Powered by the energy from a smartphone, the device can simultaneously detect three infectious disease markers from only a finger prick of blood. The test takes 15 minutes and is the first instance of a device being created capable of replicating all the electronic, mechanical and optical functions of a lab-based blood test.
HIV and syphilis are most common in parts of the developing world, where access to health care may be more limited. The creation of a cheap and portable method of diagnosis that does not rely on laboratory facilities could be truly ground breaking.
“Coupling microfluidics with recent advances in consumer electronics can make certain lab-based diagnostics accessible to almost any population with access to smartphones,” states lead researcher Samuel K. Sia. “This kind of capability can transform how health care services are delivered around the world.”
Infected women can pass HIV and syphilis on to their unborn children during pregnancy, which can lead to stillbirth or birth defects. Early identification of these diseases can reduce the spread of infection and prevent or slow the rate of these diseases’ most harmful symptoms.
Sia explains some of the benefits of the new accessory, commonly referred to as a dongle:
“By increasing detection of syphilis infections, we might be able to reduce deaths by 10-fold. And for large-scale screening where the dongle’s high sensitivity with few false negatives is critical, we might be able to scale up HIV testing at the community level with immediate antiretroviral therapy that could nearly stop HIV transmissions and approach elimination of this devastating disease.”
The dongle is both lightweight and small enough to fit into one hand. It runs assays on disposable plastic cassettes that contain reagents – the substances required for chemical analysis.
Specific care was made to ensure that the dongle has low power consumption. Power and data are transmitted to the accessory through the standard audio jack of a smartphone, and a power-consuming electrical pump was replaced with a “one-push vacuum” to mechanically move the pre-loaded reagents on the cassettes.