Blood testing coming to a touch screen near you

People with hemophilia or on blood thinners could soon skip a trip to the doc's and instead put a drop of blood on a microfluidic sticker on their smartphone screen to test how their blood is coagulating.

Elizabeth Armstrong Moore
Elizabeth Armstrong Moore is based in Portland, Oregon, and has written for Wired, The Christian Science Monitor, and public radio. Her semi-obscure hobbies include climbing, billiards, board games that take up a lot of space, and piano.
Elizabeth Armstrong Moore
2 min read
Qloudlab says the sensors normally used for finger tracking can also be used for bio-sensing detection of molecules, making blood coagulation testing possible. Qloudlab

People with hemophilia, or those taking anticoagulants to help prevent dangerous outcomes such as deep vein thrombosis, pulmonary embolism, or ischemic stroke, are unfortunately at a higher risk of bleeding easily. To better monitor these patients, health care professionals typically take blood coagulation tests in hospitals and clinics -- which can be a real burden both financially and logistically.

But soon, thanks to startup Qloudlab, based in the microengineering lab in Switzerland's EPFL tech university, these patients may be able to use the touch screens on their phones or other devices to test their blood coagulation, all in the comfort of their own homes -- or wherever.

Alain Herzog/EPFL

It's still a blood test, and thus still requires a drop of blood -- which sounds unadvisable anywhere near a smartphone, let alone right on its screen. But the tech they hope to demonstrate sometime in 2015 is actually, at least in theory, well contained.

To take the test, the patient will have to press a small plastic sticker that is just a few micrometers thick to the surface of the screen. It's a microfluidic sticker, which means it's embedded with minuscule channels that absorb the drop of blood. As the sample passes through the sticker's microchannels, the blood will come into contact with a molecule that initiates coagulation.

This is where the touch screen comes in. Using the sensors that can determine where it is being touched (i.e. where the screen's electric field is being disrupted), the screen can detect with incredible precision when and where the blood is moving through those tiny channels across the small surface area where the sticker touches the screen. Though the phone detects this movement as simple touch, the Qloudlab app translates those signals into a blood coagulation reading.

If it works, the tech could be a boon for the patients who will get to regularly test their blood at home and shoot the results off to their docs, and it could lead to other developments medically and beyond that take advantage of the powers of touch screens.