Alain Herzog / EPFL

A diagnostic tool that uses a smartphone screen to perform blood tests has been developed by a microengineering laboratory at the Swiss Federal Institute of Technology (EPFL).

The tool has been developed to allow for at-home blood analysis for people undergoing anticoagulant treatment within minutes.


People are treated with anticoagulants to prevent blood clots from forming in arteries or veins. Blocked arteries stop oxygen from getting to a particular part of the body and can lead to a stroke, heart attack of pulmonary embolism. When patients are taking anticoagulants, they need their blood flow to be regularly monitored -- something that usually takes place in hospital.

However, the system developed at EPFL's Qloudlab can produce test results using smartphone screen, meaning that patients won't need to go into hospital so often.

Qloudlab's CEO Arthur Queval told Wired.co.uk that he first had the idea in 2010 when the iPad was launched. "My father just had a stroke and I thought the concentration of technology in smartphones/tablets could be useful for medical applications. This is where I came up with this idea to turn the electric field generated by the touchscreen to perform blood diagnostic testing."

The system involves placing a single-use film -- made out of a microstructured plastic layer -- on top of the device's screen -- the latest prototype uses an unmodified Samsung Galaxy S4, but Queval is "confident" that the team can make it work on other models. A drop of blood enters the film through a capillary action and then comes into contact with a molecule that makes the blood coagulate. An app on the phone then taps into the capacitive field on the screen to look for disruptions. Changes in the electric field produced by the path of the blood in the film can be analysed to produce results. The aim is to see that the patient with thinned blood isn't at an increased risk of bleeding. "We are still working on the accuracy of the test for blood coagulation testing but we have found a way to make it work on potentially every smartphone on the market," Queval told us. The system could also be adapted to test for other blood-presenting conditions, such as looking for blood glucose levels in diabetics.

The startup has filed for a patent and received funding from Venture Kick. The aim is to start to commercialize the product by 2015.