that will be tested. “We want to go after the everyday consumer, so that would be chronic disease or wellness, and in Africa it would be more infectious diseases,” he explains. “Today’s mobile health is low-hanging fruit like accelerometers, and revolutionary things are tougher because you have to go to the FDA. We think we can make these tests so low-cost that people can monitor chronic health conditions by themselves.”

About the author

Ariel Schwartz is a Senior Editor at Co.Exist. She has contributed to SF Weekly, Popular Science, Inhabitat, Greenbiz, NBC Bay Area, GOOD Magazine and more.